1,356 results on '"lignin degradation"'
Search Results
2. Catalytic depolymerization and hydrodeoxygenation of lignin to high-density fuel precursors using Ni/Nb2O5 catalyst
- Author
-
Yu, Shitong, Xu, Pan, and Luo, Zhicheng
- Published
- 2024
- Full Text
- View/download PDF
3. Crystal structure and functional characterization of a novel bacterial lignin-degrading dye-decolorizing peroxidase
- Author
-
Catucci, G., Zhang, C., Pernaci, A., Cappa, F., Sadeghi, S.J., Di Nardo, G., and Gilardi, G.
- Published
- 2025
- Full Text
- View/download PDF
4. A combined immobilization system for high-solids cellulosic ethanol production by simultaneous saccharification and fermentation
- Author
-
Kong, Dongdong, Chen, Zhiling, Liu, Han, Qi, Xiaoting, Liu, Yanping, Xu, Shi, Ye, Yutong, Li, Juanjuan, Liang, Peiqi, Wang, Shan, Hu, Wenhao, Jin, Xinyu, Liu, Xinchun, Zhang, Cheng, and Tian, Shen
- Published
- 2025
- Full Text
- View/download PDF
5. Characterization and rational engineering of a novel laccase from Geobacillus thermocatenulatus M17 for improved lignin degradation activity
- Author
-
Sun, Bohan, Sun, Huimin, Zhang, Leshan, Hu, Wei, Wang, Xin, Brennan, Charles S., Han, Dandan, Wu, Gang, Yi, Yanglei, and Lü, Xin
- Published
- 2025
- Full Text
- View/download PDF
6. Biochemical and structural insights into pinoresinol hydroxylase from Pseudomonas sp
- Author
-
Guerriere, Teresa Benedetta, Fraaije, Marco W., and Mattevi, Andrea
- Published
- 2025
- Full Text
- View/download PDF
7. Development of a biofilm-forming bacterial consortium and quorum sensing molecules for the degradation of lignin-containing organic pollutants
- Author
-
Yadav, Sangeeta, Tripathi, Sonam, Purchase, Diane, and Chandra, Ram
- Published
- 2023
- Full Text
- View/download PDF
8. Characterization of lignin-degrading enzyme PmdC, which catalyzes a key step in the synthesis of polymer precursor 2-pyrone-4,6-dicarboxylic acid
- Author
-
Rodrigues, Andria V, Moriarty, Nigel W, Kakumanu, Ramu, DeGiovanni, Andy, Pereira, Jose Henrique, Gin, Jennifer W, Chen, Yan, Baidoo, Edward EK, Petzold, Christopher J, and Adams, Paul D
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Industrial Biotechnology ,Lignin ,Pyrones ,Crystallography ,X-Ray ,Bacterial Proteins ,NADP ,Molecular Docking Simulation ,Binding Sites ,NADP oxidoreductase ,alphafold ,computational modeling ,crystal structure ,enzyme catalysis ,ligand docking ,lignin degradation ,polymer synthesis ,pyrone 2 ,4 dicarboxylic acid ,structure-function ,Chemical Sciences ,Medical and Health Sciences ,Biochemistry & Molecular Biology ,Biological sciences ,Biomedical and clinical sciences ,Chemical sciences - Abstract
Pyrone-2,4-dicarboxylic acid (PDC) is a valuable polymer precursor that can be derived from the microbial degradation of lignin. The key enzyme in the microbial production of PDC is 4-carboxy-2-hydroxymuconate-6-semialdehyde (CHMS) dehydrogenase, which acts on the substrate CHMS. We present the crystal structure of CHMS dehydrogenase (PmdC from Comamonas testosteroni) bound to the cofactor NADP, shedding light on its three-dimensional architecture, and revealing residues responsible for binding NADP. Using a combination of structural homology, molecular docking, and quantum chemistry calculations, we have predicted the binding site of CHMS. Key histidine residues in a conserved sequence are identified as crucial for binding the hydroxyl group of CHMS and facilitating dehydrogenation with NADP. Mutating these histidine residues results in a loss of enzyme activity, leading to a proposed model for the enzyme's mechanism. These findings are expected to help guide efforts in protein and metabolic engineering to enhance PDC yields in biological routes to polymer feedstock synthesis.
- Published
- 2024
9. Comparative metagenomics reveals the metabolic flexibility of coastal prokaryotic microbiomes contributing to lignin degradation.
- Author
-
Peng, Qiannan and Lin, Lu
- Subjects
- *
CARBON cycle , *PROKARYOTIC genomes , *CONSORTIA , *SUSTAINABLE communities , *LIGNOCELLULOSE , *COASTAL wetlands - Abstract
Coastal wetlands are rich in terrestrial organic carbon. Recent studies suggest that microbial consortia play a role in lignin degradation in coastal wetlands, where lignin turnover rates are likely underestimated. However, the metabolic potentials of these consortia remain elusive. This greatly hinders our understanding of the global carbon cycle and the "bottom-up" design of synthetic consortia to enhance lignin conversion. Here, we developed two groups of lignin degrading consortia, L6 and L18, through the 6- and 18-month in situ lignin enrichments in the coastal East China Sea, respectively. Lignin degradation by L18 was 3.6-fold higher than L6. Using read-based analysis, 16S rRNA amplicon and metagenomic sequencing suggested that these consortia possessed varied taxonomic compositions, yet similar functional traits. Further comparative metagenomic analysis, based on metagenomic assembly, revealed that L18 harbored abundant metagenome-assembled genomes (MAGs) that encoded diverse and unique lignin degradation gene clusters (LDGCs). Importantly, anaerobic MAGs were significantly enriched in L18, highlighting the role of anaerobic lignin degradation. Furthermore, the generalist taxa, which possess metabolic flexibility, increased during the extended enrichment period, indicating the advantage of generalists in adapting to heterogenous resources. This study advances our understanding of the metabolic strategies of coastal prokaryotic consortia and lays a foundation for the design of synthetic communities for sustainable lignocellulose biorefining. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
10. Domestic sewage as a sustainable freshwater substitute for enhanced anaerobic digestion of lignocellulosic biomass.
- Author
-
Induchoodan, TG, Choran, Nimitha, and Kalamdhad, Ajay S.
- Subjects
- *
SEWAGE , *ENVIRONMENTAL engineering , *ORGANIC wastes , *SOLID waste , *FIELD emission electron microscopy - Abstract
Biochemical methane potential tests using water hyacinth (WH), pretreated water hyacinth (PWH), and Hydrilla verticillata (HV) as substrates using sewage media were explored. This study replaced the freshwater required to prepare the slurry for AD of organic solid waste with domestic sewage. Cow dung was used as the inoculum. WH (241.5 mL CH4/g VSadded), PWH (200.5 mL CH4/g VSadded), and HV (212 mL CH4/g VSadded) produced significant amounts of methane in the sewage medium. 16S-rRNA analysis showed that, in sewage, ~ 85% of the microbes were hydrolytic bacteria, and 7% were methanogens. This abundant quantity of hydrolytic microbes from sewage accelerated lignin degradation, achieving 28.32% and 38.34% degradation for WH and HV, respectively, within 14 days. Field emission-scanning electron microscopy images visually confirmed the enhanced substrate degradation in the presence of sewage. The net energy produced from the AD of WH and HV was significant (4664 J/g VSadded and 4109 J/g VSadded), but for PWH, it was negative, indicating that using sewage medium may be better than costly pretreatment techniques. This study demonstrated the potential of using sewage as an alternative to freshwater in AD, offering a sustainable solution for freshwater conservation and the possible utilisation of sewage for improved methane production, especially for substrates with lignin that are difficult to degrade. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Deconstruction of Alkali Lignin and Lignocellulosic Substrates by Aspergillus ochraceus DY1 Isolated from Rotten Wood.
- Author
-
Nilza, Namdol, Prasad, Ram, Varma, Ajit, and Salam, Menaka Devi
- Subjects
- *
CORN stover , *LIGNOCELLULOSE , *BUTYLATED hydroxytoluene , *WASTE paper , *SOLID-state fermentation , *LIGNINS - Abstract
The present study reports the ability of a fungal isolate Aspergillus ochraceus DY1, obtained from rotten wood, to degrade alkali lignin (AL) and lignocelluloses in an efficient manner. The efficiency of degradation was monitored by measuring the percentage of decolorization and utilizing GC-MS for identifying degradation products at different time intervals (10, 20, 30, and 40 days). The optimal degradation of alkali lignin (AL) was achieved at 0.01% concentration, 25 °C, and pH 7, resulting in 63.64% degradation after 40 days of incubation. A GC-MS analysis revealed significant degradation products, including n-hexadecanoic acid, octadecane, butylated hydroxytoluene, 2,6,11-trimethyl-dodecane, dibutyl phthalate, oleic acid, 3,5-dimethoxy-phenol acetate, and 2-(phenylmethylene)- cyclohexanone. Structural changes in AL were confirmed through HSQC 2D NMR and size-exclusion chromatography, indicating depolymerization and reduced molecular weight. Furthermore, A. ochraceus DY1 demonstrated substantial biomass loss in corn stover (62.5%) and sugarcane bagasse (50%) after 7 days of solid-state fermentation. Surface morphological depletion was observed in the bio-treated corn stover through SEM and confocal microscopy, which was not seen in the untreated one. These findings underscore the potential of A. ochraceus DY1 for efficient lignin degradation, with promising applications in biofuel production, waste management in the paper and pulp industry, and the synthesis of value-added bioproducts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Transforming Soil Stability: A Review on Harnessing Plant Cell Compounds and Microbial Products for Modifying Cation Exchange Capacity.
- Author
-
Shah, M. V., Rathod, N. M., Prajapati, D. N., Mehta, P. J., Panchal, R. R., and Upadhye, Vijay
- Subjects
BLACK cotton soil ,SOIL stabilization ,ROAD construction ,METHYLENE blue ,DNA replication - Abstract
Soil stabilization is a very important method of science and engineering for improving the properties of soil. This paper aims to stabilize expansive black cotton soil through a biological approach involving plant extracts, plant waste materials, and microorganisms. While chemical methods exist, i.e., lime stabilization, geotextiles, etc., they are not economically feasible for large-scale applications. The primary issue with black cotton soil is due to the presence of montmorillonite clay mineral, which makes it unsuitable for the construction of roads and airfields. The cation exchange capacity (CEC) can be defined as the ability of soil to absorb and exchange positively charged ions; thus, if free positively charged ions are not available, the soil will not exchange them with others. The CEC of the soil is diminished, and ultimately, the soil is stabilized to some extent. This paper explores the preparation of plant extract, which contains a high number of anions, and directly inoculates it with soil, which nullifies the positive charge of the soil and diminishes the CEC. The use of cellulose and lignin-degrading microorganisms as an energy source and other minerals that are needed for their growth will be utilized from the soil to reduce CEC, i.e., Mg required for DNA replication and Ca required for their growth and maintenance. Another approach to diminishing the CEC is to use the microorganisms that produce EPS, which require Ca and Mg as adhesions for the formation of biofilm, i.e., Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. The use of microorganisms that have specific enzymes is also used in the diminishing soil CEC, i.e., by using ureolytic enzyme-producing bacteria like Sporosarcina pasteurii, Bacillus paramycoides, Citrobacter sedlakii, and Enterobacter bugadensis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Progress in the Experimental Design and Performance Characterization of Artificial Accelerated Photodegradation of Wood.
- Author
-
Chen, Yushu, Gao, Ying, Duan, Haoran, and Xu, Xin
- Subjects
WOOD ,HUMIDITY control ,PRESERVATION of wood ,WOOD products ,ULTRAVIOLET radiation - Abstract
Wood, a natural and renewable material, is extensively utilized in furniture, construction, and outdoor landscapes due to its sustainability and esthetic appeal. However, exposure to environmental elements, particularly sunlight, leads to photodegradation, affecting wood's chemical and physical structure. This degradation results in color fading, increased surface roughness, and reduced mechanical properties, shortening the lifespan of wooden products. Artificial accelerated photodegradation tests have become a crucial method for studying wood's aging process under controlled laboratory conditions, mimicking prolonged exposure to sunlight. This review explores the mechanisms behind wood photodegradation, focusing on the effects of UV radiation on wood's major components—cellulose, hemicellulose, lignin, and extractives. Additionally, it summarizes the latest advancements in experimental design for artificial aging tests, including factors like radiation source selection, temperature, and humidity control. The paper also highlights performance characterization methods for evaluating the impact of photodegradation on wood's physical, chemical, and mechanical properties. Understanding these processes is essential for enhancing the durability of wood products and developing effective treatments for wood preservation in outdoor environments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Spectroscopic and microscopic characterization of humic acids from composts made by co-composting of green waste, spent coffee and OMWW sludge.
- Author
-
Fersi, Mariem, Hajji, Rachid, Mbarki, Khadija, Louati, Ibtihel, Jedidi, Naceur, Hassen, Abdennaceur, and Hachicha, Ridha
- Subjects
COFFEE grounds ,TRAMETES (Polyporaceae) ,DEGREE of polymerization ,NUCLEAR magnetic resonance ,SEWAGE sludge ,HUMIC acid - Abstract
Due to its important role in the formation of humic acids (HA), improving lignin degradation during composting has usually been considered a challenge. One practice that could stimulate the biodegradation of this recalcitrant molecule is inoculation with exogenous lignolytic fungal strains. Two composts (C1) and (C2) from piles (H1) and (H2) were evaluated. H1 was the control pile and H2 was inoculated at maturity with Trametes trogii, resulting in a 35% increase in lignin degradation rate compared to H1. The aim of this study was to show the main effects of this increase on the humification process in the co-composting of green waste, coffee grounds and olive mill wastewater sludge (OMWWs). Microstructure of HA1 and HA2 extracted from C1 and C2, respectively, was also investigated by scanning electron microscopy (SEM) and SEM coupled with energy-dispersive X-ray spectroscopy (X-EDS). The results showed that there were several similarities between the compost samples tested. These included the mineral content, the degree of polymerization (PD)> 1 and the compact and rigid surface of the extracted HA. However, C2 was characterized by a higher humic content (HC), degree of polymerization (PD), humification index (HI) and percentage of humic acids (PHA) than C1. Carbon-13 nuclear magnetic resonance (13C-NMR) and Fourier transmission-infrared spectroscopy (FTIR) analysis showed that aliphatic groups such as hydroxyls, alcohols and carboxyls were predominant in both composts. SEM analysis in conjunction with X-EDS analysis of HA2 showed a higher proportion of carbon and potassium (18 and 7.93%) than in HA1 (14 and 0.95%). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. A review on chemical mechanisms of kraft pulping.
- Author
-
Henriksson, Gunnar, Germgård, Ulf, and Lindström, Mikael E.
- Subjects
- *
SULFATE pulping process , *WOOD-pulp , *POLYSACCHARIDES , *GLUCOMANNAN , *DEPOLYMERIZATION , *CELLULOSE fibers , *PLANT fibers - Abstract
Kraft pulping of wood is based on efficient depolymerization and solubilization of lignin, while cellulose is relatively undamaged. Non-cellulose cell wall polysaccharides are however in some cases heavily degraded, especially pectin and to a lesser degree also glucomannan while, xylan is relatively stable. In this mini-review, the most important reactions in lignin and polysaccharide degradation in kraft pulping are described, both the technically favorable and the problematic reactions, and the chemical background to discuss the advantages and drawbacks of the process. An attempt to put the different reactions in the perspective of the goals of the pulping process is made and a special focus is on the development of color in the pulp fiber during the kraft pulping. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Effects of soil fauna on leaf litter decomposition and nutrient release during a two-year field experiment in a poplar plantation.
- Author
-
Xu, Xuan, Slade, Eleanor M., Cao, Penghe, Wang, Yuchao, Zou, Xiaoming, Wang, Weifeng, and Ruan, Honghua
- Subjects
- *
FOREST litter decomposition , *SOIL animals , *FOREST litter , *STRUCTURAL equation modeling , *NUTRIENT cycles - Abstract
Aims: Soil fauna play a key role in the litter decomposition process in two ways; directly via fragmentation and consumption of the litter, and indirectly through changes in soil structure and the activity of microorganisms. The study aimed at better understanding how soil fauna affects the release of nutrients from litter. Methods: We conducted a litter decomposition experiment using litterbags of three mesh sizes (0.01 mm, 1 mm, and 4 mm), and chemical treatments (no naphthalene; naphthalene application) to assess soil fauna effect on nutrient release in a poplar plantation in eastern China over a two-year period from Jan 2019 to Dec 2020. Results: We found that the contribution of soil fauna to the mass loss of poplar leaf litter was 29% over the two-year period, and the contribution was more pronounced within the first four months. Soil macrofauna and meso-/micro- fauna contributed similarly to leaf litter mass loss, while microbial decomposition contributed the most to the decomposition process. The presence of soil fauna significantly promoted the degradation of cellulose and lignin, and accelerated the release of nitrogen at later stages of decomposition. A structural equation model revealed that higher soil fauna abundance not only promoted the litter decay rate directly, but also indirectly through modifying nitrogen and lignin contents. Conclusions: Our results highlight the importance of soil fauna on cellulose and lignin degradation, and the importance of including this when simulating decomposition models for obtaining a better mechanistic understanding of forest litter decomposition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. 产木质素降解酶木霉菌株的筛选及其产酶特性.
- Author
-
杨丽, 孙晓东, 李琳琳, 吕国忠, and 杨红
- Subjects
EDIBLE mushrooms ,CULTIVATED mushroom ,TRICHODERMA ,SEQUENCE analysis ,GUAIACOL ,LACCASE - Abstract
Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
18. A cellulosomal yeast reaction system of lignin-degrading enzymes for cellulosic ethanol fermentation.
- Author
-
Ye, Yutong, Liu, Han, Wang, Zhipeng, Qi, Qi, Du, Jiliang, and Tian, Shen
- Subjects
CELLULOSIC ethanol ,LIGNIN structure ,LIGNOCELLULOSE ,FERMENTATION ,ENZYMES ,POLYSACCHARIDES ,YEAST - Abstract
Biofuel production from lignocellulose feedstocks is sustainable and environmentally friendly. However, the lignocellulosic pretreatment could produce fermentation inhibitors causing multiple stresses and low yield. Therefore, the engineering construction of highly resistant microorganisms is greatly significant. In this study, a composite functional chimeric cellulosome equipped with laccase, versatile peroxidase, and lytic polysaccharide monooxygenase was riveted on the surface of Saccharomyces cerevisiae to construct a novel yeast strain YI/LVP for synergistic lignin degradation and cellulosic ethanol production. The assembly of cellulosome was assayed by immunofluorescence microscopy and flow cytometry. During the whole process of fermentation, the maximum ethanol concentration and cellulose conversion of engineering strain YI/LVP reached 8.68 g/L and 83.41%, respectively. The results proved the availability of artificial chimeric cellulosome containing lignin-degradation enzymes for cellulosic ethanol production. The purpose of the study was to improve the inhibitor tolerance and fermentation performance of S. cerevisiae through the construction and optimization of a synergistic lignin-degrading enzyme system based on cellulosome. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Unraveling the roles of coastal bacterial consortia in degradation of various lignocellulosic substrates.
- Author
-
Peng, Qiannan, Lin, Lu, Tu, Qichao, Wang, Xiaopeng, Zhou, Yueyue, Chen, Jiyu, Jiao, Nianzhi, and Zhou, Jizhong
- Subjects
bacterial communities ,coastal intertidal zone ,functional gene ,lignin degradation ,lignocellulose degradation ,priming effect ,Lignin ,Ecosystem ,RNA ,Ribosomal ,16S ,Bacteria ,Cellulose - Abstract
Lignocellulose, as the most abundant natural organic carbon on earth, plays a key role in regulating the global carbon cycle, but there have been only few studies in marine ecosystems. Little information is available about the extant lignin-degrading bacteria in coastal wetlands, limiting our understanding of their ecological roles and traits in lignocellulose degradation. We utilized in situ lignocellulose enrichment experiments coupled with 16S rRNA amplicon and shotgun metagenomics sequencing to identify and characterize bacterial consortia attributed to different lignin/lignocellulosic substrates in the southern-east intertidal zone of East China Sea. We found the consortia enriched on woody lignocellulose showed higher diversity than those on herbaceous substrate. This also revealed substrate-dependent taxonomic groups. A time-dissimilarity pattern with increased alpha diversity over time was observed. Additionally, this study identified a comprehensive set of genes associated with lignin degradation potential, containing 23 gene families involved in lignin depolymerization, and 371 gene families involved in aerobic/anaerobic lignin-derived aromatic compound pathways, challenging the traditional view of lignin recalcitrance within marine ecosystems. In contrast to similar cellulase genes among the lignocellulose substrates, significantly different ligninolytic gene groups were observed between consortia under woody and herbaceous substrates. Importantly, we not only observed synergistic degradation of lignin and hemi-/cellulose, but also pinpointed the potential biological actors at the levels of taxa and functional genes, which indicated that the alternation of aerobic and anaerobic catabolism could facilitate lignocellulose degradation. Our study advances the understanding of coastal bacterial community assembly and metabolic potential for lignocellulose substrates. IMPORTANCE It is essential for the global carbon cycle that microorganisms drive lignocellulose transformation, due to its high abundance. Previous studies were primarily constrained to terrestrial ecosystems, with limited information about the role of microbes in marine ecosystems. Through in situ lignocellulose enrichment experiment coupled with high-throughput sequencing, this study demonstrated different impacts that substrates and exposure times had on long-term bacterial community assembly and pinpointed comprehensive, yet versatile, potential decomposers at the levels of taxa and functional genes in response to different lignocellulose substrates. Moreover, the links between ligninolytic functional traits and taxonomic groups of substrate-specific populations were revealed. It showed that the synergistic effect of lignin and hemi-/cellulose degradation could enhance lignocellulose degradation under alternation of aerobic and anaerobic conditions. This study provides valuable taxonomic and genomic insights into coastal bacterial consortia for lignocellulose degradation.
- Published
- 2023
20. Uncovering the lignin-degrading potential of Serratia quinivorans AORB19: insights from genomic analyses and alkaline lignin degradation
- Author
-
Nadia Sufdar Ali, Subarna Thakur, Mengwei Ye, Fanny Monteil-Rivera, Youlian Pan, Wensheng Qin, and Trent Chunzhong Yang
- Subjects
Lignin degradation ,CAZymes ,Serratia quinivorans AORB19 ,LC–UV ,Whole genome analyses ,Lignocellulosic waste ,Microbiology ,QR1-502 - Abstract
Abstract Background Lignin is an intricate phenolic polymer found in plant cell walls that has tremendous potential for being converted into value-added products with the possibility of significantly increasing the economics of bio-refineries. Although lignin in nature is bio-degradable, its biocatalytic conversion is challenging due to its stable complex structure and recalcitrance. In this context, an understanding of strain's genomics, enzymes, and degradation pathways can provide a solution for breaking down lignin to unlock the full potential of lignin as a dominant valuable bioresource. A gammaproteobacterial strain AORB19 has been isolated previously from decomposed wood based on its high laccase production. This work then focused on the detailed genomic and functional characterization of this strain based on whole genome sequencing, the identification of lignin degradation products, and the strain’s laccase production capabilities on various agro-industrial residues. Results Lignin degrading bacterial strain AORB19 was identified as Serratia quinivorans based on whole genome sequencing and core genome phylogeny. The strain comprised a total of 123 annotated CAZyme genes, including ten cellulases, four hemicellulases, five predicted carbohydrate esterase genes, and eight lignin-degrading enzyme genes. Strain AORB19 was also found to possess genes associated with metabolic pathways such as the β-ketoadipate, gentisate, anthranilate, homogentisic, and phenylacetate CoA pathways. LC–UV analysis demonstrated the presence of p-hydroxybenzaldehyde and vanillin in the culture media which constitutes potent biosignatures indicating the strain’s capability to degrade lignin. Finally, the study evaluated the laccase production of Serratia AORB19 grown with various industrial raw materials, with the highest activity detected on flax seed meal (257.71 U/L), followed by pea hull (230.11 U/L), canola meal (209.56 U/L), okara (187.67 U/L), and barley malt sprouts (169.27 U/L). Conclusions The whole genome analysis of Serratia quinivorans AORB19, elucidated a repertoire of genes, pathways and enzymes vital for lignin degradation that widens the understanding of ligninolytic metabolism among bacterial lignin degraders. The LC-UV analysis of the lignin degradation products coupled with the ability of S. quinivorans AORB19 to produce laccase on diverse agro-industrial residues underscores its versatility and its potential to contribute to the economic viability of bio-refineries.
- Published
- 2024
- Full Text
- View/download PDF
21. Metagenomic‐based discovery and comparison of the lignin degrading potential of microbiomes in aquatic and terrestrial ecosystems via the LCdb database.
- Author
-
Chen, Jiyu, Lin, Lu, Tu, Qichao, Peng, Qiannan, Wang, Xiaopeng, Liang, Congying, Zhou, Jiayin, and Yu, Xiaoli
- Subjects
- *
DATABASES , *LIGNINS , *MARINE ecology , *ECOSYSTEMS , *MICROBIAL communities , *CARBON cycle - Abstract
Lignin, as an abundant organic carbon, plays a vital role in the global carbon cycle. However, our understanding of the global lignin‐degrading microbiome remains elusive. The greatest barrier has been absence of a comprehensive and accurate functional gene database. Here, we first developed a curated functional gene database (LCdb) for metagenomic profiling of lignin degrading microbial consortia. Via the LCdb, we draw a clear picture describing the global biogeography of communities with lignin‐degrading potential. They exhibit clear niche differentiation at the levels of taxonomy and functional traits. The terrestrial microbiomes showed the highest diversity, yet the lowest correlations. In particular, there were few correlations between genes involved in aerobic and anaerobic degradation pathways, showing a clear functional redundancy property. In contrast, enhanced correlations, especially closer inter‐connections between anaerobic and aerobic groups, were observed in aquatic consortia in response to the lower diversity. Specifically, dypB and dypA, are widespread on Earth, indicating their essential roles in lignin depolymerization. Estuarine and marine consortia featured the laccase and mnsod genes, respectively. Notably, the roles of archaea in lignin degradation were revealed in marine ecosystems. Environmental factors strongly influenced functional traits, but weakly shaped taxonomic groups. Null mode analysis further verified that composition of functional traits was deterministic, while taxonomic composition was highly stochastic, demonstrating that the environment selects functional genes rather than taxonomic groups. Our study not only develops a useful tool to study lignin degrading microbial communities via metagenome sequencing but also advances our understanding of ecological traits of these global microbiomes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Uncovering the lignin-degrading potential of Serratia quinivorans AORB19: insights from genomic analyses and alkaline lignin degradation.
- Author
-
Ali, Nadia Sufdar, Thakur, Subarna, Ye, Mengwei, Monteil-Rivera, Fanny, Pan, Youlian, Qin, Wensheng, and Yang, Trent Chunzhong
- Subjects
LACCASE ,LIGNIN structure ,LIGNINS ,GENOMICS ,SERRATIA ,WHOLE genome sequencing ,PLANT cell walls ,BACTERIAL metabolism - Abstract
Background: Lignin is an intricate phenolic polymer found in plant cell walls that has tremendous potential for being converted into value-added products with the possibility of significantly increasing the economics of bio-refineries. Although lignin in nature is bio-degradable, its biocatalytic conversion is challenging due to its stable complex structure and recalcitrance. In this context, an understanding of strain's genomics, enzymes, and degradation pathways can provide a solution for breaking down lignin to unlock the full potential of lignin as a dominant valuable bioresource. A gammaproteobacterial strain AORB19 has been isolated previously from decomposed wood based on its high laccase production. This work then focused on the detailed genomic and functional characterization of this strain based on whole genome sequencing, the identification of lignin degradation products, and the strain's laccase production capabilities on various agro-industrial residues. Results: Lignin degrading bacterial strain AORB19 was identified as Serratia quinivorans based on whole genome sequencing and core genome phylogeny. The strain comprised a total of 123 annotated CAZyme genes, including ten cellulases, four hemicellulases, five predicted carbohydrate esterase genes, and eight lignin-degrading enzyme genes. Strain AORB19 was also found to possess genes associated with metabolic pathways such as the β-ketoadipate, gentisate, anthranilate, homogentisic, and phenylacetate CoA pathways. LC–UV analysis demonstrated the presence of p-hydroxybenzaldehyde and vanillin in the culture media which constitutes potent biosignatures indicating the strain's capability to degrade lignin. Finally, the study evaluated the laccase production of Serratia AORB19 grown with various industrial raw materials, with the highest activity detected on flax seed meal (257.71 U/L), followed by pea hull (230.11 U/L), canola meal (209.56 U/L), okara (187.67 U/L), and barley malt sprouts (169.27 U/L). Conclusions: The whole genome analysis of Serratia quinivorans AORB19, elucidated a repertoire of genes, pathways and enzymes vital for lignin degradation that widens the understanding of ligninolytic metabolism among bacterial lignin degraders. The LC-UV analysis of the lignin degradation products coupled with the ability of S. quinivorans AORB19 to produce laccase on diverse agro-industrial residues underscores its versatility and its potential to contribute to the economic viability of bio-refineries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Once upon a Time, There Was a Piece of Wood: Present Knowledge and Future Perspectives in Fungal Deterioration of Wooden Cultural Heritage in Terrestrial Ecosystems and Diagnostic Tools.
- Author
-
Isola, Daniela, Lee, Hyun-Ju, Chung, Yong-Jae, Zucconi, Laura, and Pelosi, Claudia
- Subjects
- *
WOOD , *WOOD decay , *CULTURAL property , *LIFE sciences , *CLIMATE change , *TEMPERATE climate , *ECOSYSTEMS , *FUNGAL communities - Abstract
Wooden Cultural Heritage (WCH) represents a significant portion of the world's historical and artistic heritage, consisting of immovable and movable artefacts. Despite the expertise developed since ancient times to enhance its durability, wooden artefacts are inevitably prone to degradation. Fungi play a pivotal role in the deterioration of WCH in terrestrial ecosystems, accelerating its decay and leading to alterations in color and strength. Reviewing the literature of the last 25 years, we aimed to provide a comprehensive overview of fungal diversity affecting WCH, the biochemical processes involved in wood decay, and the diagnostic tools available for fungal identification and damage evaluation. Climatic conditions influence the occurrence of fungal species in threatened WCH, characterized by a prevalence of wood-rot fungi (e.g., Serpula lacrymans, Coniophora puteana) in architectural heritage in temperate and continental climates and Ascomycota in indoor and harsh environments. More efforts are needed to address the knowledge fragmentation concerning biodiversity, the biology of the fungi involved, and succession in the degradative process, which is frequently centered solely on the main actors. Multidisciplinary collaboration among engineers, restorers, and life sciences scientists is vital for tackling the challenges posed by climate change with increased awareness. Traditional microbiology and culture collections are fundamental in laying solid foundations for a more comprehensive interpretation of big data. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Lignin Valorisation Using Lignolytic Microbes and Enzymes: Challenges and Opportunities
- Author
-
Dey, Satarupa, Basu, Riddhi, Shah, Maulin P., editor, and Dey, Satarupa, editor
- Published
- 2024
- Full Text
- View/download PDF
25. Biotechnological Processing of Sugarcane Bagasse through Solid-State Fermentation with White Rot Fungi into Nutritionally Rich and Digestible Ruminant Feed.
- Author
-
Khan, Nazir Ahmad, Khan, Mussayyab, Sufyan, Abubakar, Saeed, Ashmal, Sun, Lin, Wang, Siran, Nazar, Mudasir, Tan, Zhiliang, Liu, Yong, and Tang, Shaoxun
- Subjects
SOLID-state fermentation ,SUSTAINABILITY ,FEED analysis ,BAGASSE ,LIGNOCELLULOSE ,WHEAT straw ,SUGARCANE - Abstract
Sugarcane (Saccharum officinarum) bagasse (SCB) is one of the most widely produced lignocellulosic biomasses and has great potential to be recycled for sustainable food production as ruminant animal feed. However, due to severe lignification, i.e., lignin-(hemi)-cellulose complexes, ruminants can only ferment a minor fraction of the polysaccharides trapped in such recalcitrant lignocellulosic biomasses. This study was therefore designed to systematically evaluate the improvement in nutritional value, the in vitro dry matter digestibility (IVDMD), and the rate and extent of in vitro total gas (IVGP) and methane (CH
4 ) production during the 72 h in vitro ruminal fermentation of SCB, bioprocessed with Agaricus bisporus, Pleurotus djamor, Calocybe indica and Pleurotus ostreatus under solid-state fermentation (SSF) for 0, 21 and 56 days. The contents of neutral detergent fiber, lignin, hemicellulose and CH4 production (% of IVGP) decreased (p < 0.05), whereas crude protein (CP), IVDMD and total IVGP increased (p < 0.05) after the treatment of SCB for 21 and 56 days with all white-rot fungi (WRF) species. The greatest (p < 0.05) improvement in CP (104.1%), IVDMD (38.8%) and IVGP (49.24%) and the greatest (p < 0.05) reduction in lignin (49.3%) and CH4 (23.2%) fractions in total IVGP were recorded for SCB treated with C. indica for 56 days. Notably, C. indica degraded more than (p < 0.05) lignin and caused greater (p < 0.05) improvement in IVDMD than those recorded for other WRF species after 56 days. The increase in IVGP was strongly associated with lignin degradation (R2 = 0.72) and a decrease in the lignin-to-cellulose ratio (R2 = 0.95) during the bioprocessing of SCB. Our results demonstrated that treatment of SCB with (selective) lignin-degrading WRF can improve the nutritional value and digestibility of SCB, and C. indica presents excellent prospects for the rapid, selective and more extensive degradation of lignin and, as such, for the improvement in nutritional value and digestibility of SCB for ruminant nutrition. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
26. Overexpression of endogenous multi‐copper oxidases mcoA and mcoC in Rhodococcus jostii RHA1 enhances lignin bioconversion to 2,4‐pyridine‐dicarboxylic acid.
- Author
-
Rashid, Goran M. M., Sodré, Victoria, Luo, Jia, and Bugg, Timothy D. H.
- Abstract
To improve the titre of lignin‐derived pyridine‐dicarboxylic acid (PDCA) products in engineered Rhodococcus jostii RHA1 strains, plasmid‐based overexpression of seven endogenous and exogenous lignin‐degrading genes was tested. Overexpression of endogenous multi‐copper oxidases mcoA, mcoB, and mcoC was found to enhance 2,4‐PDCA production by 2.5‐, 1.4‐, and 3.5‐fold, respectively, while overexpression of dye‐decolorizing peroxidase dypB was found to enhance titre by 1.4‐fold, and overexpression of Streptomyces viridosporus laccase enhanced titre by 1.3‐fold. The genomic context of the R. jostii mcoA gene suggests involvement in 4‐hydroxybenzoate utilization, which was consistent with enhanced whole cell biotransformation of 4‐hydroxybenzoate by R. jostii pTipQC2‐mcoA. These data support the role of multi‐copper oxidases in bacterial lignin degradation, and provide an opportunity to enhance titres of lignin‐derived bioproducts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Isolation of delignifying bacteria and optimization of microbial pretreatment of biomass for bioenergy.
- Author
-
Rabi Prasad, B., Polaki, Suman, and Padhi, Radha Krushna
- Subjects
CLEAN energy ,BAGASSE ,ALTERNATIVE fuels ,LIGNOCELLULOSE ,BIOMASS ,FOSSIL fuels - Abstract
Microbial pretreatment of lignocellulosic biomass holds significant promise for environmentally friendly biofuel production, offering an alternative to fossil fuels. This study focused on the isolation and characterization of two novel delignifying bacteria, GIET1 and GIET2, to enhance cellulose accessibility by lignin degradation. Molecular characterization confirmed their genetic identities, providing valuable microbial resources for biofuel production. Our results revealed distinct preferences for temperature, pH, and incubation period for the two bacteria. Bacillus haynesii exhibited optimal performance under moderate conditions and shorter incubation period, making it suitable for rice straw and sugarcane bagasse pretreatment. In contrast, Paenibacillus alvei thrived at higher temperatures and slightly alkaline pH, requiring a longer incubation period ideal for corn stalk pretreatment. These strain-specific requirements highlight the importance of tailoring pretreatment conditions to specific feedstocks. Structural, chemical, and morphological analyses demonstrated that microbial pretreatment reduced the amorphous lignin, increasing cellulose crystallinity and accessibility. These findings underscore the potential of microbial pretreatment to enhance biofuel production by modifying the lignocellulosic biomass. Such environmentally friendly bioconversion processes offer sustainable and cleaner energy solutions. Further research to optimize these methods for scalability and broader application is necessary in the pursuit for more efficient and greener biofuel production. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Transcriptomic and metabolomic analysis reveals the influence of carbohydrates on lignin degradation mediated by Bacillus amyloliquefaciens.
- Author
-
Xiaodan Li, Zhuofan Li, Ming Li, Jingwen Li, Quan Wang, Shuxiang Wang, Shuna Li, and Hongya Li
- Subjects
LIGNINS ,LIGNIN structure ,BACILLUS amyloliquefaciens ,SODIUM carboxymethyl cellulose ,CARBOHYDRATES ,METABOLOMICS ,CARBON metabolism - Abstract
Introduction: Ligninolytic bacteria can secrete extracellular enzymes to depolymerize lignin into small-molecular aromatics that are subsequently metabolized and funneled into the TCA cycle. Carbohydrates, which are the preferred carbon sources of bacteria, influence the metabolism of lignin-derived aromatics through bacteria. Methods: In this study, untargeted metabolomics and transcriptomics analyses were performed to investigate the effect of carbohydrates on lignin degradation mediated by Bacillus amyloliquefaciens MN-13, a strain with lignin-degrading activity that was isolated in our previous work. Results: The results demonstrated that the cell growth of the MN-13 strain and lignin removal were promoted when carbohydrates such as glucose and sodium carboxymethyl cellulose were added to an alkaline lignin-minimal salt medium (AL-MSM) culture. Metabolomics analysis showed that lignin depolymerization took place outside the cells, and the addition of glucose regulated the uptake and metabolism of lignin-derived monomers and activated the downstream metabolism process in cells. In the transcriptomics analysis, 299 DEGs were screened after 24 h of inoculation in AL-MSM with free glucose and 2 g/L glucose, respectively, accounting for 8.3% of the total amount of annotated genes. These DEGs were primarily assigned to 30 subcategories, including flagellar assembly, the PTS system, RNA degradation, glycolysis/gluconeogenesis, the TCA cycle, pyruvate metabolism, and tryptophan metabolism. These subcategories were closely associated with the cell structure, generation of cellular energy, and precursors for biosynthetic pathways, based on a - log 10 (P adjust) value in the KEGG pathway analysis. Conclusion: In summary, the addition of glucose increased lignin degradation mediated by the MN-13 strain through regulating glycolysis, TCA cycle, and central carbon metabolism. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Harnessing redox proteomics to study metabolic regulation and stress response in lignin-fed Rhodococci
- Author
-
Xiaolu Li, Austin Gluth, Song Feng, Wei-Jun Qian, and Bin Yang
- Subjects
Lignin degradation ,Rhodococcus ,Redox biology ,Proteomics ,Metabolic regulation ,Biotechnology ,TP248.13-248.65 ,Fuel ,TP315-360 - Abstract
Abstract Background Rhodococci are studied for their bacterial ligninolytic capabilities and proclivity to accumulate lipids. Lignin utilization is a resource intensive process requiring a variety of redox active enzymes and cofactors for degradation as well as defense against the resulting toxic byproducts and oxidative conditions. Studying enzyme expression and regulation between carbon sources will help decode the metabolic rewiring that stymies lignin to lipid conversion in these bacteria. Herein, a redox proteomics approach was applied to investigate a fundamental driver of carbon catabolism and lipid anabolism: redox balance. Results A consortium of Rhodococcus strains was employed in this study given its higher capacity for lignin degradation compared to monocultures. This consortium was grown on glucose vs. lignin under nitrogen limitation to study the importance of redox balance as it relates to nutrient availability. A modified bottom–up proteomics workflow was harnessed to acquire a general relationship between protein abundance and protein redox states. Global proteomics results affirm differential expression of enzymes involved in sugar metabolism vs. those involved in lignin degradation and aromatics metabolism. As reported previously, several enzymes in the lipid biosynthetic pathways were downregulated, whereas many involved in β-oxidation were upregulated. Interestingly, proteins involved in oxidative stress response were also upregulated perhaps in response to lignin degradation and aromatics catabolism, which require oxygen and reactive oxygen species and generate toxic byproducts. Enzymes displaying little-to-no change in abundance but differences in redox state were observed in various pathways for carbon utilization (e.g., β‑ketoadipate pathway), lipid metabolism, as well as nitrogen metabolism (e.g., purine scavenging/synthesis), suggesting potential mechanisms of redox-dependent regulation of metabolism. Conclusions Efficient lipid production requires a steady carbon and energy flux while balancing fundamental requirements for enzyme production and cell maintenance. For lignin, we theorize that this balance is difficult to establish due to resource expenditure for enzyme production and stress response. This is supported by significant changes to protein abundances and protein cysteine oxidation in various metabolic pathways and redox processes.
- Published
- 2023
- Full Text
- View/download PDF
30. Experimental and theoretical insights into the effects of pH on catalysis of bond-cleavage by the lignin peroxidase isozyme H8 from Phanerochaete chrysosporium
- Author
-
Pham, Le Thanh Mai, Deng, Kai, Northen, Trent R, Singer, Steven W, Adams, Paul D, Simmons, Blake A, and Sale, Kenneth L
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Industrial Biotechnology ,Phanerochaete chrysosporium ,Lignin peroxidase ,Lignin degradation ,Ab initio molecular dynamic simulations ,Quantum calculation ,Chemical Engineering ,Biochemistry and cell biology ,Industrial biotechnology - Abstract
BackgroundLignin peroxidases catalyze a variety of reactions, resulting in cleavage of both β-O-4' ether bonds and C-C bonds in lignin, both of which are essential for depolymerizing lignin into fragments amendable to biological or chemical upgrading to valuable products. Studies of the specificity of lignin peroxidases to catalyze these various reactions and the role reaction conditions such as pH play have been limited by the lack of assays that allow quantification of specific bond-breaking events. The subsequent theoretical understanding of the underlying mechanisms by which pH modulates the activity of lignin peroxidases remains nascent. Here, we report on combined experimental and theoretical studies of the effect of pH on the enzyme-catalyzed cleavage of β-O-4' ether bonds and of C-C bonds by a lignin peroxidase isozyme H8 from Phanerochaete chrysosporium and an acid stabilized variant of the same enzyme.ResultsUsing a nanostructure initiator mass spectrometry assay that provides quantification of bond breaking in a phenolic model lignin dimer we found that catalysis of degradation of the dimer to products by an acid-stabilized variant of lignin peroxidase isozyme H8 increased from 38.4% at pH 5 to 92.5% at pH 2.6. At pH 2.6, the observed product distribution resulted from 65.5% β-O-4' ether bond cleavage, 27.0% Cα-C1 carbon bond cleavage, and 3.6% Cα-oxidation as by-product. Using ab initio molecular dynamic simulations and climbing-image Nudge Elastic Band based transition state searches, we suggest the effect of lower pH is via protonation of aliphatic hydroxyl groups under which extremely acidic conditions resulted in lower energetic barriers for bond-cleavages, particularly β-O-4' bonds.ConclusionThese coupled experimental results and theoretical explanations suggest pH is a key driving force for selective and efficient lignin peroxidase isozyme H8 catalyzed depolymerization of the phenolic lignin dimer and further suggest that engineering of lignin peroxidase isozyme H8 and other enzymes involved in lignin depolymerization should include targeting stability at low pH.
- Published
- 2021
31. Pseudomonas-associated bacteria play a key role in obtaining nutrition from bamboo for the giant panda (Ailuropoda melanoleuca)
- Author
-
Ruihong Ning, Caiwu Li, Maohua Xia, Yu Zhang, Yunong Gan, Yan Huang, Tianyou Zhang, Haitao Song, Siyuan Zhang, and Wei Guo
- Subjects
giant pandas ,gut microbiome ,lignin degradation ,nutrition ,adaptive evolution ,Microbiology ,QR1-502 - Abstract
ABSTRACTGut microbiota plays a vital role in obtaining nutrition from bamboo for giant pandas. However, low cellulase activity has been observed in the panda’s gut. Besides, no specific pathway has been implicated in lignin digestion by gut microbiota of pandas. Therefore, the mechanism by which they obtain nutrients is still controversial. It is necessary to elucidate the precise pathways employed by gut microbiota of pandas to degrade lignin. Here, the metabolic pathways for lignin degradation in pandas were explored by comparing 209 metagenomic sequencing data from wild species with different feeding habits. Lignin degradation central pathways, including beta-ketoadipate and homogentisate pathway, were enriched in the gut of wild bamboo-eating pandas. The gut microbiome of wild bamboo-eating specialists was enriched with genes from pathways implicated in degrading ferulate and p-coumarate into acetyl-CoA and succinyl-CoA, which can potentially provide the raw materials for metabolism in pandas. Specifically, Pseudomonas, as the most dominant gut bacteria genus, was found to be the main bacteria to provide genes involved in lignin or lignin derivative degradation. Herein, three Pseudomonas-associated strains isolated from the feces of wild pandas showed the laccase, lignin peroxidase, and manganese peroxidase activity and extracellular lignin degradation ability in vitro. A potential mechanism for pandas to obtain nutrition from bamboo was proposed based on the results. This study provides novel insights into the adaptive evolution of pandas from the perspective of lignin metabolism.IMPORTANCEAlthough giant pandas only feed on bamboo, the mechanism of lignin digestion in pandas is unclear. Here, the metabolic pathways for lignin degradation in wild pandas were explored by comparing gut metagenomic from species with different feeding habits. Results showed that lignin degradation central pathways, including beta-ketoadipate and homogentisate pathway, were enriched in the gut of wild bamboo-eating pandas. Genes from pathways involved in degrading ferulate and p-coumarate via beta-ketoadipate pathway were also enriched in bamboo-eating pandas. The final products of the above process, such as acetyl-CoA, can potentially provide the raw materials for metabolism in pandas. Specifically, Pseudomonas, as the most dominant gut bacteria genus, mainly provides genes involved in lignin degradation. Herein, Pseudomonas-associated strains isolated from the feces of pandas could degrade extracellular lignin. These findings suggest that gut microbiome of pandas is crucial in obtaining nutrition from lignin via Pseudomonas, as the main lignin-degrading bacteria.
- Published
- 2024
- Full Text
- View/download PDF
32. Catalytic Degradation of Lignin over Sulfonyl-Chloride-Modified Lignin-Based Porous Carbon-Supported Metal Phthalocyanine: Effect of Catalyst Concentrations.
- Author
-
Du, Fangli, Xian, Xuequan, Tang, Peiduo, and Li, Yanming
- Subjects
- *
METAL phthalocyanines , *POROUS metals , *LIGNINS , *FENTON'S reagent , *CATALYSTS , *METAL catalysts - Abstract
A sulfonyl-chloride-modified lignin-based porous carbon-supported metal phthalocyanine catalyst was prepared and used to replace the traditional Fenton's reagent for lignin degradation. The catalyst underwent a detailed characterization analysis in terms of functional group distributions, surface area, morphological structure, via FT-IR, XPS, BET, and SEM. The catalyst possessed a specific surface area of 638.98 m2/g and a pore volume of 0.291 cm3/g. The prepared catalyst was studied for its ability of oxidative degradation of lignin under different reaction conditions. By optimizing the reaction conditions, a maximum liquid product yield of 38.94% was obtained at 135 °C with 3.5 wt% of catalyst and 15 × 10−2 mol/L H2O2; at the same time, a maximum phenols selectivity of 32.58% was achieved. The compositions and properties of liquid products obtained from lignin degradation using different catalyst concentrations were studied comparatively via GC-MS, FT-IR, 1H-NMR, and EA. Furthermore, the structure changes of solid residues are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Lignin Degradation by Isolated Lignolytic Acinetobacter baumanii S2, Aspergillus niger SF4 and Rhodotorula glutinis and Profiling Products from Bio-Valorization Perspective.
- Author
-
Virmani, Shreya, Arora, Anju, Kaushik, Shubham, and Suman, Archna
- Abstract
With deployment of cellulosic ethanol there will be enhanced availability of lignin. Lignin, instead of low value utilization for heat generation, can be valorized for production of high value products. Ligninolytic organisms can be exploited for lignin valorization. Study was conducted to map lignin degradation and product profiles by Acinetobacter baumanii, Aspergillus and Rhodotorula strains. Bacterial strains Acinetobacter baumanii S1, S2, fungi Aspergillus nidulans and Aspergillus niger, isolated from compost through enrichment on lignin, were selected based on lignolytic enzyme activities and lignin degradation measured by decrease in absorbance at 205 nm. Highest lignin peroxidase 0.01 IU/mL and 0.36 IU/mL and lignin degradation 46.6% and 76.8% respectively by A. baumanii and A. niger were observed. LC–MS analysis of degraded lignins in alkali extracts of rice straw fermented with A. baumanii S2, A. niger, Rhodotorula glutinis under solid state, showed distinct product profile for each organism and uninoculated control. Aromatic compounds vanillin, 6, 7- dihydroxy 4-methyl coumarin were produced in higher amounts by A. niger, A. baumanii predominantly produced coumarin, sinapic acid while R. glutinis treated extracts had ferulic acid and 2-hydroxy-cinamic acid. These aromatics are suitable for conversion to high- value products. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Harnessing redox proteomics to study metabolic regulation and stress response in lignin-fed Rhodococci.
- Author
-
Li, Xiaolu, Gluth, Austin, Feng, Song, Qian, Wei-Jun, and Yang, Bin
- Subjects
METABOLIC regulation ,OXIDATION-reduction reaction ,ENZYME regulation ,LIGNINS ,LIPID metabolism ,PROTEOMICS ,BIOSYNTHESIS ,LIGNIN structure - Abstract
Background: Rhodococci are studied for their bacterial ligninolytic capabilities and proclivity to accumulate lipids. Lignin utilization is a resource intensive process requiring a variety of redox active enzymes and cofactors for degradation as well as defense against the resulting toxic byproducts and oxidative conditions. Studying enzyme expression and regulation between carbon sources will help decode the metabolic rewiring that stymies lignin to lipid conversion in these bacteria. Herein, a redox proteomics approach was applied to investigate a fundamental driver of carbon catabolism and lipid anabolism: redox balance. Results: A consortium of Rhodococcus strains was employed in this study given its higher capacity for lignin degradation compared to monocultures. This consortium was grown on glucose vs. lignin under nitrogen limitation to study the importance of redox balance as it relates to nutrient availability. A modified bottom–up proteomics workflow was harnessed to acquire a general relationship between protein abundance and protein redox states. Global proteomics results affirm differential expression of enzymes involved in sugar metabolism vs. those involved in lignin degradation and aromatics metabolism. As reported previously, several enzymes in the lipid biosynthetic pathways were downregulated, whereas many involved in β-oxidation were upregulated. Interestingly, proteins involved in oxidative stress response were also upregulated perhaps in response to lignin degradation and aromatics catabolism, which require oxygen and reactive oxygen species and generate toxic byproducts. Enzymes displaying little-to-no change in abundance but differences in redox state were observed in various pathways for carbon utilization (e.g., β‑ketoadipate pathway), lipid metabolism, as well as nitrogen metabolism (e.g., purine scavenging/synthesis), suggesting potential mechanisms of redox-dependent regulation of metabolism. Conclusions: Efficient lipid production requires a steady carbon and energy flux while balancing fundamental requirements for enzyme production and cell maintenance. For lignin, we theorize that this balance is difficult to establish due to resource expenditure for enzyme production and stress response. This is supported by significant changes to protein abundances and protein cysteine oxidation in various metabolic pathways and redox processes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Effect of co-culture of wood-decay fungus on lignin degradation rate of corn straw.
- Author
-
SHANG Jie, PAN Rui, YANG Zi-zhong, ZI Xi-jiang, and MA Ai-ying
- Subjects
- *
WOOD decay , *CORN straw , *LIGNINS , *LIGNIN structure , *MANGANESE peroxidase , *WOOD-decaying fungi , *SCANNING electron microscopes , *CORNSTALKS - Abstract
The experiment aimed to use wood rot fungi co-culture to pretreat biomass to improve lignin enzyme yield, lignin degradation and biomass resource utilization. Three kinds of wood-decay fungusi were co-cultured to pretreat corn stalks, and their ligninolytic enzymes yield and degradation efficiency were compared. The results showed that on the 20th day, the manganese peroxidase activity of corn stalks pretreated by three kinds of wood-decay fungus was significantly higher than that of single wood-decay fungus (P<0.05). The manganese peroxidase activity of corn straws co-cultured by Irpex lacteus and Fomitopsis pinicola was 933.82 U/L, which was 3.11 times that of pretreated by Fomitopsis pinicola alone. The co-culture of Cerrena unicolor and Irpex lacteus, as well as the co-culture of Irpex lacteus and Fomitopsis pinicola showed inhibitory effect on the production of laccase. Infrared spectrum analysis, lignin content determination and scanning electron microscope photos showed that the characteristic peaks of Cerrena unicolor and Fomitopsis pinicola co-cultured for 40 d were the most obvious, the lignin degradation rate was the highest, reaching 45.75%, and the surface damage of corn straw was serious. The experiment indicates that compared with the monoculture, corn straw pretreated by co-culture of different wood-decay fungus can significantly increase the yield of manganese peroxidase or the degradation rate of lignin in a certain culture time, but the activity of ligninase is not completely consistent with the degradation rate of lignin. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Insight in molecular degradation patterns and co-metabolism during rose waste co-composting.
- Author
-
de Nijs, E. A., Jansen, B., Absalah, S., Bol, R., and Tietema, A.
- Subjects
- *
COMPOSTING , *WASTE management , *ALIPHATIC compounds , *ROSES , *KALANCHOE , *LIGNINS , *TOMATOES - Abstract
Composting is recognized as a sustainable waste management strategy. However, little is known about green waste, and specifically rose waste, degradation patterns during composting. This study aimed (1) to gain insight in the underlying decomposition patterns during rose waste composting and (2) to identify co-metabolisms of ligneous material. Five different compost mixtures were tested ranging from pure rose waste to mixtures with tomato waste, kalanchoe waste or mature compost added. Samples were taken during a six-month experiment and analyzed by pyrolysis-GC/MS. The temporal trends in the relative abundance of 10 different compound groups were measured. Lignin and aliphatic compounds together accounted for ≥ 50% of the quantified pyrolysis products, but with changing contributions during composting. The relative abundance of polysaccharides and terpenes strongly decreased with more than 60% in the first 2 months. The simultaneous decrease in relative abundance of lignin and polysaccharides during initial composting phase indicated co-metabolism of lignin. The results from this study showed that while the presence of lignin is commonly regarded as a challenge in composting, it actually undergoes degradation through distinct mechanisms at the various composting stages. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. Biological pretreatment of Eichhornia crassipes (water hyacinth) by Alternaria alternata ANF238 and optimization of growth factors for enhanced delignification
- Author
-
Sharma, Anuja, Aggarwal, Neeraj K., Mishra, Richa, Khan, Azmat Ali, Ranjan, Nishant, Pandit, Soumya, and Agrawal, Sharad
- Published
- 2024
- Full Text
- View/download PDF
38. Positive influences of the application of inoculated lignocellulosic waste compost on the agronomic potential of a sandy loam soil
- Author
-
Fersi, Mariem, Louati, Ibtihel, Hadrich, Bilel, Smaoui, Yosr, Jerbi, Bouthaina, Jedidi, Naceur, Hassen, Abdennaceur, and Hachicha, Ridha
- Published
- 2024
- Full Text
- View/download PDF
39. The Termite Fungal Cultivar Termitomyces Combines Diverse Enzymes and Oxidative Reactions for Plant Biomass Conversion.
- Author
-
Schalk, Felix, Gostinčar, Cene, Kreuzenbeck, Nina, Conlon, Benjamin, Sommerwerk, Elisabeth, Rabe, Patrick, Burkhardt, Immo, Krüger, Thomas, Kniemeyer, Olaf, Brakhage, Axel, Gunde-Cimerman, Nina, de Beer, Z, Dickschat, Jeroen, Poulsen, Michael, and Beemelmanns, Christine
- Subjects
Termitomyces ,biodegradation ,lignin degradation ,lignocellulose ,metabolites ,redox chemistry ,redox proteins ,secondary metabolism ,symbiosis ,Animals ,Biomass ,Ecosystem ,Gastrointestinal Microbiome ,Gene Expression Profiling ,Genome ,Fungal ,Isoptera ,Lignin ,Oxidation-Reduction ,Oxidative Stress ,Plants ,Symbiosis ,Termitomyces - Abstract
Macrotermitine termites have domesticated fungi in the genus Termitomyces as their primary food source using predigested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer. While most previous work suggests that lignocellulose degradation is accomplished predominantly by the fungal cultivar, our current understanding of the underlying biomolecular mechanisms remains rudimentary. Here, we provide conclusive omics and activity-based evidence that Termitomyces employs not only a broad array of carbohydrate-active enzymes (CAZymes) but also a restricted set of oxidizing enzymes (manganese peroxidase, dye decolorization peroxidase, an unspecific peroxygenase, laccases, and aryl-alcohol oxidases) and Fenton chemistry for biomass degradation. We propose for the first time that Termitomyces induces hydroquinone-mediated Fenton chemistry (Fe2+ + H2O2 + H+ → Fe3+ + •OH + H2O) using a herein newly described 2-methoxy-1,4-dihydroxybenzene (2-MH2Q, compound 19)-based electron shuttle system to complement the enzymatic degradation pathways. This study provides a comprehensive depiction of how efficient biomass degradation by means of this ancient insects agricultural symbiosis is accomplished. IMPORTANCE Fungus-growing termites have optimized the decomposition of recalcitrant plant biomass to access valuable nutrients by engaging in a tripartite symbiosis with complementary contributions from a fungal mutualist and a codiversified gut microbiome. This complex symbiotic interplay makes them one of the most successful and important decomposers for carbon cycling in Old World ecosystems. To date, most research has focused on the enzymatic contributions of microbial partners to carbohydrate decomposition. Here, we provide genomic, transcriptomic, and enzymatic evidence that Termitomyces also employs redox mechanisms, including diverse ligninolytic enzymes and a Fenton chemistry-based hydroquinone-catalyzed lignin degradation mechanism, to break down lignin-rich plant material. Insights into these efficient decomposition mechanisms reveal new sources of efficient ligninolytic agents applicable for energy generation from renewable sources.
- Published
- 2021
40. A key O-demethylase in the degradation of guaiacol by Rhodococcus opacus PD630.
- Author
-
Le Xue, Yiquan Zhao, Ling Li, Xinran Rao, Xinjie Chen, Fuying Ma, Hongbo Yu, and Shangxian Xie
- Subjects
- *
GUAIACOL , *LIGNINS , *RHODOCOCCUS , *CYTOCHROME P-450 , *DEMETHYLATION , *CATECHOL - Abstract
Rhodococcus opacus PD630 is a high oil-producing strain with the ability to convert lignin-derived aromatics to high values, but limited research has been done to elucidate its conversion pathway, especially the upper pathways. In this study, we focused on the upper pathways and demethylation mechanism of lignin-derived aromatics metabolism by R. opacus PD630. The results of the aromatic carbon resource utilization screening showed that R. opacus PD630 had a strong degradation capacity to the lignin-derived methoxy-containing aromatics, such as guaiacol, 3,4-veratric acid, anisic acid, isovanillic acid, and vanillic acid. The gene of gcoAR, which encodes cytochrome P450, showed significant up-regulation when R. opacus PD630 grew on diverse aromatics. Deletion mutants of gcoAR and its partner protein gcoBR resulted in the strain losing the ability to grow on guaiacol, but no significant difference to the other aromatics. Only co-complementation alone of gcoAR and gcoBR restored the strain's ability to utilize guaiacol, demonstrating that both genes were equally important in the utilization of guaiacol. In vitro assays further revealed that gcoAR could convert guaiacol and anisole to catechol and phenol, respectively, with the production of formaldehyde as a by-product. The study provided robust evidence to reveal the molecular mechanism of R. opacus PD630 on guaiacol metabolism and offered a promising study model for dissecting the demethylation process of lignin-derived aromatics in microbes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
41. How temperature and aridity drive lignin decomposition along a latitudinal transect in western Siberia.
- Author
-
Dao, Thao Thi, Mikutta, Robert, Wild, Birgit, Sauheitl, Leopold, Gentsch, Norman, Shibistova, Olga, Schnecker, Jörg, Lashchinskiy, Nikolay, Richter, Andreas, and Guggenberger, Georg
- Subjects
- *
LIGNINS , *LIGNIN structure , *TUNDRAS , *PLANT litter decomposition , *SOIL horizons , *SOIL profiles , *PRINCIPAL components analysis , *SOIL moisture - Abstract
Climate change drives a northward shift of biomes in high‐latitude regions. This might have consequences on the decomposition of plant litter entering the soil, including its lignin component, which is one of the most abundant components of vascular plants. In order to elucidate the combined effect of climate and soil characteristics on the decomposition pattern of lignin, we investigated lignin contents and its degree of oxidative decomposition within soil profiles along a climosequence in western Siberia. Soil samples were collected from organic topsoil to mineral subsoil at six sites along a 1500‐km latitudinal transect, stretching from tundra, through taiga and forest steppe to typical steppe. The stage of lignin degradation, as mirrored by decreasing organic carbon‐normalized lignin contents and increasing oxidative alteration of the remnant lignin (acid‐to‐aldehyde ratios of vanillyl‐ and syringyl‐units [(Ac/Al)V and (Ac/Al)S]) within soil horizons, increased from tundra to forest steppe and then decreased to the steppe. Principal component analysis, involving also climatic conditions such as mean annual temperature and aridity index, showed that the different states of lignin degradation between horizons related well to the activity of phenoloxidases and peroxidases, enzymes involved in lignin depolymerization that are produced primarily by fungi and less importantly by bacteria. The low microbial lignin decomposition in the tundra was likely due to low temperature and high soil moisture, which do not favour the fungi. Increasing temperature and decreasing soil moisture, facilitating a higher abundance of fungi, led to increased fungal lignin decomposition towards the forest‐steppe biome, while drought and high pH might be responsible for the reduced lignin decomposition in the steppe. We infer that a shift of biomes to the north, driven by climate change, might promote lignin decomposition in the northern parts, whereas in the south a further retardation might be likely. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Ergosterol and Its Metabolites Induce Ligninolytic Activity in the Lignin-Degrading Fungus Phanerochaete sordida YK-624.
- Author
-
Wang, Jianqiao, Yin, Ru, Hashizume, Yuki, Todoroki, Yasushi, Mori, Toshio, Kawagishi, Hirokazu, and Hirai, Hirofumi
- Subjects
- *
ERGOSTEROL , *PHANEROCHAETE , *ELECTROSPRAY ionization mass spectrometry , *NUCLEAR magnetic resonance , *SULFATE pulping process , *METABOLITES - Abstract
White-rot fungi are the most important group of lignin biodegraders. Phanerochaete sordida YK-624 has higher ligninolytic activity than that of model white-rot fungi. However, the underlying mechanism responsible for lignin degradation by white-rot fungi remains unknown, and the induced compounds isolated from white-rot fungi for lignin degradation have never been studied. In the present study, we tried to screen ligninolytic-inducing compounds produced by P. sordida YK-624. After large-scale incubation of P. sordida YK-624, the culture and mycelium were separated by filtration. After the separation and purification, purified compounds were analyzed by high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance. The sterilized unbleached hardwood kraft pulp was used for the initial evaluation of ligninolytic activity. Ergosterol was isolated and identified and it induced the lignin-degrading activity of this fungus. Moreover, we investigated ergosterol metabolites from P. sordida YK-624, and the ergosterol metabolites ergosta-4,7,22-triene-3,6-dione and ergosta-4,6,8(14),22-tetraen-3-one were identified and then chemically synthesized. These compounds significantly improved the lignin-degrading activity of the fungus. This is the first report on the ligninolytic-inducing compounds produced by white-rot fungi. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. The input of microorganisms to the cultivation of mushrooms on lignocellulosic waste
- Author
-
Margarita Saubenova, Yelena Oleinikova, Amankeldi Sadanov, Zhanerke Yermekbay, and Didar Bokenov
- Subjects
lignocellulosic crop residue ,substrate composting ,microbial community ,lignin degradation ,higher fungi ,bacterial-fungal interactions ,mushroom growth-promoting ,antagonistic activity ,endofungal bacteria ,Agriculture (General) ,S1-972 ,Food processing and manufacture ,TP368-456 - Abstract
Lignocellulosic crop waste is the world's most abundant renewable raw material. Its burning leads to the loss of an energy valuable resource and causes enormous environmental damage. An environmentally friendly and promising biotechnological process for such waste utilization is the production of mushrooms for food and medicine. However, the energy intensity of substrate preparation hinders the development of work in this direction. Another significant challenge in this field is to increase the biological efficiency of substrate processing. The purpose of our investigation was to reveal the contribution of microorganisms to solving this and other problems of mushroom cultivation based on a review of the latest scientific research on the topic. The literature from databases of Google Scholar, Scopus, and Web of Science was selected by various combinations of search queries concerning mushrooms, substrates, microbial communities, and their effects. The current state of the issue of mushrooms and microorganisms' interactions is presented. The review considers in detail the contribution of microorganisms to the substrate preparation, describes microbial communities in various phases of the mushroom cultivation process, and identifies the main groups of microorganisms associated with lignocellulose degradation, mushroom growth promotion, and protection against pathogens. The significant contribution of bacteria to mushroom cultivation is shown. The review demonstrates that the contribution of bacteria to lignin degradation in lignocellulosic substrates during mushroom cultivation is largely underestimated. In this process, various genera of the bacterial phyla Bacillota, Pseudomonadota, and Actinomycetota are involved. The correct combinations of microorganisms can provide controllability of the entire cultivation process and increase required indicators. However, expanding research in this direction is necessary to remove gaps in understanding the relationship between microorganisms and mushrooms.
- Published
- 2023
- Full Text
- View/download PDF
44. Degradation of lignin in different lignocellulosic biomass by steam explosion combined with microbial consortium treatment
- Author
-
Wen Zhang, Chenyang Diao, and Lei Wang
- Subjects
Lignin degradation ,Microbial consortium ,Biomass pretreatment ,Biotechnology ,TP248.13-248.65 ,Fuel ,TP315-360 - Abstract
Abstract The difficulty of degrading lignin is the main factor limiting the high-value conversion process of lignocellulosic biomass. The biodegradation of lignin has attracted much attention because of its strong environmental friendliness, but it still faces some dilemmas such as slow degradation rate and poor adaptability. The microbial consortia with high lignin degradation efficiency and strong environmental adaptability were obtained in our previous research. To further increase the lignin degradation efficiency, this paper proposes a composite treatment technology of steam explosion combined with microbial consortium degradation to treat three kinds of biomass. We measured the lignin degradation efficiency, selectivity value (SV) and enzymatic saccharification efficiency. The structural changes of the biomass materials and microbial consortium structure were also investigated. The experimental results showed that after 1.6 MPa steam explosion treatment, the lignin degradation efficiency of the eucalyptus root reached 35.35% on the 7th days by microbial consortium. At the same time, the lignin degradation efficiency of the bagasse and corn straw treated by steam explosion followed by microbial biotreatment was 37.61–44.24%, respectively, after only 7 days of biotreatment. The microbial consortium also showed strong selectivity degradation to lignin. The composite treatment technology can significantly improve the enzymatic saccharification efficiency. Saccharomycetales, Ralstonia and Pseudomonadaceae were the dominant microorganisms in the biomass degradation systems. It was proved that the combined treatment technology of steam explosion and microbial consortium degradation could overcome the drawbacks of traditional microbial pretreatment technology, and can facilitate the subsequent high-value conversion of lignocellulose.
- Published
- 2023
- Full Text
- View/download PDF
45. Qualitative and quantitative analysis of lignin degradative enzymes in Ganoderma strains under arid conditions
- Author
-
Mawar, Ritu, Kumar, Mahesh, and Mathur, Tanu
- Published
- 2022
46. Combinations of mild chemical and bacterial pretreatment for improving enzymatic saccharification of corn stover
- Author
-
Guoqing Liu, Dongjing Han, and Shaohua Yang
- Subjects
Biological pretreatment ,corn stover ,lignin degradation ,enzymatic saccharification ,Biotechnology ,TP248.13-248.65 - Abstract
AbstractBiological pretreatment of lignocellulosic biomass plays an important role for the enzymatic hydrolysis. In this study, a nitrogen-fixing and lignin-degrading strain of bacteria was isolated from an abandoned termite colony. Then, it was identified and named as R. ornithinolytica RS-1. To improve the degradation and enzymatic saccharification in corn stover, we used pretreatment with strain RS-1 to deplete the lignin, combined with a 2.5% mild NaOH pretreatment to further deplete the hemicellulose. After only seven days, lignin was degraded by the bacteria RS-1 with a 19% decrease, while the relative content of cellulose increased with 21%. Furthermore, the corn stover cellulose conversion was up to 48.58% by a two-stage process with 2.5% NaOH pretreatment. Meanwhile, significant lignin and hemicellulose removal were observed. Manganese peroxidase activity was highest on Day 3 with the value 181.0256 U/L and lignin peroxidase activity was highest on Day 5 with the value 37.473 U/L, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses showed significant chemical structural changes after the combined pretreatment. Therefore, strain RS-1 provided an efficient strategy to enhance the enzymatic hydrolysis efficiency by pretreatment of corn stover.
- Published
- 2022
- Full Text
- View/download PDF
47. WHITE-ROT FUNGAL PRETREATMENT OF WHEAT STRAW: EFFECT ON ENZYMATIC HYDROLYSIS OF CARBOHYDRATE POLYMERS.
- Author
-
KNEŽEVIĆ, ALEKSANDAR, ĐOKIĆ, IVANA, TOSTI, TOMISLAV, POPOVIĆ, SLAĐANA, MILOJKOVIĆ-OPSENICA, DUŠANKA, and VUKOJEVIĆ, JELENA
- Subjects
- *
HYDROLYSIS , *WHEAT straw , *CARBOHYDRATES , *FUNGI , *LIGNINS - Abstract
The aim of the study was the comparative analysis of degradation of wheat straw lignin by white-rot fungi and its implications on the efficiency of enzymatic hydrolysis of holocellulose. Peroxidases were found to be predominantly responsible for lignin degradation, even though high laccase activities were detected, especially in the initial stages of fungal culturing. The studied fungal species showed various ability to degrade lignin in wheat straw, which further affected the release of reducing sugars during enzymatic saccharification. The highest rate of lignin, hemicelluloses and cellulose degradation was noticed in the sample pretreated with Irpex lacteus. Among all the tested species, only Ganoderma resinaceum was found as a suitable lignin degrader, with 2-fold higher hydrolysis yield (51.1 ± 4.7%) than in the control. A key mechanism that enhances convertibility of carbohydrates is the selective lignin removal from biomass. Operating time, holocellulose loss and unpredictable fungal response to culturing conditions are the main challenges in fungal pretreatment of lignocellulosic feedstock. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. 棉秆固体发酵中木质素降解与酶活性变化的关联分析.
- Author
-
李佩琪, 孙庆培, 王志慧, 秦新政, and 樊永红
- Abstract
Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
49. A high throughput screening process and quick isolation of novel lignin-degrading microbes from large number of natural biomasses
- Author
-
Nadia Sufdar Ali, Fang Huang, Wensheng Qin, and Trent Chunzhong Yang, PhD
- Subjects
High throughput screening ,Lignin degradation ,Laccase ,β-glucanase ,Xylanase ,Biotechnology ,TP248.13-248.65 - Abstract
High throughput screening approaches can significantly speed up the identification of novel enzymes from natural microbial consortiums. A two-step high throughput screening process was proposed and explored to screen lignin-degrading microorganisms. By employing this modified culture enrichment method and screening based on enzyme activity, a total of 82 bacterial and 46 fungal strains were isolated from fifty decayed wood samples (100 liquid cultures) collected from the banks of the Ottawa River in Canada. Among them, ten bacterial and five fungal strains were selected and identified based on their high laccase activities by 16S rDNA and ITS gene sequencing, respectively. The study identified bacterial strains from various genera including Serratia, Enterobacter, Raoultella, and Bacillus, along with fungal counterparts including Mucor, Trametes, Conifera and Aspergillus. Moreover, Aspergillus sydowii (AORF21), Mucor sp. (AORF43), Trametes versicolor (AORF3) and Enterobacter sp. (AORB55) exhibited xylanase and β- glucanase activities in addition to laccase production. The proposed approach allowed for the quick identification of promising consortia and enhanced the chance of isolating desired strains based on desired enzyme activities. This method is not limited to lignocellulose and lignin-degrading microorganisms but can be applied to identify novel microbial strains and enzymes from different natural samples.
- Published
- 2023
- Full Text
- View/download PDF
50. Heterologous expression, purification and structural features of native Dictyostelium discoideum dye-decolorizing peroxidase bound to a natively incorporated heme
- Author
-
Özlem Kalkan, Sravya Kantamneni, Lea Brings, Huijong Han, Richard Bean, Adrian P. Mancuso, and Faisal H. M. Koua
- Subjects
biocatalysis ,dye-decolorizing peroxidases ,heme incorporation ,lignin degradation ,polycyclic dyes ,structural enzymology ,Chemistry ,QD1-999 - Abstract
The Dictyostelium discoideum dye-decolorizing peroxidase (DdDyP) is a newly discovered peroxidase, which belongs to a unique class of heme peroxidase family that lacks homology to the known members of plant peroxidase superfamily. DdDyP catalyzes the H2O2-dependent oxidation of a wide-spectrum of substrates ranging from polycyclic dyes to lignin biomass, holding promise for potential industrial and biotechnological applications. To study the molecular mechanism of DdDyP, highly pure and functional protein with a natively incorporated heme is required, however, obtaining a functional DyP-type peroxidase with a natively bound heme is challenging and often requires addition of expensive biosynthesis precursors. Alternatively, a heme in vitro reconstitution approach followed by a chromatographic purification step to remove the excess heme is often used. Here, we show that expressing the DdDyP peroxidase in ×2 YT enriched medium at low temperature (20°C), without adding heme supplement or biosynthetic precursors, allows for a correct native incorporation of heme into the apo-protein, giving rise to a stable protein with a strong Soret peak at 402 nm. Further, we crystallized and determined the native structure of DdDyP at a resolution of 1.95 Å, which verifies the correct heme binding and its geometry. The structural analysis also reveals a binding of two water molecules at the distal site of heme plane bridging the catalytic residues (Arg239 and Asp149) of the GXXDG motif to the heme-Fe(III) via hydrogen bonds. Our results provide new insights into the geometry of native DdDyP active site and its implication on DyP catalysis.
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.