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Formononetin is a natural flavonoid existing widely in plants with many pharmacological effects. However, its application is limited by structure, poor water solubility and low bioavailability. In this study, Bacillus velezensis LQ5 was isolated from the inter-root soil of Glycyrrhiza uralensis Fisch for the first time and formononetin was firstly structurally modified by whole-cell catalysis of LQ5 to obtain formononetin-7-O-β-D-glucoside (FG), formononetin-7-O-β-(6''-O-succinyl)-D-glucoside (FGS) and formononetin-7-O-phosphate (FP). The selective preparation of the three products was achieved by adjusting the content of yeast extract, type and content of sugars, metal ions, pH and ATP content. The result confirmed that FP had the ideal drug-likeness properties and showed a greater ability to reduce intracellular reactive oxygen species levels and regulate oxidative enzymes. This work successfully established a biotransformation method for the efficient transformation of formononetin to produce high-value formononetin derivatives. [Display omitted] • Bacillus velezensis was firstly screened for the efficient biotransformation of formononetin. • Three rare formononetin derivatives were highly produced by LQ5. • Among products, formononetin-7-O-phosphate showed the ideal drug-likeness properties. • Formononetin-7-O-phosphate has good neuroprotective activity with low toxicity. [ABSTRACT FROM AUTHOR]

The biotransformation of phytosterol into high value steroid intermediates such as 9α-hydroxyandrost-4-ene-3,17-dione (9-OHAD) in Mycolicibacterium is the cornerstone of the steroid pharmaceuticals. However, the limited permeability of the dense mycobacterial cell wall severely hinders the efficient transportation of phytosterol and their bioconversion to 9-OHAD. In this study, we disrupted the genetic pathways involved in trehalose biosynthesis, trehalose recycle and by-product formation, leading to alterations in cell wall formation, cell permeability and 9-OHAD productivity. This manipulation led to an increase of 63.7% in the yield of 9-OHAD, reaching 10.8 g/L at a phytosterol concentration of 20 g/L in shake flask. The enhancement of cell permeability and 9-OHAD production were achieved through the deletion of genes TreS , TreY , OtsA , LpqY , and SugC , as well as the inactivation of regulator PadR. Notably, it was found that the increase in TMM content of cell wall components via TLC analysis directly affected the distribution of 9-OHAD within and outside the cell, ultimately leading to an increase in extracellular production of 9-OHAD from 12% to 32.1%. Therefore, this study provides with an effective strategy for enhancing 9-OHAD production by increasing cell permeability while minimizing by-product 4-AD formation. • Identification genes OtsA , TreS , TreY , LpqY and SugC involved in the formation of mycobacterial cell wall. • Disruption of cell wall formation dominated by trehalose supplement enhanced cell permeability and sterol uptake efficiency. • Deficiency of genes associated with trehalose synthesis and trehalose recycle improved the production of 9-OHAD. • Transcriptional regulator PadR associated with steroid compounds degradation and transport was located. [ABSTRACT FROM AUTHOR]

Lignin valorization presents significant opportunities for advancing a sustainable bioeconomy and carbon neutrality goals. In this case, biological conversion of lignin offers promising pathways for the production of aromatic fine chemicals, effectively addressing the challenges associated with the heterogeneous and macromolecular structure of lignin. However, the pathways for converting lignin derivatives into aromatic chemicals remain underdeveloped, and their conversion efficiency remains unsatisfactory. This work aims to prospect the bioconversion pathways of lignin toward valuable aromatics, which aligns with the principles of the atom economy concept. A comprehensive overview of critical pathways for converting lignin into aromatic chemicals is presented together with a thorough discussion on advanced technologies essential for enhancing lignin bioconversion and aromatic synthesis. Furthermore, existing challenges and emerging strategies are explored. The findings of this study are expected to offer valuable insights into recent advancements and future directions in the biological conversion of lignin. These insights can facilitate lignin valorization and promote the development of a lignin-based bioeconomy. [ABSTRACT FROM AUTHOR]

An arsenic-resistant bacteria (strain PKA 200) was isolated from the Hindon River (Ghaziabad) after analyzing its water sample. Strain PKA 200 belongs to the Pseudomonas genus and can convert harmful arsenite [As(III)] into less harmful arsenate [As(V)]. Strain PKA 200 exhibits a remarkable ability to sense and move towards arsenite. Strain PKA 200 is a promising candidate for studying how bacteria sense and transform arsenic. Here, we report a novel circular plate assay to demonstrate both chemotaxis and biotransformation of arsenite by Pseudomonas sp. PKA 200. [ABSTRACT FROM AUTHOR]

The present study was aimed to evaluate five different microbial consortia for rapid composting of paddy straw and analyse the quality of compost produced. The experimental study on rapid composting of paddy straw was taken at ICAR-NBAIM, Kushmaur, Mau, Uttar Pradesh, India, during the period February to April 2022. The paddy straw was collected from the farm of ICAR-IISS, Mau, U.P., India and the collected paddy straw was chopped into 4-5 cm and further used for the study. The composting experiment was performed in bio-conversion bags of size [12 (L) x 4 (B) x 3 (H) feet]. There were six treatments in which five treatments were taken to evaluate five different microbial consortia and one control (no microbial consortium added). The five different microbial consortia tested were BIOFAST, BIO-COMPOST, NCOF, PUSA and TEJAS. The results showed that Carbon-Nitrogen (C:N) ratio was reached to less than 20 at 60 days in BIO-FAST applied paddy straw followed by NCOF. While, the C:N ratio of control at 60 days was 33.71. Similarly, the primary nutrients (N, P and K) were higher (p < 0.05) in BIO-FAST followed by NCOF applied compost. The microbial activity and enzymatic activities were found to be insignificant (p < 0.05) in microbial consortia added treatments. The diluted extract of compost (50% and 20%) had higher germination index and no phytotoxicity effect. Thus, the results revealed that the addition of BIO-FAST accelerate the composting process and produce quality compost from paddy straw in 60 days. [ABSTRACT FROM AUTHOR]

Chironomids are keystone primary benthic consumers with semi‐aquatic life cycles. They support aquatic and terrestrial consumers at higher trophic levels by conveying dietary nutrients, such as fatty acids. In this study, we combined field sampling and laboratory experiments to examine the effects of environmental parameters, including diet, on fatty acid composition and metabolism in chironomid larvae and imagines. Results from 53 lakes showed that lake size, depth, dissolved organic carbon (DOC) concentrations, and trophic state had only marginal effects on the content of long‐chain polyunsaturated fatty acids (LC‐PUFA) in chironomids. Compound‐specific stable hydrogen isotope analyses confirmed that chironomids actively bioconvert dietary fatty acid precursors to LC‐PUFA in all lake types, independent of nutrient or DOC concentrations. Moreover, fatty acid‐specific stable carbon isotope data indicated that the diet of chironomids was subsidized, particularly in oligotrophic lakes in spring, by terrestrial C18 fatty acid precursors that were converted to LC‐PUFA. Data from feeding experiments further confirmed that decreased dietary availability of LC‐PUFA enhanced the conversion of dietary short‐chain precursors to LC‐PUFA. These results suggest that chironomids are PUFA regulators that can sustain LC‐PUFA levels under varying environmental conditions. Furthermore, our results indicate that they bioconvert terrestrial low‐quality material to high‐quality resources, which, via chironomid emergence, support terrestrial food webs. Chironomids are abundant and widespread, and thus, the trophic transfer of LC‐PUFA can have significant implications for the fitness and production of upper trophic level consumers in both aquatic and terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

The poultry industry has seen significant growth in response to the expanding global population, resulting in an increased demand for white meat. Recently, agricultural by-products derived from poultry have gained attention for their potential use in various applications. However, the large-scale utilization of by-products like keratin faces challenges such as low thermoplasticity and difficulty in dissolving keratin, as well as limited knowledge about the properties and processability of the resulting products. To address these issues, both chemical and biological methods are employed to extract keratin and produce different products. One promising strategy is the bioconversion of these by-products into valuable materials using enzymes. A small peptide product obtained through enzymatic biodegradation can be used in green biotechnology for industrial applications as a feed additive or a significant protein source. This review aims to discuss the eco-friendly fermentation process for feather by-products and their multifunctional applications in areas such as water purification, cosmetics, and biomedical uses. Additionally, it addresses the challenges associated with the utilization of chicken feathers and proposes possible solutions to overcome them. [Display omitted] • Adding value to agro-industrial waste can be accomplished through bioconversion. • Byproduct utilization is hindered by nutritional, technological, and economic obstacles. • Chicken feathers are a huge bioresource for developing multifunctional materials. • Keratin-derived materials hold promise to replace petro-based materials. [ABSTRACT FROM AUTHOR]

D-Mannose possesses many health effects and is commercially used in pharmaceutical, nutraceutical, and food industries. D-Mannose 2-epimerase (MEase) is responsible for bioconversion between D-glucose and D-mannose. In this study, two novel MEases were identified from Dyadobacter sp. CY327 and Rhabdobacter roseus DSM 105074. They were both homodimers with two identical subunits of approximately 45 kDa, and both showed the optimum pH and temperature at pH 8.0 and 40 °C, with the property of metal-independence. The melting temperatures (T m) of Dyadobacter sp. and R. roseus MEases were 51.49 and 51.60 °C, respectively. The specific activity, K m , k cat , and k cat / K m of Dyadobacter sp. MEase on D-glucose were 2.58 U/mg, 220 mM, 143 min−1, and 0.65 mM−1 min−1, respectively, and those of R. roseus MEase were 2.42 U/mg, 178 mM, 104 min−1, and 0.584 mM−1 min−1, respectively. Dyadobacter sp. and Rhabdobacter roseus (1 U/mL) produced 113.65 and 116.65 g/L of D-mannose from 500 g/L D-glucose at pH 8.0 and 40 °C for 48 h, with the yield of 22.74 % and 23.33 %, respectively. [Display omitted] • Two novel D-mannose 2-epimerases (MEase) were identified. • They were metal-independent MEases with optimal pH and temperature of 8.0 and 40 °C. • They showed high specific activities on D-glucose and D-mannose. • Two MEases produced 113.65 and 116.65 g/L of D-mannose from 500 g/L D-glucose. [ABSTRACT FROM AUTHOR]

Biomass and organic residues are increasingly recognized as valuable resources for bioenergy production. Lignocellulosic biomass offers sustainable alternatives to fossil fuels for generation of bioenergy (such as biogas, bioethanol, biodiesel, and biohydrogen). Pretreatment plays a crucial role in a biomass biorefinery. It increases biomass homogeneity and production yields, thereby overcoming transportation and storage problems. However, the absence of a clear plan for biomass pretreatment represents a challenge for biomass conversion procedures. The socio-economic effects of biomass utilization are not unequivocally constructive. High investment and capital costs, technological maturity of biofuels, large-scale biomass supply, and policy and regulatory issues are among the key challenges. Despite these challenges, with the right strategies and solutions, complete biomass valorization is achievable. Solutions such as quick capital cost estimation, upgrading existing plants, optimizing biomass feedstock blends, utilizing waste biomass resources, and improving machinery efficiencies can address these challenges. Policy and regulatory challenges can be tackled through clear and long-term targets, financial and fiscal incentives, mandates and obligations, and sustainability governance supported by regulations and certifications. However, the realization of these benefits would depend on various factors such as the specific context of the biomass utilization, the available resources, and the market conditions. Thus, this work critically reviews the status of bioenergy production, the socio-economic challenges of biomass pretreatment, and its diversity in the bioenergy set-up. [ABSTRACT FROM AUTHOR]

Microbial biotransformation of argentatin A (1), isoargentatin A (2) and argentatin B (3), the cycloartane- and lanostane-type triterpenoid constituents of guayule (Parthenium argentatum) resin, with Cunninghamella elegans ATCC 9245-A0 afforded eight new metabolites 4–11. These were identified as products formed as a result of: (i) α- and β-hydroxylation at C-7 and C-11; (ii) sequential oxidation of these newly formed alcohols to their corresponding carbonyl analogues; and (iii) rearrangement of the 9(10)-cyclopropane ring. The observed regiospecific hydroxylation reactions are possibly catalyzed by cytochrome P450 enzymes known to be produced by C. elegans. It is interesting that among the biotransformation products 9–11 of argentatin B (3) with a carbonyl group at C-11, only 11 had resulted from the rearrangement of the 9(10)-cyclopropane ring under the conditions used for biotransformation. This constitutes the first report of biotransformation of argentatins by C. elegans. [ABSTRACT FROM AUTHOR]

Xylitol, as an important food additive and fine chemical, has a wide range of applications, including food, medicine, chemical, and feed. This review paper focuses on the research progress of xylitol biosynthesis, from overcoming the limitations of traditional chemical hydrogenation and xylose bioconversion, to the full biosynthesis of xylitol production using green and non-polluting glucose as substrate. In the review, the molecular strategies of wild strains to increase xylitol yield, as well as the optimization strategies and metabolic reconfiguration during xylitol biosynthesis are discussed. Subsequently, on the basis of existing studies, the paper further discusses the current status of research and future perspectives of xylitol production using glucose as a single substrate. The evolution of raw materials from xylose-based five-carbon sugars to glucose is not only cost-saving, but also safe and environmentally friendly, which brings new opportunities for the green industrial chain of xylitol. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to produce an engineered recombinant laccase from extremophilic Halalkalibacterium halodurans C-125 (Lac-HhC-125) with higher protein yield, into a more active conformation and with properties that meet the fundamental needs of biotechnological application. Results: The rLac-HhC125 was partially purified by size exclusion chromatography and concentrated by ultrafiltration (10 kDa) with a yield of 57.6%. Oxidation reactions showed that adding 2 mM CuSO4 to the assay solution led to activating the laccase. To increase its initial activity, the rLac-HhC125 was treated at 50 °C for 20 min before the assays, improving its performance by fourfold using the syringaldazine as a substrate. When treated with EDTA, methanol, ethanol, and DMSO, the rLac-HhC125 maintained more than 80% of its original activity. Interestingly, the acetonitrile induced a twofold activity of the rLac-HhC125. The putative rLac-HhC125 demonstrated a capability of efficient transformation of different organic compounds at pH 6, known as dye precursors, into coloured molecules. Conclusion: The rLac-HhC125 was active at high temperatures and alkaline pH, exhibited tolerance to organic solvents, and efficiently transformed different hydroxy derivatives into coloured compounds, which indicates that it can be used in various biotechnological processes. [ABSTRACT FROM AUTHOR]

Cow colostrum is the first milk produced after birth and is a rich natural source of nutrients, immunoglobulins, peptides, and growth factors. The bioconversion of milk and whey changes the immobilization and biochemical characterization. However, the cellular mechanism and the anti-melanin synthesis effects of hydrolyzed cow colostrum extract (BCFM) in alpha-MSH-induced B16F1 cells have not been examined. In this study, we investigated the anti-melanogenesis mechanism by examining the effects of BCFM in alpha-MSH-induced B16F1 cells. Cells were treated with BCFM in the presence or absence of alpha-MSH and co-cultured for 24, 48, and 72 h. The treatment of B16F1 cells with alpha-MSH resulted in the darkening of the color of the cells and induction of melanin synthesis. In addition, the expression levels of MC1R and cAMP, as well as phosphorylation levels of CREB and PKA, were increased by alpha-MSH treatment. However, concomitant treatment with BCFM resulted in a significant decrease in these factors and phosphorylated MITF. At the same time, the expressive amount of TRP-1 and tyrosinase was also decreased in B16F1 cells. These results demonstrate the potential of BCFM for the prevention of melanogenesis progression via the regulation of the MC1R-cAMP signaling pathway in alpha-MSH-induced B16F1 cells. The administration of BCFM suppressed the expression of TRP-1 and/or tyrosinase by regulating the CREB/MITF signaling pathways in the B16F1 cells. We propose that hydrolyzed cow colostrum extract (BCFM) is suitable for use as a novel active agent for skin whitening or pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Chiral amines are key building blocks for the synthesis of many active pharmaceutical ingredients (APIs). Biocatalytic routes offer significant advantages to provide sustainable access to such motifs on commercial scale, with sacubitril valsartan sodium hydrate as a recent example. In this study a deeper mechanistic and kinetic understanding of the central biocatalytic step in the synthesis of sacubitril valsartan sodium hydrate, applying the evolved transaminase CDX‐043, was gained. The equilibrium of the transamination reaction was investigated in detail, and two kinetic models (ping‐pong two‐substrate kinetics and Michaelis–Menten double substrate kinetics) were established, considering substrate and product inhibition. The determined equilibrium constant indicates that the equilibrium lies strongly on the product side. The results of the kinetic studies demonstrate that the transaminase reaction is in conformity with the Michaelis–Menten double substrate kinetic model. Product inhibition was found to be more severe than substrate inhibition. The application of a plug flow reactor (PFR) was shown to be the preferred reactor setup to reduce the occurring inhibition. [ABSTRACT FROM AUTHOR]

Utilizing pressure as a process parameter can make biotechnological processes more efficient and attractive compared to established ones. This paper presents a high‐pressure reactor setup for enzymatically catalyzed gas–liquid reactions, which can be operated up to 15.0 MPa. The reactor is equipped with optical measurement technology for inline and in situ monitoring of the oxygen concentration under high‐pressure conditions. The setup is characterized by assessing the influence of the process parameter pressure on the conversion of the glucose oxidation to d‐glucono‐δ‐lactone by immobilized glucose oxidase. The study demonstrates that the increased oxygen availability due to higher solubility reduces the reaction time in a batch reactor from 270 to 90 min. [ABSTRACT FROM AUTHOR]

AbstractAgricultural byproducts generally contain abundant bioactive compounds (e.g., cellulose/hemicellulose, phenolic compounds (PCs), and dietary fibers (DFs)), but most of them are neglected and underutilized. Owing to the complicated and rigid structures of agricultural byproducts, a considerable amount of bioactive compounds are entrapped in the polymer matrix, impeding their further development and utilization. In recent years, the prominent performance of cellulolytic fungi to grow and degrade agricultural byproducts has been applied to achieve efficient biotransformation of byproducts to high-value compounds, which is a green and sustainable strategy for the reutilization of agricultural byproducts. This review comprehensively summarizes recent progress in the value-added biotransformation of agricultural byproducts by cellulolytic fungi, including (1) direct utilization of agricultural byproducts for biochemicals and bioethanol production via a consolidated bioprocessing, (2) recovery and biotransformation of bounded PCs from agricultural byproducts for higher bioactive properties, as well as (3) modification and conversion of insoluble DF from agricultural byproducts to produce functional soluble DF. The functional enzymes, potential mechanisms, and metabolic pathways involved are emphasized. Moreover, promising advantages and current bottlenecks using cellulolytic fungi have also been elucidated, shedding further perspectives for sustainable and efficient reutilization of agricultural byproducts by cellulolytic fungi. [ABSTRACT FROM AUTHOR]

Biogenic methane (BM) production from coal is quite limited due to its complex chemical nature, which makes the responsible microbes sensitive to its denaturation. In the current investigation, wheat straw (WS) at different concentrations as a cosubstrate were used with coal to augment methane generation from coal. Results revealed that the codigestion approach significantly enhanced the cumulative methane generation in CS1 (17.25 mmol) (coal:straw, 75:25), which was 59.52%–256.47% higher than the CS2 (coal:straw, 85:15), and WS single digestion, respectively. Moreover, the lowest methane yield (0.295 mmol/g) was achieved from single coal digestion. Particularly, the highest methane content, 68.37% in the collected biogas, was observed in CS1, followed by CS2 (49.53%), WS (44.92%), and coal (3.53%). Microbial community analysis illustrates that Methanobacteriaceae (51.33%) and Methanosarcinaceae (48.66%) were the leading archaeal communities at the peak methanogenic stage in CS1. While the abundant bacteria at this stage were Hungateiclostridiaceae (40.18%), Rhodobacteriaceae (21.40%), and Lentimicrobiaceae (19.20%) in CS1. According to scanning electron microscopy (SEM) analysis, several microbes were seen to be attached to the coal surface in CS1 and CS2. Moreover, the nontargeted metabolomic results showed that aromatics, aliphatic, long‐chain fatty acids, and alkane (C19–C36) compounds were found to be highly expressed in only coal, CS1, and CS2 reactors compared to WS. In addition, volatile fatty acids (VFAs) analysis showed that acetic acids were abundantly present in CS1 (2,190,175 ng/ml), followed by WS (1,543,492.88 ng/ml), CS2 (1,159,050 ng/ml), and coal (50,998.31 ng/ml). These results promote the significance of using WS as a cosubstrate with coal to enhance methane production, which can be used as a fuel in power plants. Further studies are required to investigate the potential cosubstrate with coal to enhance methane production and identify the specific metabolic pathways involved. [ABSTRACT FROM AUTHOR]

Biotransformation of ferrihydrite (Fh) by dissimilatory iron-reducing bacteria (DIRB) into various secondary minerals assemblages widely occurs in anaerobic environments. While respiration-driven supply rates of Fe(II) have been proposed as a primary factor controlling kinetics and mineral products of this process, the specific mechanism by which DIRB respiration rates regulate Fh biotransformation remains elusive. Here, to minimize the complex effects of microbial cells, we conducted Fh transformation using 1 mM biogenic Fe(II) (BioFe(II)), added at different rates to mimic diverse respiration-driven supply rates of Fe(II) by DIRB. For comparison, transformation experiments with FeSO 4 alone and FeSO 4 plus citrate (CitFe(II)) added at the corresponding supply rates were performed to decouple the specific effects of Fe(II) addition rates and extracellular polymeric substances (EPS) associated with BioFe(II). Decreasing FeSO 4 supply rates favored the transformation of Fh to lepidocrocite (Lp) over to Gt and the subsequent transformation of Lp to magnetite (Mt), altering the transformation pathway from Fh → Lp/Gt → Gt to Fh → Lp/Gt → Mt/Gt. These results underscore the significant effect of aqueous Fe(II) supply rates on the competition of olation and oxolation of labile Fe(III) intermediates into different secondary minerals. In the experiments with BioFe(II) and CitFe(II), although EPS or citrate slightly increased Fe(II) adsorption and Fe(III) labile generation, the increase in sorbed Fe(II) was minimal compared to the variations in aqueous Fe(II) concentrations caused by the different Fe(II) supply rates. At the same Fe(II) supply rates, EPS or citrate notably inhibited the transformation of Fh to Gt and the further conversion of Lp, altering the pathway from Fh → Mt/Gt/Lp to primarily Fh → Lp. These effects became more pronounced with the decrease of BioFe(II) and CitFe(II) supply rates. Our findings provide new insights into how DIRB respiration rates control kinetics, pathways, and mineral products of Fh transformation, which is crucial for elucidating the relevant biogeochemical cycling of nutrients and (im)mobilization of contaminants. [ABSTRACT FROM AUTHOR]

Formate dehydrogenases (FDHs) catalyze the oxidation of formate to CO2 while reducing NAD(P)+ to NAD(P)H and are classified into two main classes: metal‐dependent (Mo‐ or W‐containing) and metal‐independent FDHs. The latter are oxygen‐tolerant and relevant as a cofactor regeneration system for various bioprocesses and gained more and more attention due to their ability to catalyze the reverse CO2 reduction. This review gives an overview of metal‐independent FDHs, the recent advances made in this field, and their relevance for future applications in biocatalysis. This includes the exploitation of novel FDHs which have altered co‐substrate specificity as well as enzyme engineering approaches to improve process stability and general performance. [ABSTRACT FROM AUTHOR]

Background: The black soldier fly (Hermetia illucens) has emerged as a promising tool in sustainable waste management, owing to its larvae's ability to efficiently convert organic waste into valuable biomass. Objective: This study investigates the impact of various substrate compositions on the growth, waste reduction efficiency, and bioconversion rate of black soldier fly (BSF) larvae (Hermetia illucens). The aim is to optimize feeding strategies to enhance the effectiveness of BSF larvae in sustainable waste management and protein production. Methods: A controlled experiment was conducted over a 20-day period, using four different substrate types: 100% sludge, 75% sludge + 25% chicken feed, 25% sludge + 75% chicken feed, and 100% chicken feed. Each treatment had three replicates with 100 larvae each. Larval growth metrics, including weight and width, were recorded bi-daily. The waste reduction efficiency and bioconversion rate were calculated based on the remaining substrate weight and larval biomass, respectively. Elemental analysis was performed to determine the impact of substrate type on the accumulation of various elements in the larvae. Results: Significant differences were observed in larval growth, waste reduction efficiency, and bioconversion rates across the different substrates. The 100% chicken feed substrate led to the highest larval growth (M = 0.0881 g/day, SD = 0.0042) and bioconversion rate (M = 7.52%, SD = 0.34), while the 100% sludge substrate achieved the highest waste reduction rate (M = 86.2%, SD = 2.15). ANOVA tests indicated that substrate composition significantly affected these outcomes (p < 0.05). Elemental analysis showed substantial variations in the concentrations of calcium, cadmium, and nickel among the substrates, with the 100% sludge substrate having the highest nickel accumulation (M = 0.2763 ppm, SD = 0.023), significantly different from the other treatments (p < 0.001). Conclusions: The results demonstrate that substrate composition is crucial for optimizing BSF larvae growth and waste reduction efficiency. Nutrient-rich substrates, such as chicken feed, significantly enhance bioconversion rates and larval biomass production, although careful consideration of elemental accumulation, especially heavy metals, is essential for safe application in animal feed. [ABSTRACT FROM AUTHOR]

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Abstract5-aminolevulinic acid (ALA) is a non-protein amino acid that has been widely used in the fields of medicine and agriculture. This study aims to engineer the C5 pathway of the ALA biosynthesis in Escherichia coli BL21 to enhance ALA production. The ALA synthase genes gltX, hemA, and hemL were overexpressed in E. coli BL21 to lead to the increase in the production of ALA. The sRNA RyhB was also overexpressed to downregulate the expression of ALA dehydratase to reduce the downstream bioconversion of ALA to porphobilinogen. Next, the gene arcA was knocked out by CRISPR-Cas9 technology to open the TCA cycle to promote the respiratory metabolism of the strain to reduce the feedback inhibition of heme to ALA. The fermentation conditions of the engineered strain were optimized by response surface experiments. The time-course analysis of the ALA production was carried out in a 1 L shake flask. Through these efforts, the production of ALA in engineered strain reached 2953 mg/L in a 1 L shake flask. This study contributes to the industrial production of ALA by the engineered E. coli in the future. [ABSTRACT FROM AUTHOR]

Vanilla flavour is widely used in various industries and is the most broadly used flavouring agent in the food industry. The demand for this flavour is, therefore, extremely high, yet vanilla bean extracts can only meet about 1% of the overall demand. Vanillin, the main constituent of vanilla flavour, can easily be obtained through chemical synthesis. Nonetheless, consumer demands for natural products and environmentally friendly industrial processes drive the development of biotechnological approaches for its production. Some microorganisms can naturally produce vanillin when fed with various substrates, including eugenol, isoeugenol, and ferulic acid. The characterisation of the genes and enzymes involved in these bioconversion pathways, as well as progress in the understanding of vanillin biosynthesis in Vanilla orchids, allowed the development of genetic engineering and synthetic biology approaches to increase vanillin production in naturally vanillin-producing microorganisms, or to implement novel vanillin biosynthetic pathways in microbial chassis. This review summarises and discusses these genetic engineering and synthetic biology approaches for the microbial production of vanillin. [ABSTRACT FROM AUTHOR]

Economic progress, urban expansion, and enhanced quality of life in India have led to the formation of densely populated megacities and a significant increase in municipal solid waste generation. Such waste consists of a substantial volume of residues from food waste, kitchen waste originating from residential complexes, restaurants, and remnants of agricultural activities. Consequently, handling municipal solid waste has become a critical issue. Though composting is being practiced as an eco-friendly means of recycling organic waste, it is laborious and time-consuming. In the recent past, researchers have suggested the use of black soldier fly larvae (BSFL) as an effective solution for solid waste management. This study aims to assess the degradation potential of BSFL, which is gaining attention in recycling technology due to its composting capabilities, and its ability to produce soil amendments suitable for agricultural purposes. To evaluate the ability of BSFL to degrade different types of organic wastes, with a focus on cooked food waste, the compost formed after 14 days of degradation was analyzed based on elemental composition and other parameters. Comparative examinations were made with different vermicompost samples and hermicompost produced using BSFL to check the effect on plant growth. The analysis showed a higher percentage of nitrogen (4.21%), and phosphorus (0.5%) in hermicompost. The C:N ratio was 12:1 which is suitable for agronomical purposes. This study concludes that, BSFL are useful as versatile bioconversion agents of cooked food waste and provide a promising organic recycling strategy for sustainable waste management. [ABSTRACT FROM AUTHOR]

The bioconversion of low value-added phytosterols into high value-added 9α-hydroxy-4-androstene-3,17-dione (9-OHAD) in Mycolicibacterium neoaurum is a representative step in the steroid pharmaceutical industry. However, the complex mycobacterial cell walls with extremely low permeability and flowability greatly decrease the overall conversion efficiency. Herein, we preliminarily identified two key acyltransferases encoded by Mn_TmaT and Mn_SucT required for the proper synthesis of cell wall in mycobacteria and achieved a significant increase in cell permeability by disrupting them without affecting the cell wall structural stability. At length, the destruction of Mn_TmaT and Mn_SucT alone increased the conversion rate of 9-OHAD from 45.3% (6.67 ± 0.39 g/L) to 62.4% (9.19 ± 0.58 g/L) and 67.9% (10.02 ± 0.62 g/L) while the continuous destruction of Mn_TmaT and Mn_SucT did not further improve the conversion efficiency of 9-OHAD. Notably, it was investigated that the continuous destruction of Mn_TmaT and Mn_SucT led to alterations in both the covalent and non-covalent binding layers of the cell wall, resulting in excessive changes in cell morphology and structure, which ultimately decreased 9-OHAD production. Therefore, this study deciphered a pivotal biosynthetic path of cell wall and provided an efficient and feasible construction strategy of 9-OHAD synthesis in mycobacteria. [ABSTRACT FROM AUTHOR]

9-Carbon aldehydes such as (2E)-nonenal, (3Z)-nonenal, and (2E,6Z)-nonadienal are important melon and cucumber fragrance compounds. Currently, these molecules are produced either synthetically, which faces consumer aversion, or through biotransformation using plant-extracted enzymes, which is costly and inefficient. In this study, we constructed a Saccharomyces cerevisiae platform for the whole cell biotransformation of polyunsaturated fatty acids (PUFAs) to 9-carbon aldehydes. Heterologous expression of lipoxygenase (LOX) from Nicotiana benthamiana and hydroperoxide lyase (HPL) from Cucumis melo (melon) in S. cerevisiae enabled the production of (2E)-nonenal from readily available polyunsaturated fatty acid substrates. A 5.5-fold increase in (2E)-nonenal titer was then achieved utilizing genetic and reaction condition enhancement strategies. The highest titer of (2E)-nonenal was more than 0.11 mM, with about 9% yield. This platform can potentially be used to produce a variety of other aldehyde products by customizing with LOX and HPL enzymes of different regio-selectivities. Key points: • Establishment of a S. cerevisiae whole-cell biotransformation platform for cost-efficient, high-yield conversion of PUFAs into high value 9-carbon aldehyde compounds • 5.5-Fold improvement of (2E)-nonenal titer to > 0.11 mM achieved by enhancing reaction conditions and gene expression levels of LOX and HPL [ABSTRACT FROM AUTHOR]

The dynamic tracking of antibody‒drug conjugates (ADCs) in serum is crucial. However, a versatile bioanalytical platform is lacking due to serious matrix interferences, the heterogeneity and complex biotransformation of ADCs, and the recognition deficiencies of traditional affinity technologies. To overcome this, a multiepitope recognition technology (MERT) was developed by simultaneously immobilizing CDR and non-CDR ligands onto MOF@AuNPs. MERT's excellent specificity, ultrahigh ligand density, and potential synergistic recognition ability enable it to target the different key regions of ADCs to overcome the deficiencies of traditional technologies. The binding capacity of MERT for antibodies is ten to hundred times higher than that of the mono-epitope or Fc-specific affinity technologies. Since MERT can efficiently capture target ADCs from serum, a novel bioanalytical platform based on MERT and RPLC‒QTOF-MS has been developed to monitor the dynamic changes of ADCs in serum, including the fast changes of drug-to-antibody ratio from 3.67 to 0.22, the loss of payloads (maytansinol), and the unexpected hydrolysis of the succinimide ring of the linker, which will contribute to clarify the fate of ADCs and provide a theoretical basis for future design. In summary, the MERT-based versatile platform will open a new avenue for in-depth studies of ADCs in biological fluids. A novel bioanalytical platform based on multiepitope recognition technology (MERT) and RPLC‒QTOF-MS was developed to monitor the dynamic changes of ADCs in serum. [Display omitted] [ABSTRACT FROM AUTHOR]

Ginkgo biloba extract (EGB) has been approved by the Food and Drug Administration in the United States for clinical studies on memory disorders. Ginkgolide B (GB) is the major terpene lactone component of EGB and is a specific and potent antagonist of platelet-activating factor (PAF). In a previous study, we reported the medium composition for the conversion of ginkgolides to GB by Coprinus comatus. In the present study, we applied the response surface methodology (RSM) to optimize the conversion conditions in a 20 L fermenter and applied HPLC-MS/MS, circular dichroism (CD) and infrared (IR) spectroscopy analyses, and nuclear magnetic resonance (NMR) to further confirm the sample structure. The optimal conversion conditions consisted of 12.7 L/min of ventilation, a 156 h conversion time, a 132 rpm rotating speed, a 0.04 MPa fermenter pressure, and a 27.8 °C conversion temperature. Under the optimal conditions, the GB conversion rate was 98.62%, and the GB content of the sample was higher than 98%. HPLC-MS/MS, CD, IR, and NMR analyses showed that the molecular formula of the sample was C20H24O10 and the chemical structure of the sample was in good agreement with the standard GB. Our current study lays the groundwork for the industrial production of GB. [ABSTRACT FROM AUTHOR]

As a high-value bulk chemical, ethylene glycol plays an important role in many fields such as energy, the chemical industry, and automobile manufacturing. At the same time, methanol, as an economical and efficient raw material, has shown great potential in promoting the innovation of bio-based chemicals and fuels. In view of this, this study focused on the excavation and innovative application of enzymes, and successfully designed an efficient artificial cascade catalytic system. The system cleverly converts methanol into ethylene glycol, and the core is composed of methanol dehydrogenase, glycolaldehyde synthase, and lactoaldehyde–pyruvate oxidoreductase. The three enzyme systems work together, which not only simplifies the metabolic pathway, but also realizes the efficient reuse of coenzymes. Subsequently, after ribosome-binding site (RBS) optimization, isopropyl β-D-Thiogalactoside (IPTG) induction regulation, and methanol concentration adjustment, the concentration of ethylene glycol reached 14.73 mM after 48 h of reaction, and the conversion rate was 58.92%. Furthermore, a new breakthrough in ethylene glycol production was achieved within 48 h by using a two-stage biotransformation strategy and fed-batch feeding in a 5 L fermentor, reaching 49.29 mM, which is the highest yield of ethylene glycol reported so far. This achievement not only opens up a new way for the biotransformation of ethylene glycol, but also lays a foundation for the industrial application in this field in the future. [ABSTRACT FROM AUTHOR]

In today's global context, challenges persist in preventing agri-food waste due to factors like limited consumer awareness and improper food-handling practices throughout the entire farm-to-fork continuum. Introducing a forward-thinking solution, the upcycling of renewable feedstock materials (i.e., agri-food waste and by-products) into value-added ingredients presents an opportunity for a more sustainable and circular food value chain. While multi-product cascade biorefining schemes show promise due to their greater techno-economic viability, several biotechnological hurdles remain to be overcome at many levels. This mini-review provides a succinct overview of the biotechnological and societal challenges requiring attention while highlighting valuable food-grade compounds derived from biotransformation processes. These bio-based ingredients include organic acids, phenolic compounds, bioactive peptides, and sugars and offer diverse applications as antioxidants, preservatives, flavorings, sweeteners, or prebiotics in foodstuffs and other consumer goods. Therefore, these upcycled products emerge as a sustainable alternative to certain potentially harmful artificial food additives that are still in use or have already been banned from the industry. [ABSTRACT FROM AUTHOR]

Bi‐continuous jammed emulsion (bijel) membrane reactors, integrating simultaneous reaction and separation, offer a promising avenue for enhancing membrane reactor processes. In this study, we present a comprehensive macroscopic‐scale physicochemical model for tubular bijel membrane reactors and a numerical solution strategy for solving the governing partial differential equations. The model captures the co‐continuous network of two immiscible phases stabilized by nanoparticles at the liquid–liquid interface. We present the derivation of model equations and an efficient numerical solution strategy. The model is validated with experimental results from a conventional enzymatic biphasic membrane reactor for oleuropein hydrolysis, already reported in the literature. Simulation results indicate accurate prediction of reactor behavior, highlighting the potential superiority of bijel membrane reactors over current technologies. This research contributes a valuable tool for scale‐up, design, and optimization of bijel membrane reactors, filling a critical gap in this emerging field. [ABSTRACT FROM AUTHOR]

Implants made of biodegradable polymers are replaced by regenerating tissues through inflammation. The changes occurring in tissues and the organism are of practical interest for studying the biocompatibility of the material and searching for systemic markers in the blood that reflect inflammation in peri-implantation tissues. The highly sensitive C-reactive protein (hs-CRP) measurements in blood and morphometric studies of tissue surrounding the implant were carried out in the experiment within three months of implantation of a biopolymer consisting of polycaprolactone (PCL) and polytrimethylene carbonate (PTMC). During the first month, tissue inflammation decreased, and the blood level of hs-CRP did not increase. The polymer biotransformation began in the tissues after a month of implantation and was accompanied by inflammation moving deeper into the matrix. Proliferation of inflammatory cells in tissues was reflected in an increase in the hs-CRP level three months after polymer installation. The result achieved confirmed the polymer's bioinertness. The level of hs-CRP in the blood of the animals correlated with the level of inflammation in peri-implantation tissues, reflecting the activity of inflammation in the process of polymer biotransformation. This inflammation protein can be recommended for assessing tissue processes following implantation of biopolymers and their biocompatibility. [ABSTRACT FROM AUTHOR]

The widely used non-steroidal anti-inflammatory drug, diclofenac, detected in increasing concentrations in freshwater ecosystems, is among the most pressing environmental problems today. In this study, the bacterial isolate Stenotrophomonas humi strain DIC_5 was capable of degrading diclofenac. It eliminated 75.1% of diclofenac at an initial concentration of 1.5 mg/L after 8 days in the presence of glucose (3.0 g/L). During the process, nitro-diclofenac was identified as a resulting metabolite, whose concentration increased significantly in the bacterial medium from the 7th day of the experiment, while the concentration of diclofenac decreased correspondingly. The ecotoxicological tests on Aliivibrio fischeri and zebrafish embryos showed that the bacterial metabolites without diclofenac have a higher toxicity (up to 35.5% bacterial bioluminescence inhibition and 36.7% embryo mortality) than the diclofenac degradation residues (28% and 26.7%, respectively). Based on these results, neither diclofenac nor its degradation products exhibit toxic effects on the test organisms. Conversely, the toxic effect caused by the bacteria was reduced in the presence of diclofenac. Our work highlights the importance of using biotic controls in biotransformation trials, especially when the foreign material is applied in intermediate or environmentally relevant concentration ranges. Key points: • Biotransformation of diclofenac by bacteria isolated from a bacterial biofilm. • Biotransformation of diclofenac led to the formation of nitro-diclofenac. • Microorganisms are alternatives for reducing the concentration of diclofenac in water. [ABSTRACT FROM AUTHOR]

Sustainably grown biomass is a promising alternative to produce fuels and chemicals and reduce the dependency on fossil energy sources. However, the efficient conversion of lignocellulosic biomass into biofuels and bioproducts often requires extensive testing of components and reaction conditions used in the pretreatment, saccharification, and bioconversion steps. This restriction can result in a significant and unwieldy number of combinations of biomass types, solvents, microbial strains, and operational parameters that need to be characterized, turning these efforts into a daunting and time-consuming task. Here we developed a high-throughput feedstocks-to-fuels screening platform to address these challenges. The result is a miniaturized semi-automated platform that leverages the capabilities of a solid handling robot, a liquid handling robot, analytical instruments, and a centralized data repository, adapted to operate as an ionic-liquid-based biomass conversion pipeline. The pipeline was tested by using sorghum as feedstock, the biocompatible ionic liquid cholinium phosphate as pretreatment solvent, a "one-pot" process configuration that does not require ionic liquid removal after pretreatment, and an engineered strain of the yeast Rhodosporidium toruloides that produces the jet-fuel precursor bisabolene as a conversion microbe. By the simultaneous processing of 48 samples, we show that this configuration and reaction conditions result in sugar yields (~70%) and bisabolene titers (~1500 mg/L) that are comparable to the efficiencies observed at larger scales but require only a fraction of the time. We expect that this Feedstocks-to-Fuels pipeline will become an effective tool to screen thousands of bioenergy crop and feedstock samples and assist process optimization efforts and the development of predictive deconstruction approaches. [ABSTRACT FROM AUTHOR]

The reduction of oximes was recently identified as a promiscuous activity of Old Yellow Enzymes (OYEs). This reaction involves a two‐step reduction of α‐oxime‐ß‐ketoesters to the corresponding amines, which spontaneously dimerise to yield pyrazine derivatives. This biotransformation is currently limited to substrates with small substituents like methyl/ethyl on the keto moiety. We used a structure‐based approach to engineer 12‐oxophytodienoate reductase 3 (OPR3) from Solanum lycopersicum as a prototypical OYE to accept oximes with bulkier substituents. To this end, three single and two double variants were prepared and tested on six oxime substrates. The engineered variants indeed showed activity on some of the bulkier substrates, which had not been converted at all by the wild‐type enzyme, including the diester compound diethyl‐2‐(hydroximino) malonate. While we were unable to identify variants capable of converting substrates with branched and aromatic substituents, the results demonstrate the validity of our engineering approach, suggesting potential pathways for expanding the substrate scope of OYEs. [ABSTRACT FROM AUTHOR]

Background: Biotransformation of steroid compounds into therapeutic products using microorganisms offers an eco-friendly and economically sustainable approach to the pharmaceutical industry rather than a chemical synthesis way. The biotransformation efficiency of progesterone into the anticancer compound testololactone using Penicillium chrysogenum Ras3009 has been investigated. Besides, maximization of testololactone formation was achieved by studying the kinetic modelling and impact of some fermentation conditions on the biotransformation process. Results: The fungal strain Ras3009 was selected among twelve fungal strains as the most runner for the transformation of 81.18% of progesterone into testololactone. Ras3009 was identified phenotypically and genotypically as Penicillium chrysogenum, its 18 S rRNA nucleotide sequence was deposited in the GenBank database by the accession number OR480104. Studying the impact of fermentation conditions on biotransformation efficiency indicated a positive correlation between substrate concentration and testololactone formation until reaching the maximum velocity vmax. Kinetic studies revealed that vmax was gL− 1hr− 1 with high accuracy, giving R2 of 0.977. The progesterone transformation efficiency generally increased with time, reaching a maximum of 100% at 42 h with testololactone yield (Ypt/s) 0.8700 mg/mg. Moreover, the study indicated that the enzymatic conversion by P. chrysogenum Ras3009 showed high affinity to the substrate, intracellularly expressed, and released during cell disruption, leading to higher efficiency when using whole microbial cell extract. Conclusions: Fungi can be promising biocatalysts for steroid transformation into valuable chemicals and pharmaceutical compounds. The study revealed that the new fungal isolate P. chrysogenum Ras3009 possesses a great catalytic ability to convert progesterone into testololactone. Kinetic modelling analysis and optimization of the fermentation conditions lead to higher transformation efficiency and provide a better understanding of the transformation processes. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The potential for the efficient conversion of lignocellulosic biomass has been extensively explored to produce a wide range of bioproducts. Many approaches have been sought for the deep conversion of lignin to generate products that are toxin‐free and beneficial for processing into high‐value‐added components.This study reported a fungus isolated from the deep sea with strong synthesis of multiple lignocellulases, conversion of lignin and guaiacol (0.1%) by 71.6% and 86.1% within 9 days at 30 °C respectively, and outstanding environmental adaptability (20–50 °C and pH 3–8). Metabolic pathway profiling showed that this fungus utilized lignin to rapidly activate multiple ring‐opening reactions including the 2,3‐ and 3,4‐cleavage pathways, with the 2,3‐cleavage pathway predominating after 5 days. Conversion of metabolic intermediates confirmed the superb potential of this strain for lignin treatment. Meanwhile, its shikimic acid pathway was metabolically active under lignin.This further expands the potential to produce valuable bioproducts during lignin treatment, especially under ambient conditions, which can significantly enhance high‐value precursor compound production. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fatty acids (FAs) are vital biomolecules crucial for determining food quality for higher trophic levels. To investigate FA transfer and turnover time in predators, we conducted a diet switch experiment using jellyfish polyps. These polyps were fed food sources including Artemia sinica nauplii and FA‐manipulated copepod Pseudodiaptomus annandalei, maintained on distinct algal diets with varied FA compositions. Our findings reveal that copepods may have a strong potential to synthesize long‐chain polyunsaturated FA to maintain biochemical homeostasis when consuming low‐quality food. Consequently, the species‐specific fatty acid composition within plankton, combined with effects of seasonal environmental fluctuations and climate change, leads to changes in the FA composition of foundational food web components. These alterations create a complex "nutrient black box" effect as they propagate up trophic levels. Our study shows that jellyfish polyps fail to accumulate EPA and DHA but display high levels of ARA compared to their zooplankton and phytoplankton food sources, suggesting a potential association with dietary EPA and DHA through an unidentified pathway. Certain FA components indicate variations in the turnover time when polyps undergo a dietary shift. Understanding the trajectory of FA metabolism across the "phytoplankton–zooplankton" interface, along with its turnover time, provides crucial insights for modeling diet estimation of components within food webs. [ABSTRACT FROM AUTHOR]

Since ancient times, humans have turned to medicinal plants for treating various ailments and curing specific diseases, as these natural plants serve as the primary source of a range of phytochemicals, including triterpenes. Maslinic acid (MA), also known as (2α,3β)-2,3-dihydroxyolean-12-en-28-oic acid, is a pentacyclic triterpene acid present in numerous plants including olive, known for its high safety profile in humans. Recent experimental data increasingly suggests that MA exhibits diverse biological properties and therapeutic effects on various organ diseases, highlighting its significant potential for clinical applications due to its diverse potential pharmacological activities that promote health and resist various diseases, such as hypoglycemic, neuroprotective, anti-tumor, anti-inflammatory, antioxidant and multiple other biological activities. However, the undesirable pharmacokinetic properties of MA, such as high lipophilicity, pose a limitation to its application and development, impacting its bioavailability. Consequently, extensive research spanning decades has focused on structurally modifying MA to overcome these limitations and enhance its pharmacokinetic and therapeutic characteristics, leading to the identification of several potential lead compounds. In this review, we focus on the progress of research in recent years on MA with interest to its chemical and enzymatic modifications as well as the relationships between the modified structures or derivatives and their biological activities. [ABSTRACT FROM AUTHOR]

Clonazolam is a designer triazolobenzodiazepine first synthesized in 1971 and is primarily used for its anxiolytic and sedative effects. It became a drug of misuse in 2012 and is known for its high potency and long duration of effect. Previous studies of nitrobenzodiazepines, such as nitrazepam, clonazepam, and flunitrazepam, as well as their metabolites, have demonstrated that bacterial species native to the gastrointestinal tract and active during postmortem (PM) decomposition are capable of affecting positivity and compound-to-metabolite ratios. Further studies have not been performed with clonazolam; however, it possesses the nitro functional group necessary for this biotransformation. To understand whether clonazolam may be similarly affected, PM cases (n  = 288) and driving under the influence of drugs (DUID, n  = 54) cases, positive for 8-aminoclonazolam reported by NMS Laboratories from 2020 to 2023, were selected for inclusion in this study. Concentrations of clonazolam and 8-aminoclonazolam were evaluated, and concurrent identification of parent drugs and their metabolites occurred less frequently in PM cases (n  = 1, 0.30% of cases) than in DUID cases (n  = 21, 38% of cases). The clonazolam concentration in one PM case was 13 ng/mL. In DUID cases, the median clonazolam concentration was 4.0 ng/mL and ranged from 2.0 to 10 ng/mL. 8-Aminoclonazolam had median concentrations of 13 and 19 ng/mL, with ranges 2.0–580 and 2.8–59 ng/mL for PM and DUID cases, respectively. Due to the ever-changing landscape of the designer benzodiazepine market, in vitro studies of PM microbial biotransformation of clonazolam are unavailable. The data reported herein provide valuable information in the absence of such studies and represent an alternative method of investigating this phenomenon as a potential cause of parent nitrobenzodiazepine to metabolite conversion. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the kinetic resolution of building blocks for the synthesis of β-blockers using Candida rugosa lipases, which could be potentially used to synthesize enantiomerically pure β-blockers further. Reaction mixtures were incubated in a thermostated shaker. Qualitative and quantitative analyses of the reaction mixtures were performed using chiral stationary phases and the UPLC-IT-TOF system. Of the 24 catalytic systems prepared, a system containing lipase from Candida rugosa MY, [EMIM][BF4] and toluene as a two-phase reaction medium and isopropenyl acetate as an acetylating agent was optimal. This resulted in a product with high enantiomeric purity produced via biotransformation, whose enantioselectivity was E = 67.5. Using lipases from Candida rugosa enables the enantioselective biotransformation of the β-blockers building block. The biocatalyst used, the reaction environment, and the acetylating agent significantly influence the efficiency of performer kinetic resolutions. The studies made it possible to select an optimum system, a prerequisite for obtaining a product of high enantiomeric purity. As a result of the performed biotransformation, the (S)-enantiomer of the β-blocker derivative was obtained, which can be used to further synthesize enantiomerically pure β-blockers. [ABSTRACT FROM AUTHOR]

Flavonoids are a class of polyphenolic compounds found in plants that offer extensive health benefits and have applications in the pharmaceutical, cosmetic, and food industries. Currently, flavonoid production largely depends on plant extraction methods, which face limitations owing to low yields and seasonal and environmental impacts. To address these issues, the potential of microbial fermentation, which leverages advances in metabolic engineering and genetic tools, has been discussed as an innovative alternative to overcome these challenges, thus offering an environmentally friendly and sustainable approach to flavonoid production. However, the integration of complex biosynthesis pathways into microbial systems presents challenges such as the inefficient expression of plant-derived genes, metabolic conflicts, and toxicity or feedback inhibition by accumulated flavonoids within the microbial cells. This comprehensive review highlights recent advancements in engineering strategies to address these challenges, focusing on biotransformation, single-strain fermentation, and co-culture systems, each with its own unique characteristics and potential for optimizing flavonoid production in a cost-effective and scalable manner. [ABSTRACT FROM AUTHOR]

3-ketosteroid-9α-hydroxylase (KSH), a two-component monooxygenase consisting of a Rieske oxygenase KshA and a ferredoxin reductase KshB, is a crucial enzyme involved in C-9 hydroxylation and is indispensable in the microbial catabolism of sterols. However, the in vivo function of KshB remains unclear. In this study, two reductase subunits, KshB1 and KshB2 from Mycobacterium fortuitum ATCC 35855, were first characterized and then engineered in the strain MFΔ kstD , which produces 9-OHAD (9α-hydroxy-4-androstene-3,17-dione), to construct the strains producing AD (4-androstene-3,17-dione). The transcriptional level and specific enzyme activity of KshB1 under phytosterols induction was significantly higher compared to KshB2. After knocking out kshB1 , AD peaked at 1.77 g/L at 48 h, subsequently being fully converted to 9-OHAD. Furthermore, we developed the stable AD-producer MFΔ kstD Δ kshB by null mutation both kshB1 and kshB2 , although no AD was detected by single knocking out kshB2. Through gene complementation and the bioconversion of phytosterols, KshB1 emerged as the primary reductase in the KSH system, with KshB2 serving a complementary role. The stable AD-producer MFΔ kstD Δ kshB could produce 5.18 g/L, 6.91 g/L, and 9.03 g/L AD from the transformation of 10 g/L, 15 g/L, and 20 g/L phytosterols, respectively. In conclusion, these findings highlight a new strategy for the metabolic engineering of Mycobacterium fortuitum , involving the inactivation of the reductase KshB to facilitate the production of C9 non-hydroxylated steroidal intermediates. [Display omitted] • Two reductases, KshB1 and KshB2, were identified in Mycobacterium fortuitum. • KshB1 functions as the primary reductase in the KSH system. • The KshBs were inactivated to construct a strain producing AD (4-androstene-3,17-dione). • The AD-producer yielded 5.18 g/L, 6.91 g/L, and 9.03 g/L AD from 10 g/L, 15 g/L, and 20 g/L phytosterols, respectively. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: HpnG plays a crucial role in the production of ribosylhopane, a key intermediate in the biosynthesis of bacteriohopanepolyol. Despite early extensive studies, the precise function of HpnG has remained elusive. Here, we report functional characterization of HpnG as a purine nucleoside phosphorylase, which converts adenosylhopane to phosphoribosylhopane in the presence of phosphate. HpnG demonstrates broad substrate specificity and impressive stability, making it a valuable enzymatic tool for applications in nucleoside processing and related biotechnology. [ABSTRACT FROM AUTHOR]

Microbial biotransformation of lemongrass oil to geraniol and geranic acid, high value compounds of citral biosynthetic pathway has been reported. Biotransformation studies were carried out using a fungus Aspergillus niger strain AUD-C2 isolated from the rhizospheric soil of lemongrass, as catalyst. Three different methodologies using culture broth, spore suspension and cell-free extract, have been utilized for biotransformation and successfully demonstrated at litre scale in bioreactors. Overall 55% geraniol and 75% geranic acid were obtained by biotransformation of lemongrass oil in 48 h using spore suspension and cell free extract, respectively. [ABSTRACT FROM AUTHOR]

Microbial biotransformation is valuable for obtaining pharmaceutical, nutritional, and cosmetical potential molecules. Basically, for its realization, only a parental molecule, a microorganism, and a suitable fermentation system are needed. Regarding the last requirement, the most common resource used for screenings are the shaken flasks (a.k.a., conical flasks or Erlenmeyers). Despite their popularity, several concerning points discussed here limit their utilization. Multiparametric bioreactors give more reliable results but are expensive and the need for many of them for parallelized screenings becomes inaccessible for many research groups. In this review, we present some problems associated with this issue and strategies to solve them. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: HpnG plays a crucial role in the production of ribosylhopane, a key intermediate in the biosynthesis of bacteriohopanepolyol. Despite early extensive studies, the precise function of HpnG has remained elusive. Here, we report functional characterization of HpnG as a purine nucleoside phosphorylase, which converts adenosylhopane to phosphoribosylhopane in the presence of phosphate. HpnG demonstrates broad substrate specificity and impressive stability, making it a valuable enzymatic tool for applications in nucleoside processing and related biotechnology. [ABSTRACT FROM AUTHOR]

Food waste (FW) biotransformation into bioenergy has garnered a lot of scientific interest as a way to address the energy crisis and trash disposal issues. FW is converted into biogas, a gaseous combination of biomethane and carbon dioxide. In order to valorize FW, anaerobic digestion (AD) with combined pretreatment (hydrothermal (HT) and ultrasonic (US)) is used as a potential method. Three digesters were investigated: the control (unpretreated), HT(121°C) + US, and HT(134°C) + US, respectively. Based on changes in the combined pretreatment conditions, the paper assessed the methane productivity. Furthermore, kinetic modeling was evaluated with six kinetic models. The results show that the HT pretreatment at 121°C combined with US improves the volatile solid (VS) removal to 73 ± 5% and the methane yield to 529.7 ± 11 NmL/gVS. Both the Transference model and the first order have the greatest fits in terms of R2, and they also have the best fits in terms of relative errors, and methane production rate, respectively. The combined pretreatment has a positive impact on increasing methane yield as well as stabilizing the anaerobic digestion process. [ABSTRACT FROM AUTHOR]

Microbial cultures repurposing organic industrial residues for value-added metabolite production is pivotal for sustainable resource use. Highlighting polyunsaturated fatty acids (PUFAs), particularly gamma-linolenic acid (GLA), renowned for their nutritional and therapeutic value. Notably, Zygomycetes' filamentous fungi harbor abundant GLA-rich lipid content, furthering their relevance in this approach. In this study, the strain C. elegans NRRL Y-1392 was evaluated for its capability to metabolize glycerol and produce lipids rich in GLA under different culture conditions. Various carbon-to-nitrogen ratios (C/N = 11.0, 110.0, and 220.0 mol/mol) were tested in batch-flask cultivations. The highest GLA production of 224.0 mg/L (productivity equal to 2.0 mg/L/h) was observed under nitrogen excess conditions, while low nitrogen content promoted lipid accumulation (0.59 g of lipids per g of dry biomass) without yielding more PUFAs and GLA. After improving the C/N ratio at 18.3 mol/mol, even higher PUFA (600 mg/L) and GLA (243 mg/L) production values were recorded. GLA content increased when the fungus was cultivated at 12 °C (15.5% w/w compared to 12.8% w/w at 28 °C), but productivity values decreased significantly due to prolonged cultivation duration. An attempt to improve productivity by increasing the initial spore population did not yield the expected results. The successful scale-up of fungal cultivations is evidenced by achieving consistent results (compared to flask experiments under corresponding conditions) in both laboratory-scale (Working Volume—Vw = 1.8 L; C/N = 18.3 mol/mol) and semi-pilot-scale (Vw = 15.0 L; C/N = 110.0 mol/mol) bioreactor experiments. To the best of our knowledge, cultivation of the fungus Cunninghamella elegans in glycerol-based substrates, especially in 20 L bioreactor experiments, has never been previously reported in the international literature. The successful scale-up of the process in a semi-pilot-scale bioreactor illustrates the potential for industrializing the bioprocess. [ABSTRACT FROM AUTHOR]

Purpose: Some literature on feeding kitchen food waste (KFW) to domestic animals is available. However, the quantifi-cation of such consumption by those animals is limited. This study attempts to investigate how various domes-tic animals contribute to disposing of the KFW by feeding in rural and semi-urban areas of the eastern province of Sri Lanka. Method: Simple random sampling was used to select 75 households from the Sammanthurai DS division. The KFW was collected, segregated, and weighed from each of the households. The weight of KFW fed to domestic and stray animals was recorded before feeding. A semi-structured questionnaire was also used to collect the necessary data from the households selected. Results: The study found that the KFW accounted for 49%. 25% of the households disposed of their KFW by feeding to the domestic animals and another 3% was consumed by stray animals. The village chickens consumed the highest KFW (59.5%) per day. Each village chicken, cow, other birds, dog, and cat consumed 47.8 g, 695 g, 43.3 g, 128 g, and 91.7 g of KFW per day, respectively, on average. By feeding the KFW to domestic animals, the reduction in greenhouse gas emission was estimated to be 871 kg of carbon dioxide equivalent (CO2-e) per day. Conclusion: A quarter of the households fed their KFW to domestic animals they grow. The village chickens were the highest contributor to the disposal of KFW by consuming them. Feeding KFW to domestic animals reduces greenhouse gas emissions and contributes to rural food security through bioconversion. [ABSTRACT FROM AUTHOR]