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Ricinoleic acid (RA) from castor oil was employed in biotransformation of peach-flavoured γ-decalactone (GDL), using a Candida parapsilosis strain (MTCC13027) which was isolated from waste of pineapple crown base. Using four variables—pH, cell density, amount of RA, and temperature—the biotransformation parameters were optimized using RSM and BBD. Under optimized conditions (pH 6, 10 % of microbial cells, 10 g/L RA at 28°C), the conversion was maximum and resulted to 80 % (+)-GDL (4.4 g/L/120 h) yield in shake flask (500 mL). Furthermore, optimization was achieved by adjusting the aeration and agitation parameters in a 3 L bioreactor, which were then replicated in a 10 L bioreactor to accurately determine the amount of (+)-GDL. In bioreactor condition, 4.7 g/L (>85 %) of (+)-GDL is produced with 20 % and 40 % dissolved oxygen (1.0 vvm) at 150 rpm in 72 h and 66 h, respectively. Further, a new Al-Mg-Ca-Si composite column-chromatography method is developed to purify enantiospecific (+)-GDL (99.9 %). This (+)-GDL is 100 % nature-identical as validated through 14C-radio-carbon dating. Thorough chemical investigation of enantiospecific (+)-GDL is authenticated for its use as flavour. This bioflavour has been developed through a cost-effective biotechnological process in response to the demand from the food industry on commercial scale. • Efficient Candida parapsilosis (MTCC 13027) strain produces (+)- γ -Decalactone (GDL). • Biotransformation parameters were optimized through RSM and Box Behnken Design. • (+)- γ -GDL is produced 4.4 g/L/120 h in shake-flask and 4.7 g/L/64 h in 10 L bioreactor. • Novel Al-Mg-Ca-Si composite produced to purify 99 % (+)- γ -GDL through Column. • (+)-GDL is identified 100 % biobased and safe for food-flavour application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Larvae of Hermetia illucens regularly develop on PVC-MPs-supplemented diet. • PVC-MPs are ingested by the larvae and reduced in their size. • Midgut morphology is not affected by PVC-MPs in the larval diet. • PVC-MPs in the larval diet do not affect microbial alpha- and beta-diversity. • PVC-MPs selectively affect the abundances of gut bacterial and fungal taxa. In a world with a population exceeding 8 billion people and continuing to grow, pollution from food and plastic waste is causing long-term issues in ecosystems. Potential solutions may be found by exploiting insect-based bioconversion. In this context, we investigated the impact of polyvinyl chloride microparticles (PVC-MPs) on the development of Hermetia illucens (black soldier fly; BSF) and its midgut bacterial and fungal microbiota. The impact of PVC-MPs was evaluated feeding BSF larvae with a PVC-MPs-supplemented diet. The larvae exposed to different PVC-MPs concentrations (2.5%, 5%, 10% and 20% w/w) developed into adults with no significant increase in pupal mortality. Faster development and smaller pupae were observed when 20% PVC-MPs was provided. The BSF larvae ingest PVC-MPs, resulting in a reduction in MPs size. Larvae exposed to PVC-MPs did not exhibit differences in gut morphology. Regarding the impact of PVC-MPs on the structure of both bacterial and fungal communities, the overall alpha- and beta-diversity did not exhibit significant changes. However, the presence of PVC-MPs significantly affected the relative abundances of Enterobacteriaceae and Paenibacillaceae among the bacteria and of Dipodascaceae and Plectospharellaceae among the fungi (including yeast and filamentous life forms), suggesting that PVC-MP contamination has a taxa-dependent impact. These results indicate that BSF larvae can tolerate PVC-MPs in their diet, supporting the potential use of these insects in organic waste management, even in the presence of high levels of PVC-MP contamination. [ABSTRACT FROM AUTHOR]

• Acidification and fermentation preserved a high BSFL-rearing performance. • Acidification and fermentation contribute to the all-year provision of feedstock. • Acidification led to a higher bioconversion rate compared to fermentation. • The nutrient-rich feedstock did not benefit from inoculating lactic acid bacteria. Maintaining a consistent supply of feedstock for efficient bioconversion of black soldier fly larvae (BSFL) presents challenges due to the fluctuating availability of biowastes and agri-food products. To address the challenge of consistent feedstock supply for BSFL, this study investigated the influence of three preservation methods: wild fermentation, inoculated fermentation, and acidification on agri-food by-products applied over three storage durations (1, 7, and 14 days), evaluating their impact on BSFL bioconversion, and feedstock nutrient and microbiota composition. The preserved feedstocks were characterized for gross nutrient, sugar, fermentation metabolite, and bacterial community analyses. All feedstock preservation methods and storage durations had a high bioconversion rate (21–25 % dry mass) and wet larval mass (170–196 mg). Notably, 7-and-14-day acidified feedstock had a significantly higher bioconversion rate compared to fermented feedstock. Acidification preserved feedstock nutrients best with only a 10 % difference compared to initial nutrient values. Fermentation produced typical lactic acid fermentation metabolites with reducing sugar contents; however, adding a lactic acid bacterial inoculum (7 log 10 CFU kg feedstock−1) had no benefit, presumably due to the high nutrient content and existing richness in lactic acid bacteria. Preservations had little influence on Enterobacteriaceae (6.2–7.5 log 10 CFU g−1) in freshly harvested larvae. Future research should assess the acidification and fermentation of different BSFL feedstocks and investigate the roles of feedstock pH, organic acids, and fermentation metabolites in more detail. Therefore, this study advances toward reliable and efficient insect-based nutrient recovery from agri-food by-products within the food system. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop an efficient method for enhancing the production of bioethanol in a single‐reactor system (SRS) by implementing acid–base pretreatment and enzymatic hydrolysis techniques, thereby eliminating differentiation and removal processes. The aim was to establish a process for bioethanol synthesis using hydrolyzed palm oil mill effluent (POME) and a locally sourced cellulase enzyme. The pretreatment and enzymatic hydrolysis methods were successfully optimized, resulting in a maximum yield of reducing sugars of 26.6 g/L (53.14%). To achieve the highest bioethanol yield, fermentation was carried out using both the one‐factor‐at‐a‐time (OFAT) and face‐centered central composite design (FCCCD) approaches. The OFAT approach was employed to obtain the maximum bioethanol production, which yielded 6.75% v/v of bioethanol from the hydrolyzed POME using the same bioreactor. In the case of the FCCCD process, the optimal conditions led to a bioethanol production of 7.64% v/v during the fermentation stage. Kinetic analyses of the bioethanol produced revealed a specific growth rate (μ) of 0.198 h−1 and a specific product formation rate (qp) of 0.239 h−1 after 3 days of fermentation. These findings highlight a promising strategy for efficient management of POME through the production of biofuels, which could contribute to the economic growth of the country. [ABSTRACT FROM AUTHOR]

Seaweed industries are producing solid waste composting of about 60–70% w/w fiber, which is rich in cellulose. Conversion of cellulose-rich waste into sugar and ethanol can provide a zero-waste industry. The objectives of this study were to characterize the solid waste biomass (SWBS) of agar processing industries and convert it into sugar and ethanol. The chemical composition and morphology of SWBS samples from three agar extraction plants (SWBS EP1, SWBS EP2, and SWBS EP3) were examined. Results showed that the SWBS had 3.01–16.4% cellulose, hemicellulose of 3.41–11.53%, lignin of 5.49–6.45%, agar of 7.28–17.03%, and ash content of 59.18–78.75%. X-ray diffraction (XRD) analysis supported the Fourier transform infrared (FTIR) result while revealing that the filter aid of the SWBS EP3 sample was not the same with the two others. SWBS EP3 sample contained more biomass and less filter aid, and it was selected to convert into sugar and ethanol in a 250-L tank. The concentration biosugar reached 21.45 g/L with the addition of the cellulase after the agarase (A24S24), and 15 g/L when the cellulase was mixed together with the agarase (AS24). The highest ethanol production was obtained when agarase and cellulase were added simultaneously for 24-h saccharification followed by yeast fermentation. [ABSTRACT FROM AUTHOR]

Bioconversion using insect larvae has proven to be a feasible option for food waste disposal and has generated products with high economic value. Technological optimization can further improve costs and applicability. In this study, the effects of different substrate intensities and feeding methods on housefly larvae bioconversion were investigated using the solid-phase fraction of kitchen waste obtained after a three-phase separation as the raw material. The results showed that a substrate intensity of 30 kg/m2 combined with one-time feeding was the most appropriate. Under these conditions, an appropriate substrate temperature prevented the escape and early pupation of larvae, and the bioconversion and reduction rates of kitchen waste reached 16.75% and 50.51%, respectively. In addition, the physical and chemical properties of frass were found to be conducive to subsequent aerobic composting. [ABSTRACT FROM AUTHOR]

Ginsenoside, the principal active constituent of ginseng, exhibits enhanced bioavailability and medicinal efficacy in rare ginsenosides compared to major ginsenosides. Current research is focused on efficiently and selectively removing sugar groups attached to the major ginsenoside sugar chains to convert them into rare ginsenosides that meet the demands of medical industry and functional foods. The methods for preparing rare ginsenosides encompass chemical, microbial, and enzymatic approaches. Among these, the enzyme conversion method is highly favored by researchers due to its exceptional specificity and robust efficiency. This review summarizes the biological activities of different rare ginsenosides, explores the various glycosidases used in the biotransformation of different major ginsenosides as substrates, and elucidates their respective corresponding biotransformation pathways. These findings will provide valuable references for the development, utilization, and industrial production of ginsenosides. [Display omitted] • The bioactivities of different rare ginsenosides are summarized. • Enzymes used in the preparation of rare ginsenosides and conversion rates are summarized. • Clarification of the biotransformation pathway of rare ginsenosides. • A valuable reference for the utilization and industrial production of ginsenosides. [ABSTRACT FROM AUTHOR]

Bioaromas can be produced by lipases either through their hydrolytic or (trans)esterifying activities. Therefore, this work reports the development of a lipase-catalyzed biotransformed licuri oil, forming volatile ethyl esters with odor notes resembling tropical fruits. Ethyl octanoate formation was promoted when 7.0 % (m/v) Lipozyme 435® was used to convert a grain alcohol:licuri oil mixture (51:49, v/v) at 58ºC and 70 rpm for 6 hours. The biotransformed oil has shown antimicrobial activity against Staphylococcus hominis , S. epidermidis, and Corynebacterium xerosis , bacteria associated with bad skin odor. Finally, this biotransformed oil was used without further treatments (e.g., recovery or purification procedures) to prepare two cosmetic formulations (in a dosage of 1.5 %), aiming for both fragrant and deodorant activity. • Odor-active ethyl esters were formed in lipase-biotransformed licuri oil. • 8.22 g/L ethyl octanoate was formed with 7 % lipase, 51:49 alcohol:oil ratio at 58°C. • Antibacterial activity of biotransformed oil could prevent bad skin odor. • Cosmetic formulations were prepared with 1.5 % biotransformed licuri oil. • No purification procedures were needed to use a natural fragrant mixture. [ABSTRACT FROM AUTHOR]

A key aspect of sustainable bioeconomy is the recirculation of renewable, agricultural waste streams as substrates for microbial production of high-value compounds. One approach is the bioconversion of corn stover, an abundant maize crop byproduct, using the fungal maize pathogen Ustilago maydis. U. maydis is already used as a unicellular biocatalyst in the production of several industrially-relevant compounds using plant biomass hydrolysates. In this study, we demonstrate that U. maydis can grow using untreated corn stover as its sole carbon source. We developed a small-scale bioreactor platform to investigate U. maydis processing of corn stover, combining online monitoring of fungal growth and metabolic activity profiles with biochemical analyses of the pre- and post-fermentation residues. Our results reveal that U. maydis primarily utilizes soluble sugars i.e., glucose, sucrose and fructose present in corn stover, with only limited exploitation of the abundant lignocellulosic carbohydrates. Thus, we further explored the biotechnological potential of enhancing U. maydis´ lignocellulosic utilization. Additive performance improvements of up to 120 % were achieved when using a maize mutant with increased biomass digestibility, co-fermentation with a commercial cellulolytic enzyme cocktail, and exploiting engineered fungal strains expressing diverse lignocellulose-degrading enzymes. This work represents a key step towards scaling up the production of sustainable compounds from corn stover using U. maydis and provides a tool for the detailed monitoring of the fungal processing of plant biomass substrates. [ABSTRACT FROM AUTHOR]

1.Challenges, strategies and new technologies in the field of biotransformation were presented and discussed at the 5th European Biotransformation Workshop, which was held on March 14, 2024 on the Novartis Campus in Basel, Switzerland.2. In this meeting report we summarise the presentations and discussions from this workshop.3. The topics covered are listed below:Advances in understanding drug induced liver injury (DILI) risks of carboxylic acids and targeted covalent inhibitorsBiotransformation of oligonucleotide-based therapeutics including automated software tools for metabolite identificationRecent advances in metabolite synthesisQualification and validation of a new compact Low Energy Accelerator Mass Spectrometry (LEA) system for metabolite profiling Advances in understanding drug induced liver injury (DILI) risks of carboxylic acids and targeted covalent inhibitorsBiotransformation of oligonucleotide-based therapeutics including automated software tools for metabolite identificationRecent advances in metabolite synthesisQualification and validation of a new compact Low Energy Accelerator Mass Spectrometry (LEA) system for metabolite profiling [ABSTRACT FROM AUTHOR]

Renal clearable nanoparticles have been drawing much attention as they can avoid prolonged accumulation in the body by efficiently clearing through the kidneys. While much effort has been made to understand their interactions within the kidneys, it remains unclear whether their transport could be influenced by other organs, such as the liver, which plays a crucial role in metabolizing and eliminating both endogenous and exogenous substances through various biotransformation processes. Here, by utilizing renal clearable IRDye800CW conjugated gold nanocluster (800CW4‐GS18‐Au25) as a model, we found that although 800CW4‐GS18‐Au25 strongly resisted serum‐protein binding and exhibited minimal accumulation in the liver, its surface was still gradually modified by hepatic glutathione‐mediated biotransformation when passing through the liver, resulting in the dissociation of IRDye800CW from Au25 and biotransformation‐generated fingerprint message of 800CW4‐GS18‐Au25 in urine, which allowed us to facilely quantify its urinary biotransformation index (UBI) via urine chromatography analysis. Moreover, we observed the linear correlation between UBI and hepatic glutathione concentration, offering us a noninvasive method for quantitative detection of liver glutathione level through a simple urine test. Our discoveries would broaden the fundamental understanding of in vivo transport of nanoparticles and advance the development of urinary probes for noninvasive biodetection. [ABSTRACT FROM AUTHOR]

To 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]

Three delignification treatments of corncob residues (CCR), including NaOH, formic acid, and sulfite treatments, were compared at the respective optimized condition and in light of chemical compositions, sugar recovery, and ethanol production. NaOH and sulfite treatment can remove lignin in the CCR efficiently. Though NaOH treatment showed a superior ability of delignification, its solid cellulose recovery is lower than that of sulfite treatment. The sulfite treatment has the highest selectivity between delignification and cellulose conservation. The formic acid-treated CCR still had high lignin contents because formic acid also accelerated the solvation of cellulose. In fed-batch simultaneous saccharification and fermentation (SSF) with 25% substrate loading, the highest 77.1 ± 2.33 g/L ethanol was from NaOH-treated CCR, corresponding to a CCR-to-ethanol yield of 0.208 ± 0.0021 g/g. However, the sulfite pretreated CCR also produced 68.2 ± 2.22 g/L ethanol, with a higher CCR-to-ethanol yield of 0.219 ± 0.0012 g/g. The high substrate dosage is beneficial to ethanol concentration but not beneficial to CCR-to-ethanol yield. The optimal substrate dosage required for ethanol production depends on the targeted aim (ethanol concentration or CCR-to-ethanol yield). [ABSTRACT FROM AUTHOR]

The unwashed alkali-treated lignocellulose can be directly enzymatically hydrolyzed and fermented via pH adjustment with acids. The use of acids would give a burden on production cost. Furfural residue (FR) which is the acidic solid waste from lignocellulose-derived furfural production process was employed in this study as a pH regulator. The corn cob-derived FR was used to adjust the pH value of alkali-treated corn stover (PCS) to 4.8 for enzymatic hydrolysis and ethanol fermentation. The unwashed PCS adjusted by FR got higher enzymatic hydrolysis efficiency (EHE) than the washed PCS samples. Meanwhile, the mixing of PCS and FR had a synergistic effect on the EHE of PCS. The fermentation of enzymatic hydrolysate from unwashed PCS-FR mixture at 20% solid concentration could attain ethanol production of 26.54 ± 0.02 mg/mL with a yield of 89.53 ± 0.08%. This work created a novel recycling way of FR as a pH regulator for improving the bioconversion of alkali-treated lignocellulose. It also provided a novel clue for the valuable valorization of wastes from corn production. [ABSTRACT FROM AUTHOR]

SUMMARY: Improvement of photosynthesis requires a thorough understanding of electron partitioning under both natural and strong electron sink conditions. We applied a wide array of state‐of‐the‐art biophysical and biochemical techniques to thoroughly investigate the fate of photosynthetic electrons in the engineered cyanobacterium Synechocystis sp. PCC 6803, a blueprint for photosynthetic biotechnology, expressing the heterologous gene for ene‐reductase, YqjM. This recombinant enzyme catalyses the reduction of an exogenously added substrate into the desired product by utilising photosynthetically produced NAD(P)H, enabling whole‐cell biotransformation. Through coupling the biotransformation reaction with biophysical measurements, we demonstrated that the strong artificial electron sink, outcompetes the natural electron valves, the flavodiiron protein‐driven Mehler‐like reaction and cyclic electron transport. These results show that ferredoxin‐NAD(P)H‐oxidoreductase is the preferred route for delivering photosynthetic electrons from reduced ferredoxin and the cellular NADPH/NADP+ ratio as a key factor in orchestrating photosynthetic electron flux. These insights are crucial for understanding molecular mechanisms of photosynthetic electron transport and harnessing photosynthesis for sustainable bioproduction by engineering the cellular source/sink balance. Furthermore, we conclude that identifying the bioenergetic bottleneck of a heterologous electron sink is a crucial prerequisite for targeted engineering of photosynthetic biotransformation platforms. Significance Statement: We coupled the photosynthetic and biocatalytic (whole‐cell biotransformation) performance of model cyanobacteria. We employed a heterologous NAD(P)H utilising enzyme, as a strong artificial electron sink, allowing us to gain a comprehensive understanding of photosynthetic electron partitioning. We demonstrated that the strong electron sink outcompetes natural electron sinks and cyclic electron transport. [ABSTRACT FROM AUTHOR]

Ginsenoside F2 is a protopanaxadiol saponin compound with various biological activities, including antioxidant, anti-inflammatory, and anticancer properties. Ginsenoside F2 can be found in ginseng, but in low quantities. Therefore, ginsenoside F2 production predominantly relies on the biotransformation of various ginsenosides, such as ginsenosides Rb1 and Rd. In this study, we reported the production of ginsenoside F2 by gypenoside biotransformation with Aspergillus niger JGL8, isolated from Gynostemma pentaphyllum. Ginsenoside F2 could be produced by two different biotransformation pathways, namely Gyp-V–Rd–F2 and Gyp-XVII–F2. The product exhibited antioxidant activity against free radicals (DPPH) with IC50 value of 29.54 µg/mL. Optimal biotransformation conditions were a pH of 5.0, temperature of 40 °C, and 2 mg/mL of substrate. Enzyme kinetic parameters revealed that the hydrolysis rate of Gyp-V, Rd, and Gyp-XVII was 0.625, 0.588, and 0.417 mM/h, respectively. In conclusion, we demonstrated that gypenoside is a substitutable substrate for ginsenoside F2 biotransformation. [ABSTRACT FROM AUTHOR]

Mushroom cultivation is currently being widely ventured by farmers in Malaysia due to its high profits in a short time and low production cost. Mushrooms can be grown on various substrates such as rice husk and stalks, coconut fiber, and sawdust. This study was performed to find out the ability of using pineapple leaves waste as a substrate for the cultivation of Pleurotus pulmonarius (gray oyster mushroom) and Pleurotus ostreatus (white oyster mushroom) and compare the results obtained with mushrooms grown using traditional substrates (sawdust). The mushroom bags were prepared using a dry and wet medium of pineapple leaves waste. The results revealed that 60% of dry and wet pineapple leaves waste produced the highest output of P. pulmonarius and P. ostreatus in comparison to other percentages. The growing of P. pulmonarius on dry pineapple leaves waste substrate revealed the maximum average weight and number of fruiting bodies while P. ostreatus showed the best growth performance in wet pineapple leaves waste substrate. The nutritional content of 60% dry and wet pineapple leaves waste for both P. pulmonarius and P. ostreatus shown superior value in percentages of moisture, protein, fat, and carbohydrate compared to control. In the meantime, the mineral analysis revealed that 60% of the dry and wet pineapple leaves waste had greater levels of Cu, P, and Pb than the control. These findings suggested that the pineapple leaves waste can become a great alternative substrate for both P. pulmonarius and P. ostreatus cultivation for better economic and environmental benefits. [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]

Methanol is a promising feedstock for biomanufacturing, but the efficiency of methanol-based bioprocesses is limited by the low rate of methanol utilization pathways and methanol toxicity. Yeast diversity is an attractive biological resource to develop efficient bioprocesses since any effort with strain improvement is more deserving if applied to innate robust strains with relevant catabolic and biosynthetic potential. The present study is in line with such rational and describes the isolation and molecular identification of seven isolates of the methylotrophic species Candida boidinii from waters derived from the traditional curation of olives, in different years, and from contaminated superficial soil near fuel stations. The yeast microbiota from those habitats was also characterized. The four C. boidinii isolates obtained from the curation of olives' water exhibited significantly higher maximum specific growth rates (range 0.15–0.19 h−1), compared with the three isolates obtained from the fuel contaminated soils (range 0.05–0.06 h−1) when grown on methanol as the sole C-source (1% (v/v), in shake flasks, at 30°C). The isolates exhibit significant robustness towards methanol toxicity that increases as the cultivation temperature decreases from 30°C to 25°C. The better methanol-based growth performance exhibited by C. boidinii isolates from olives´ soaking waters could not be essentially attributed to higher methanol tolerance. These methanol-efficient catabolizing isolates are proposed as a promising platform to develop methanol-based bioprocesses. [ABSTRACT FROM AUTHOR]

A biotransformation pair consisting of vinblastine: vincristine present in the Catharanthus roseus plant is of immense pharmacological significance. In this study, we successfully transformed vinblastine into vincristine outside the plant using Pseudomonas aeruginosa 8485 and Pseudomonas fluorescens 2421 and evaluated the antiangiogenic potential of thus produced vincristine through the CAM assay. The toxicity assay showed that both Pseudomonas spp. can tolerate varying concentrations (25–100 µl of 1 mg/ml) of vinblastine. The biotransformation was performed in a liquid nutrient broth medium containing vinblastine (25–100 µl), and Pseudomonas spp. inoculums (50–150 µl) by incubating at 30 °C and 37 °C, respectively for 8 days. The process was optimized for substrate and culture concentrations, pH, temperature, and rotation speed (rpm) for the highest conversion. Analysis using LC–MS/MS confirmed the presence of vincristine as a product of the vinblastine biotransformation by two Pseudomonas spp. P. fluorescens 2421 showed a faster conversion rate with 95% of vinblastine transformed within 24 h than P. aeruginosa 8485, which demonstrated a conversion rate of 92% on the 8th day. From LC–MS/MS analysis, the optimal conditions for the reaction were determined as vinblastine (25 µl), microbial inoculums (150 µl or 200 × 106 and 210 × 106 CFU/ml), pH 7.4, rotation speed of 180 rpm, and temperatures of 30 °C and 37 °C with incubation time of 8 days. The vincristine produced exhibited potent antiangiogenic activity in the CAM assay reducing the thickness and branching of blood vessels in a dose-dependent manner. The study concludes that both Pseudomonas spp. showed promise for vincristine production from vinblastine, without compromising its antiangiogenic properties. [ABSTRACT FROM AUTHOR]

Ginsenoside Compound K (GCK) is the main metabolite of natural protopanaxadiol ginsenosides with diverse pharmacological effects. Gut microbiota contributes to the biotransformation of GCK, while the effect of gut microbiota on the pharmacokinetics of GCK in vivo remains unclear. To illustrate the role of gut microbiota in GCK metabolism in vivo, a systematic investigation of the pharmacokinetics of GCK in specific pathogen free (SPF) and pseudo-germ-free (pseudo-GF) rats were conducted. Pseudo-GF rats were treated with non-absorbable antibiotics. Liquid chromatography tandem mass spectrometry (LC–MS/MS) was validated for the quantification of GCK in rat plasma. Compared with SPF rats, the plasma concentration of GCK significantly increased after the gut microbiota depleted. The results showed that GCK absorption slowed down, Tmax delayed by 3.5 h, AUC0-11 increased by 1.3 times, CLz/F decreased by 0.6 times in pseudo-GF rats, and Cmax was 1.6 times higher than that of normal rats. The data indicated that gut microbiota played an important role in the pharmacokinetics of GCK in vivo. [ABSTRACT FROM AUTHOR]

Consistent introduction of novel enzymes is required for developing efficient biocatalysts for challenging biotransformations. Absorbing catalytic modes from organocatalysis may be fruitful for designing new‐to‐nature enzymes with novel functions. Herein we report a newly designed artificial enzyme harboring a catalytic pyrrolidine residue that catalyzes the asymmetric Michael addition of cyclic ketones to nitroolefins through enamine activation with high efficiency. Diverse chiral γ‐nitro cyclic ketones with two stereocenters were efficiently prepared with excellent stereoselectivity (up to 97 % e.e. >20 : 1 d.r.) and good yield (up to 86 %). This work provides an efficient biocatalytic strategy for cyclic ketone functionalization, and highlights the usefulness of artificial enzymes for extending biocatalysis to further non‐natural reactions. [ABSTRACT FROM AUTHOR]

Cellobiose has received increasing attention in various industrial sectors, ranging from food and feed to cosmetics. The development of large-scale cellobiose applications requires a cost-effective production technology as currently used methods based on cellulose hydrolysis are costly. Here, a one-pot synthesis of cellobiose from sucrose was conducted using a recombinant Pichia pastoris strain as a reusable whole-cell biocatalyst. Thermophilic sucrose phosphorylase from Bifidobacterium longum (BlSP) and cellobiose phosphorylase from Clostridium stercorarium (CsCBP) were co-displayed on the cell surface of P. pastoris via a glycosylphosphatidylinositol-anchoring system. Cells of the BlSP and CsCBP co-displaying P. pastoris strain were used as whole-cell biocatalysts to convert sucrose to cellobiose with commercial thermophilic xylose isomerase. Cellobiose productivity significantly improved with yeast cells grown on glycerol compared to glucose-grown cells. In one-pot bioconversion using glycerol-grown yeast cells, approximately 81.2 g/L of cellobiose was produced from 100 g/L of sucrose, corresponding to 81.2% of the theoretical maximum yield, within 24 h at 60 °C. Moreover, recombinant yeast cells maintained a cellobiose titer > 80 g/L, even after three consecutive cell-recycling one-pot bioconversion cycles. These results indicated that one-pot bioconversion using yeast cells displaying two phosphorylases as whole-cell catalysts is a promising approach for cost-effective cellobiose production. [ABSTRACT FROM AUTHOR]

Icaritin, a hydrolysate from total flavonoids of Epimedii (TFE), which has better anti-hepatoma activity than its glycosylated form. In this work, immobilized enzymes 4LP-Tpebgl3@Na-Y and DtRha@ES-107 were used to hydrolyze TFE to prepare icaritin. Five different hydrophobic deep eutectic solvents (HDES) were prepared and the most ideal HDES was successfully selected, which was composed of dodecyl alcohol and thymol with the molar ratio of 2:1. The relative enzyme activity of 4LP-Tpebgl3@Na-Y and DtRha@ES-107 was about 102.4 % and 112.5 %, respectively. In addition, the thermal and binding stability of 4LP-Tpebgl3@Na-Y and DtRha@ES-107 in HDES was not affected negatively. In the biphasic system composed of 50 % (v / v) HDES and Na 2 HPO 4 -citric acid buffer (50 mM, pH 5.5), 4LP-Tpebgl3@Na-Y (1.0 U/mL) and TFE (1 g/L) were reacted at 80 °C for 1 h, and then reacted with DtRha@ES-107 (20 U/mL) at 80 °C for 2 h. Finally, TFE was completely converted to 301.8 mg/L icaritin (0.82 mM). After 10 cycles, 4LP-Tpebgl3@Na-Y/DtRha@ES-107 still maintained 84.1 % original activity. In this study, we developed an efficient methodology for icaritin preparation through the integration of enzymatic catalysis and adsorption separation, presenting a viable approach for large-scale, cost-effective production of icaritin. [Display omitted] • Immobilized enzymes 4LP-Tpebgl3@Na-Y and DtRha@ES-107 have highly efficient biotransformation of TFE to icaritin. • The HDES composed of dodecyl alcohol and thymol was efficiently maintained the catalytic activity and stability of immobilized enzymes. • The yield of icaritin reached 301.8 mg/L in the HDES-buffer biphasic system, which maintained 84.1% initial yield after 10 times of reuse. [ABSTRACT FROM AUTHOR]

Protein engineering is crucial to improve enzymes' efficiency and robustness for industrial biocatalysis. NOV1 is a bacterial dioxygenase that holds biotechnological potential by catalyzing the one-step oxidation of the lignin-derived isoeugenol into vanillin, a popular flavoring agent used in food, cleaning products, cosmetics and pharmaceuticals. This study aims to enhance NOV1 activity and operational stability through the identification of distal hotspots, located at more than 9 Å from the active site using Zymspot, a tool that predicts advantageous distant mutations, streamlining protein engineering. A total of 41 variants were constructed using site-directed mutagenesis and the six most active enzyme variants were then recombined. Two variants, with two and three mutations, showed nearly a 10-fold increase in activity and up to 40-fold higher operational stability than the wild-type. Furthermore, these variants show 90–100 % immobilization efficiency in metal affinity resins, compared to approximately 60 % for the wild-type. In bioconversions where 50 mM of isoeugenol was added stepwise over 24-h cycles, the 1D2 variant produced approximately 144 mM of vanillin after six reaction cycles, corresponding to around 22 mg, indicating a 35 % molar conversion yield. This output was around 2.5 times higher than that obtained using the wild-type. Our findings highlight the efficacy of distal protein engineering in enhancing enzyme functions like activity, stability, and metal binding selectivity, thereby fulfilling the criteria for industrial biocatalysts. This study provides a novel approach to enzyme optimization that could have significant implications for various biotechnological applications. [Display omitted] • NOV1 catalyzes the one-step coenzyme-free formation of vanillin from isoeugenol. • Computational tools predicted beneficial mutations distal from active site. • Distal mutations significantly enhance NOV1 activity and stability properties. • Distal mutations improved immobilization efficiency in metal affinity resins. • Our study emphasizes distal interactions' role in enhancing enzymatic properties. [ABSTRACT FROM AUTHOR]

enviPath is a widely used database and prediction system for microbial biotransformation pathways of primarily xenobiotic compounds. Data and prediction system are freely available both via a web interface and a public REST API. Since its initial release in 2016, we extended the data available in enviPath and improved the performance of the prediction system and usability of the overall system. We now provide three diverse data sets, covering microbial biotransformation in different environments and under different experimental conditions. This also enabled developing a pathway prediction model that is applicable to a more diverse set of chemicals. In the prediction engine, we implemented a new evaluation tailored towards pathway prediction, which returns a more honest and holistic view on the performance. We also implemented a novel applicability domain algorithm, which allows the user to estimate how well the model will perform on their data. Finally, we improved the implementation to speed up the overall system and provide new functionality via a plugin system. Scientific contribution: The main scientific contributions are the development of a pathway prediction model applicable to diverse chemicals, a specialized evaluation method for holistic performance assessment, and a novel applicability domain algorithm for user-specific performance estimation. The introduction of two new data sets, and the creation of links to EC classes make enviPath a unique resource in microbial biotransformation research. [ABSTRACT FROM AUTHOR]

Cheese whey is an industrial by-product that is generated in excess during the cheese production process in the dairy industry. Despite the potential utility of whey, it continues to pose environmental threats in the industry. This study comprehensively evaluates the utilization of two fermentation techniques (solid-state fermentation and submerged fermentation) for producing fungal biomass from cheese whey powder, employing Aspergillus oryzae, Rhizopus oryzae, and Neurospora intermedia for sustainable food production. It has been observed that submerged fermentation is more effective in increasing the protein content of whey powder compared to solid-state fermentation. The highest biomass yield was achieved with A. oryzae (5.29 g/L, 0.176 g biomass/g substrate), followed by N. intermedia (3.63 g/L, 0.121 g biomass/g substrate), and R. oryzae (1.9 g/L, 0.063 g biomass/g substrate). In the bubble column reactor, the protein content of the substrate (78.65 g/kg) increased by 165.54 and 176.69% with A. oryzae (208.85 g/kg) and N. intermedia (217.62 g/kg), respectively. This study has demonstrated that whey powder can be converted into protein-rich biomass through fungal bioconversion. The obtained biomass has the potential to be developed as an alternative food and feed source, contributing to waste management and sustainable food production. [ABSTRACT FROM AUTHOR]

In acidic paddy fields of South China, rice (Oryza sativa L.) faces the dual challenges of cadmium (Cd) toxicity and silicon (Si) deficiency. Although previous studies have highlighted the functions of Si application timing and strategies in mitigating Cd-stressed rice, the precise mechanisms underlying the health restoration of Cd-toxic rice and the assurance of grain safety remain elusive. This study explored Cd translocation and detoxification in the shoots of rice regulated by various Si fertilization regimes: Si(T) (all Si added before transplanting), Si(J) (all Si added at jointing), and Si(TJ) (half Si added both before transplanting and at jointing). The findings revealed that the regime of Si(TJ) was more beneficial to rice health and grain safety than Si(T) and Si(J). The osmotic regulators such as proline, soluble sugars, and soluble proteins were significantly boosted by Si(TJ) compared to other Si treatments, and which enhanced membrane integrity, balanced intracellular pH, and increased Cd tolerance of rice. Furthermore, Si(TJ) was more effective than Si(T) and Si(J) on the Cd sequestration in the cell wall, Cd bio-passivation, and the down-regulated expression of the Cd transport genes. The concentrations of Cd in the xylem and phloem treated with Si(TJ) were reduced significantly. Additionally, Si(TJ) facilitated much more Cd bound with the outer layer proteins of grains, and promoted Cd chelation and complexation by phytic acid, phenolics, and flavonoids. Overall, Si (TJ) outperformed Si(T) and Si(J) in harmonizing the phycological processes, inhibiting Cd translocation, and enhancing Cd detoxification in rice plant. Thereby the split Si application strategy offers potential for reducing Cd toxicity in rice grain. [ABSTRACT FROM AUTHOR]

The microsomal metabolism of phenol (11 °C) over an annual reproductive cycle from June to December was studied using fall spawning adult brook trout (Salvelinus fontinalis). Hepatic microsomes were isolated from three male and three female fish each month. Incubations were optimized for time, cofactor concentration, pH, and microsomal protein concentration. The formation of phase I ring-hydroxylation metabolites, i.e., hydroquinone (HQ) and catechol (CAT), was quantified by HPLC with dual-channel electrochemical detection. Sample preparation and chromatographic conditions were optimized to achieve the separation and sensitivity required for the analysis of these labile products. Biotransformation of phenol over a range of substrate concentrations (1 to 150 mM) was quantified for the calculation of Michaelis–Menten constants (Km and Vmax) for each month. Results indicate a nearly equal production of HQ and CAT among males and females in late June. At the peak of maturity in October, there was an approximate ten-fold greater production of ring-hydroxylation metabolites noted in females in comparison with males on a total liver basis. In vitro phase II biotransformation of phenol glucuronidation was assessed by determining the Michaelis–Menten constants (Km, Vmax) using brook trout hepatic microsomes over a range of substrate concentrations (1 to 60 mM). Initially, there were no significant differences in the glucuronide rate of formation (pmol/min/mg protein) or total capacity (nmol/min/liver) between females and males. At the peak of maturation, the maximum rate of glucuronide formation was 4-fold less in females; however, the total capacity was 2-fold less in females due to the increased liver size in the females. The alterations in biotransformation coincided with increases in the hepatic and gonadal somatic indices and with changes in plasma hormone concentrations. These experiments provide insight into the metabolic deactivation of xenobiotics and to provide data for the prediction of altered hepatic biotransformation rates and pathways during the reproductive cycle. [ABSTRACT FROM AUTHOR]

Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is a crucial cofactor in metabolic networks. The efficient regeneration of NADPH is one of the limiting factors for productivity in biotransformation processes. To date, many metabolic engineering tools and static regulation strategies have been developed to regulate NADPH regeneration. However, traditional static regulation methods often lead to the NADPH/NADP+ imbalance, causing disruptions in cell growth and production. These methods also fail to provide real-time monitoring of intracellular NADP(H) or NADPH/NADP+ levels. In recent years, various biosensors have been developed for the detection, monitoring, and dynamic regulate of the intracellular NADP(H) levels or the NADPH/NADP+ balance. These NADPH-related biosensors are mainly used in the cofactor engineering of bacteria, yeast, and mammalian cells. This review analyzes and summarizes the NADPH metabolic regulation strategies from both static and dynamic perspectives, highlighting current challenges and potential solutions, and discusses future directions for the advanced regulation of the NADPH/NADP+ balance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Flax lignan has attracted much attention because of its potential bioactivities. However, the bioavailability of secoisolariciresinol diglucoside (SDG), the main lignan in flaxseed, depends on the bioconversion by the colon bacteria. Lactic acid bacteria (LAB) with β‐glucosidase activity has found wide application in preparing bioactive aglycone. RESULTS: LAB strains with good β‐glucosidase activity were isolated from fermented tofu. Their bioconversion of flax lignan extract was investigated by resting cell catalysis and microbial fermentation, and the metabolism of SDG by Lactiplantibacillus plantarum C5 following fermentation was characterized by widely targeted metabolomics. Five L. plantarum strains producing β‐glucosidase with broad substrate specificity were isolated and identified, and they all can transform SDG into secoisolariciresinol (SECO). L. plantarum C5 resting cell reached a maximum SDG conversion of 49.19 ± 3.75%, and SECO generation of 21.49 ± 1.32% (0.215 ± 0.013 mm) at an SDG substrate concentration of 1 mM and 0.477 ± 0.003 mm SECO was produced at 4 mm within 24 h. Although sixteen flax lignan metabolites were identified following the fermentation of SDG extract by L. plantarum C5, among them, four were produced following the fermentation: SECO, demethyl‐SECO, demethyl‐dehydroxy‐SECO and isolariciresinol. Moreover, seven lignans increased significantly. CONCLUSION: Fermentation significantly increased the profile and level of flax lignan metabolites, and the resting cell catalysis benefits from higher bioconversion efficiency and more straightforward product separation. Resting cell catalysis and microbial fermentation of flax lignan extract by the isolated β‐glucosidase production L. plantarum could be potentially applied in preparing flax lignan ingredients and fermented flaxseed. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

α-L-Rhamnosidases with desirable activity and thermostability profiles could be used for the biocatalytic production of the flavonoid glucoside isoquercetin from natural rutin for functional food. Herein, to improve the catalytic activity of GH78 α-L-rhamnosidase BtRha78A from Bacteroides thetaiotaomicron VPI-5482, a list of residues located at the conserved general acid motif were selected for targeted mutagenesis by the sequence alignment of BtRha78A with homologous α-L-rhamnosidases. Ala-scanning mutagenesis and site-directed mutagenesis based on sequence alignment were performed, and the relative activity on rutin was evaluated. Furthermore, the reaction time curves and enzyme kinetics of better mutants were determined. The results indicate that the conversion rates of mutants V338A, V338I, S340A, and G341A were increased by 21.3%, 20.1%, 13.2%, and 1.6%, respectively, compared with the wild type when using whole-cell biotransformation. Moreover, the catalytic efficiency kcat/KM value of mutant V338A was 1.3-fold higher than that of the wild type. The best mutant, V338A, was employed for the enzymatic preparation of isoquercetin via the biotransformation of rutin at a concentration of 2 mM, and 1.80 g of isoquercetin was obtained. The identification of the best mutant V338A lays the foundation for the efficient preparation of isoquercetin via the biotransformation of rutin, which in turn provides theoretical guidance for its large-scale production. [ABSTRACT FROM AUTHOR]

Flavonoids comprise a group of natural compounds with diverse bioactivities; however, their low water solubility and limited bioavailability often impede their potential health benefits for humans. In this study, five derivatives, namely 2′,5′-dihydroxyflavanone (1), 2′-dihydroxyflavanone-5′- O -4″- O -methyl- β - d -glucoside (2), 2′-dihydroxyflavanone-6- O -4″- O -methyl- β - d -glucoside (3), 2′-dihydroxyflavanone-3′- O -4″- O -methyl- β - d -glucoside (4) and hydroxyflavanone-2′- O -4″- O -methyl- β - d -glucoside (5), were biosynthesized from 2′-hydroxyflavanone through microbial transformation using Beauveria bassiana ATCC 7159. Product 1 was identified as a known compound while 2 – 5 were structurally characterized as new structures through extensive 1D and 2D NMR analysis. The water solubility of biotransformed products 1 – 5 was enhanced by 30–280 times compared to the substrate 2′-hydroxyflavanone. Moreover, the antioxidant assay revealed that 1 and 2 exhibited improved 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity relative to the substrate, decreasing the logIC 50 from 8.08 ± 0.11 μM to 6.19 ± 0.08 μM and 7.15 ± 0.08 μM, respectively. Compound 5 displayed significantly improved anticancer activity compared to the substrate 2′-hydroxyflavanone against Glioblastoma 33 cancer stem cells, decreasing the IC 50 from 25.05 μM to 10.59 μM. Overall, fungal biotransformation represents an effective tool to modify flavonoids for enhanced water solubility and bioactivities. [Display omitted] [ABSTRACT FROM AUTHOR]

A genome of Rhodococcus rhodochrous IEGM 1362 was sequenced and annotated. This strain can transform monoterpene alcohol (–)-isopulegol with the formation of two novel pharmacologically promising metabolites. Nine genes encoding cytochrome P450, presumably involved in (–)-isopulegol transformation, were found in the genome of R. rhodochrous IEGM 1362. Primers and PCR conditions for their detection were selected. The obtained data can be used for the further investigation of genes encoding enzymes involved in monoterpene biotransformation. [ABSTRACT FROM AUTHOR]

The use of organic-inorganic hybrid nanoflowers as a support material for enzyme immobilization has gained significant attention in recent years due to their high stability, ease of preparation, and enhanced catalytic activity. However, a major challenge in utilizing these hybrid nanoflowers for enzyme immobilization is the difficulty in handling and separating them due to their low density and high dispersion. To address this issue, magnetic nanoflowers have emerged as a promising alternative enzyme immobilization platform due to their easy separation, structural stability, and ability to enhance catalytic efficiency. This review focuses on different methods for designing magnetic nanoflowers, as well as future research directions. Additionally, it provides examples of enzymes immobilized in the form of magnetic nanoflowers and their applications in environmental remediation, biosensors, and food industries. Finally, the review discusses possible ways to improve the material for enhanced catalytic activity, structural stability, and scalability. The magnetic hybrid nanoflowers embedded with enzymes exhibit superior catalytic activity, excellent stability, and ease of separation which can be used in a wide range of applications. Magnetic nanoflowers can be used as a novel platform for enzyme immobilization. There are three different approaches to the synthesis of efficient magnetic nanoflower. The magnetic nanoflowers provides excellent stability and good reusability of enzymes. The hybrid biocatalyst was applied in biotransformation, environmental, and food applications. The challenges and their remedies of hybrid biocatalyst have been discussed. [ABSTRACT FROM AUTHOR]

Organic-rich industrial residues can serve as renewable feedstocks for the generation of useful products by microbial fermentation. We investigated fermenting communities enriched in a mixture of ultra-filtered milk permeate (UFMP) and acid whey from cottage cheese (CAW), two dairy coproducts rich in lactose. To evaluate how operational pH and temperature affect microbial communities and fermentation products, we operated 12 bioreactors for 140 days, each fed a 1:1 mixture of UFMP and CAW at either 35 °C or 50 °C and at either a pH of 4.8 or 5.5. The bioreactors operated at a pH of 4.8 resulted in the incomplete conversion of lactose, while those operated at a pH of 5.5 consistently fermented lactose, primarily into lactic, acetic, and hexanoic acids. The metagenomic analyses revealed that microbial communities obtained at a pH of 5.5 were dominated by lactic acid-producing organisms. Additionally, an inverse relationship was found between the abundance of chain elongating organisms and lactic acid accumulation, with 50 °C reducing the abundance of these organisms and enhancing lactic acid yields. We conclude that the pH and temperature are important determinants of the fermentation of dairy coproducts with a pH of 5.5 and 50 °C yielding the most promising results for lactic acid production. Additional research is required to better understand the factors affecting functional consistency of the process. [ABSTRACT FROM AUTHOR]

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This study aimed, for the first time, to determine the nutritional composition, beta-glucan and ergosterol contents, phenolic compound composition, and biological and functional activities of a novel mycoprotein produced through a bioconversion process of Durvillaea spp., a brown seaweed. An untargeted metabolomics approach was employed to screen metabolites and annotate molecules with nutraceutical properties. Two products, each representing a distinct consortia of co-cultured fungi, named Myco 1 and Myco 2, were analysed in this study. These consortia demonstrated superior properties compared to those of Durvillaea spp., showing significant increases in total protein (~238%), amino acids (~219%), and β-D-glucans (~112%). The protein contains all essential amino acids, a low fatty acid content, and exhibits high antioxidant activity (21.5–25.5 µmol TE/g). Additionally, Myco 2 exhibited the highest anti-alpha-glucosidase activity (IC50 = 16.5 mg/mL), and Myco 1 exhibited notable anti-lipase activity (IC50 = 10.5 mg/mL). Among the 69 top differentially abundant metabolites screened, 8 nutraceutical compounds were present in relatively high concentrations among the identified mycoproteins. The proteins and polysaccharides in the mycoprotein may play a crucial role in the formation and stabilization of emulsions, identifying it as a potent bioemulsifier. In conclusion, the bioconversion of Durvillaea spp. results in a mycoprotein with high-quality protein, significant nutritional and functional value, and prebiotic and nutraceutical potential due to the production of unique bioactive compounds. [ABSTRACT FROM AUTHOR]

Banana peel waste is one of the major contributors in the issue raised from solid waste, however, it can be valorized effectively due to high content of cellulose and hemicellulose. Significant conversion of banana waste includes cellulolytic enzymes and bioenergy production. In the present study, bacterial cellulase was produced using raw banana peel and ripe banana peel under SSF. Additionally, impact of acid pretreatment was investigated as one of strategy to improve cellulolytic enzyme production. A comparative evaluation of raw and ripe banana peels showed that ripe banana peels showed better enzyme production after pretreatment with 0.5% dilute HCl acid. In the series of enhancement of the enzyme production, temperature and pH of the SSF medium were also investigated, and found temperature 35 °C and pH 6.0 were optimum to produce maximum 3.5-U/ml FPA, 39-U/ml BGL, and 54-U/ml EG in 18-h SSF incubation. The study presented eco-friendly waste management to produce industrial enzyme for its promising application in waste valorization and biorefinery area. [ABSTRACT FROM AUTHOR]

The utilization of yellow mealworm, Tenebrio molitor (Linnaeus, Coleoptera: Tenebrionidae), for food and feed is gaining interest globally. However, its production is hindered by expensive commercial diets. This study assessed mealworm growth performance, survival, bioconversion, and nutritional composition when fed on wheat bran (WB) with different inclusion levels (25%, 50%, 75%, and 100%) of Irish potato waste (PW). Results indicated that mealworms fed on diets with 25%–75% PW had increased body length and 1–2 times higher weight gain compared to sole WB and PW diets. The survival rate was 93%–94% across all diets. Mealworms fed on WB had a feed conversion ratio of 3.26, while the efficiency of diet conversion increased with PW inclusion levels. Mealworms fed on diets with 75% PW inclusion had the highest crude fat (48%) and energy levels (598 kcal/100 g), while sole WB produced mealworms with the highest crude protein (55%). The acid detergent fiber achieved using 100% WB was 2- to 3-fold higher, but the crude fiber and neutral detergent fiber did not vary significantly. Considerable amounts of lysine (1.6–2 mg/100 g), methionine (0.5–0.7 mg/100 g), leucine (1.4–2 mg/100 g), and threonine (0.8–1 mg/100 g) were achieved in the mealworm larvae. Our findings revealed that cheap agricultural by-products could be successfully used for the mass production of mealworms, substantially contributing to reduced production costs. Further exploration of the nutrient-dense mealworm larvae for the development of novel food and feed products is crucial. [ABSTRACT FROM AUTHOR]

Consumers' growing knowledge of healthy, environmentally friendly flavors and scents drives the demand for vanillin bioproduction. To save costs on nitrogen during the bioproduction of vanillin, this study investigated the feasibility of using corn steep as a substitute. Using the response surface methodology (RSM) model, the synergistic effects of three variables on vanillin yield were evaluated using Box–Behnken design (BBD). When corn steep liquid, ferulic acid concentration, and pH were 7.72 g/L, 2.33 g/L, and 9.34, respectively, the highest vanillin production of 386 mg/L was achieved. The findings indicated that a maximum overall desirability (D) of 1.0 and a significant (p < 0.05) quadratic model with a regression coefficient (R2) of 0.995 can be used to establish ideal circumstances for the bioproduction of vanillin. This study demonstrated the effectiveness of using corn steep liquor as a low-cost nitrogen source in the medium formulation for the extraction and production of vanillin. [ABSTRACT FROM AUTHOR]

The use of anaerobic fermentation to produce volatile fatty acids (VFAs) is an environmentally sustainable alternative for cheese whey (CW) valorization. This study evaluates the effect of pH control on the conversion of organic matter to VFAs from CW and assesses VFA recovery using a novel approach based on gas-permeable membranes. VFA bioconversion and composition were studied with initial and sequential control of pH, both in acidic and alkaline conditions. Bioconversion efficiencies for assays with initial pH control were 36% and 45% for acidic and alkaline conditions, respectively. Sequential control of pH resulted in an increase in bioconversion to 54% under acidic conditions. Under acidic conditions, a variety of VFA was produced (mainly butyric, acetic, and propionic acids), while under alkaline conditions the majority was acetic acid. VFA recovery using a novel system of tubular gas-permeable membranes accounted for 15% and 100% of the total VFA from effluent 1 (butyric, acetic, and propionic acids) and effluent 2 (mainly acetic acid), respectively. [ABSTRACT FROM AUTHOR]

Introduction: Daily, large amounts of rumen contents are produced as waste in slaughterhouses, which are not used and released into the environment, which causes environmental issues and problems (Rezai et al 2018). Potato (Solanum tuberosum) is one of the crops with high production throughout the world a large amount of which is removed from the consumption cycle as waste during different stages, and if not used correctly, it can cause environmental pollution (FAO 2019). The main method of using potato waste is to use it in fresh or dried form to feed domestic animals. Although drying waste potatoes for use in animal feed seems like a good idea, but its high cost has made this uneconomical. Therefore, it is necessary to transform potato waste into a sustainable product that has a higher economic value (Haas et al 2008). Compared to other processing methods, bioconversion is a new and desirable method for agricultural waste management. Ruminal fluid, as a rich source of enzymes, can be used in the bioconversion of agricultural waste. The microbial population present in the rumen is a rich source of new enzymes that have a high potential for industrial use (Pourbayramian et al 2021). Various studies using different methods, such as the use of Saccharomyces yeasts and Lactobacillus species for the biological conversion of potato waste to ethanol (Moza et al 2022), producing biogas from solid potato waste in a two-step process anaerobic digestion (Parawira et al 2005), fermentation of potato waste by mixed culture to produce lactic acid (Liang et al 2014), enzymatic hydrolysis of potato pulp to produce glucose and ethanol (Lesiecki et al 2012) and using various bacterial species have been used for the biological conversion of potato pulp into cellulose (Shigematsu et al 2005). The objective of this study was to investigate the effect of different levels of slow-release non-protein nitrogen on the bioconversion of potato waste by ruminal microorganisms. Materials and methods: Potato waste was collected from potato storage stocks and after cleaning the waste materials, it was boiled and then grated before incubation. The required rumen fluid was obtained from the slaughterhouse and after being filtered with a four-layer cheesecloth, it was added to the glass bottles of the rumen digestion simulator apparatus (DaisyII) and immediately transferred to the apparatus and incubated at 39 degrees Celsius for 24 hours. Experimental groups were: 1) 400 ml of rumen fluid + 200 g of waste potato (N0), 2) 400 ml of rumen fluid + 200 g of waste potato + 1.5 g of nitrogen from a slow-release nitrogen source (N1.5), 3) 400 ml of rumen fluid + 200 grams of waste potatoes + 3 grams of nitrogen from a slow release nitrogen source (N3) and 4) 400 ml of rumen fluid + 200 grams of waste potatoes + 4.5 grams of nitrogen from a slow release nitrogen source (N4.5). After the end of the incubation time, the samples were removed from incubation bottles, and after filtering and separating the solid and liquid parts from each other for further tests. The liquid portion of the incubation medium was analyzed for protozoa count, volatile fatty acids, ammonia nitrogen, and hydrolytic enzymes and compared to the fresh initial rumen fluid used for the incubation. The resulting data were analyzed in the form of a completely randomized design using SAS software (2003). Means were shown as Least Squares (LSMEAN) along with standard error and mean comparisons at a significance level of five percent. Results and discussion: Protozoa count in the liquid portion of the incubation medium was affected by the experimental groups. Rumen fluid had the highest number of protozoa and supplementing the culture medium with a non-protein nitrogen source had a decreasing effect on the protozoa population. The activities of carboxy-methyl cellulase, alpha-amylase, microcrystalline cellulose, and filter-papers enzymes were affected by the levels of supplementation from slowrelease non-protein nitrogen sources and the highest carbohydrate-degrading activities were recorded at 1.5 gr nitrogen supplementation per 100 gr potato waste (P<0.05). The level of urease and protease enzyme activity was also affected by different levels of non-protein nitrogen sources and 4.5 grams of nitrogen from non-protein nitrogen sources showed the highest level of activity. Supplementing the incubation medium increased its ammonia concentration and the highest value was observed at 4.5 grams of slow-release non-protein nitrogen level (P<0.05). For all enzyme activities, initial fresh rumen fluid had the lowest activities. Volatile fatty acid production was affected by supplementation with non-protein nitrogen levels and the amount of volatile fatty acids in the liquid phase of the incubation medium showed the highest values with 3 grams of non-protein slow-release nitrogen supplementation. Conclusion: Based on the results of the present study, the addition of slow-release non-protein nitrogen to the incubation medium of potato waste with rumen liquid microorganisms significantly increases their power in the biotransformation of potato waste. Also, the liquid part of the culture medium can be considered as a source of enzymes and acids for use on an industrial scale due to the increased activity of hydrolytic enzymes and volatile fatty acids that are the product of the fermentation process. The use of the processed rumen fluid resulting from this incubation as a source of enzymes and nutrients in feeding livestock and poultry will be an environmentally friendly method, in this way, the rumen fluid of slaughterhouses and potato waste will be used with a proper management methods. According to the results of the present study, rumen liquid microorganisms with a non-protein nitrogen source can be used more effectively in the bioconversion of potato waste to increase its nutritional value and produce a liquid rich in volatile fatty acids as well as a source of favorable enzyme activities. [ABSTRACT FROM AUTHOR]

AbstractMicrobial 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]

Astaxanthin is a red xanthophyll with high economic and industrial value in the pharmaceutical, nutraceutical, cosmetic and food industries. In recent years, the biotechnological production of astaxanthin has attracted much attention as a sustainable alternative to the predominating petrochemical-dependent chemical synthesis. In this regard, Xanthophyllomyces dendrorhous is regarded as a promising microorganism for industrial production of astaxanthin. Unfortunately, biotechnological production of the carotenoid is currently expensive. The present study investigated soy molasses (SM) and residual brewers' yeast as cheap fermentation feedstocks for the cultivation of X. dendrorhous and astaxanthin production. Yeast extract was obtained from residual brewers' yeast using various techniques and then combined with SM to formulate a two-component growth medium which was subsequently used to cultivate X. dendrorhous. Generally, the yeast extract produced from residual brewers' yeast supported X. dendrorhous growth and astaxanthin production at levels comparable to those seen with commercial yeast extract. Overall, cultivating X. dendrorhous in an SM-based medium containing 5% SM and 0.2% yeast extract obtained from residual brewers' yeast resulted in significantly higher (> 20% more) biomass accumulation compared to the control media (YPD). A similar slightly higher astaxanthin output (up to 14% more) was recorded in the SM-based medium compared to YPD. The formulated cultivation medium in this study provides an opportunity to reduce the production cost of astaxanthin from X. dendrorhous while simultaneously reducing the environmental impact related to the disposal of the industrial waste used as feedstock. Key points: • Cheap culture media were formulated from soy molasses and brewers' spent yeast • The formulated medium resulted in at least 20% more biomass than the control • Up to 14% more astaxanthin was produced in molasses-based medium [ABSTRACT FROM AUTHOR]

Epigallocatechin gallate (EGCG), a typical flavone-3-ol polyphenol containing eight free hydroxyl groups, is associated with a variety of bioactivities, such as antioxidant, anti-inflammatory, anti-cancer, and antibacterial activities. However, the poor bioavailability of EGCG restricts its use. In this review, we discuss the processes involved in the absorption and metabolism of EGCG, with a focus on its metabolic interactions with the gut microbiota. Next, we summarize the bioactivities of some key metabolites, describe the biotransformation of EGCG by different microorganisms, and discuss its catabolism by specific bacteria. A deeper understanding of the absorption, metabolism, and biotransformation of EGCG may enable its disease-preventive and therapeutic properties to be better utilized. This review provides a theoretical basis for further development and utilization of EGCG and its metabolites for improving the gut microbiota and physiological health. [ABSTRACT FROM AUTHOR]

Background: Discarded potato is the most abundant potato waste and represents a worldwide disposal problem to the potato industry. This agricultural waste contains valuable nutrients that could be used as substrate to obtain diverse high value-added microbial products, such as biopigments. The aim of this work was to evaluate the use of discarded potato as a sole substrate source for producing blue pigments by Streptomyces lydicus PM7 through submerged fermentation. Results: Initially, the traditional culture medium ISP2 was established as suitable for inoculum preparation, as it allowed high growth rates and consumption of ~ 75% reducing sugar, leading to 1.3 g L−1 dry biomass at 72 h of incubation. The formulated discarded potato broth (DPB) medium was evaluated together with five other traditional liquid culture media (potato dextrose broth, ISP2, ISP3, ISP4, and ISP5) for producing blue pigments by S. lydicus PM7. The highest blue pigment production was obtained by using DPB medium, reaching ~ 0.97 g L−1, followed by ISP5 (~ 0.36 g L−1). In terms of evaluating the concentration of discarded potato powder, the highest concentration of blue pigments was obtained with 16 g L−1, compared to concentrations of 4, 8, and 32 g L−1. In general, a notable increase in total proteins (~ 14 g L−1 in biomass; ~ 8 g L−1 in medium) and reducing sugars (~ 5 g L−1) on the fifth day of DPB fermentation was observed, at which time the production of blue pigments began. These data proved that S. lydicus PM7 is able to degrade potato wastes during submerged fermentation and to direct metabolism towards the formation of biopigments. Chromatographic analysis revealed that the main blue pigment produced by new strain in this complex medium is actinorhodin. Conclusions: Discarded potato favored the production of blue pigments by S. lydicus PM7 under submerged fermentation, leading to final product concentration almost three times higher than others traditional Streptomyces culture media. To the best of our knowledge, this is the first report on the production of actinorhodin by the specie S. lydicus, as well as on this pigment synthesis based on an agricultural waste as a sole nutrient source for fermentation process. The findings showed that potato waste could be a potential byproduct for replacement of commercial culture media using for this same purpose. [ABSTRACT FROM AUTHOR]

Background: Over the last two decades, hybridization has been a powerful tool used to construct superior yeast for brewing and winemaking. Novel hybrids were primarily constructed using at least one Saccharomyces cerevisiae parent. However, little is known about hybrids used for other purposes, such as targeted flavor production, for example, 2-phenylethanol (2-PE). 2-PE, an aromatic compound widely utilised in the food, cosmetic, and pharmaceutical industries, presents challenges in biotechnological production due to its toxic nature. Consequently, to enhance productivity and tolerance to 2-PE, various strategies such as mutagenesis and genetic engineering are extensively explored to improved yeast strains. While biotechnological efforts have predominantly focused on S. cerevisiae for 2-PE production, other Saccharomyces species and their hybrids remain insufficiently described. Results: To address this gap, in this study, we analysed a new interspecies yeast hybrid, II/6, derived from S. uvarum and S. kudriavzevii parents, in terms of 2-PE bioconversion and resistance to its high concentration, comparing it with the parental strains. Two known media for 2-PE biotransformation and three different temperatures were used during this study to determine optimal conditions. In 72 h batch cultures, the II/6 hybrid achieved a maximum of 2.36 ± 0.03 g/L 2-PE, which was 2–20 times higher than the productivity of the parental strains. Our interest lay not only in determining whether the hybrid improved in productivity but also in assessing whether its susceptibility to high 2-PE titers was also mitigated. The results showed that the hybrid exhibited significantly greater resistance to the toxic product than the original strains. Conclusions: The conducted experiments have confirmed that hybridization is a promising method for modifying yeast strains. As a result, both 2-PE production yield and tolerance to its inhibitory effects can be increased. Furthermore, this strategy allows for the acquisition of non-GMO strains, alleviating concerns related to additional legislative requirements or consumer acceptance issues for producers. The findings obtained have the potential to contribute to the development of practical solutions in the future. [ABSTRACT FROM AUTHOR]

Rhododendrons produce a variety of methoxyflavonoids, including rarely found 3-methoxyflavonoids and 5-methoxyflavonoids. It was thus suggested that they have a series of regiospecific flavonoid O-methyltransferases (FOMTs). The 18 Class II O-methyltransferase (OMT) genes were retrieved from the Rhododendron delavayi genome, designating them as RdOMTs. A comprehensive biochemical characterization of RdOMTs was performed to identify functional FOMTs. The FOMT activity of recombinant RdOMTs was assayed with flavonoid substrates of different subclasses. Among the examined RdOMTs, RdOMT3, RdOMT10, and RdOMT12 showed FOMT activity for diverse flavonoids. In particular, RdOMT3 consumed only flavonols as a substrate. Structural analyses of the methylated products demonstrated that RdOMT3, RdOMT10, and RdOMT12 catalyze regiospecific methylation of flavonoids at the 3'/5'-, 3-, and 4'-hydroxyl groups, respectively. Their broad substrate spectrum and different regiospecificity suggest that these RdOMTs contribute to the formation of complex methoxyflavonoids in R. delavayi. Bioconversion of flavonoids using E. coli harboring each RdOMT demonstrated that RdOMT3, RdOMT10, and RdOMT12 are useful tools for the biotechnological production of valuable methoxyflavonoids, including the rarely found 3-methoxyflavonoids. [ABSTRACT FROM AUTHOR]

The freshwater microbiome harbours numerous copiotrophic bacteria that rapidly respond to elevated substrate concentrations. We hypothesized that their high centimetre‐scale beta diversity in lake water translates into pronounced metabolic variability, and that a large fraction of microbial 'metabolic potential' originates from point sources such as fragile organic aggregates. Three experiments were conducted in pre‐alpine Lake Zurich over the course of a harmful cyanobacterial bloom: Spatially explicit 9 ml 'syringe' samples were collected in situ at centimetre distances along with equally sized 'mixed' samples drawn from pre‐homogenized lake water and incubated in BIOLOG EcoPlate substrate arrays. Fewer compounds promoted bacterial growth in the syringe than in the mixed samples, in particular during the pre‐ and late bloom periods. Community analysis of enrichments on three frequently utilized substrates revealed both pronounced heterogeneity and functional redundancy. Bacterial consortia had higher richness in mixed than in syringe samples and differed in composition. Members of the Enterobacter cloacae complex dominated the EcoPlate assemblages during the mid‐bloom period irrespective of treatment or substrate. We conclude that small‐scale functional dispersal limitation among free‐living copiotrophs in lake water reduces local biotransformation potential, and that lacustrine blooms of harmful cyanobacteria can be environmental reservoirs for metabolically versatile potential pathogens. [ABSTRACT FROM AUTHOR]