Search

Stainless steel mesh (SSM) is a cost-effective, readily available catalyst and conductive substrate for large-scale hydrogen production in microbial electrolysis cells (MEC). This study reveals that variations in wire diameter and aperture size of SSM affect both the electroactive area for hydrogen evolution reaction (HER) and the formation and diffusion of hydrogen micro-nano bubbles, impacting MEC performance. In-situ hydrogen microbubble observation shows that 60-mesh SSM provides optimal hydrogen evolution due to its large electrochemical active area and many nucleation sites, minimizing the "bubble shielding effect". The SSM-60 MEC achieves the highest hydrogen recovery (75 ± 5.1%) and energy recovery efficiency (85 ± 6.2%). This study combines electroactivity testing with microscopic in-situ reaction observation to provide a novel strategy for understanding efficient hydrogen evolution catalysts. [Display omitted] • HER activity of SSM with varying mesh numbers in neutral media was investigated. • In-situ observation analyzed effects of SSM mesh number on H 2 bubble formation. • Smaller bubbles and quick detachment improved hydrogen evolution efficiency. • SSM-60 MEC achieved highest hydrogen recovery and energy recovery efficiency. [ABSTRACT FROM AUTHOR]

Propanethiol oxidoreductase (PTO) is a novel thiol-oxidizing enzyme from Pseudomonas putida S-1 that utilizes thiols as the sole nutrition source. This enzyme has shown application potential in the bioremediation of thiols, its substrate selectivity, however, has not yet been elucidated. This study reveals that PTO exhibits catalytic activity towards ethanethiol, propanethiol, and butanethiol, but not methanethiol or phenylmethanethiol, indicating unique substrate specificity. Through directed evolution and semi-rational design, we engineered a PTO mutant (A54V&G316T) with twice the specific activity towards propanethiol than the wild type (from 17.3 to 40.7 μg/mg/h). Applying voltage in electrode bioreactors enhanced the microbial degradation of propanethiol, with the mutant PTO further accelerating this process. Both non-native expression in E. coli and native expression in engineered P. putida S-1 demonstrated the mutant PTO's effectiveness in increasing PT removal rates. The PT degradation efficiency of engineered P. putida S-1 increases by 3-fold compared to the wild-type in the first 5 hours. These findings highlight the potential of combining metabolic and electrochemical engineering to enhance bioremediation of toxic compounds. The engineered PTO mutant improves PT degradation efficiency and broadens its application in practical bioremediation strategies. [Display omitted] • Propanethiol oxidoreductase oxidizes ethanethiol, propanethiol, and butanethiol. • A propanethiol oxidoreductase mutant showed increased activity to propanethiol. • The mutant included two amino acid changes and named as A54V&G316T. • The bacteria with mutant (A54V&G316T) showed enhanced propanethiol degradation. • Applying voltage in bioreactor enhances microbial propanethiol degradation. [ABSTRACT FROM AUTHOR]

Myricitrin is a member of flavonols, natural phenolic compounds extracted from plant resources. It has gained great attention for various biological activities, such as anti-inflammatory, anti-cancer, anti-diabetic, as well as cardio-/neuro-/hepatoprotective activities. These effects have been demonstrated in both in vitro and in vivo models, making myricitrin a favorable candidate for the exploitation of novel functional foods with potential protective or preventive effects against diseases. This review summarized the health benefits of myricitrin and attempted to uncover its action mechanism, expecting to provide a theoretical basis for their application. Despite enormous bioactive potential of myricitrin, low production, high cost, and environmental damage caused by extracting it from plant resources greatly constrain its practical application. Fortunately, innovative, green, and sustainable extraction techniques are emerging to extract myricitrin, which function as alternatives to conventional techniques. Additionally, biosynthesis based on synthetic biology plays an essential role in industrial-scale manufacturing, which has not been reported for myricitrin exclusively. The construction of microbial cell factories is absolutely an appealing and competitive option to produce myricitrin in large-scale manufacturing. Consequently, state-of-the-art green extraction techniques and trends in biosynthesis were reviewed and discussed to endow an innovative perspective for the large-scale production of myricitrin. [ABSTRACT FROM AUTHOR]

This investigation probes the role of the electron mediator, neutral red (NR), in the electrosynthesis process, specifically examining its effect on the production of succinic acid by Actinobacillus succinogenes. Our findings reveal that NR, when integrated into the cell membrane, is pivotal for sustaining MEC efficiency. Nevertheless, it is susceptible to both intrinsic and MECs-induced degradation. Notably, during the exponential growth phase of the bacteria, NR is readily incorporated into the cell membrane. However, the supplemental addition of NR fails to significantly enhance the MEC's capacity for succinic acid synthesis, no matter what stage of bacterial growth. And significant depletion of membrane-associated NR is not adequately compensated by the NR present in the fermentation liquid. The ORP feedback-regulated MECs adeptly conserve the NR on the cell membrane, which is essential for maintaining the efficiency of long-term electrosynthesis. The presence of NR on the cell membrane is essential for the functionality of MECs, yet its external replenishment hard. Implementing precise electro-potential regulation strategies can effectively diminish the degradation of NR, thus maintaining the system's efficiency. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, glycerol, glycosyl, and tetraethyleneglycol monomethyl ether group substituted BODIPY compounds were successfully synthesized and characterized. The antioxidant, antidiabetic, antibiofilm, microbial cell viability, antimicrobial, antimicrobial photodynamic therapy, and DNA cleavage abilities of the BODIPY derivates were also tested. The highest antioxidant activity at 100 mg/L was 87.12% for BODIPY‐1, 85.61% for BODIPY‐2, and 92.78% for BODIPY‐3. The most effective inhibition of microbial cell viability was obtained for these BODIPY molecules at 100% at 50 and 100 mg/L. It was also observed that these BODIPY molecules exhibited excellent biofilm inhibition activities. The derivates were found to exhibit higher antibiofilm abilities against Staphylococcus aureus compared to Pseudomonas aeruginosa. When the antidiabetic effects of water‐soluble BODIPY compounds were examined, the highest effect was found to be 64.40% for BODIPY‐1 at 200 mg/L. [ABSTRACT FROM AUTHOR]

Background: In microbial cell factories, substrate accessibility to enzyme is a key factor affecting the biosynthesis of natural products. As a robust chassis cells for biofuels and bioproducts, Saccharomyces cerevisiae also encounters the challenge since different enzymes and precursors are typically compartmentalized in different organelles. Such spatial separation could largely limit the efficiency of enzymatic reactions. In this study, the production of the hydrophobic product (vitamin A) was highly improved by metabolic engineering combined with degrading lipid droplets (the primary organelle storing β-carotene) to achieve efficient contact between β-carotene and 15, 15'-β-carotene monooxygenases in Saccharomyces cerevisiae. Results: To efficiently produce vitamin A in Saccharomyces cerevisiae, ten 15, 15'-β-carotene monooxygenases (BCMOs) were firstly evaluated. The strain carrying marine bacterium 66A03 (Mb. BCMO) achieved the highest vitamin A titer. Co-adding 10% dodecane and 1% dibutylhydroxytoluene increased vitamin A titer to 19.03 mg/L in two-phase fermentation. Since most β-carotene is stored in LDs while BCMO is located in the cytosol, we developed a strategy to release β-carotene from LDs to better contact with BCMO. By overexpressing TGL3 and TGL4 using an ion-responsive promoter after high accumulation of β-carotene in LDs, LDs were sequentially degraded, which dramatically improved vitamin A production. Finally, by overexpressing tHMG1, ERG20, and CrtI and introducing Vitreoscilla hemoglobin, vitamin A titer reached 219.27 mg/L, which was a 10.52-folds increase over the original strain in shake flasks, and finally reached 1100.83 mg/L in fed-batch fermentation. The effectiveness of LDs degradation on promoting the formation of β-carotene cleaved product has also been verified in β-ionone synthesis with 44.07% increased yield. Conclusions: Overall, our results highlighted the significance of sequential degrading LDs on vitamin A overproduction in recombinant yeast, and verified that combining metabolic and LDs engineering is an efficient strategy to improve vitamin A production. This integrated strategy can be applied to the overproduction of other hydrophobic compounds with similar characteristics. [ABSTRACT FROM AUTHOR]

Ginseng, a cornerstone of traditional herbal medicine in Asia, garnered significant attention for its therapeutic potential. Central to its pharmacological effects are ginsenosides, the primary active metabolites, many of which fall within the dammarane-type and share protopanaxadiol as a common precursor. Challenges in extracting protopanaxadiol and ginsenosides from ginseng arise due to their low concentrations in the roots. Emerging solutions involve leveraging microbial cell factories employing genetically engineered yeasts. Here, we optimized the fermentation conditions via the Design of Experiment, realizing 1.2 g/L protopanaxadiol in simple shake flask cultivations. Extrapolating the optimized setup to complex ginsenosides, like compound K, achieved 7.3-fold (0.22 g/L) titer improvements. Our adaptable fermentation conditions enable the production of high-value products, such as sustainable triterpenoids synthesis. Through synthetic biology, microbial engineering, and formulation studies, we pave the way for a scalable and sustainable production of bioactive compounds from ginseng. [Display omitted] • Cultivation optimization to increase protopanaxadiol production above 1.2 g/L in a shake flask by engineered yeast. • The M3 medium also supported high production of other triterpenoids (lupeol-type and dammarane-type) by engineered yeasts. • The simple cultivation fosters clone screening and small-scale synthesis, paving the way for triterpenoids biosynthesis. [ABSTRACT FROM AUTHOR]

Background: Yeast Saccharomyces cerevisiae is widely recognised as a versatile chassis for constructing microbial cell factories. However, producing chemicals from toxic, highly concentrated, or cell-impermeable substrates, or chemicals dependent on enzymatic reactions incompatible with the yeast's intracellular environment, remains challenging. One such chemical is 2-O-(α-D-glucopyranosyl)-sn-glycerol (glucosyl glycerol, αGG), a natural osmolyte used in the cosmetics and healthcare industries. This compound can be synthesised in a one-enzyme reaction from sucrose and glycerol by Leuconostoc mesenteroides sucrose phosphorylase (SucP), an enzyme which, in a low-water, glycerol-rich, phosphate-free environment, transfers the glucosyl moiety from sucrose to glycerol. Results: In this study, we engineered a yeast microbial cell factory for αGG production. For this purpose, we first focused on the abundant yeast GPI-anchored cell wall protein Ccw12 and used our insights to develop a miniature Ccw12-tag, which adds only 1.1 kDa to the enzyme of interest while enabling its covalent attachment to the cell wall. Next, we Ccw12-tagged SucP and expressed it in an invertase-negative strain of yeast S. cerevisiae from the PHO5 promoter, i.e., promoter strongly induced under phosphate-free conditions. Such SucP isoform, covalently C-terminally anchored to the outer cell surface, produced extracellularly 37.3 g l− 1 (146 mM) of αGG in five days, while the underlying chassis metabolised reaction by-products, thereby simplifying downstream processing. Conclusions: The here-described S. cerevisiae strain, displaying C-terminally anchored sucrose phosphorylase on its cell surface, is the first eukaryotic microbial cell factory capable of a one-step αGG production from the readily available substrates sucrose and glycerol. [ABSTRACT FROM AUTHOR]

Background: The successful production of industrially relevant natural products hinges on two key factors: the cultivation of robust microbial chassis capable of synthesizing the desired compounds, and the availability of reliable genetic tools for expressing target genes. The development of versatile and portable genetic tools offers a streamlined pathway to efficiently produce a variety of compounds in well-established chassis organisms. The σ70lac and tet expression systems – adaptations of the widely used lac and tet regulatory systems developed in our laboratory – have shown effective regulation and robust expression of recombinant proteins in various Gram-negative bacteria. Understanding the strengths and limitations of these regulatory systems in controlling recombinant protein production is essential for progress in this area. Results: To assess their capacity for combinatorial control, both the σ70lac and tet expression systems were combined into a single plasmid and assessed for their performance in producing fluorescent reporters as well as the terpenoids lycopene and β-carotene. We thoroughly characterized the induction range, potential for synergistic effects, and metabolic costs of our dual σ70lac and tet expression system in the well-established microorganisms Escherichia coli, Pseudomonas putida, and Vibrio natriegens using combinations of fluorescent reporters. The dynamic range and basal transcriptional control of the σ70 expression systems were further improved through the incorporation of translational control mechanisms via toehold switches. This improvement was assessed using the highly sensitive luciferase reporter system. The improvement in control afforded by the integration of the toehold switches enabled the accumulation of a biosynthetic intermediate (lycopene) in the β-carotene synthesis pathway. Conclusion: This study presents the development and remaining challenges of a set of versatile genetic tools that are portable across well-established gammaproteobacterial chassis and capable of controlling the expression of multigene biosynthetic pathways. The enhanced σ70 expression systems, combined with toehold switches, facilitate the biosynthesis and study of enzymes, recombinant proteins, and natural products, thus providing a valuable resource for producing a variety of compounds in microbial cell factories. [ABSTRACT FROM AUTHOR]

This study investigates novel zinc and indium phthalocyanines with Schiff base and sulphur moieties, focusing on their potential for cancer therapy and antimicrobial applications. It explores the effectiveness of photochemical and sono-photochemical methods to enhance singlet oxygen production, which is crucial for photodynamic therapy. The synthesized complexes in this study demonstrated high singlet oxygen quantum yields, with D3 (ZnPc) and D4 (InPc) showing ΦΔPDT values of 0.71 and 0.75, and ΦΔSPDT values of 0.91 and 0.94, respectively. Furthermore, the evaluation for biological properties revealed that both D3 and D4 exhibit significant antidiabetic properties, DPPH radical scavenging activity, DNA cleavage, antimicrobial activity, biofilm inhibition, and microbial cell viability impacts, both with and without photodynamic therapy. Notably, D3 and D4 achieved antimicrobial cell viability inhibition rates of 84.67 ± 4.67% and 98.32 ± 5.96%, respectively, showcasing their effectiveness in photodynamic antimicrobial therapy. Overall, the study highlights the potential of these phthalocyanine complexes as advanced photosensitizers, with strong singlet oxygen generation and promising biological activities, paving the way for future therapeutic applications. [ABSTRACT FROM AUTHOR]

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

Despite its high cost, Pt is the usual catalyst for hydrogen production in the cathode of Microbial Electrolysis Cells (MECs). Its effectiveness depends not only on the amount deposited but also on the availability and distribution of Pt nanoparticles on the cathode surface. This work provides a comprehensive study of the effectiveness of the Pt coating with five deposition techniques: spray, electrospray, brush painting, doctor blade and sputtering. The performance of the cathodes was studied with different Pt loadings by monitoring the current intensity and H 2 production in MECs. Furthermore, cathodes were characterized morphologically using scanning electron microscopy together with energy-dispersive X-ray spectroscopy to study their Pt surface distribution and composition. Sputtering was initially discarded due to Pt detachment. When using the same amount of Pt (0.50 mg Pt cm−2), the highest current density was obtained for electrospray (2.0 mA cm−2), followed by spray (1.9 mA cm−2), brush painting (1.6 mA cm−2) and doctor blade (1.2 mA cm−2). Hence, electrospray improved 20 % the results obtained by the default method of brush painting. Electrospray and spray provided better performance because of the direct deposition of Pt on the carbon fibres creating a compact Pt layer on the electrode surface. Furthermore, it was observed that the cell performance decreased significantly with decreasing amount of Pt per cm2, observing the best performance with the highest Pt load tested (0.5 mg Pt cm−2) regardless of the deposition technique. • Different Pt deposition methods were studied to produce MEC cathodes. • Brush painting, doctor blade, electrospray, spray, and sputtering were compared. • The spraying techniques showed the best long.-term performance >2 m3H 2 m−3d−1. • Sputtering led to Pt detachment and to a failure in the long-term operation. • MEC performance relies on Pt amount and accessibility (on dispersion technique). [ABSTRACT FROM AUTHOR]

Background: Uricase is a bio-drug used to reduce urate accumulation in gout disease. Thus, there is a continuous demand for screening soil samples derived from a variety of different sources in order to isolate a strain that possesses a high potential for producing uricase. Methods: Streptomyces sp. strain NEAE-5 demonstrated a significant capacity for uricase production was identified based on the physiological, morphological and biochemical characteristics, as well as 16S rDNA sequencing analysis. Using a Plackett–Burman statistical design, the impact of eighteen process factors on uricase production by Streptomyces griseorubens strain NEAE-5 was investigated. Using central composite design, the most important variables that had a favourable positive impact on uricase production by Streptomyces griseorubens strain NEAE-5 were further optimized. Results: It is clear that the morphological and chemotaxonomic features of Streptomyces sp. strain NEAE-5 are typical for the Streptomyces genus. Phylogenetic analysis indicated that Streptomyces sp. strain NEAE-5 belongs to the genus Streptomyces and closely related to Streptomyces griseorubens which it has a 95–96% identity in 16S rDNA gene sequencing. Accordingly, the strain is proposed to be identified as Streptomyces griseorubens strain NEAE-5. The three factors that had the significant positive impacts on uricase production were uric acid, hypoxanthine, and yeast extract. As a result, the best conditions for achieving the highest experimental uricase production by Streptomyces griseorubens strain NEAE-5 after central composite design were (g/L): uric acid 6.96, glycerol 5, hypoxanthine 5.51, MgSO4.7H2O 0.1, KNO3 2, CaCl2 0.5, K2HPO4 0.5, NaCl 0.5, yeast extract 1.08. In addition, the period of incubation is seven days, pH 7.5 and 37 °C with an inoculum size of 2 mL (105 cfu/mL) /100 mL medium. Conclusions: After optimization, the obtained uricase activity was 120.35 U/mL, indicating that the Streptomyces griseorubens strain NEAE-5 is a potent uricase producer and that the statistical approach used for optimization was appropriate. [ABSTRACT FROM AUTHOR]

ABSTRACT In this research, the emulsification method was used to encapsulate Lactobacillus reuteri in microparticles of whey protein concentrate (WPC) at different levels (1%, 2%, and 4%) and gum Arabic (GA) at three levels (0/5%, 1%, and 1/5%) and a constant level of sunflower oil (5%). The results showed that emulsions with higher quantities of wall materials exhibited better encapsulation efficiency (67%/57%) and preservation ability at different temperatures, different pH, and presence of 1% bile salt. During the storage time, the droplet size of the emulsion increased more than two times (from 2.2 to 4.6 μm) and the absolute zeta potential of the optimal emulsion decreased (from −19/63 to −16/76 mV). Encapsulating Lactobacillus reuteri in the stabilized emulsion with the highest concentration of wall material improved the cells' protection during storage. The study also observed a decline in the number of primary encapsulated live cells in the gastrointestinal tract (from 4/32 to 3/58 Log CFU/mL) after 90 days of storage. In the case of the nonencapsulated sample, the initial live population decreased from 2.8 to 1 Log CFU/mL after 90 days of storage. The electron microscope images showed that the emulsions became unstable after 30, 60, and 90 days of storage, but the microbial cells were still visible in the continuous phase. Overall, encapsulating Lactobacillus reuteri using emulsification technique can preserve the probiotics during storage and “in vitro” gastrointestinal digestion. [ABSTRACT FROM AUTHOR]

The pathogenic bacterium Campylobacter jejuni is a major food safety concern as it can form biofilms that increase its survival and infective potential. Biofilms consist of microbial cells and extracellular matrix (ECM), which is made of water and extracellular polymeric substances (EPS), which are critical for structural integrity and pathogenicity. The aim of this study was to optimize a protocol for the isolation of C. jejuni ECM. We employed eight physical and chemical isolation methods to extract and purify ECM, followed by different qualitative and quantitative analyses using gel electrophoresis and spectroscopy. This comprehensive approach enabled the evaluation of ECM composition in terms of polysaccharides, proteins, and extracellular DNA. The isolation methods resulted in different yields and purities of the extracted ECM components. Centrifugation in combination with chemical treatments proved to be most effective, isolating higher concentrations of polysaccharides and proteins. Additionally, extraction with ether solution facilitated the recovery of high-molecular-weight extracellular DNA. Overall, we provide a refined methodology for ECM extraction from C. jejuni. As polysaccharides and proteins participate in biofilm stability and microbial communication, and extracellular DNA participates in genetic exchange and virulence, our study contributes towards a better understanding of the persistence of this pathogen in the food industry. [ABSTRACT FROM AUTHOR]

Malonyl‐coenzyme A (CoA) is a key precursor for the biosynthesis of multiple value‐added compounds by microbial cell factories, including polyketides, carboxylic acids, biofuels, and polyhydroxyalkanoates. Owing to its role as a metabolic hub, malonyl‐CoA availability is limited by competition in several essential metabolic pathways. To address this limitation, we modified a genome‐reduced Pseudomonas putida strain to increase acetyl‐CoA carboxylation while limiting malonyl‐CoA utilization. Genes involved in sugar catabolism and its regulation, the tricarboxylic acid (TCA) cycle, and fatty acid biosynthesis were knocked‐out in specific combinations towards increasing the malonyl‐CoA pool. An enzyme‐coupled biosensor, based on the rppA gene, was employed to monitor malonyl‐CoA levels in vivo. RppA is a type III polyketide synthase that converts malonyl‐CoA into flaviolin, a red‐colored polyketide. We isolated strains displaying enhanced malonyl‐CoA availability via a colorimetric screening method based on the RppA‐dependent red pigmentation; direct flaviolin quantification identified four engineered strains had a significant increase in malonyl‐CoA levels. We further modified these strains by adding a non‐canonical pathway that uses malonyl‐CoA as precursor for poly(3‐hydroxybutyrate) biosynthesis. These manipulations led to increased polymer accumulation in the fully engineered strains, validating our general strategy to boost the output of malonyl‐CoA–dependent pathways in P. putida. [ABSTRACT FROM AUTHOR]

Paraprobiotics are inactivated microbial cells that improve the health status of consumers when taken in adequate doses. They can be used instead of probiotics to eliminate disadvantages such as instability in production and storage difficulties. They can also be an alternative nutritional supplement for individuals sensitive to fermented products. In this study, a paraprobiotic supplement obtained from Lactobacillus plantarum was added to a soy dairy‐free beverage at two concentrations of 108 and 109 CFU/mL. Then, total soluble solids, pH, color, titratable acidity, antioxidant activity, and total phenolic content of the beverage were measured, and sensory analysis was also performed. The results indicate that paraprobiotic addition significantly increased (p < 0.05) the antioxidant activity (75.44 ± 0.23 µmol TE/g sample), total phenolic content (834.32 ± 6.69 mg GAE/g), protein (3.28 ± 0.18%), fat (2.35 ± 0.06), and ash content (0.57 ± 0.08). These results were also validated using the Raman spectroscopy technique. The paraprobiotic‐supplemented soy dairy‐free beverage had the highest taste and overall impression values. Since the parabiotic addition did not affect the physicochemical properties of the beverage, manufacturers can develop commercial products containing paraprobiotics without altering the production process. Practical Application: Paraprobiotics provide an alternative for individuals sensitive to fermented products but still desire the health benefits of probiotics. They additionally provide practical and technological advantages, including a longer shelf life without a need for a cold chain to preserve the viability and stability of microorganisms. The results of this study can be a reference for the industry to develop food products containing paraprobiotics with increased antioxidative and nutritional properties. [ABSTRACT FROM AUTHOR]

Heme, an iron-containing tetrapyrrole in hemoproteins, including: hemoglobin, myoglobin, catalase, cytochrome c, and cytochrome P450, plays critical physiological roles in different organisms. Heme-derived chemicals, such as biliverdin, bilirubin, and phycocyanobilin, are known for their antioxidant and anti-inflammatory properties and have shown great potential in fighting viruses and diseases. Therefore, more and more attention has been paid to the biosynthesis of hemoproteins and heme derivatives, which depends on the adequate heme supply in various microbial cell factories. The enhancement of endogenous biosynthesis and exogenous uptake can improve the intracellular heme supply, but the excess free heme is toxic to the cells. Therefore, based on the heme-responsive regulators, several sensitive biosensors were developed to fine-tune the intracellular levels of heme. In this review, recent advances in the: biosynthesis, acquisition, regulation, and upcycling of heme were summarized to provide a solid foundation for the efficient production and application of high-value-added hemoproteins and heme derivatives. [ABSTRACT FROM AUTHOR]

Microbial electrochemical processes are primary platforms for generating electricity or value-added products by relying on the interaction between electroactive microorganisms and electrodes by utilizing electron carriers like hydrogen and enzyme through the oxidation–reduction reactions. Microbial electrosynthesis (MES), initially introduced as electricity-driven bioproduction from CO2, offered a novel pathway to produce biochemicals that eventually contribute to the CO2 sequestration. While most of the previous reviews concentrate on these microbial electrochemical platforms jointly referred to as MXC, such as Microbial fuel cell and microbial electrolysis cell, MES has grown tremendously in recent years, requiring a severe update on the scientific information on this topic. In this mini-review, the significant achievements in MES, specifically towards the production of a wide array of specialty chemicals, have been addressed by summarizing the recent scientific breakthroughs of the MES technology. Furthermore, improving MES's performance through modification of electrodes and membranes and outlook section with the technical challenges and probable solutions have been discussed. The review summarizes the technological drawbacks of the MES's towards a sustainable commercial platform for industrial commodities production and proposes ways to overcome the existing technical challenges in a nutshell towards turning MES in a full-fledged industrial-scale production platform. [ABSTRACT FROM AUTHOR]

Isolating high-performance phenol degradation microorganisms with high salt tolerance and studying their resistance mechanisms are urgent issues. To address these issues, a typical bacteria (Klebsiella sp. YP-1) with high salt and phenol tolerance was isolated. Its strategies for resisting high salt and high phenol stress were studied. The results indicated that Klebsiella sp. YP-1 was able to degrade 1000 mg/L phenol within 44 h at 70 g/L NaCl, which was faster than most microorganisms reported in the literature. Lyxose secreted by Klebsiella sp. YP-1 played an important role on assisting Klebsiella sp. YP-1 to resist stress. Lyxose increased phenol degradation rate by microorganisms due to its protection on cell membrane. Quantum chemical calculation results indicated that lyxose was more likely attacked by free radical than cell membrane. In addition, lyxose could bind to the cell membrane through hydrogen bonds. Thus, lyxose prevented reactive oxygen species from harming cell membranes. Moreover, lyxose has broad protective effect on microbial cell membranes. This study provides a novel idea for microorganisms to resist oxidative stresses. [Display omitted] • A strain of Klebsiella sp. YP1 with high salt-phenol tolerance was isolated. • A novel strategy for Klebsiella sp. to resist stress was presented: secreting lyxose. • Lyxose improves the ability of microbe to degrade high salt-phenol wastewater. • The mechanism of lyxose protecting cell membrane was revealed for the first time. • Lyxose has broad protection effect on microbial cell membranes. [ABSTRACT FROM AUTHOR]

Methicillin-Resistant Staphylococcus aureus forming into biofilms can trigger chronic inflammation and disrupt skin wound healing processes. Prolonged and excessive use of antibiotics can expedite the development of resistance, primarily because of their limited ability to penetrate microbial membranes and biofilms, especially antibiotics with intracellular drug targets. Herein, we devise a strategy in which virus-inspired nanoparticles control the release of antibiotics through rapid penetration into both bacterial cells and biofilms, thereby combating antimicrobial-resistant infections and promoting skin wound healing. Lipid-based nanoparticles based on stearamine and cholesterol were designed to mimic viral highly ordered nanostructures. To mimic the arginine-rich fragments in viral protein transduction domains, the primary amines on the surface of the lipid-based nanoparticles were exchanged by guanidine segments. Levofloxacin, an antibiotic that inhibits DNA replication, was chosen as the model drug to be incorporated into nanoparticles. Hyaluronic acid was coated on the surface of nanoparticles acting as a capping agent to achieve bacterial-specific degradation and guanidine explosion in the bacterial microenvironment. Our virus-inspired nanoparticles displayed long-acting antibacterial effects and powerful biofilm elimination to overcome antimicrobial-resistant infections and promote skin wound healing. This work demonstrates the ability of virus-inspired nanoparticles to achieve a dual penetration of microbial cell membranes and biofilm structures to address antimicrobial-resistant infections and trigger skin wound healing. [Display omitted] • This work demonstrates virus-inspired nanoparticles for solving bacterial infection. • Nanoparticles deeply penetrate microbial membranes and biofilm structures. • Nanoparticles exhibit long-term antimicrobial activity with low resistance risk. • Nanoparticles defeat microbial through a multitarget interference approach. • Nanoparticles accelerate skin wound repair and display excellent biosafety. [ABSTRACT FROM AUTHOR]

The production of bioethanol from lignocellulosic biomass requires the efficient conversion of glucose and xylose to ethanol, a process that depends on the ability of microorganisms to internalize these sugars. Although glucose transporters exist in several species, xylose transporters are less common. Several types of transporters have been identified in diverse microorganisms, including members of the Major Facilitator Superfamily (MFS) and Sugars Will Eventually be Exported Transporter (SWEET) families. Considering that Saccharomyces cerevisiae lacks an effective xylose transport system, engineered yeast strains capable of efficiently consuming this sugar are critical for obtaining high ethanol yields. This article reviews the structure-function relationship of sugar transporters from the MFS and SWEET families. It provides information on several tools and approaches used to identify and characterize them to optimize xylose consumption and, consequently, second-generation ethanol production. [ABSTRACT FROM AUTHOR]

Background: The target of this paper is to improve the performance of the microbial electrolysis cell (MEC). The performance of MEC including bio-hydrogen production and energy recovery is depending on the values of three controlling parameters including buffer concentration, dilution factor, and applied voltage. Problem: Therefore, defining the optimal values of three controlling parameters is the challenge of the work. Methodology: In this paper the artificial gorilla troops optimization has been combined with and ANFIS modelling to increase the bio-hydrogen production from MEC. At first, using measured data, a model is created to simulate the MEC in terms of three controlling parameters. Then, for first time, an artificial gorilla troops optimization (AGTO) has been used to determine the optimal values of buffer concentration, dilution factor, and applied voltage to boost simultaneously bio-hydrogen production and energy recovery of MEC. To demonstrate the superiority of integration between ANFIS modelling and AGTO, the obtained results are compared with RSM methodology, and artificial neural network integrated with particle swarm optimization. Findings: For hydrogen yield model, the RMSE lowered from 67.5 using RSM to 5.562 using ANFIS (decreased by 91.7%) as compared to RSM. The R-square for prediction rises from 0.94 (using RSM) to 0.99 (using ANFIS) by about 5.32%. For the ANFIS model of energy recovery, the RMSE decreased from 31.7 to 2.83 utilising ANFIS, a decrease of 91%. The R-square for prediction rises from 0.95 (using RSM) to 0.986 (using ANFIS) by about 3.8%. Compared with measured data, the integration between ANFIS and AGTO succeed to increase the hydrogen yield from 576.3 mL/g-VS to 843.32 mL/g-VS. in sum, the total performance of the MEC has been increased by 34.74%, 29.9% and 24.38% respectively compared to measured data, RSM and ANN-PSO. [ABSTRACT FROM AUTHOR]

The formation of inclusion bodies (IBs) in microbial cell factories is a very common process occurring during recombinant protein production. Different protocols have been developed for the extraction of soluble proteins from IBs using several strategies, ranging from the use of harsh denaturing and high concentrations of chaotropic agents and reducing agents to the use of mild protocols based on the use of non-denaturing detergents. However, in recent years, the biological vision of IBs has changed and research studies have demonstrated that these protein aggregates contain biologically active and properly folded recombinant proteins. This drives us to redefine the methodologies currently used to obtain soluble protein using IB as a protein source. Hence, we propose the extraction of IB protein via the simple spontaneous solubilization of IB as a strategy broadly applicable to all kinds of recombinant proteins without the negative effects of detergents and chaotropic agents on final biological activity. We prove the wide applicability of spontaneous solubilization processes to different types of IBs and that protocols can be easily customized for each protein in terms of timing and incubation temperature by monitoring the protein activity of the solubilized fraction. [ABSTRACT FROM AUTHOR]

Kefir traditionally is based on pasteurised milk and the use of other substrates is unusual. Kefir beverages made with raw milk (RMK), pasteurised milk (PMK) or whey (WK), were obtained and fractionated in microbial cells and supernatants. Antioxidant and antibacterial activity of fractions against Cronobacter sakazakii and Escherichia coli were analysed. The highest antioxidant activity was obtained for PMK with values between 8500 and 10 000 μm TE/mg. Microbial extracts from RMK and PMK showed a reduction of C. sakazakii of 7 log units; while microbial extracts and supernatants from RMK decreased E. coli in 3 and 5 log units, respectively. These results indicate that dairy kefir beverages can be an excellent source of defensive agents to fight against bacteria that cause gastrointestinal disorders. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Succinic acid (SA) is an important bio-based C4 platform chemical with versatile applications, including the production of 1,4-butanediol, tetrahydrofuran, and γ-butyrolactone. The non-conventional yeast Yarrowia lipolytica has garnered substantial interest as a robust cell factory for SA production at low pH. However, the high concentrations of SA, especially under acidic conditions, can impose significant stress on microbial cells, leading to reduced glucose metabolism viability and compromised production performance. Therefore, it is important to develop Y. lipolytica strains with enhanced SA tolerance for industrial-scale SA production. Results: An SA-tolerant Y. lipolytica strain E501 with improved SA production was obtained through adaptive laboratory evolution (ALE). In a 5-L bioreactor, the evolved strain E501 produced 89.62 g/L SA, representing a 7.2% increase over the starting strain Hi-SA2. Genome resequencing and transcriptome analysis identified a mutation in the 26S proteasome regulatory subunit Rpn1, as well as genes involved in transmembrane transport, which may be associated with enhanced SA tolerance. By further fine-tuning the glycolytic pathway flux, the highest SA titer of 112.54 g/L to date at low pH was achieved, with a yield of 0.67 g/g glucose and a productivity of 2.08 g/L/h. Conclusion: This study provided a robust engineered Y. lipolytica strain capable of efficiently producing SA at low pH, thereby reducing the cost of industrial SA fermentation. [ABSTRACT FROM AUTHOR]

Background: Vaginal infections caused by multidrug-resistant pathogens such as Candida albicans and Gardnerella spp. represent a significant health challenge. Current treatments often fail because of resistance and toxicity. This study aimed to synthesize and characterize a novel amphiphilic polypeptide, KF-5, and evaluate its antibacterial and antifungal activities, biocompatibility, and potential mechanisms of action. Results: The KF-5 peptide was synthesized via solid-phase peptide synthesis and self-assembled into nanostructures with filamentous and hydrogel-like configurations. Characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) confirmed the unique nanostructural properties of KF-5. KF-5 (125, 250, or 500 µg/ml) demonstrated potent antibacterial and antifungal activities, with significant inhibitory effects on drug-resistant Candida albicans and Gardnerella spp. (P < 0.05). In vitro assays revealed that 500 µg/ml KF-5 disrupted microbial cell membranes, increased membrane permeability, and induced lipid oxidation, leading to cell death (P < 0.05). Cytotoxicity tests revealed minimal toxicity in human vaginal epithelial cells, keratinocytes, and macrophages, with over 95% viability at high concentrations. Molecular dynamics simulations indicated that KF-5 interacts with phospholipid bilayers through electrostatic interactions, causing membrane disruption. In vivo studies using a mouse model of vaginal infection revealed that 0.5, 1, and 2 mg/ml KF-5 significantly reduced fungal burden and inflammation, and histological analysis confirmed the restoration of vaginal mucosal integrity (P < 0.01). Compared with conventional antifungal treatments such as miconazole, KF-5 exhibited superior efficacy (P < 0.01). Conclusions: KF-5 demonstrates significant potential as a safe and effective antimicrobial agent for treating vaginal infections. Its ability to disrupt microbial membranes while maintaining biocompatibility with human cells highlights its potential for clinical application. These findings provide a foundation for further development of KF-5 as a therapeutic option for combating drug-resistant infections. [ABSTRACT FROM AUTHOR]

Peptidoglycan (PG), a mesh-like structure which is the primary component of the bacterial cell wall, is crucial to maintain cell integrity and shape. While most bacteria rely on penicillin binding proteins (PBPs) for crosslinking, some species also employ LD-transpeptidases (LDTs). Unlike PBPs, the essentiality and biological functions of LDTs remain largely unclear. The Hyphomicrobiales order of the Alphaproteobacteria, known for their polar growth, have PG which is unusually rich in LD-crosslinks, suggesting that LDTs may play a more significant role in PG synthesis in these bacteria. Here, we investigated LDTs in the plant pathogen Agrobacterium tumefaciens and found that LD-transpeptidation, resulting from at least one of 14 putative LDTs present in this bacterium, is essential for its survival. Notably, a mutant lacking a distinctive group of 7 LDTs which are broadly conserved among the Hyphomicrobiales exhibited reduced LD-crosslinking and tethering of PG to outer membrane β-barrel proteins. Consequently, this mutant suffered severe fitness loss and cell shape rounding, underscoring the critical role played by these Hyphomicrobiales-specific LDTs in maintaining cell wall integrity and promoting elongation. Tn-sequencing screens further revealed non-redundant functions for A. tumefaciens LDTs. Specifically, Hyphomicrobiales-specific LDTs exhibited synthetic genetic interactions with division and cell cycle proteins, and a single LDT from another group. Additionally, our findings demonstrate that strains lacking all LDTs except one displayed distinctive phenotypic profiles and genetic interactions. Collectively, our work emphasizes the critical role of LD-crosslinking in A. tumefaciens cell wall integrity and growth and provides insights into the functional specialization of these crosslinking activities. Author summary: Peptidoglycan (PG) is essential for bacterial cell wall integrity. While most bacteria use penicillin binding proteins (PBPs) for crosslinking, some also employ LD-transpeptidases (LDTs); however, the essentiality and functions of LDTs remain poorly understood. Interestingly, Hyphomicrobiales bacteria have PG rich in LD-crosslinks, suggesting that LDTs play a vital role in maintaining cell wall integrity in these organisms. Our study of Agrobacterium tumefaciens revealed that LD-transpeptidation, mediated by at least one of 14 putative LDTs, is essential for maintaining both viability and morphogenesis. A mutant lacking 7 Hyphomicrobiales-specific LDTs suffered fitness and shape loss due to reduced LD-crosslinking and PG tethering to the outer membrane. Our results provide new insights into LD-transpeptidase specialized functions and conditional essentiality. The conservation of these enzymes across diverse polar-growing species suggests broader implications for understanding microbial cell wall growth and adaptation to environmental stresses. [ABSTRACT FROM AUTHOR]

This review provides a comprehensive examination of strategies aimed at advancing low-temperature electrolysis for sustainable hydrogen production. It begins by exploring the significance and challenges associated with water splitting, followed by an in-depth discussion on the fundamentals of electrochemical water splitting and crucial performance indicators, including reversible hydrogen electrode potential, specific and mass activities, overpotential, Tafel slope, stability and durability, and Faradaic and energy efficiencies. The article then extensively discusses various emerging strategies, such as decoupled water electrolysis, hybrid water electrolysis (including reagent-sacrificing, pollutant-degrading, and value-added types), tandem water electrolysis, microbial electrolysis cells (covering reactor configurations, electrode materials, microbial populations, and substrates), and the application of external stimuli like ultrasonic, magnetic, and super gravity fields. Additionally, the challenges and advancements in seawater electrolysis are reviewed, with a focus on electrocatalysts, seawater electrolyzers, and future directions. Furthermore, the article addresses current challenges in electrolysis and electrolyzer development, offering perspectives on the future of these techniques. By delving into these strategies, this review aims to contribute to the advancement of clean energy technologies and the transition towards a hydrogen-based economy. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (NPs) have become highly promising agents in the field of biomedical science, offering wide therapeutic potential due to their unique physicochemical properties. The unique characteristics of silver NPs, such as their higher surface-area-to-volume ratio, make them ideal for a variety of biological applications. They are easily processed thanks to their large surface area, strong surface plasmon resonance (SPR), stable nature, and multifunctionality. With an emphasis on the mechanisms of action, efficacy, and prospective advantages of silver NPs, this review attempts to give a thorough overview of the numerous biological applications of these particles. The utilization of silver NPs in diagnostics, such as bioimaging and biosensing, as well as their functions in therapeutic interventions such as antimicrobial therapies, cancer therapy, diabetes treatment, bone repair, and wound healing, are investigated. The underlying processes by which silver NPs exercise their effects, such as oxidative stress induction, apoptosis, and microbial cell membrane rupture, are explored. Furthermore, toxicological concerns and regulatory issues are discussed, as well as the present difficulties and restrictions related to the application of silver NPs in medicine. [ABSTRACT FROM AUTHOR]

In this study, new peripherally substituted symmetric zinc and magnesium phthalocyanines (4 and 5) were successfully prepared by cyclotetramerization of the tetrahydropyrimidone (THPM)-linked phthalonitrile 3. The identity of the compounds were confirmed primarily through spectroscopic analysis including NMR, FT-IR, UV-Vis and MALDI-TOF mass spectroscopy. The photophysical and photochemical properties of the synthesized phthalocyanines (Pcs) were examined using UV–Vis absorption and fluorescence emission spectroscopy techniques. The quantum yields of singlet oxygen were found to be 0.50 and 0.33 for compounds 4 and 5 in DMSO, respectively. In addition to photo-physicochemical properties, the enhanced biological activities of compounds 4 and 5 were investigated using a range of biological assays, namely, antibiofilm, microbial cell viability, antioxidant, DNA cleavage, antimicrobial and photodynamic antimicrobial assays. The maximum DPPH inhibition of 4 and 5 was detected as 40.46% and 25.76% at 100 mg L−1, respectively. Fragmentation of the DNA molecule was observed at concentrations of 25 mg L−1, 50 mg L−1 and 100 mg L−1 for 4 and 5. Additionally, effective inhibition of microbial cell viability was observed with the targeted Pcs. The antibiofilm properties of these compounds were found to be concentration-dependent. The biofilm inhibition activities of 4 and 5 were found to be 96.01% and 92.04% for S. aureus, while they were 95.42% and 91.27%, for P. aeruginosa, respectively. The antimicrobial activities of 4 and 5 on different microorganisms were evaluated using the microdilution assay. In the case of photodynamic antimicrobial treatment, the newly synthesized Pcs showed more effective antimicrobial inhibition compared to the control. These findings suggest that compounds 4 and 5 can be used as promising photodynamic antimicrobial agents for the treatment of many diseases, particularly infectious diseases. [ABSTRACT FROM AUTHOR]

Filamentous fungi are well-known for their efficiency in producing valuable molecules of industrial significance, but applications of fungal biomass remain relatively less explored despite its abundant and diverse opportunities in biotechnology. One promising application of mycelial biomass is as a platform to immobilize different cell types such as animal, plant, and microbial cells. Filamentous fungal biomass with little to no treatment is a sustainable biomaterial which can also be food safe compared to other immobilization supports which may otherwise be synthetic or heavily processed. Because of these features, the fungal-cell combination can be tailored towards the targeted application and be applied in a variety of fields from bioremediation to biomedicine. Optimization efforts to improve cell loading on the mycelium has led to advancements both in the applied and basic sciences to understand the inter- and intra-kingdom interactions. This comprehensive review compiles for the first time the current state of the art of the immobilization of animal, yeast, microalgae, bacteria, and plant cells in filamentous fungal supports and presents outlook of applications in intensified fermentations, food and biofuel production, and wastewater treatment. Opportunities for further research and development were identified to include elucidation of the physical, chemical, and biological bases of the immobilization mechanisms and co-culture dynamics; expansion of the cell-fungus combinations investigated; exploration of previously unconsidered applications; and demonstration of scaled-up operations. It is concluded that the potential exists to leverage the unique qualities of filamentous fungus as a cellular support in the creation of novel materials and products in support of the circular bioeconomy. [ABSTRACT FROM AUTHOR]

The production of bioethanol from lignocellulosic biomass requires the efficient conversion of glucose and xylose to ethanol, a process that depends on the ability of microorganisms to internalize these sugars. Although glucose transporters exist in several species, xylose transporters are less common. Several types of transporters have been identified in diverse microorganisms, including members of the Major Facilitator Superfamily (MFS) and Sugars Will Eventually be Exported Transporter (SWEET) families. Considering that Saccharomyces cerevisiae lacks an effective xylose transport system, engineered yeast strains capable of efficiently consuming this sugar are critical for obtaining high ethanol yields. This article reviews the structure–function relationship of sugar transporters from the MFS and SWEET families. It provides information on several tools and approaches used to identify and characterize them to optimize xylose consumption and, consequently, second-generation ethanol production. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Currently, the synthesis of compounds based on microbial cell factories is rapidly advancing, yet it encounters several challenges. During the production process, engineered strains frequently encounter disturbances in the cultivation environment or the impact of their metabolites, such as high temperature, acid-base imbalances, hypertonicity, organic solvents, toxic byproducts, and mechanical damage. These stress factors can constrain the efficiency of microbial fermentation, resulting in slow cell growth, decreased production, significantly increased energy consumption, and other issues that severely limit the application of microbial cell factories. Results: This study demonstrated that sterol engineering in Kluyveromyces marxianus, achieved by overexpressing or deleting the coding genes for the last five steps of ergosterol synthase (Erg2-Erg6), altered the composition and ratio of sterols in its cell membrane, and affected its multiple tolerance. The results suggest that the knockout of the Erg5 can enhance the thermotolerance of K. marxianus, while the overexpression of the Erg4 can improve its acid tolerance. Additionally, engineering strain overexpressed Erg6 improved its tolerance to elevated temperature, hypertonic, and acid. YZB453, obtained by overexpressing Erg6 in an engineering strain with high efficiency in synthesizing xylitol, produced 101.22 g/L xylitol at 45oC and 75.11 g/L xylitol at 46oC. Using corncob hydrolysate for simultaneous saccharification and fermentation (SSF) at 46oC that xylose released from corncob hydrolysate by saccharification with hemicellulase, YZB453 can produce 45.98 g/L of xylitol, saving 53.72% of the cost of hemicellulase compared to 42oC. Conclusions: This study elucidates the mechanism by which K. marxianus acquires resistance to various antifungal drugs, high temperatures, high osmolarity, acidity, and other stressors, through alterations in the composition and ratio of membrane sterols. By employing sterol engineering, the fermentation temperature of this unconventional thermotolerant K. marxianus was further elevated, ultimately providing an efficient platform for synthesizing high-value-added xylitol from biomass via the SSF process at temperatures exceeding 45 °C. [ABSTRACT FROM AUTHOR]

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

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

Yeast can be used to screen chemical libraries of human G protein-coupled receptors (GPCRs) faster and more cost-efficiently than mammalian cell line reporters. Yeast-based biosensors can screen and mate with microbial cell factories, based on relevant product titers, to accelerate the search for high-performance cell factories. Yeast mating correlates with surface-displayed protein–protein interaction strength and can be used to isolate strong binders, while machine learning-assisted protein engineering supports iterative high-quality libraries destined for experimental exploration by surface display on yeast. Engineered yeast systems can decode complex cellular communication, produce signaling modulators, and participate in human immune cell communication. The density of yeast surface-displayed signaling molecules can be GPCR-controlled to robustly target immune cell phenotypes via cell–cell communication. Detailed molecular understanding of the human organism is essential to develop effective therapies. Saccharomyces cerevisiae has been used extensively for acquiring insights into important aspects of human health, such as studying genetics and cell–cell communication, elucidating protein–protein interaction (PPI) networks, and investigating human G protein-coupled receptor (hGPCR) signaling. We highlight recent advances and opportunities of yeast-based technologies for cost-efficient chemical library screening on hGPCRs, accelerated deciphering of PPI networks with mating-based screening and selection, and accurate cell–cell communication with human immune cells. Overall, yeast-based technologies constitute an important platform to support basic understanding and innovative applications towards improving human health. [ABSTRACT FROM AUTHOR]

Microbial biomineralization is a phenomenon involving deposition of inorganic minerals inside or around microbial cells as a direct consequence of biogeochemical cycling. The microbial metabolic processes often create environmental conditions conducive for the precipitation of silicate, carbonate or phosphate, ferrate forms of ubiquitous inorganic ions. Till date the fundamental mechanisms underpinning two of the major types of microbial biomineralization such as, microbially controlled and microbially induced remains poorly understood. While microbially-controlled mineralization (MCM) depends entirely on the genetic makeup of the cell, microbially-induced mineralization (MIM) is dependent on factors such as cell morphology, cell surface structures and extracellular polymeric substances (EPS). In recent years, the organic template-mediated nucleation of inorganic minerals has been considered as an underlying mechanism based on the principles of solid-state bioinorganic chemistry. The present review thus attempts to provide a comprehensive and critical overview on the recent progress in holistic understanding of both MCM and MIM, which involves, organic–inorganic biomolecular interactions that lead to template formation, biomineral nucleation and crystallization. Also, the operation of specific metabolic pathways and molecular operons in directing microbial biomineralization have been discussed. Unravelling these molecular mechanisms of biomineralization can help in the biomimetic synthesis of minerals for potential therapeutic applications, and facilitating the engineering of microorganisms for commercial production of biominerals. [ABSTRACT FROM AUTHOR]

A novel Pseudochrobactrum saccharolyticum strain NBRI-CRB 13, isolated from tannery sludge, was studied to grow up to 500 mgL−1 of Cr(VI) and showed Cr(VI) detoxification by reducing > 90% of Cr(VI) at different concentrations 25, 50 and 100 mgL−1. Kinetic studies showed that first-order models were fitted (R2 = 0.998) to the time-dependent Cr(VI) reduction with degradation rate constant (k) (1.03–0.429 h−1). Cr(VI) detoxification was primarily related to the extracellular fraction of microbial cells, which showed a maximum extracellular reductase enzyme activity led to 94.6% reduction of Cr(VI). Moreover, the strain showed maximum extracellular polymeric substances (EPS) production at 100 mgL−1 Cr(VI), which is presumably the reason for Cr(VI) removal as EPS serves as the metal binding site for Cr(VI) ions. Further, an optimization study using Box-Behnken design was conducted considering parameters viz., pH, temperature, and initial concentration of Cr(VI). The maximum percent reduction of Cr(VI) was obtained at pH 6.5, temperature 30 °C with 62.5 mgL−1Cr(VI) concentration. Further, the Cr(VI) reduction and adsorption ability of strain P. saccharolyticum NBRI-CRB13 were confirmed by SEM–EDS, FTIR, and XRD analyses. FTIR analysis confirmed the presence of functional groups (–OH, –COOH, –PO4) on bacterial cell walls, which were more likely to interact with positively charged chromium ions. The study elucidated the reduction of Cr(VI) by the novel bacterium within 24 h using the response surface methodology approach and advocated its application in real-time situations. [ABSTRACT FROM AUTHOR]

The recent discovery of nanoplastics in most ecosystems is a major, yet poorly known health issue. Here, we review nanoplastics with focus on their presence in the environment, their methods of detection, and their impact on the nitrogen cycle. Nanoplastics are widely distributed in ecosystems; however, their real concentrations are not known due to the limitation of actual detection methods. Detection methods include techniques based on mass spectrometry, optical instruments, and total organic carbon. Total organic carbon-based methods involve first membrane filtration and oxidation as pretreatment, then the measurement of total organic carbon as the total concentration of nanoplastics. Total organic carbon-based methods are easy and cost-effective, compared with other methods. Nanoplastics negatively impact ecosystems and nitrogen removal. Nanoplastics can adsorb on microbial cell membranes then disrupt the membrane integrity. Nanoplastics can also induce oxidative stress. Nitrogen cycling is substantially inhibited by nanoplastics during laboratory tests. [ABSTRACT FROM AUTHOR]

Carotenoids are one of the most studied groups of biologically active compounds. They have antioxidant, anti-inflammatory, anti-cancer, and coloring properties and are particularly interesting for the pharmaceutical, nutraceutical, food, feed, cosmetic, and textile industries. Rapidly growing consumer demand for natural products has led to a significant increase in research and development of opportunities for their production from natural sources. Among the sources of carotenoids of natural origin, various microorganisms are of greater interest. This mini-review briefly summarizes the information published mainly during the last decade about carotenoid-producing microorganisms, the physiological importance of carotenoids for microbial cells, and the possibilities to improve their biosynthesis. This review also describes some new approaches/directions to make biotechnological production of microbial carotenoids more efficient. [ABSTRACT FROM AUTHOR]

In the process of flue gas desulfurization and denitrification, the generation of high-sulfate wastewater containing nitrogen is a significant challenge for biological wastewater treatment. In this study, halophilic activated sludge was inoculated in a Sequencing Batch Reactor to remove nitrogen from wastewater with a high sulfate concentration (60 g/L). With the influent concentration of 180 mg/L, the removal rate of total nitrogen was more than 96.7%. The effluent ammonium nitrogen concentration was lower than 1.94 mg/L, and the effluent nitrate nitrogen and nitrite nitrogen concentrations were even lower than 0.77 mg/L. The salt tolerance of activated sludge is mainly related to the increase in the content of ectoine in microbial cells. The Specific Nitrite Oxidation Rate is quite low, while the Specific Nitrite Reduction Rate and Specific Nitrate Reduction Rate are relatively strong. In the system, there are various nitrogen metabolic processes, including aerobic nitrification, anaerobic denitrification, and simultaneous nitrification–denitrification processes. By analyzing the nitrogen metabolic mechanisms and microbial community structure of the reaction system, dominate bacteria can be identified, such as Azoarcus, Thauera, and Halomonas, which have significant nitrogen removal capabilities. [ABSTRACT FROM AUTHOR]

This review focuses on the physical disruption techniques in extracting intracellular compounds, a critical step that significantly impacts yield and purity. Traditional chemical extraction methods, though long-established, face challenges related to cost and environmental sustainability. In response to these limitations, this paper highlights the growing shift towards physical disruption methods—high-pressure homogenization, ultrasonication, milling, and pulsed electric fields—as promising alternatives. These methods are applicable across various cell types, including bacteria, yeast, and algae. Physical disruption techniques achieve relatively high yields without degrading the bioactivity of the compounds. These techniques, utilizing physical forces to break cell membranes, offer promising extraction efficiency, with reduced environmental impacts, making them attractive options for sustainable and effective intracellular compound extraction. High-pressure homogenization is particularly effective for large-scale extracting of bioactive compounds from cultivated microbial cells. Ultrasonication is well-suited for small to medium-scale applications, especially for extracting heat-sensitive compounds. Milling is advantageous for tough-walled cells, while pulsed electric field offers gentle, non-thermal, and highly selective extraction. This review compares the advantages and limitations of each method, emphasizing its potential for recovering various intracellular compounds. Additionally, it identifies key research challenges that need to be addressed to advance the field of physical extractions. [ABSTRACT FROM AUTHOR]

BACKGROUND: This work studied the treatment of a synthetic sphalerite acid mine drainage (AMD). The treatment was carried out by means of a previous concentration stage using electrodialysis, followed by electrodeposition using a bioelectrochemical system (BES). RESULTS: The best concentration results were obtained when operating the electrodialysis at 8 V and at a diluate/concentrate volume ratio of 3. This treatment yielded a concentrate fraction of about 25% of the volume and a clear fraction of about 75% of the volume. The concentrated fraction was treated in a BES for the electrodeposition of the metal contained. By operating a microbial fuel cell (MFC), the spontaneous reactions took place and, in 2 days, all the Fe3+ was reduced to Fe2+; then, all the Cu2+ was electrodeposited as pure Cu0 in about 8 days. The maximum current density attained in this stage was 0.1 mA cm−2 and the maximum power was 0.05 W cm−2. Then, a subsequent operation of a microbial electrolysis cell (MEC) allowed for the simultaneous recovery of the Fe2+, Ni2+, Zn2+, and Cd2+ as a mixed metal mass. CONCLUSION: The electrodialysis yielded a clear effluent representing 75% of the total volume and a concentrated effluent accounting for 25%. It was possible to treat the concentrated effluent in an MFC, recovering pure Cu0 with a net electricity generation. The non‐spontaneous metal reductions were subsequently accomplished by means of MEC, the electricity requirements being lower than those in the case of the raw AMD due to the higher mass transfer rate and the reduction of the Ohmic loses. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Despite their relatively short lifespan, neutrophils are tasked with counteracting pathogens through various functions, including phagocytosis, production of reactive oxygen species, neutrophil extracellular traps (NETs), and host defense peptides. Regarding the latter, small cationic cathelicidins present a conundrum in neutrophil function. Although primarily recognized as microbicides with an ability to provoke pores in microbial cell walls, the ability of cathelicidin to modulate key neutrophil functions is also of great importance, including the release of chemoattractants, cytokines, and reactive oxygen species, plus prolonging neutrophil lifespan. Cumulative evidence indicates a less recognized role of cathelicidin as an "immunomodulator"; however, this term is not always explicit, and its relevance in neutrophil responses during infection and inflammation is seldom discussed. This review compiles and discusses studies of how neutrophils use cathelicidin to respond to infections, while also acknowledging immunomodulatory aspects of cathelicidin through potential crosstalk between sources of the peptide. [ABSTRACT FROM AUTHOR]

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]

Inaccessibility and expensiveness of vital infrastructures are the main problems in some urban and rural areas to supply fresh water, sustainable energy, and wastewater treatment. An effective solution is the integration of several systems in an environmentally friendly technology of the photosynthetic microbial desalination cell (PMDC). The aim of this study is to assess the process characterisation of an algae-based PMDC, which was loaded with a high-strength mixture of human feces and urine (HFS). The PMDC was also able to efficiently remove COD and total nitrogen of HFS by 50% and 94%, respectively. The maximum power density, voltage, and desalination efficiency of 362.5 mW/m², 175.2 mV, and 60% were accomplished. Adequate parameter adjustment led to a remarkable maximum of 2.25 g/L.d in the ion removal rate. In addition, an energy balance was governed showing that zero or positive net energy in PMDC is feasible by replacing the main energy consumers. Based on the results, this type of MDC had a high efficiency for simultaneous saline water desalination and HFS treatment, which makes it attractive for further studies of upscaling and its application in remote areas. [ABSTRACT FROM AUTHOR]

Holobionts are highly organized assemblages of eukaryotic hosts, cellular microbial symbionts, and viruses, whose interactions and evolution involve complex biological processes. It is largely unknown which specific determinants drive similarity or individuality in genetic diversity between holobionts. Here, we combine short- and long-read sequencing and DNA-proximity-linkage technologies to investigate intraspecific diversity of the microbiomes, including host-resolved viruses, in individuals of a model marine sponge. We find strong impacts of the sponge host and the cellular hosts of viruses on strain-level organization of the holobiont, whereas substantial overlap in nucleotide diversity between holobionts suggests frequent exchanges of microbial cells and viruses at intrastrain level in the local sponge population. Immune-evasive arms races likely restricted virus-host co-evolution at the intrastrain level, generated holobiont-specific genome variations, and linked virus-host genetics through recombination. Our work shows that a decoupling of strain- and intrastrain-level interactions is a key factor in the genetic diversification of holobionts. Marine host-associated microbiomes retain a tremendous pool of genetic diversity, which is key to the health of marine ecosystems. This study on reef sponges shows that genomic diversification of individual microbiomes follows different rules at strain- and intrastrain-levels. [ABSTRACT FROM AUTHOR]