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Abstract Fungal endophytes, as an untapped resource of glycoside hydrolase biocatalysts, need to be further developed. Mogroside V, the primary active compound in Siraitia grosvenorii fruit, can be converted into other various bioactive mogrosides by selective hydrolysis of glucose residues at C3 and C24 positions. In present study, 20 fungal strains were randomly selected from our endophytic fungal strain library to assess their capability for mogroside V transformation. The results revealed that relatively high rate (30%) endophytic fungal strains exhibited transformative potential. Further analysis indicated that endophytic fungi could produce abundant mogrosides, and the pathways for biotransforming mogroside V showed diverse. Among the given fungal endophytes, Aspergillus sp. S125 almost completely converted mogroside V into the end-products mogroside II A and aglycone within just 2 days of fermentation; Muyocopron sp. A5 produced rich intermediate products, including siamenoside I, and the end-product mogroside II E. Subsequently, we optimized the fermentation conditions for Aspergillus sp. S125 and Muyocopron sp. A5 to evaluate the feasibility of large-scale mogroside V conversion. After optimization, Aspergillus sp. S125 converted 10 g/L of mogroside V into 4.5 g/L of mogroside II A and 3.6 g/L of aglycone after 3 days of fermentation, whereas Muyocopron sp. A5 selectively produced 4.88 g/L of siamenoside I from 7.5 g/L of mogroside V after 36 h of fermentation. This study not only identifies highly effective biocatalytic candidates for mogrosides transformation, but also strongly suggests the potential of plant endophytic fungi as valuable resources for the biocatalysis of natural compounds.

Abstract A former work conducted in our Lab, lead to in a effective scale up of vitamin D3 bioconversion into calcitriol by Actinomyces (A.) hyovaginalis isolate CCASU-A11-2 in Lab fermenter (14 L) resulting in 32.8 µg/100 mL of calcitriol. However, the time needed for such a bioconversion process was up to 5 days. Therefore, the objective of this study was to shorten the bioconversion time by using cell-free lysate and studying different factors influencing bioconversion. The crude cell lysate was prepared, freeze-dried, and primarily fractionated into nine fractions, of which, only three fractions, 50, 100, and 150 mM NaCl elution buffers showed 22, 12, and 2 µg/10 mL, calcitriol production, respectively. Ammonium sulfate was used for protein precipitation, and it did not affect the bioconversion process except at a concentration of 10%w/v. Secondary fractionation was carried out using 80 mL of the 50 mM NaCl elution buffer and the results showed the 80 mL eluent volume was enough for the complete elution of the active protein. The pH 7.8, temperature 28 °C, and 6 h reaction time were optimum for maximum calcitriol production (31 µg/10 mL). In conclusion, the transformation of vitamin D3 into calcitriol was successfully carried out within 6 h and at pH 7.8 and 28 °C using fractionated cell lysate. This process resulted in a 10-fold increase in calcitriol as compared to that produced in our previous study using a 14 L fermenter (32.8 µg/100 mL). Therefore, cell-free lysate should be considered for industrial and scaling up vitamin D3 bioconversion into calcitriol.

Hermetia illucens, well-known as black soldier fly (BSF), is an insect easily found in subtropical and tropical regions. It contains high protein and lipids. BSF is known as one of the biological agents consuming organic components, thus having a high potential to overcome organic waste problems. BSF has promising advantages due to its long development time in the larval stage (compared to other flies) and its ability to self-separate from organic waste. BSF with large protein and lipid content can substitute the commonly used protein source in aquaculture, poultry and livestock compound diet formulation, which can be an option to overcome limited sources of future food and feed insecurity. This review analyses the latest study of bioconversion using BSF from the viewpoint of nutrient composition, degradation rate and biomass results from different feed treatments. Various feed and growth mediums have been studied to obtain high protein and lipid biomass. Hopefully, the information will provide new research directions and solutions for converting agro-industrial waste using bioconversion with BSF.

[Display omitted] • Food waste particle sizes below 2 mm is adverse to bioconversion by BSFL. • Lactobacillus and Enterococcus dominate gut microbial communities. • Prolonged exposure to low pH causes a high abundance of pathogenic bacteria. • The substrate microbial communities are mainly influenced by abiotic factor. Treating food waste using black soldier fly larvae (BSFL) is widely regarded as a promising nature-based measure. This study explored the influence of food waste particle sizes on substrate properties and its subsequent effects on bioconversion efficiency and gut microbiota. The results indicated that particle sizes mainly ranging from 4 mm to 10 mm (T1) significantly increased the weight loss rate of food waste by 35 % and larval biomass by 38 % compared to those in T4 (particle sizes mostly less than 2 mm) and promoted the bioconversion of carbon and nitrogen into larvae and gases. Investigation of substrates properties indicated that the final pH value of T1 was 7.79 ± 0.10, with Anaerococcus as the predominant substrate microorganism (relative abundance: 57.4 %), while T4 exhibited a final pH value of 5.71 ± 0.24, with Lactobacillus as the dominant microorganism (relative abundance: 95.2 %). Correlation analysis between substrate chemical properties and microbial community structure unveiled a strong relationship between substrate pH and the relative abundance of Anaerococcus and Lactobacillus. Furthermore, beneficial microorganisms such as Lactobacillus and Enterococcus colonized the BSFL gut of T1, while pathogenic bacterium Morganella , detrimental to BSFL gut function, was enriched in T4 (relative abundance: 60.9 %). Nevertheless, PCA analysis indicated that alterations in the gut microbial community structure may not be attributed to the substrate microorganisms. This study establishes particle size as a crucial parameter for BSFL bioconversion and advances understanding of the relationship between gut microbiota and substrate microbiota. [ABSTRACT FROM AUTHOR]

Cryogel (CRG) is a cross-linked form of hydrogel (HDG) synthesized at subzero temperature via freeze-drying technique with unique features including broad surface area, 3-D sponge-appearing architecture, controlled porosity, low-weight, mechanical strength and so on. However, in order to enlarge their scope of applications, thereby limiting their deficiencies, nanoparticulates are embedded within these materials to enhance their performances resulting in the fabrication of cryogel nanoarchitectures. Therefore, this paper elucidates recently emerging trends in development, fabrication, characterization, features and multifarious applications of cryogel polymeric nanoarchitectures. [ABSTRACT FROM AUTHOR]

Agricultural residue is produced in large quantities during crop harvesting, and open burning of this waste causes environmental pollution and health risks. Due to the structural complexity of the lignocellulose and problems associated with physical and chemical methods of its pretreatments, there is an utmost need for an eco-friendly pretreatment strategy. Biological pretreatment involving microorganisms and their enzymes is an environment-benign and economic process due to lack of release or requirement of toxic chemicals during the process. Among microorganisms, filamentous fungi (mainly Basidiomycetes) with efficient enzymatic machinery have been used in efficient delignification and bioconversion of lignocellulosic biomass. Enzyme-mediated pretreatment has further improved the saccharification of plant biomass with no sugar loss as in case of microbial pretreatment. Composting, ensiling, solid state fermentation, and biogas production are based on biological pretreatment, which are used for the generation of value-added products. Biological pretreatment does not require/release toxic chemicals but, is highly useful in detoxification of such toxic compounds. Biological pretreatment is significantly affected by biotic and abiotic factors. Pretreated biomass is hydrolyzed by cellulases and xylanases into sugars that are fermented into biofuels, organic acids, enzymes, and other products. The slow and long incubation nature of biological pretreatment has been overcome by combining with milder physico-chemical methods. Furthermore, the consolidated bioprocessing-based biorefinery approach has enhanced the potential of biological pretreatment by involving microbial consortium for the production of biofuels and other value-added products in a single step. Therefore, biological pretreatment-based biorefinery approach would be quite beneficial for the large-scale production of value-added products from lignocellulose with concomitant reduction in environmental pollution and solid waste management. [ABSTRACT FROM AUTHOR]

• GWP of housefly larvae treatment is significantly higher in summer than in winter. • Bioconversion itself contributed very little to GWP. • GWP will increase slightly when larvae are stored by drying rather than freezing. • There is a contradiction between a higher mature larvae production and a lower GWP. The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option. It can provide a source of protein while treating biomass waste, which means that nutrients can be returned to the natural food chain. However, the performance of this technology in terms of its environmental impacts is still unclear, particularly with regards to global warming potential (GWP).This study used a life cycle assessment (LCA) approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day. The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46–32.81 kg CO 2 equivalent (CO 2 -eq)/ton biomass waste and 5.37–10.08 kg CO 2 -eq/ton biomass waste, respectively. The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer, which consumes more power. The main GWP contributions are from (1) electricity needs (accounting for 78.6% of emissions in summer and 70.2% in winter) and (2) product substitution by mature housefly larvae and compost (both summer and winter accounting for 96.8% of carbon reduction). [Display omitted] [ABSTRACT FROM AUTHOR]

• Biohythane from two-stage anaerobic digestion (TSAD) of food waste (FW) is reviewed. • Main principle and influence factors of the TSAD of FW are identified. • Main strategies for enhancing biohythane from TSAD of FW are summarized. • Future research directions for biohythane from TSAD of FW are proposed. The biotransformation of food waste (FW) to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal problems. To this end, a promising technique is two-stage anaerobic digestion (TSAD), in which the FW is transformed to biohythane, a gaseous mixture of biomethane and biohydrogen. This review summarises the main characteristics of FW and describes the basic principle of TSAD. Moreover, the factors influencing the TSAD performance are identified, and an overview of the research status; economic aspects; and strategies such as pre-treatment, co-digestion, and regulation of microbial consortia to increase the biohythane yield from TSAD is provided. Additionally, the challenges and future considerations associated with the treatment of FW by TSAD are highlighted. This paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

A former work conducted in our Lab, lead to in a effective scale up of vitamin D3 bioconversion into calcitriol by Actinomyces (A.) hyovaginalis isolate CCASU-A11-2 in Lab fermenter (14 L) resulting in 32.8 µg/100 mL of calcitriol. However, the time needed for such a bioconversion process was up to 5 days. Therefore, the objective of this study was to shorten the bioconversion time by using cell-free lysate and studying different factors influencing bioconversion. The crude cell lysate was prepared, freeze-dried, and primarily fractionated into nine fractions, of which, only three fractions, 50, 100, and 150 mM NaCl elution buffers showed 22, 12, and 2 µg/10 mL, calcitriol production, respectively. Ammonium sulfate was used for protein precipitation, and it did not affect the bioconversion process except at a concentration of 10%w/v. Secondary fractionation was carried out using 80 mL of the 50 mM NaCl elution buffer and the results showed the 80 mL eluent volume was enough for the complete elution of the active protein. The pH 7.8, temperature 28 °C, and 6 h reaction time were optimum for maximum calcitriol production (31 µg/10 mL). In conclusion, the transformation of vitamin D3 into calcitriol was successfully carried out within 6 h and at pH 7.8 and 28 °C using fractionated cell lysate. This process resulted in a 10-fold increase in calcitriol as compared to that produced in our previous study using a 14 L fermenter (32.8 µg/100 mL). Therefore, cell-free lysate should be considered for industrial and scaling up vitamin D3 bioconversion into calcitriol. Key points: Biotransformation of vitamin D into calcitriol has been achieved within 6 h using a cell-free lysate of A. hyovaginalis isolate CCASU-A11-2. pH 7.8 and incubation temperatures 28 °C were optimum for maximum calcitriol production using the cell-free lysate. This study results in a 10-fold (31 µL/10 mL) to that obtained using a 14 L Lab fermenter. Bioconversion using cell-free lysate should be considered for industrial production of calcitriol. [ABSTRACT FROM AUTHOR]

C20- and C22-dihydroxy fatty acids (DiHFAs) are bioactive lipid mediators (LMs) in humans. Among them, leukotrienes are inflammatory mediators, whereas resolvins generated by M2 macrophages in humans are anti-inflammatory mediators. However, the synthesis of LMs by chemical or biological methods is inefficient. Here, we discovered a double-oxygenating arachidonate (ARA) 15R-lipoxygenase (15R-LOX) with the highest catalytic activity among the reported ARA LOXs. Cells expressing double-oxygenating 15R-LOX converted ARA, eicosapentaenoic acid, and docosahexaenoic acid (DHA) and DHA-rich fish oil hydrolyzates into 5R,15R-dihydroxyeicosatetraenoic acid, 5R,15R-dihydroxyeicosapentaenoic acid, and 7R,17R-dihydroxydocosahexaenoic acid as isomers of leukotriene B4, resolvin E4, and resolvin D5, which were identified as new compounds, within 1.5 h, with concentrations >1.5 g L−1, conversions >77% (w/w), and productivity >1.0 g L−1 h−1, respectively. Double-oxygenating 15R-LOX was altered to single-oxygenating 15R-LOX by the L606F mutation using structure-guided engineering. Cells expressing single-oxygenating 15R-LOX produced 15R-hydroxyeicosatetraenoic acid, 15R-hydroxyeicosapentaenoic acid, and 17R-hydroxydocosahexaenoic acid, respectively. These results demonstrated that the six medicinally important LMs could be prepared from C20- and C22-polyunsaturated fatty acids and inexpensive DHA-rich fish oil hydrolyzates by cost-effective, eco-friendly, and efficient biosynthesis using the discovered double-oxygenating and engineered single-oxygenating LOXs. [ABSTRACT FROM AUTHOR]

• Thermal pretreatment had negative/no effect on larval performance. • Mechanical pretreatment increased bioconversion rate for both substrates. • Bioconversion rate of grass clippings improved by 23–44%. • Mechanical pretreatment affected physical properties and microbial respiration. Black soldier fly larvae (BSFL , Hermetia illucens (L.)) are recognized for efficient biowaste reduction while yielding valuable proteins and fats for animals. However, lignocellulosic fibers in biowastes are difficult to digest by biowaste and larval digestive tract microorganisms as well as the larvae themselves. This study investigated two biowaste physical pretreatments (thermal, mechanical) for improving BSFL processing of fibrous biowastes. Cow manure, spent grain, and grass clippings were thermally pretreated at 90 °C for three durations (0.5, 1 and 4 h). Contrary to expectations, thermal pretreatment resulted in either no improvement or decreased larval performance on all substrates, regardless of treatment duration. In contrast, mechanical pretreatment of spent grain and grass clippings, involving milling with three screen sizes (0.5, 1 and 2 mm) showed promising results. Specifically, bioconversion rates on 0.5 mm-milled spent grain and grass clippings increased by 0–53 % and 25–44 % dry mass, respectively compared to untreated. Additionally, larval protein conversion increased by 41 % and 23 % on spent grain and grass clippings, respectively. However, mechanical pretreatment did not affect fiber degradation by larval conversion, as hemicellulose decreased by 25 % and 75 % for spent grain and grass clippings, respectively, regardless of particle size. Particle size reduction influenced substrate microbial respiration (CO 2 mg/min), with 0.5-mm milled grass clippings exhibiting higher respiration compared to untreated, although this effect was not observed for spent grain. This study highlights mechanical pretreatment's potential in enhancing BSFL bioconversion of fibrous biowastes and the importance of understanding substrate physical properties influencing substrate microorganisms and BSFL. [ABSTRACT FROM AUTHOR]

Recent publications have shown the benefits of deacetylation disc-refining (DDR) as a pretreatment process to deconstruct biomass into sugars and lignin residues. Major advantages of DDR pretreatment over steam and dilute acid pretreatment are the removal of acetyl and lignin during deacetylation. DDR does not generate hydroxymethylfurfural (HMF) and furfural which are commonly produced from steam and dilute acid pretreatments. Acetate, lignin, HMF, and furfural are known inhibitors during enzymatic hydrolysis and fermentation. Another advantage of deacetylation is the production of lignin-rich black liquor, which can be upgraded to other bioproducts. Furthermore, due to the lack of sugar degradation during deacetylation, DDR has significantly less sugar loss than other pretreatment methods. Previous studies for DDR have primarily focused on corn stover, but lacked the investigative studies of other feedstocks. This study was designed to screen various DDR process conditions at pilot scale using three different feedstocks, including corn stover, poplar, and switchgrass. The impact of the pretreatment conditions was evaluated by testing hydrolysates for bioconversion to 2,3-butanediol. Pretreatment of biomass by DDR showed high-conversion-yields and 2,3-BDO fermentation production yields. Techno-economic analysis (TEA) of the pretreatment for biomass to sugar was also developed based on NREL's Aspen Model. This study shows that the cellulose and hemicellulose in poplar was more recalcitrant than herbaceous feedstocks which ultimately drove up the sugar cost. Switchgrass was also more recalcitrant than corn stover but less than poplar. [ABSTRACT FROM AUTHOR]

Simple Summary: This review explores the potential of black soldier fly larval frass (which is a mixture of insect excrements and leftover substrates) in organic agriculture. Frass can work as a natural fertilizer for agriculture, enriching soil with nutrients and beneficial bacteria. The study investigates how the composition of frass depends on the substrate for larval feed, and how it affects different crops. By categorizing crops and evaluating the impact of frass, the research sheds light on its potential benefits and drawbacks in farming practices. Overall, understanding how black soldier fly frass can enhance soil fertility offers a sustainable solution for agriculture, reducing waste while promoting healthier crop growth. Hermetia illucens has received a lot of attention as its larval stage can grow on organic substrates, even those that are decomposing. Black soldier fly breeding provides a variety of valuable products, including frass, a mixture of larval excrements, larval exuviae, and leftover feedstock, that can be used as a fertilizer in agriculture. Organic fertilizers, such as frass, bringing beneficial bacteria and organic materials into the soil, improves its health and fertility. This comprehensive review delves into a comparative analysis of frass derived from larvae fed on different substrates. The composition of micro- and macro-nutrients, pH levels, organic matter content, electrical conductivity, moisture levels, and the proportion of dry matter are under consideration. The effect of different feeding substrates on the presence of potentially beneficial bacteria for plant growth within the frass is also reported. A critical feature examined in this review is the post-application beneficial impacts of frass on crops, highlighting the agricultural benefits and drawbacks of introducing Hermetia illucens frass into cultivation operations. One notable feature of this review is the categorization of the crops studied into distinct groups, which is useful to simplify comparisons in future research. [ABSTRACT FROM AUTHOR]

Background: Biotransformation of waste oil into value-added nutraceuticals provides a sustainable strategy. Thraustochytrids are heterotrophic marine protists and promising producers of omega (ω) fatty acids. Although the metabolic routes for the assimilation of hydrophilic carbon substrates such as glucose are known for these microbes, the mechanisms employed for the conversion of hydrophobic substrates are not well established. Here, thraustochytrid Schizochytrium limacinum SR21 was investigated for its ability to convert oils (commercial oils with varying fatty acid composition and waste cooking oil) into ω-3 fatty acid; docosahexaenoic acid (DHA). Results: Within 72 h SR21 consumed ~ 90% of the oils resulting in enhanced biomass (7.5 g L− 1) which was 2-fold higher as compared to glucose. Statistical analysis highlights C16 fatty acids as important precursors of DHA biosynthesis. Transcriptomic data indicated the upregulation of multiple lipases, predicted to possess signal peptides for secretory, membrane-anchored and cytoplasmic localization. Additionally, transcripts encoding for mitochondrial and peroxisomal β-oxidation along with acyl-carnitine transporters were abundant for oil substrates that allowed complete degradation of fatty acids to acetyl CoA. Further, low levels of oxidative biomarkers (H2O2, malondialdehyde) and antioxidants were determined for hydrophobic substrates, suggesting that SR21 efficiently mitigates the metabolic load and diverts the acetyl CoA towards energy generation and DHA accumulation. Conclusions: The findings of this study contribute to uncovering the route of assimilation of oil substrates by SR21. The thraustochytrid employs an intricate crosstalk among the extracellular and intracellular molecular machinery favoring energy generation. The conversion of hydrophobic substrates to DHA can be further improved using synthetic biology tools, thereby providing a unique platform for the sustainable recycling of waste oil substrates. [ABSTRACT FROM AUTHOR]

In the current study, chromatographic and in silico techniques were applied to investigate the biotransformation of ethyl 5-(4-bromophenyl)-1-(2-(2-(2-hydroxybenzylidene) hydrazinyl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (11b) in hepatocytic media. The initial chromatographic procedure was based on the employment of the conventional octadecyl stationary phase method for estimation of the chemical stability. Subsequently, a novel and rapid chromatographic approach based on a phenyl–hexyl column was developed, aiming to separate the possible metabolites. Both methods were performed on a Dionex 3000 ThermoScientific (ACM 2, Sofia, Bulgaria) device equipped with a diode array detector set up at 272 and 279 nm for analytes detection. An acetonitrile: phosphate buffer of pH 3.5: methanol (17:30:53 v/v/v) was eluted isocratically as a mobile phase with a 1 mL/min flow rate. A preliminary purification from the biological media was achieved by protein precipitation with methanol. A validation procedure was carried out, where the method was found to correspond to all ICH (Q2) and M10 set criteria. Additionally, an in silico-based approach with the online server BioTransformer 3.0 was applied in an attempt to predict the possible metabolites of the title compound 11b. It was hypothesized that four CYP450 isoforms (1A2, 2C9, 3A4, and 2C8) were involved in the phase I metabolism, resulting in the formation of 12 metabolites. Moreover, docking studies were conducted to evaluate the formation of stable complexes between 11b and the aforementioned isoforms. The obtained data indicated three metabolites as the most probable products, two of which (M9_11b and M10_11b) were synthesized by a classical approach for verification. Finally, liquid chromatography with a mass detector was implemented for comprehensive and summarized analysis, and the obtained results revealed that the metabolism of the 11b proceeds possibly with the formation of glucuronide and glycine conjugate of M11_11b. [ABSTRACT FROM AUTHOR]

A fungal isolate Aspergillus terreus PDB-B (accession number: MT774567.1), which could tolerate up to 500 mg/L of cypermethrin, was isolated from the lake sediments of Kulamangalam tropical lake, Madurai, and identified by internal transcribed spacer (ITS) sequencing followed by phylogenetic analysis. The biotransformation potential of the strain was compared with five other strains (A, J, UN2, M1 and SM108) as a consortium, which were tentatively identified as Aspergillus glaucus, Aspergillus niger, Aspergillus flavus, Aspergillus terreus, and Aspergillus flavus, respectively. Batch culture and soil microcosm studies were conducted to explore biotransformation using plate-based enzymatic screening and GC-MS. A mycotransformation pathway was predicted based on a comparative analysis of the transformation products (TPs) obtained. The cytotoxicity assay revealed that the presence of (3-methylphenyl) methanol and isopropyl ether could be relevant to the high rate of lethality. [ABSTRACT FROM AUTHOR]

The increase in population has resulted in a rapid increase in waste that is being dumped within the environment. The addition of various harmful and contaminating compounds results in the degradation of the environment and has a direct impact on human health. Various research studies that are taking place in recent times help in the enhancement of the naturally available microbes to degrade toxic compounds that are liberated into the environment. Although various types of bioremediation techniques are available, microbe-associated remediation is proven to be the best option due to its effectiveness, no generation of toxic by-products, and natural availability of microbes with the ability to take up nutrients from the toxic contaminants that exist on the surface of the earth. Both ex situ and in situ bioremediation can be accomplished with the help of these microbes. In most cases, this is done through biofilm-assisted seclusion of pollutants, more precisely by means of extracellular polymeric substances (EPSs) of biofilm matrix. In recent times, various types of techniques have been implemented like proteomics, genomics, fluxomics and transcriptomics for bringing about maximum remediation by the microbial species. In order to explore the different kinds of microbial communities involved in natural bioremediation, the strategic approach of metagenomic analysis is adopted, which has brought about a technological drift in remediation, even at a genomic level. As chemical mode of remediating wastes are associated with the release of various harmful chemicals those can be toxic to the environment, the use of biological systems can be a potential agent in the conversion of complex waste materials to simpler substances so that it mixes with the environment in easier manner. Microbes are the potential entities that can easily act on the waste materials and bring about remediation in an effective manner. [ABSTRACT FROM AUTHOR]

A plasmid containing the genes encoding a fungal 17β-hydroxysteroid dehydrogenase, which ca-talyzes the reduction of 17-oxo group, and a mycobacterial glucose-6-phosphate dehydrogenase, which promotes the recycling of the essential coenzyme NAD(P)H, was constructed. Its constitutive expression in well-studied Mycolicibacterium neoaurum strains made it possible to increase the yield of C-17 hydroxysteroids significantly. In particular, recombinant strains created on the basis of M. neoaurum VKM Ac-1815D and M. neoaurum NRRL B-3805 ΔkstD exhibited predominant accumulation of testosterone, while the strain based on M. neoaurum VKM Ac-1816D accumulated 1(2)-dehydrotestosterone and testosterone simultaneously. [ABSTRACT FROM AUTHOR]

Betulinic acid (BA), a betulin derivative, is an important plant-based natural product. BA has many biological activities and attracts attention especially as a promising antitumour drug. Extraction from plants or semi-synthesis from betulin are the common methods to obtain BA, but these methods have some drawbacks. In recent years, microbial biotransformation of betulin to BA has been anticipated as an alternative method. Betulin is abundant in the outer bark of birch (Betula spp.) and obtained from these plants, however endophytes of Betula spp. have not been investigated for biotransformation of betulin to BA before. Therefore, this study aimed to investigate the culturable endophytes of Betula pubescens var. litwinowii (Doluch.) Ashburner & McAll and to determine their biotransformation capacity of betulin to BA. To this end, bacterial and fungal endophytes were isolated from the surface-sterilized root, stem, and branch samples. A total of 37 endophytes (11 bacteria and 26 fungi) were identified by polyphasic approach. All endophytes were screened for the biotransformation of betulin to BA. Betulin and BA content of the extracts were determined by RP-HPLC analysis. Two different bacterial and fungal biotransformation processes were designed. It was found that the fungus BRF59 produced BA via betulin biotransformation under the Fungal Biotransformation Process-2 when the fungus was acclimatized to betulin before biotransformation, and glycerol was used as a carbon source, instead of glucose, during bioprocess. The highest BA yield and BA concentration was obtained as 12.22±0.94 % and 80.85±2.64 µg/ml, respectively, under non-optimized conditions. The fungal isolate BRF59, belonging to the genus Fusarium according to ITS analysis, was further identified based on RPB2 sequence analysis and found that Fusarium lacertarum. In conclusion, this study demonstrated that betulin was biotransformed to BA by an endophytic fungus isolated from the genus Betula for the first time. F. lacertarum BRF59 might be a good candidate for production of BA through betulin biotransformation and, using glycerol as a carbon source during biotransformation might enable this by-product to convert value-added chemical. [Display omitted] • Culturable endophytes of Betula pubescens var. litwinowii (Doluch) was investigated. • Biotransformation of betulin to betulinic acid by endophytes was investigated. • Fusarium lacertarum BRF59 produced betulinic acid via betulin biotransformation. • The highest betulinic acid production was 80.85±2.64 µg/ml. • Acclimatization to betulin and using glycerol induced betulinic acid production. [ABSTRACT FROM AUTHOR]

Microbial biotransformation is an efficient process for making high-value natural products in a controlled and environment friendly manner. Bioconversion of low value monoterpenes to high value products using fungi offers an effective strategy for producing desirable products. Efficient conversion of D-limonene, a monoterpene, into carveol is reported in this study by using an endophytic fungus, Aspergillus flavus IIIMF4012, isolated from the root of Rosa damascena. By optimizing different parameters, isolated strain resulted in the hydroxylation of D-limonene to carveol effectively and the process was carried out at 1 L scale which resulted in the formation of a mixture of carveol isomers (cis- carveol 23.82%, trans- carveol 17.21%). Further, the biotransformation was scaled up in 5 L fermenter and the product was characterized by GC-MS and NMR (1H & 13C). As a result, an efficient procedure was established for biotransforming a low-value molecule i.e., D-limonene into a high-value product i.e.,carveol. [ABSTRACT FROM AUTHOR]

Herein, we report the use of whole cells of Brazilian marine-derived fungi in the biotransformation and biodegradation of organic compounds, particularly, Knoevenagel adducts. A preliminary screening with five marine-derived fungi revealed that these microorganisms promoted the bioreduction and biodegradation of four Knoevenagel adducts. Additionally, a biotransformation pathway for these compounds was proposed, which suggested the presence of ene-reductase and alcohol dehydrogenase in the marine-derived fungi, which catalysed the microbial transformation of the substrates. In summary, the fast biodegradation of organic molecules has an ecological relevance since several of these compounds and their biotransformed products have aquatic environment impact. [ABSTRACT FROM AUTHOR]

Verbenone is a natural monoterpene present as an essential component in rosemary oil from Rosmarinus officinalis, Verbena triphylla and Eucalyptus globule. Microbial biotransformation of monoterpenoids to value-added products has immense industrial potential. This study involves the biotransformation of (-)-verbenone to (-)-10-hydroxyverbenone by a fungus i.e. Talaromyces purpurogenus strain MRS-F13 in fermentation broth during the exponential phase. Biotransformation reaction has been successfully demonstrated at 15 L scale in the bioreactor with 70% conversion within 96 h. The anti-inflammatory activity investigations revealed that (-)-verbenone and its biotransformed product exhibited moderate inhibition of TNF-α and nitric oxide, whereas (-)-10-hydroxyverbenone presented an improved anti-oxidant activity. Talaromyces purpurogenus catalysed biotransformation of (-)-verbenone to (-)-10-hydroxyverbenone has been demonstrated. Approximately 70% bioconversion was obtained in 96 h in submerged culture at 15L bioreactor scale. Biotransformed product (-)-10-hydroxyverbenone has shown improved anti-inflammatory activity without cytotoxicity. [ABSTRACT FROM AUTHOR]

In this work, biotransformations of pregnenolone 1 by Ulocladium chartarum MRC 72584, Cladosporium sphaerospermum MRC 70266 and Cladosporium cladosporioides MRC 70282 have been reported. U. chartarum MRC 72584 only hydroxylated 1 at C-7β and hydroxylated 1 at either C-7β or C-14α, accompanied with a concurrent epoxidation from the β-face. The same fungus hydroxylated a small amount of 1 at both C-7 and C-14α, accompanied with a subsequent oxidation at C-7. 3β,14α-Dihydroxy-5β,6β-epoxypregnan-20-one 4 and 3β,7β-dihydroxy-5β,6β-epoxypregnan-20-one 5 obtained from the incubation of 1 with this fungus were determined as new metabolites. C. sphaerospermum MRC 70266 converted most of 1 into a 3-keto-4-ene steroid and independently hydroxylated it at C-6α, C-6β and C-7β. This fungus also hydroxylated 1 at C-7 and C-11α and then oxidized it at C-7. C. cladosporioides MRC 70282 converted almost half of 1 into a 3-keto-4-ene steroid. The same fungus reduced some of this 3-keto-4-ene steroid by a 5α-reductase activity while it hydroxylated the rest at C-6α and C-6β. [ABSTRACT FROM AUTHOR]

The inadequate disposal of organic waste generated in insect biofactories breeding biological agents may become a potential environmental problem. The use of Hermetia illucens (Diptera: Stratiomyidae) may play an important role in the circular economy of this process, transforming waste into high‐quality biomass. Therefore, this work aims to analyse the degradation of organic residues of Ephestia kuehniella (Lepidoptera: Pyralidae) production using the black soldier fly. Four types of waste from the moth breeding process were evaluated: residues of the meal diet when moth larvae were in the last instar; residues of the meal diet when completing the cycle; residues formed by webs in the pupation process mixed with residual exoskeleton, and residues of dead adults. These residues were tested in isolation and in mixtures of 50%, using as control a standard diet composed of chicken feed. Survival rate, development time, emerged adults, weight, size, residue reduction, and bioconversion were evaluated. The residue used in diets affected the total development time of H. illucens. The mean number of survivors differed from 87% to 74% for larvae that reached the pre‐pupal stage. The viability of pre‐pupae to adult stage ranged from 54% to 6% for residue treatments and 97% for the control. Differences in the growth and weight gain of larvae were significantly different. The rate of residue reduction from 54% to 80% and bioconversion into larval biomass were satisfactory. However, regarding adult emergence, the numbers show variations, indicating that certain residues are not suitable for the maintenance of fly breeding. [ABSTRACT FROM AUTHOR]

Feathers are by-products that are generated in significant quantities by the poultry industry. Microbial bioconversion has been investigated as a promising strategy for the processing of feathers, since, along with the degradation of these keratinous materials, bioprocessing can result in value-added products. Thus, from the perspective of industrial microbiology, chicken feathers can be considered a raw material for obtaining microbial proteases. Within this context, this research investigated and characterized the production of extracellular proteases by Aspergillus sp., isolated from soil of the Amazon Rainforest. The enzymatic production was evaluated using several growth substrates (whole feathers, feather meal, human hair, casein, gelatin, peptone and chicken beaks). With highest enzyme production was obtained the feather meal (FM) and peptone. After 48 h of fermentation, FM degradation was 15.82%. The crude protease showed optimal activity at pH 5.0 and 37 °C and enzymatic activity was enhanced with the addition of 1 and 5 mM of CaCl2, MnSO4, KCl, MgSO4 and CuSO4 . The detergents Tween 20 and Triton x-100, at concentrations 0.5 and 1% (v/v), tended to stimulate activity. The presence of 0.5 and 1% (v/v) of organic solvents (methanol, acetone, butanol, acetonitrile, isopropanol and DMSO), maintained the enzymatic activity. β–mercaptoethanol stimulated proteolytic activity in the enzymatic assays. This study suggested new direction for waste management with industrial applications giving rise to green technology for sustainable development. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET), the most abundantly produced polyester plastic, can be depolymerized by the Ideonella sakaiensis PETase enzyme. Based on multiple PETase crystal structures, the reaction has been proposed to proceed via a two-step serine hydrolase mechanism mediated by a serine-histidine-aspartate catalytic triad. To elucidate the multi-step PETase catalytic mechanism, we use transition path sampling and likelihood maximization to identify optimal reaction coordinates for the PETase enzyme. We predict that deacylation is likely rate-limiting, and the reaction coordinates for both steps include elements describing nucleophilic attack, ester bond cleavage, and the "moving-histidine" mechanism. We find that the flexibility of Trp185 promotes the reaction, providing an explanation for decreased activity observed in mutations that restrict Trp185 motion. Overall, this study uses unbiased computational approaches to reveal the detailed reaction mechanism necessary for further engineering of an important class of enzymes for plastics bioconversion. Polyethylene terephthalate (PET) can be depolymerized by the Ideonella sakaiensis PETase enzyme, however, questions remain about the precise catalytic mechanism. Here, the authors use unbiased QM/MM MD simulations to determine optimal mechanistic descriptions of the acylation and deacylation reactions, revealing the rate-limiting step and key interactions within the catalytic triad and Trp185 conformation. [ABSTRACT FROM AUTHOR]

The rising global demand for sustainable and eco-friendly practices has led to a burgeoning interest in circular bioeconomy, wherein waste materials are repurposed into valuable resources. Lignocellulosic waste, abundant in agricultural residues and forestry by-products, represents a significant untapped resource. This article explores the potential of fungal-mediated processes for the valorisation of lignocellulosic waste, highlighting their role in transforming these recalcitrant materials into bio-based products. The articles delve into the diverse enzymatic and metabolic capabilities of fungi, which enable them to efficiently degrade and metabolise lignocellulosic materials. The paper further highlights key fungal species and their mechanisms involved in the breakdown of complex biomass, emphasising the importance of understanding their intricate biochemical pathways for optimising waste conversion processes. The key insights of the article will significantly contribute to advancing the understanding of fungal biotechnology for circular bioeconomy applications, fostering a paradigm shift towards a more resource-efficient and environmentally friendly approach to waste management and bio-based product manufacturing. [ABSTRACT FROM AUTHOR]

[Display omitted] • BSFL has the strongest adsorption capacity for Zn and As in pig manure. • Addition of BC facilitates the migration of HMs into the BSFL body. • B. bacillus is beneficial for BSFL to accumulate more HMs. • The content of F1+F2 in the BSFL residue decreased due to the addition of BC. • HM speciation is affected by Firmicutes, Bacteroidetes, and Proteobacteria. During the conversion of pig manure by black soldier fly larvae (BSFL), the accumulation and speciation changes of heavy metals (HMs) have adverse effects on the environment. In this study, corn straw, rice straw, bamboo chips (BC), wood chips, and rice husk char were added to a bioconversion system to study the accumulation, migration, speciation changes, and microbial correlations of HMs. The results indicated that the addition of BC was most beneficial for the accumulation of HMs (47–72 %) in the BSFL body. In the BC group, the accumulation effect of the BSFL body on zinc (Zn) and arsenic (As) was the most evident (72 and 71 %, respectively). The results of linear fitting (R2 > 0.90) and redundancy analysis (RDA; 90 %) indicated that the bacterium Bacillaceae (Bacillus) was beneficial for increasing the larval weight (LW) of BSFL, and a higher LW accumulated HMs. The addition of BC helped reduce the total amount (6–51 %) of available states (weak acid extraction and reducible states) in the BSFL residue. The RDA results indicated that bacteria (55–92 %) affected the transformation of HM speciation. For example, Zn and cadmium were mainly affected by Firmicutes, whereas copper and chromium were affected by Bacteroidetes. Proteobacteria and Pseudomonas formosensis affected the conversion of lead and As. This study provides important insights into the adsorption of HMs from pig manure by BSFL. [ABSTRACT FROM AUTHOR]

• Long hydraulic retention time ensured stable carboxylate production. • Microbial robustness mediated stable performance against pH oscillations. • 20 d of retention time was identified as an upper threshold of process efficiency. • Metabolic redundancy is key for a robust microbiome development. The effect of operational conditions on the stability of acidogenic fermentation (AF) devoted to volatile fatty acids (VFAs) production still presents numerous gaps to achieve high yields and fully understand the responses of open microbiomes associated to this technology. To cope with that, this investigation was designed to assess the stability of VFAs production via AF of agro-food wastes at high hydraulic retention times (HRTs) (20 and 30 d) and pH oscillations (5.8–6.2). Similar bioconversion efficiencies (∼50 %) were reached regardless of the HRT, revealing that HRT of 20 d can be considered as a threshold from which, no further improvement was achieved. The combination of long HRTs, 25 °C and acid pHs promoted a robust microbiome that resulted in a stable outcome against pH variations, being Clostridiales order identified as key player of AF stability. These conditions mediated a high selectivity in the VFAs production profile, with acetic and butyric acids, prevailing in the VFAs pool (∼80 % of total VFAs) at HRT 20 d. The selection of appropriated conditions was shown to be critical to maximize the hydrolysis and acidogenesis of the substrate and attain a stable effluent against pH oscillations. [ABSTRACT FROM AUTHOR]

Background: The main challenge for large-scale production of bacterial cellulose (BC) includes high production costs interlinked with raw materials, and low production rates. The valorization of renewable nutrient sources could improve the economic effectiveness of BC fermentation while their direct bioconversion into sustainable biopolymers addresses environmental pollution and/or resource depletion challenges. Herein a green bioprocess was developed to produce BC in high amounts with the rather unexplored bacterial strain Komagataeibacter rhaeticus, using waste streams such as wine distillery effluents (WDE) and biodiesel-derived glycerol. Also, BC was evaluated as a bio-adsorbent for phenolics, dyes and metals removal to enlarge its market diversification. Results: BC production was significantly affected by the WDE mixing ratio (0–100%), glycerol concentration (20–45 g/L), type of glycerol and media-sterilization method. A maximum BC concentration of 9.0 g/L, with a productivity of 0.90 g/L/day and a water holding capacity of 60.1 g water/g dry BC, was achieved at 100% WDE and ≈30 g/L crude glycerol. BC samples showed typical cellulose vibration bands and average fiber diameters between 37.2 and 89.6 nm. The BC capacity to dephenolize WDE and adsorb phenolics during fermentation reached respectively, up to 50.7% and 26.96 mg gallic acid equivalents/g dry BC (in-situ process). The produced BC was also investigated for dye and metal removal. The highest removal of dye acid yellow 17 (54.3%) was recorded when 5% of BC was applied as the bio-adsorbent. Experiments performed in a multi-metal synthetic wastewater showed that BC could remove up to 96% of Zn and 97% of Cd. Conclusions: This work demonstrated a low-carbon approach to produce low-cost, green and biodegradable BC-based bio-adsorbents, without any chemical modification. Their potential in wastewater-treatment-applications was highlighted, promoting closed-loop systems within the circular economy era. This study may serve as an orientation for future research towards competitive or targeted adsorption technologies for wastewater treatment or resources recovery. [ABSTRACT FROM AUTHOR]

AbstractTo investigate the biocatalytic potential of Amazonian actinomycetes for monoterpenes biotransformation. To carry out the present study, eleven actinomycetes of the genus Streptomyces isolated from inga-cipó (Inga edulis Mart.) rhizospheres were tested for their ability to bioconvert the substrates R-(+)-limonene, S-(-)-limonene, 1S-(-)-α-pinene, and (-)–β–pinene as sole carbon and energy source. According to gas chromatography-mass spectrometry analysis, three strains, LabMicra B270, LaBMicrA B310, and LaBMicrA B314, were able to biotransform 1S-(-)-α-pinene after 96 h of growth. However, Streptomyces LaBMicrA B270 was the most promising since it converted after only 72 h all the 1S-(-)-α-pinene mainly into cis-verbenol (74.9±1.24%) and verbenone (18.2±1.20%), compounds that have important biological activities and great industrial interest as additives in foods and cosmetics. These findings can stimulate the development of natural aromas using naturally abundant monoterpenes, ratify the potential of microorganisms from almost unexplored niches such as the Amazonian rhizosphere, and reinforce the importance of preserving those niches. [ABSTRACT FROM AUTHOR]

Background: The mycotoxin zearalenone (ZEA) produced by toxigenic fungi is widely present in cereals and its downstream products. The danger of ZEA linked to various human health issues has attracted increasing attention. Thus, powerful ZEA-degrading or detoxifying strategies are urgently needed. Biology-based detoxification methods are specific, efficient, and environmentally friendly and do not lead to negative effects during cereal decontamination. Among these, ZEA detoxification using degrading enzymes was documented to be a promising strategy in broad research. Here, two efficient ZEA-degrading lactonases from the genus Gliocladium, ZHDR52 and ZHDP83, were identified for the first time. This work studied the degradation capacity and properties of ZEA using purified recombinant ZHDR52 and ZHDP83. Results: According to the ZEA degradation study, transformed Escherichia coli BL21(DE3) PLySs cells harboring the zhdr52 or zhdp83 gene could transform 20 µg/mL ZEA within 2 h and degrade > 90% of ZEA toxic derivatives, α/β-zearalanol and α/β-zearalenol, within 6 h. Biochemical analysis demonstrated that the optimal pH was 9.0 for ZHDR52 and ZHDP83, and the optimum temperature was 45 °C. The purified recombinant ZHDR52 and ZHDP83 retained > 90% activity over a wide range of pH values and temperatures (pH 7.0–10.0 and 35–50 °C). In addition, the specific activities of purified ZHDR52 and ZHDP83 against ZEA were 196.11 and 229.64 U/mg, respectively. The results of these two novel lactonases suggested that, compared with ZHD101, these two novel lactonases transformed ZEA into different products. The slight position variations in E126 and H242 in ZDHR52/ZEA and ZHDP83/ZEA obtained via structural modelling may explain the difference in degradation products. Moreover, the MCF-7 cell proliferation assay indicated that the products of ZEA degradation using ZHDR52 and ZHDP83 did not exhibit estrogenic activity. Conclusions: ZHDR52 and ZHDP83 are alkali ZEA-degrading enzymes that can efficiently and irreversibly degrade ZEA into non-estrogenic products, indicating that they are potential candidates for commercial application. This study identified two excellent lactonases for industrial ZEA detoxification. [ABSTRACT FROM AUTHOR]

The hunt for renewable and alternative fuels has driven research towards the biological conversion of lignocellulosic biomass (LCB) into biofuels, including bioethanol and biohydrogen. Among the natural biomass utilization systems (NBUS), termites represent a unique and easy-to-access model system to study host–microbe interactions towards lignocellulose bioconversion/valorization. Termites have gained significant interest due to their highly efficient lignocellulolytic systems. The wood-feeding termites apply a unique and stepwise process for the hydrolysis of lignin, hemicellulose, and cellulose via biocatalytic processes; therefore, mimicking their digestive metabolism and physiochemical gut environments might lay the foundation for an innovative design of nature-inspired biotechnology. This review highlights the gut system of termites, particularly the wood-feeding species, as a unique model for future biorefinery. The gut system of termites is a treasure-trove for prospecting novel microbial species, including protists, bacteria, and fungi, having higher biocatalytic efficiencies and biotechnological potentials. The significance of potential bacteria and fungi for harnessing the enzymes appropriate for lignocellulosic biorefinery is also discussed. Termite digestomes are rich sources of lignocellulases and related enzymes that could be utilized in various industrial processes and biomass-related applications. Consideration of the host and symbiont as a single functioning unit will be one of the most crucial strategies to expedite developments in termite-modeled biotechnology in the future. [ABSTRACT FROM AUTHOR]

Arabinoxylans (AXs) are hemicellulosic polysaccharides consisting of a linear backbone of β-1,4-linked xylose residues branched by high content of α-L-arabinofuranosyl (Araf) residues along with other side-chain substituents, and are abundantly found in various agricultural crops especially cereals. The efficient bioconversion of AXs into monosaccharides, oligosaccharides and/or other chemicals depends on the synergism of main-chain enzymes and de-branching enzymes. Exo-α-L-arabinofuranosidases (ABFs) catalyze the hydrolysis of terminal non-reducing α-1,2-, α-1,3- or α-1,5- linked α-L-Araf residues from arabinose-substituted polysaccharides or oligosaccharides. ABFs are critically de-branching enzymes in bioconversion of agricultural biomass, and have received special attention due to their application potentials in biotechnological industries. In recent years, the researches on microbial ABFs have developed quickly in the aspects of the gene mining, properties of novel members, catalytic mechanisms, methodologies, and application technologies. In this review, we systematically summarize the latest advances in microbial ABFs, and discuss the future perspectives of the enzyme research. [ABSTRACT FROM AUTHOR]

Multi-enzymatic strategies have shown improvement in bioconversion during cofactor regeneration. In this study, purified l-arabinitol 4-dehydrogenase (LAD) and nicotinamide adenine dinucleotide oxidase (Nox) were immobilized via individual, mixed, and sequential co-immobilization approaches on magnetic nanoparticles, and were evaluated to enhance the conversion of l-arabinitol to l-xylulose. Initially, the immobilization of LAD or Nox on the nanoparticles resulted in a maximum immobilization yield and relative activity of 91.4% and 98.8%, respectively. The immobilized enzymes showed better pH and temperature profiles than the corresponding free enzymes. Furthermore, co-immobilization of these enzymes via mixed and sequential methods resulted in high loadings of 114 and 122 mg/g of support, respectively. Sequential co-immobilization of these enzymes proved more beneficial for higher conversion than mixed co-immobilization because of better retaining Nox residual activity. Sequentially co-immobilized enzymes showed a high relative conversion yield with broader pH, temperature, and storage stability profiles than the controls, along with high reusability. To the best of our knowledge, this is the first report on the mixed or sequential co-immobilization of LAD and Nox on magnetic nanoparticles for l-xylulose production. This finding suggests that selecting a sequential co-immobilization strategy is more beneficial than using individual or mixed co-immobilized enzymes on magnetic nanoparticles for enhancing conversion applications. [ABSTRACT FROM AUTHOR]

The dense lignocellulosic structure inherent in particleboard poses a challenge to its efficient energy utilization, necessitating pretreatment prior to use. This study is aimed at exploring an optimal ionic liquid pretreatment process to enhance the utilization efficiency of waste particleboard. Response surface methodology (RSM) and analysis of variance (ANOVA) were employed to investigate the effects of various parameters, including reaction time, temperature, and concentration of tetrabutylammonium hydroxide ([TBA] [OH]) solution on glucose production during the lignocellulosic hydrolysis process. Under the optimal pretreatment conditions (68 min, 65 °C, and 11.44% [TBA] [OH] concentration), the glucose yields from enzymatic hydrolysis of waste particleboard reached 324.48 mg/g, exhibiting a remarkable 34.75% increase compared to untreated samples. Scanning electron microscope (SEM) analysis revealed the disruptive effects of pretreatment on the lignocellulosic structure. Fourier transform infrared spectroscopy (FT-IR) demonstrated the removal of hemicellulose, as evidenced by the disappearance of the peak at 1740 cm−1. X-ray diffraction (XRD) analysis indicated a 5.08% increase in the crystallization index of the pretreated biomass. Composition analysis further confirmed the partial removal of hemicellulose and lignin, resulting in the enhanced exposure of cellulose and subsequently increasing the accessibility of cellulase. This improvement ultimately led to an enhancement in enzymatic hydrolysis efficiency. [ABSTRACT FROM AUTHOR]

In this comprehensive study, we delved into the capabilities of five fungal strains: Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium glabrum, and Penicillium rubens (the latter isolated from heavy crude oil [HCO]) in metabolizing HCO as a carbon source. Employing a meticulously designed experimental approach, conducted at room temperature (25 °C), we systematically explored various culture media and incubation periods. The results unveiled the exceptional resilience of all these fungi to HCO, with A. flavus standing out as the top performer. Notably, A. flavus exhibited robust growth, achieving a remarkable 59.1% expansion across the medium’s surface, accompanied by distinctive macroscopic traits, including a cottony appearance and vibrant coloration. In an effort to further scrutinize its biotransformation prowess, we conducted experiments in a liquid medium, quantifying CO2 production through gas chromatography, which reached its zenith at day 30, signifying substantial bioconversion with a 38% increase in CO2 production. Additionally, we monitored changes in surface tension using the Du Noüy ring method, revealing a reduction in aqueous phase tension from 72.3 to 47 mN/m. This compelling evidence confirms that A. flavus adeptly metabolizes HCO to fuel its growth, while concurrently generating valuable biosurfactants. These findings underscore the immense biotechnological potential of A. flavus in addressing challenges related to HCO, thereby offering promising prospects for bioremediation and crude oil bioupgrading endeavors. [ABSTRACT FROM AUTHOR]

Tyrosinase hydroxylates monophenols to ortho-diphenols through monophenolase activity and oxidizes the ortho-diphenols to ortho-quinones through diphenolase activity. Here, the biotransformation of naringenin, a flavonoid having various biological activities, was attempted using a recombinant tyrosinase of Bacillus megaterium DY804 strain (DY804) as a biocatalyst. DY804 sequentially produced two hydroxylated products, eriodictyol (a catechol) and dihydrotricetin (a gallol), from naringenin (a phenol) in the presence of L-ascorbic acid. The k cat and K m values of DY804 toward naringenin were 161 min−1 and 1060 μM, respectively, to produce eriodictyol. When eriodictyol was the substrate, the k cat and K m of DY804 were 25.7 min−1 and 130 μM, respectively. The maximum concentrations of eriodictyol and dihydrotricetin produced by DY804 were 1074 μM (54% yield) and 315 μM (16% yield), respectively. The maximum productivities were 1038 μM/h (299 mg/L/h) of eriodictyol and 241 μM/h (73 mg/L/h) of dihydrotricetin. The activity of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase was reduced by naringenin, eriodictyol, and dihydrotricetin, their half maximal inhibitory concentration (IC 50) values were 1192, 2401, and 751 µM, respectively. Therefore, three tested flavonoid compounds can be used as antihyperlipidemic agents. It is suggested that DY804 can be applied in the pharmaceutical industry as a biocatalyst to produce high-value-added flavonoids. [Display omitted] • Tyrosinase DY804 produced dihydrotricein from naringenin through eriodictyol. • Kinetic parameters of DY804 toward naringenin and eriodicytol were determined. • Ability of DY804 to produce catechol and gallol compounds was investigated. • Naringenin, eriodictyol, and dihydrotricetin showed cholesterol-lowering efficacy. [ABSTRACT FROM AUTHOR]

As the demand for tea (Camellia sinensis) has grown across the world, the amount of biomass waste that has been produced during the harvesting process has also increased. Tea consumption was estimated at about 6.3 million tonnes in 2020 and is anticipated to reach 7.4 million tonnes by 2025. The generation of tea waste (TW) after use has also increased concurrently with rising tea consumption. TW includes clipped stems, wasted tea leaves, and buds. Many TW-derived products have proven benefits in various applications, including energy generation, energy storage, wastewater treatment, and pharmaceuticals. TW is widely used in environmental and energy-related applications. Energy recovery from low- and medium-calorific value fuels may be accomplished in a highly efficient manner using pyrolysis, anaerobic digestion, and gasification. TW-made biochar and activated carbon are also promising adsorbents for use in environmental applications. Another area where TW shows promise is in the synthesis of phytochemicals. This review offers an overview of the conversion procedures for TW into value-added products. Further, the improvements in their applications for energy generation, energy storage, removal of different contaminants, and extraction of phytochemicals have been reviewed. A comprehensive assessment of the sustainable use of TWs as environmentally acceptable renewable resources is compiled in this review. [ABSTRACT FROM AUTHOR]

Chlorinated paraffins (CPs) are widely used persistent organic pollutants (POPs). Based on the carbon chain length, CPs can be classified as short-chain (C10-13) CPs (SCCPs), medium-chain (C14-17) CPs (MCCPs), and long-chain (C≥18) CPs (LCCPs). Since SCCPs have been listed as POPs of particular concern by the Stockholm Convention, the production of MCCPs and LCCPs is increased sharply. Therefore, the number of studies focusing on MCCPs and LCCPs has increased recently. Herein, we comprehensively reviewed recent studies on the biological occurrence, bioaccumulation, transmission, and transformation of CPs. CPs are pervasively distributed across biotas and exhibit diverse accumulation properties in different tissues. MCCPs and LCCPs are more abundant than SCCPs in some organisms. The absorption, translocation, and elimination behaviors of CPs directly influence their accumulation in organisms. The maternal transfer is an elimination pathway for CPs and could explain the discrepancy in CPs accumulation in opposite sexes of some organisms. With the establishment of novel screening methods, several transformation products of CPs have been identified in plants, microorganisms, and humans. By comparing the biotransformation pathways of CPs in different organisms, common and unique pathways have been identified in various species, although further studies on the transformation of CPs in humans and other animals are required. This review describes some noteworthy and prospective studies focused on the biological behavior of CPs. The review also derives novel conclusions based on recent studies in this field to provide a comprehensive understanding of the environmental fate of CPs. [ABSTRACT FROM AUTHOR]

Abstract The agri-food industry is increasingly recognizing the environmental impact of the over-exploitation of natural resources and waste production, which has prompted a search for sustainable alternatives based on circular bioeconomy principles. Insects can efficiently transform food substrates into reusable biomass, thus making them valuable contributors to a circular bioeconomy system. However, the relationship between the circular bioeconomy and the insect industry has so far appeared relatively unexplored in the existing research. To address this gap, a meta-synthesis has been conducted through a systematic literature review. By identifying the state of the art and assessing the role of insects in the transition of closed-loop systems, the aim of this research has been to shed light on the opportunities and challenges of integrating insects in circular bioeconomy strategies. The research revealed three main topics: (1) waste management by insects, i.e., the use of insects as a tool for waste management and with which to create high-value substrates; (2) insect-based feeds, namely the use of insects as alternative food sources in farming systems; (3) insect-based food acceptance by consumers. The results underscore the significant potential of this market within the circular bioeconomy context, highlighting the obstacles that need to be addressed and future strategies that could be adopted.

The high energy potential of organic waste allows its use in bioconversion technologies, where waste from one production cycle is a raw material for further production to produce environmentally friendly fertilizers, energy carriers and feed additives. The article presents the results of experimental studies on the environmental efficiency of vermiculture on organic waste from livestock, crop production, gardening and forestry under anthropogenic load. It is proved that due to the biological characteristics of vermiculture, which allows to consume a large amount of organic residues, enrich them with its own microflora, enzymes, biologically active substances and release them as processed products (coprolites), this technology to some extent solves the problems of balanced nature management. It has been determined that in the conditions of intensification of production processes, secondary organic raw materials contain a number of pollutants - heavy metals and toxic metals that can accumulate in coprolites (vermicompost). An approach is proposed that solves the problem of pollutant migration and involves the introduction of 3% zeolite from the Sokyrnytsia deposit in the Transcarpathian region into the vermiculture substrate. Experimental and analytical determination of the environmental efficiency of the proposed approach has shown that its practical application in solving the problems of balanced nature management allows to reduce the accumulation of Plumbum by 13.6 % and Cadmium by 22.6 % in vermicompost, which improves the quality of this organic fertilizer and creates prerequisites for obtaining environmentally friendly products.

ABSTRACTTaken separately, a single sweet sorghum stem bioconversion process for bioethanol and biomethane production only leads to a partial conversion of organic matter. The direct fermentation of crushed whole stem coupled with the methanization of the subsequent solid residues in a two-stage process was experimented to improve energy bioconversion yield, efficiency, and profitability. The raw stalk calorific value was 17,144.17 kJ/kg DM. Fermentation step performed using Saccharomyces cerevisiae resulted in a bioconversion yield of 261.18 g Eth/kg DM, i.e. an energy recovery efficiency of 6921.27 kJ/kg DM. The methanogenic potentials were 279 and 256 LCH4/kg DM, respectively, for raw stem and fermentation residues, i.e. energy yields of 10,013.31 and 9187.84 kJ/kg DM, respectively. Coupling processes have significantly increased yield and made it possible to reach 13,309.57 kJ/kg DM, i.e. 77.63% of raw stem energy recovery yield, compared to 40.37% and 58.40%, respectively, for single fermentation and methanization processes.

An efficient conversion of ortho, meta and para fluoro- and trifluoromethyl-substituted benzoic acids to the corresponding benzamides in fermentations of the soil bacterium Streptomyces sp. JCM9888 is described. We also report the efficient reduction of the same class of substrates to the corresponding benzyl alcohols with the fungi Cunninghamella elegans. These biotransformations were surprisingly efficient and may have value as disruptive technologies in process chemistry. [ABSTRACT FROM AUTHOR]