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[Display omitted] • Alkaline pretreatment of LCB was essential to achieve open one-pot production of PHB. • Open one-pot fermentation significantly promoted enzymatic hydrolysis of LCB. • Multi-objective optimization maximized the value of one-pot production of PHB. • Developed an open dual one-pot fermentation for whole LCB components conversion. • The open dual one-pot-fed-batch fermentation produced 20.88 g/L of PHB. The high cost associated with polyhydroxybutyrate (PHB) production demands immediate attention to advance its commercial viability. Herein, we innovatively construct highly efficient production of PHB from low-cost lignocellulosic biomass (LCB) using an open one-pot fermentation by the alkali-halophilic Halomonas alkalicola M2 developed in our previous work. We first develop alkaline pretreatment of LCB to achieve open one-pot fermentation and efficient conversion. Multi-objective optimization of fermentation conditions produces 103.421 mg/L of PHB with a content of 14.437 % and effectively promotes saccharification with cellulose and xylan enzymatic efficiencies of 82.948 % and 73.710 %, respectively. We then develop an open dual one-pot fermentation process, involving the conversion of lignin- and lignin-derived compounds-enriched slurry in the first pot and subsequent polysaccharide conversion in the second pot, to achieve efficient whole LCB components conversion, yielding a record 9.57 g/L of PHB. More importantly, we extend an open dual one-pot-fed-batch fermentation, producing 0.80 g/L of PHB with 27.69 % content in the first pot and 20.08 g/L of PHB with 61.86 % content in the second pot, showing significantly higher than many reported strains. Overall, this work demonstrates the effectiveness of utilizing cheap LCB in a newly designed fermentation process to produce PHB efficiently, representing a significant advancement in this field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Citricoccus sp. P2 degraded 44.63% of lignin and produced 23.96% of lipid content. • Citricoccus sp. P2 has demonstrated high effectiveness in LDCs conversion. • Genome sequencing revealed a biological funneling pathway for LDCs into lipid. • Lipid yield was 0.39 g/g LMS-treated lignin. • Non-sterilized fermentation efficiently improved lipid production from LDCs. Lignin-derived compounds (LDCs) bioconversion into lipids is a promising yet challenging task. This study focuses on the isolation of the ligninolytic bacterium Citricoccus sp. P2 and investigates its mechanism for producing lipids from LDCs. Although strain P2 exhibits a relatively low lignin degradation rate of 44.63%, it efficiently degrades various concentrations of LDCs. The highest degradation rate is observed when incubated with 0.6 g/L vanillic acid, 0.6 g/L syringic acid, 0.8 g/L p-coumaric acid, and 0.4 g/L phenol, resulting in respective lipid yields of 0.16 g/L, 0.13 g/L, 0.24 g/L, and 0.13 g/L. The genome of strain P2 provides insights into LDCs bioconversion into lipids and stress tolerance. Moreover, Citricoccus sp. P2 has been successfully developed a non-sterilized lipid production using its native alkali-halophilic characteristics, which significantly enhances the lipid yield. This study presents a promising platform for lipids production from LDCs and has potential to promote valorization of lignin. [ABSTRACT FROM AUTHOR]

Lignin bioconversion into polyhydroxybutyrate (PHB) has emerged as a promising valorization, however, it is suffering from inadequate conversion efficiency. Herein, an efficient strategy for addressing this challenge by employing an alkali-halophilic strain Halomonas alkalicola M2 is developed. Up to 58.5% of lignin is degraded when incubates in the non-sterilized lignin (NSL) medium under a glucose concentration of 1.055 g/L, peptone concentration of 0.596 g/L, and incubation time of 6.89 d, demonstrating enhanced proficiency compared to thermally sterilized lignin (TSL) method due to the improved cell growth, lignin-degrading enzyme activities, and secreted protein contents. Consequently, PHB production demonstrates a 50% increase using NSL method compared to TSL method. A separate route of enzymatic hydrolysis and fermentation (SHF) is proposed to further improve the PHB production, resulting in a record yield of PHB which is 1.89 g/L. This work creatively develops a non-sterilization strategy to improve PHB production from lignin, showing great potential for promoting biological lignin valorization. [Display omitted] • Non-sterilization efficiently increased the lignin degradation rate to 58.5%. • NSL produced higher cell growth, enzyme activity, and secreted protein contents. • Approximately 1.5-fold PHB titer was produced in the NSL medium. • Developed a non-sterilized SHF with a record yield of 1.89 g/L PHB production. [ABSTRACT FROM AUTHOR]

[Display omitted] • An alkali-halophilic was isolated for lignin degradation and PHA production. • An open unsterile PHA production from lignocellulose was developed. • A record yield of 2.1 g/L PHA was produced from the APL. • A total of 5.9 g PHA was accumulated from 100 g bamboo powder. The alkali-halophilic Halomonas alkalicola M2 was isolated and developed for an open unsterile polyhydroxyalkanoate (PHA) fermentation from lignocellulose at pH 10.0 and NaCl 70 g/L. The alkaline pretreatment liquid (APL) was converted into PHA by the strain, which was significantly affected by the cultural conditions, including pH, NaCl concentration, nitrogen source, and APL concentration. The extracted PHA was composed of three monomers and similar in physicochemical properties to conventional short chain-length PHA. A record yield of 2.1 and 5.9 g of PHA was accumulated from 100 g dry bamboo powder (BP) by using APL and APL combined with hydrolysate during a 48-h open unsterile fermentation process, respectively. In summary, the alkali-halophilic H. alkalicola M2 achieved the open unsterile fermentation for lignocellulose efficient bioconversion into PHA under high alkalinity and salinity conditions and would be an ideal producer in the field. [ABSTRACT FROM AUTHOR]

Bioconversion lignocellulosic biomass (LCB) to 2,3-butanediol (2,3-BDO) is a sustainable and energy-intensive practice, but its economic feasibility has been hindered by costly pretreatment and the cumbersome fermentation process. Herein, the hindgut metagenome of Cyrtotrachelus buqueti is assembled and sequenced to construct bacterial consortia for efficient LCB degradation. One of these consortia, named artificial synthetic bacteria community II (ASCII), is effective in degrading unpretreated LCB, achieving degradation rates of 85.33% for cellulose, 77.43% for hemicellulose, and 57.63% for lignin. The secretory protein extracted from ASCII is used for simultaneous saccharification and fermentation (SSF) from unpretreated LCB. Furthermore, fed-batch SSF resulted in 40.62 g/L of 2,3-BDO with a productivity of 0.42 g/L/h reached by Klebsiella sp. CQHG35. This study provides a new approach for the construction of bacterial consortia and their use in SSF for the production of 2,3-BDO from unpretreated LCB, representing a significant breakthrough in this field. [Display omitted] [ABSTRACT FROM AUTHOR]

A one-pot route for the preparation of TiO 2 @carbon nanocomposite from Ti4+/polysaccharide coordination complex has been developed and shown advantages in operation, cost, environment, etc. However, the photodegradation rate of methylene blue (MB) needs to be improved. N-doping has been proven as an efficient means to enhance photodegradation performance. Thus, the present study upgraded the TiO 2 @carbon nanocomposite to N-doped TiO 2 @carbon nanocomposite (N-TiO 2 @C) from Ti4+-dopamine/sodium alginate multicomponent complex. The composites were characterized by FT-IR, XRD, XPS, UV–vis DRS, TG-DTA, and SEM-EDS. The obtained TiO 2 was a typical rutile phase, and the carboxyl groups existed on N-TiO 2 @C. The photocatalyst consequently showed high removal efficiency of MB. The cycling experiment additionally indicated the high stability of N-TiO 2 @C. The present work provided a novel route for preparing N-TiO 2 @C. Moreover, it can be extended to prepare N-doped polyvalent metal oxides@carbon composites from all water-soluble polysaccharides such as cellulose derivatives, starch, and guar gum. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Halomonas sp. Y3 secreted laccase through Tat and Type I secretion system. • Biodesign of a highly efficient laccase secretion apparatus. • Heterologous expression of laccase achieved enzyme activity of 184 U/mL. • Up to 55 % lignin was degraded by the engineered strain Y3_05. • Co-transformation of Y3_05 and Y3_08 produced 740 and 1314 mg/L from lignin and APL. Lignin degradation represents a significant challenge in biological valorization, but it is suffering from insufficiency, putting barriers to efficient lignin conversion. Herein, the study first develops a highly efficient laccase secretion apparatus, enabling high enzyme activity of 184 U/mL, complementing the biochemical limits on lignin depolymerization well in Halomonas sp. Y3. Further engineering of PHA biosynthesis produces a significantly high PHA titer of 286, 742, and 868 mg/L from alkaline lignin, catechol, and protocatechuate, respectively. The integration of laccase-secretion and PHA production modules enables a record titer of 693 and 1209 mg/L in converting lignin and lignin-containing stream to PHA, respectively. The titer is improved furtherly to 740 and 1314 mg/L by developing a non-sterilized fermentation. This study advances a cheaper and greener production of valuable chemicals from lignin by constructing a biosynthetic platform for PHA production and provides novel insight into the lignin conversion by extremophilic microbes. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 /C nanocomposite with adsorption-photocatalytic synergistic effect were prepared. • Competitive coordination strategy was first used to adjust crystal phases of TiO 2. • The degradation ratio of methylene blue reached 96.46% within 10 min. • The C-TiO 2 /CaCO 3 presented excellent cycling stability. The synergistic adsorption-photodegradation effect has been used to form TiO 2 -based photocatalyst but is limited by the multi-step preparation strategy. The present study employed the "one-pot" method to form the precursor via a competitive coordination strategy. Ca2+/Ti4+-alginate coordination complex was prepared and further carbonized to C-TiO 2 /CaCO 3 nanocomposites for methylene blue (MB) removal. The resultant materials were characterized by FT-IR, XRD, XPS, UV–Vis DRS, TG-DTA, BET, and SEM-EDS techniques, and their synergistic adsorption-photodegradation performance on MB was also studied under simulated sunlight. Results indicated that the anatase-rutile phase of TiO 2 in the nanocomposite transformed to the anatase phase by adding CaCl 2. The C-TiO 2 /CaCO 3 nanocomposite presented higher specific surface area, pore volume, and mean pore size and consequently showed enhanced adsorption capacity. Low bandgap energy determined an excellent photocatalytic activity, and the degradation ratio of MB reached 96.46% within 10 min. The cycling photodegradation of MB indicated high cycling stability. The C-TiO 2 /CaCO 3 composites made by this simple method have synergistic adsorption-photodegradation performance and can be reused after regeneration, opening up a sustainable opportunity for wastewater treatment. [ABSTRACT FROM AUTHOR]

The biorefining of lignocelluloses using microbial degradation methods based on highly efficient microbial strains has received widespread attention. In the present study, a cellulolytic bacterium Serratia marcescens LY1 was isolated and the complete genome sequence of S. marcescens LY1 was assembled into a ring chromosome of 5,171,649 bp and a circle plasmid of 143,701 bp. Functional annotation revealed that a total of 130 genes were annotated in CAZyme families. Secretome sequencing revealed glycoside hydrolase family 3 protein and l -arabinose isomerase, which were annotated. The enzyme activities showed that the endoglucanase, xylanase, laccase, and lignin peroxidase activities peaked on the third day, while exoglucanase, manganese peroxidase, and β-glucosidase peaked on the fourth day. Furthermore, the secretome of S. marcescens LY1 was extracted for bamboo biomass hydrolysis, resulting in the highest yield of released reducing sugars was detected from the third day of secretome culture, with a value of 42.27 ± 0.46 g/L, and the secretomes of the third and fourth days were combined, resulting in the highest reducing sugar quantity of 51.59 ± 1.04 g/L. These findings indicate that the strain S. marcescens LY1 exhibits efficient saccharification of bamboo biomass and has potential use in bamboo biomass bioconversion and energy utilization. [ABSTRACT FROM AUTHOR]

Neosinocalamus affinis, a type of cluster bamboo, is a good candidate feedstock for biomass energy. In this study, we identified 686 genes as members of CAZyme families in the N. affinis transcriptome. These genes included 222 glycoside hydrolases (GHs), 288 glycosyltransferases (GTs), 64 carbohydrate esterases (CEs), 70 auxiliary activities (AAs), 37 carbohydrate binding modules (CBMs) and five polysaccharide lyases (PLs). Expression profile analysis revealed that several CAZyme genes, particularly GT, GH, AA and CE family members, were up‐regulated after insect infestation. Lignocellulose assays showed that the contents of three components, namely, cellulose, hemicellulose and lignin, increased after insect infestation. CAZyme genes were abundant in the N. affinis transcriptome and were involved in herbivory response. These findings could be applied to the protection of bamboo against herbivores, such as the bamboo snout beetle Cyrtotrachelus buqueti, and in the development of low‐cost chemical feedstock from bamboo. [ABSTRACT FROM AUTHOR]

Insects and gut symbiotic bacteria have shown promise in the degradation of lignocellulosic biomass (LCB). Cyrtotrachelus buqueti is being studied as a resource for LCB degradation, but its mechanisms are not fully understood. This study investigates the host transcriptome and gut microbiome to identify the inherent mechanisms behind efficient LCB degradation. The gut secretory protein showed degradation rates of 30.23%− 38.24% for cellulose, 58.56%− 70.96% for hemicellulose, and 28.71%− 43.43% for lignin, while microbiota had degradation rates of 28.41%− 38.31% for cellulose, 53.45%− 66.15% for hemicellulose, and 25.65%− 38.37% for lignin. Core genera (>80%) of bacteria are identified in the foregut, midgut, and hindgut, with the hindgut containing the most abundant lignin degradation potential genera Serratia and Dysgonomonas , and the midgut has the highest abundance of cellulose and hemicellulose degradation likely genera Lactococcus and Enterococcus. The transcriptome reveals highly abundant and diversified lignocellulolytic genes encoding carbohydrate-active enzymes (CAZymes), with lignin-modifying enzyme genes highly expressed in the hindgut and cellulase and hemicellulase genes highly expressed in the foregut and midgut. Integrative analysis reveals a significant correlation between the gut microbiome and transcriptome, contributing to efficient LCB degradation. This study first provides a deeply comprehensive insight into the unique mechanisms of LCB degradation by C. buqueti. [Display omitted] • Lignocellulose was effectively degraded by the gut secretory protein and microbiota. • Microbiome and transcriptome analysis identified the core microbiota and CAZymes. • Microbiome and transcriptome intensely correlated revealed by integrative analysis. • Revealed the mechanism for lignocellulose degradation by bamboo snout beetle. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) is a biopolyester with great potential, but its high production cost via the propionate-dependent pathway has hindered its development. Herein, we engineer Halomonas sp. Y3 to achieve efficient conversion of various LDCs into PHBV without propionate supplement. Initially, we successfully achieve PHBV production without propionate supplement by overexpressing threonine synthesis. The resulting biopolyester exhibits a 3 HV proportion of up to 7.89 mol%, comparable to commercial PHBV (8 mol%) available from Sigma Aldrich (403105). To further enhance PHBV production, we rationally design the reconstruction of aromatic compound catabolism. The engineered strain Y3_18 efficiently assimilates all LDCs containing syringyl (S), guaiacyl (G), and p -hydroxyphenyl-type (H) units. From 1 g/L of S-, G-, and H-type LDCs, Y3_18 produces PHBV at levels of 449 mg/L, 488 mg/L, and 716 mg/L, respectively, with yields of 44.9 % (g/g), 48.8 % (g/g), and 71.6 % (g/g). Moreover, to improve PHBV yield from lignin, we integrate laccase-secretion and PHBV production modules. This integration leads to the accumulation of 425.84 mg/L of PHBV with a yield of 21.29 % (g/g) and a 3 HV proportion of 6.38 mol%. By harnessing the capabilities of Halomonas sp. Y3, we demonstrate an efficient and sustainable approach for PHBV production from a variety of LDCs. • PHBV production from LDCs by Halomonas sp. Y3 via the propionate-dependent pathway • Knockout PrpC enabled PHBV production from LDCs without propionate supplementation. • Overexpressing threonine synthesis pathway improved PHBV production from LDCs. • Engineering aromatic compound catabolism improving PHBV content and 3 HV proportion • Co-transformation of Y3_05 and Y3_18 produced 426 mg/L of PHBV from lignin. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate (PHB) production from lignocellulosic biomass is challenging due to the need for whole components and energy-effective conversion. Herein, Halomonas sp. Y3, a ligninolytic bacterium with the capacity to produce PHB from lignin and cellulose- and hemicellulose-derived sugars, is employed to explore its feasibility. This strain shows high sugar tolerance up to 200 g/L of glucose and 120 g/L of xylose. A dual anti-microbial contamination system (DACS) containing alkali-halophilic system (AHS) and phosphite-urea system (PUS) is presented, successfully achieving a completely aseptic effect and resulting in a total of 8.2 g of PHB production from 100 g bamboo biomass. We further develop a stage-fed-batch fermentation to promote the complete utilization of xylose. Approximately 69.99 g of dry cell weight (DCW) and 46.45 g of PHB with 66.35 % are obtained from a total of 296.58 g of sugars and 5.70 g of lignin, showing a significant advancement for LCB bioconversion. We then delete the native phosphate transporters, rendering the strain unable to grow on phosphate-loaded media, effectively improving the strain biosafety without compromising its ability to produce PHB. Overall, our findings demonstrate the potential of Y3 as a classic bacterium strain for PHB production with potential uses in industry. [Display omitted] • Halomonas sp. Y3 demonstrated high efficiency in converting whole LCB into PHB. • Non-sterilized PHB production by Y3 via a dual antimicrobial contamination system • PHB of 46.45 g was synthesized via non-sterilized stage-fed-batch fermentation of LCB. • Deletion of the native Pi transporters improved the biosafety of strain Y3. [ABSTRACT FROM AUTHOR]