The large-scale emissions of CO₂ have led to a continuous rise in its concentration in the atmosphere, resulting in serious environmental and ecological problems, such as the greenhouse effect and climate change. As a result, there has been a significant increase in interest in theories, technologies, and methods related to CO₂ capture, conversion, and utilization, especially in achieving “carbon neutrality.” Among various carbon capture and utilization strategies, the biological process is an attractive option for converting CO₂ to valuable chemicals and fuels, offering remarkable reaction selectivity, efficiency, and mild reaction conditions. This review article reviewed and summarized various strategies for the biological conversion of CO₂. Specifically, more emphasis was given to in vitro enzymatic systems and microbial electrocatalytic system. We briefly introduced the background of biological CO₂ capture and utilization. Following this, the advancements in CO₂ reduction through the catalysis of single and multi-enzyme cascades were reviewed. We highlighted various approaches to improve the stability and activity of enzymes and develop cost-effective and sustainable reaction systems. Furthermore, the progress and application of microbial electrocatalytic CO₂ reduction were discussed. Finally, future developments and a perspective on biological CO₂ conversion are envisioned.

3D printing (3DP) has emerged as a promising strategy for the rapid, flexible, and cost-effective fabrication of innovative microbial reactor components like engineered living materials (ELMs). Traditional microbial synthesis for CO₂ reduction, such as microbial photosynthesis, microbial electrochemical technologies (MET), and enzyme immobilization, face significant challenges, primarily due to low production yields and higher costs relative to conventional fossil fuel-based methods. 3D printing-assisted microbial synthesis provides an innovative way to overcome these limitations. This review presents a concise overview of current applications of 3DP in microbial fields, with an emphasis on ELMs designed to enhance the stability of bioactive agents and improve mass transfer through optimized 3D architectures. The applications of 3DP in microbial synthesis systems aimed at carbon neutrality are systematically examined, including the fabrication of printed ELMs and other functional reactor components, as well as their potential to advance mechanistic understanding and optimize bioreactor design. By evaluating existing applications, this review identifies key challenges and outlines directions for future improvement. We call for intensified research efforts to broaden the adoption of 3DP in microbial synthesis technologies, thereby advancing their industrial scalability and supporting global carbon neutrality objectives.

Methanol is a one-carbon compound that has emerged as a promising carbon source for microbial bioproduction due to its abundance and sustainability. Despite the development of synthetic methylotrophic cell factories, challenges, such as the accumulation of toxic intermediates and suboptimal growth rates, have hindered their industrial application. This review summarizes the engineering strategies for methylotrophic cell factory synthesis, including pathway engineering for methanol assimilation optimization, detoxification methods targeting formaldehyde accumulation, and optimization of cell resource utilization. Future challenges and prospects of advancing microbial methanol assimilation in biotechnological applications are also highlighted.

Fruit wine is an alcoholic beverage made from fruit through processes such as fermentation and ageing. It comes in a wide variety of types and styles. The flavour of fruit wine is a critical indicator of its quality. The aroma characteristics of fruit wine have been found to be significantly correlated with the composition and concentration of aromatic compounds present. Findings demonstrate that properly balanced aromatic substances contribute to better organoleptic qualities, enhanced product standards, and increased market appeal of fruit wines. Therefore, we should adopt appropriate methods to increase the content of aromatic compounds in fruit wine, thereby enhancing its popularity. This paper reviews several strategies for enhancing the aroma of fruit wine from various perspectives, including the selection of brewing materials, the regulation of microbial metabolism, the use of enzymes, the optimisation of the fermentation process, and the application of genetic engineering. It provides a reference for improving the flavour quality of fruit wine in the future.

Sprouted seeds are attracting growing interest because of their improved digestibility, high nutritional value, variety, low cost and ease of production. However, their microbiological fragility and elevated levels of certain anti-nutritional factors can sometimes pose problems for their use in both food and feed. Recent research has shown that combining fermentation with germination can effectively solve these problems. Fermentation not only improves nutritional value by lowering levels of anti-nutritional factors, but also improves microbiological safety, making it a promising approach to extending shelf life. Additionally, fermented sprouted seeds have beneficial properties may be of use in the formulation of functional foods, particularly for managing metabolic diseases such as diabetes. Despite these positive points, there is still room for improvement in the fermentation of sprouted seeds. This literature review explores current knowledge of seed germination, the advantages of fermenting sprouted seeds, and discusses the disadvantages and potential axes for improvement.

Rare sugars such as L-fucose, L-rhamnose, and D-altrose possess diverse biological activities and increasing industrial relevance in pharmaceuticals, food, and biomaterials. Microbial exopolysaccharides (EPS) are a renewable and structurally diverse source of these sugars; however, their natural abundance in EPS is often limited. Emerging evidence shows that environmental stress—such as osmotic pressure, pH variation, nutrient limitation, and temperature shifts—can significantly alter EPS composition and promote the incorporation of rare sugars. This review provides a comprehensive overview of the occurrence and biological significance of these uncommon monosaccharides in bacterial polysaccharides. It highlights the influence of environmental stress on microbial metabolism and EPS structure, with emphasis on stress-induced changes in gene expression, sugar nucleotide biosynthesis, and glycosyltransferase regulation. Biotechnological strategies, including stress-optimized fermentation, co-culture systems, metabolic engineering, and synthetic biology, are also discussed as tools to enhance the biosynthesis and incorporation of structurally distinct sugar residues into the polysaccharide matrix. By integrating insights from microbial physiology, metabolic control, and process engineering, this review underscores the potential of environmental stress as a sustainable and versatile approach for producing rare sugar-enriched EPS. Future research opportunities and current knowledge gaps are also addressed, with a focus on systems-level understanding and translational applications.

Methanosarcina mazei is a metabolically versatile methanogenic archaeon that extends far beyond its classical role in methane production. Recent advances in genomics, proteomics, and systems biology have revealed a rich repertoire of unique genetic, enzymatic, and regulatory elements that make M. mazei a powerful chassis for biotechnological and biomedical applications. With a genome of~4.1 Mbp and exceptional substrate flexibility, including acetate, methanol, methylamines, and H₂/CO₂, M. mazei demonstrates superior tolerance to salinity, ammonia, and organic acids, enabling its dominance in stressed anaerobic ecosystems. Emerging genetic engineering tools, including CRISPR-Cas systems, inducible promoters, and codon expansion via pyrrolysyl-tRNA synthetases, have opened new avenues for metabolic engineering, enzyme design, and synthetic biology. Notably, M. mazei supports sustainable bioplastic production, heavy metal bioremediation, and degradation of toxic pollutants under anoxic conditions. In biomedicine, its orthogonal translation system enables the precise incorporation of non-canonical amino acids, supporting applications in protein labeling, prodrug design and DNA repair. Furthermore, their involvement in the human microbiome, particularly in gut disorders and colorectal cancer, has sparked interest in their diagnostic and therapeutic potentials. This review summarizes the current knowledge of its unique biological features, engineered toolkits, and translational applications, establishing it as a next-generation model organism for systems biotechnology and archaeal synthetic biology.

As a representative one-carbon compound, methanol has emerged as an ideal alternative substrate for biomanufacturing applications, owing to its abundant availability and low production cost. However, the challenge faced by heterotrophic microbial cells in utilizing methanol to synthesize chemicals is the insufficient energy driving force. Here, a light-driven ATP supply system was constructed to enhance the efficiency of malate production using methanol as a substrate in E. coli. Firstly, a methanol-utilizing malate biosynthesis pathway was constructed in E. coli, resulting in strain ZY-1 with malate production and methanol consumption reaching 9.79 g/L and 15.21 mM, respectively. Then, a light-driven ATP supply system was constructed through intracellular synthesis of MgP molecules, and the ATP supply efficiency was further optimized by co-expression of genes nadD and ubiV, resulting in a 49.80% increase in the intracellular ATP content of strain ZY-5. Finally, light-driven methanol utilization for malate production was achieved by developing iLCRC strategy, resulting in malate production and methanol consumption of strain ZY-5 reaching 17.18 g/L and 68.55 mM, respectively. This light-driven ATP supply system offers novel insights into improving the future resource utilization of one-carbon compounds.

As a naturally occurring substance derived from plants, β-farnesene represents a significant volatile sesquiterpene with potential applications in the fields of pest control and pharmaceutical intermediates. Nevertheless, the trace and transient production of farnesene from plants imposes limitations on its utilisation. Cyanobacteria, the sole oxygenic photosynthetic bacteria, are optimal chassis cells for farnesene synthesis from CO₂. In order to achieve efficient and sustained release of β-farnesene, a synthetic pathway based on the endogenous methylerythritol phosphate (MEP) pathway was designed and created in a fast-growing Synechocystis sp. PCC 6803, which is high-light-tolerant and was recently found (named as HL6803). The β-farnesene synthase gene (AaFS) and isopentenyl diphosphate isomerase gene (AaIDI) from Artemisia annua were introduced into the cyanobacterial strain HL6803 for β-farnesene production. A combination of basic engineering strategies resulted in a β-farnesene productivity of up to 2.0±0.4 mg/L/day. This is the highest productivity reported using similar engineering strategies. This work contributes to the engineering cyanobacteria for farnesene production from CO₂, as well as providing a novel fast-growing Synechocystis strain for the production of useful chemicals from CO₂.

This study investigates the biochemical and metabolomic changes in hot-water extract of Elaeocarpus sylvestris var. ellipticus (HES) fermented with Lactobacillus kimchicus (LK) and Lactobacillus plantarum (LP). The fermentation process led to significant alterations in the chemical composition and metabolomic profile of HES, resulting in enhanced antioxidant, anti-inflammatory, and anticancer properties. Antioxidant activity was notably improved, as demonstrated by increased DPPH and ABTS radical scavenging activities. This suggests that lactic acid bacteria (LAB) fermentation produced bioactive compounds such as polyphenols and organic acids. Fermentation of HES with either LK (LK-HES) or LP (LP-HES) effectively reduced the expression of pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor- α (TNF-α), indicating potential anti-inflammatory effects through the modulation of the nuclear factor kappa B (NF-κB) signaling pathway. Cytotoxicity assays demonstrated selective cytotoxicity of both LK-HES and LP-HES, particularly against cancer cells, highlighting their therapeutic potential. Metabolomic analysis showed significant changes in carboxylic acids, amino acids, and organooxygen compounds during fermentation, reflecting the dynamic biochemical transformations induced by LAB. These findings suggest that LAB fermentation enhances the bioactivity of HES, making it a promising functional ingredient for antioxidant, anti-inflammatory, and anticancer applications.

Ethyl carbamate (EC) is an endogenous pollutant in traditional fermented foods and has potential carcinogenicity. In this work, a yeast capable of degrading EC was screened from the microecology of Zhimaxiangxing baijiu (ZB). The strain, which exhibited excellent fermentation performance and strong resistance to acids and ethanol, was identified as Pichia manshurica and named Pichia manshurica AHXJ-p4 by homologous alignment analysis of its ITS gene sequence. Then its optimised solid-state fermentation (SSF) culture conditions were determined as follows: the addition ratio of wheat bran to corn meal ranged from 4.6:0.9 to 4.8:0.7 (w/w), the water content was 55% (w/w), the inoculation amount was 10% (v/v), and the pH was 5.0. This study expanded the research on the application of yeast in baijiu brewing and provided a theoretical basis for establishing a production process for Fuqu with an EC-reducing function. Furthermore, this work is significant for enhancing the quality of the baijiu industry and controlling food safety.

The difference of flavor substances is one of the important factors affecting the quality of liquor. Climate factors affect the composition of microbiota in liquor fermentation, and then affect the composition of flavor substances. Therefore, it is of great significance to analyze the differences of flavor substance-producing microbiota in four seasons of Chinese liquor fermentation. In this study, the seasonal differences of microbiota and flavor substances during the fermentation of Qingke liquor were investigated, and the difference of flavor substance-producing microbiota were analyzed. Lactobacillus, Saccharomycopsis, Wikcerhamaomyces and Saccharomyces were the dominant microbial genera. Phenylethyl alcohol, 3-methyl-1-butanol, 2-methyl-1-propanol, ethyl acetate, linoleic acid ethyl ester, ethyl palmitate and diethyl succinate were the dominant flavor substances. ANOSIM analysis indicated that both microbiota and flavor substances were significantly different (P<0.01) across four seasons. Based on the Spearman correlation analysis, Weissella, Lactococcus, Bacillus, Lactobacillus, Pichia, Saccharomycopsis, Saccharomyces and Mucor were the main differential flavor substance-producing microbiota. Source Tracker analysis showed that the total contributions of environmental microbiota on differential flavor substance-producing microbiota in fermented grains across four seasons were 23.81% (spring), 62.10% (summer), 83.75% (autumn) and 44.65% (winter), respectively. Besides, environmental microbiota played an extremely crucial role in the flavor substance-producing microbiota succession during liquor fermentation.

Dehydroepiandrosterone (DHEA), a pivotal steroid hormone precursor, holds significant clinical and industrial value for its role in hormone synthesis. Traditional chemical and chemo-enzymatic production methods face challenges such as complex processes, low yields, and environmental concerns. This study presents a green, all-enzymatic route for the synthesis of DHEA from 4-androstene-3,17-dione (4-AD) using engineered molecular machines. By leveraging SpyCatcher-SpyTag and cohesin-dockerin interactions, we constructed dual- and triple-enzyme complexes to spatially organize 3β-ketosteroid isomerase, carbonyl reductase, and formate dehydrogenase. The dual-enzyme system achieved an 84% conversion rate for 10 g/L 4-AD, while the triple-enzyme complex further enhanced conversion to 90% (10 g/L) and 98% (2.5 g/L). This strategy overcomes the instability of the intermediate 5-androstene-3,17-dione (5-AD) through enzyme proximity, and eliminate chemical reactions. This work establishes a sustainable, highly efficient biocatalytic synthesis of DHEA, offering a novel strategy for challenging steroidal transformations and advancing green pharmaceutical manufacturing.

The human intestinal symbiotic microorganism Bacteroides thetaiotaomicron has a unique lipooligosaccharide structure, which promotes its beneficial symbiosis with the host. But its synthesis mechanism is not fully understood. In this study, protein sequence alignment revealed that the protein encoded by B. thetaiotaomicron VPI 5482 BT_2747 gene shares 24% sequence identity with Escherichia coli WaaA. The expression vector was used to overexpress BT_2747 in E. coli lipopolysaccharide mutant strains constructed by knocking out the waaC-waaF, lpxL or lpxM genes, resulting in the recombinant strains WH001(ΔwaaA)/pBT2747, WL003(ΔwaaAwaaC-F)/pBT2747, WL004(ΔwaaAwaaC-FlpxL)/pBT2747, WL005(ΔwaaAwaaC-FlpxM)/pBT2747 and WL006(ΔwaaAwaaC-FlpxLlpxM)/pBT2747. Lipid A/Kdo-lipid A were extracted from these recombinant strains and analyzed by liquid chromatography-mass spectrometry. The results showed that BT_2747 could convert a portion of the lipid IV_A into Kdo-lipid IV_A, but no Kdo₂-lipid IV_A structure was detected in E. coli. Small amounts of hexa-acylated Kdo-lipid A were also detected in the recombinant strains WH001/pBT2747 and WL003/pBT2747, and a small amount of penta-acylated Kdo-lipid A was found in WL004/pBT2747. The recombinant strain was further modified by introducing lpxF that enabled to synthesize Kdo-lipid IV_A-1-phosphate. The results revealed that the BT_2747 gene in B. thetaiotaomicron VPI 5482 encodes the Kdo transferase of lipid A which uses lipid IV_A as a substrate and only transfers single Kdo residue to lipid IV_A. This study extends our understanding of the Kdo-lipid A structure and synthesis mechanism of B. thetaiotaomicron, which might provide a new perspective on how intestinal commensal bacteria regulate host immune homeostasis through unique Kdo-lipid A structure.

Lactic acid (LA) is an important building block for high added value polymers with technological and biomedical applications, such as 3d printing filaments, surgical sutures or food packaging. The traditional manufacture of these materials uses harmful organic solvents, metallic catalysts and high temperatures. The current trend in green chemistry demands a cleaner and more sustainable process. In this research, the esterification reaction of low-cost racemic LA was explored in a reusable biphasic water/heptane system at low temperature (30 ºC). The chosen catalyst was Candida antarctica lipase B (CALB), in the free and immobilized form. The functional groups of the recovered solid products were identified by DRIFTS spectroscopy. The commercial immobilized CALB (Novozym435^®) did not return any solid product under the explored conditions and significant leaching of the enzyme was observed by UV-Vis spectroscopy. On the other hand, the commercial CALB broth produced variable amounts of solid product in the water/heptane interphase with conversions (X) in the range of 2–47%, measured by HPLC. The highest product recovery was reached at 24 h when conversion of LA achieved 37%. After that time the reaction went backwards. The LA polycondensation products were mostly water-soluble oligomers. The results suggest that CALB can start a new chain with either R or S-LA, but is stereoselective towards the R-LA for the chain growth. Additional experimental difficulties arose from the lipase broth’s excipients like sorbitol and glycerol which interfere in the esterification reaction. The outcomes presented herein provide a new starting point for LA polycondensation.

This study aimed to attain high PHB yield using alkaline-pretreated hemp as a feedstock for microbial fermentation by optimizing key process parameters, including pretreatment and fermentation conditions. Hemp was pretreated with 1% sodium hydroxide at 130 °C for 1 h, which enhanced hydrolysis efficiency with the least resource consumption compared to among various other pretreatment conditions tested (NaOH concentrations of 1–2%, temperatures of 130–170 °C, and durations of 30–120 min), ultimately yielding recovery of 97.9% glucose and 99.8% xylose. During batch fermentation, nitrogen and phosphorus concentrations were optimized to enhance cell growth and sugar consumption rates, while 50 mM phosphate buffer was used to maintain pH stability. To improve PHB production, we investigated monocultures and co-cultures of Cupriavidus necator and Paraburkholderia sacchari. C. necator, which primarily utilizes glucose, achieved a maximum PHB yield of 0.433 g/g sugars (productivity of 0.258 g/l/h) at 48 h, whereas P. sacchari, capable of metabolizing both glucose and xylose, exhibited a lower yield. However, their co-culture demonstrated synergistic effects, improving xylose utilization compared to a monoculture of C. necator and increasing PHB yield to 0.341 g/g sugars (productivity of 0.196 g/l/h) compared to a monoculture of P. sacchari. Overall, higher PHB yields were achieved in hydrolysates than in control conditions, demonstrating the effectiveness of process optimization in improving PHB production from lignocellulosic biomass.

Discovery and identification of robust biodetoxification strain is crucial for the sustainable and efficient operation of lignocellulosic biorefining process. Paecilomyces variotii FN89, a recently isolated mesophilic filamentous fungi, was herein shown to be able to biodegrade lignocellulose-derived inhibitors including furfural (1.5 g/L), 5-hydroxymethylfurfural (4 g/L), acetic acid (4 g/L), hydroxybenzaldehyde (0.2 g/L), syringaldehyde (0.2 g/L), and vanillin (1.5 g/L) efficiently and completely. P. variotii FN89 was adapted to mixed inhibitors and relatively low dissolved oxygen conditions, which can detoxify both the highly viscosity hydrolysate and solid biomass with the well preserve of fermentable sugars and no addition of any nutrients. Two biorefinery chains involving biodetoxification process were thus established to cope with different forms of pretreated biomass for cellulosic lactic acid production. The cellulosic lactic acid titers were above 100 g/L from 25% (w/w) solids loading pretreated wheat straw. The global transcriptome analysis of P. variotii FN89 in the presence of mixed inhibitors suggested that the glycolysis pathway and pentose phosphate pathway were repressed while tricarboxylic acid cycle was enhanced, ensuring the complete degradation of the inhibitors-derived intermediates and efficient energy supply. This study provided a unique and practical biodetoxification strain for lignocellulosic biorefinery, as well as enriched the knowledge of the molecular basis of lignocellulose-derived inhibitors tolerance and carbohydrates metabolism of P. variotii.

This study provides the first comprehensive analysis of antibiotic resistance & genomic characterization of Staphylococcus saprophyticus isolated from Southern Ocean. Antibiotic susceptibility profiling of S. saprophyticus revealed complete resistance to Cefixime, Norfloxacin, Azithromycin, and Metronidazole, while susceptibility was observed for Ampicillin, Doxycycline, Tetracycline, Ciprofloxacin, and Co-trimoxazole. Whole-genome sequencing and comparative genomics analysis with 21 closely related strains identified antimicrobial resistance (AMR) genes viz a viz vanY (in the vanM cluster), sdrM, sepA, norC, salE, fusD, and fosBx1. Among these, vanY exhibited the highest prevalence, followed by sdrM and sepA. Study also showed varying AMR gene distributions, with some strains harboring all seven resistance genes. The presence of antibiotic-resistant S. saprophyticus in the Southern Ocean highlights the potential anthropogenic influence on microbial communities leading to AMR among native microbial communities and highlights the urgent need for further studies on AMR in remote marine environments and its mitigation strategies. The study enhances understanding of the global dissemination of AMR by investigating S. saprophyticus in one of the pristine and isolated ecosystems on Earth. Our findings demonstrates that even remote environments are not immune to the spread of AMR. Furthermore, the study provides crucial insights into resistance mechanisms and the identification of resistance genes in a non-clinical, extreme environment puts light on microbial adaptability, and ecological resilience in response to environmental stressors.

Microbial fermentation is one of the primary approaches for inosinic acid (IMP) production. However, most IMP-producing strains are non-model organisms, which limits the application of genetic engineering for further strain improvement. Additionally, these strains require expensive substrates as feedstock, increasing production costs. In this study, we engineered Escherichia coli, a well-characterized model microorganism, as the chassis for IMP biosynthesis from glucose by systematically optimizing its metabolic network. First, we reprogrammed the metabolic flux of the pentose phosphate pathway to increase the intracellular availability of phosphoribosyl pyrophosphate (PRPP), a key precursor of IMP, achieving an IMP titer of 484.6 mg/L. Then, the alleviation of feedback inhibition in the purine biosynthetic pathway increased the IMP titer to 562.0 mg/L. Furthermore, by identifying the rate-limiting steps in the purine synthesis pathway and knocking out competing pathways for IMP synthesis, we further increased the IMP titer to 1409.6 mg/L. Finally, by enhancing the supply of cofactor N₁₀-formyl-tetrahydrofolate, the titer of IMP reached 2.1 g/L in shake-flasks and 3.1 g/L in 5-L bioreactors. This study provides new insights for the construction of cell factories for the synthesis of nucleotide derivatives.

Promoters are crucial expression elements in synthetic biology, and Bacillus licheniformis serves as an excellent chassis cell for industrial production. However, the diversity and quantity of available promoter elements remain particularly limited. Existing promoters are categorized into constitutive and carbon source-inducible types, both exhibiting deficiencies in transcriptional strength and diversity of environmental signal responsiveness. As essential nutrients for microbial growth comparable to carbon sources, nitrogen sources hold significance. The development of nitrogen source-responsive promoters is vital for enriching synthetic biology toolkits and enhancing chassis cell performance. This study initially predicted nitrogen-responsive promoter elements through genomic analysis. Using enhanced green fluorescent protein (egfp) as a reporter gene, transcriptional initiation characteristics were evaluated. Results demonstrated that PglnR and Pgcv promoters could initiate transcription in response to sodium glutamate, with transcriptional intensities 200% and 100% higher than the control group at 36 h. Subsequently, these screened promoters (PglnR and Pgcv) were employed to mediate the expression of transglutaminase gene from Streptomyces mobaraensis. Under optimized conditions (37 °C, 10 g/L soluble starch, and 10 g/L glutamine), recombinant strains exhibited enhanced secretory expression. The maximum extracellular enzyme activity reached 2.61 U/mL. In fed-batch fermentation using a 5-L glass fermentor, the BL-TG3 recombinant strain achieved peak enzyme activity of 14.7 U/mL. The discovery, characterization, and application of novel nitrogen-responsive promoters establish a foundation for optimizing B. licheniformis expression systems.