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.
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.
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.
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.
Two types of thioesterases are commonly found in natural product biosynthetic clusters: type I thioesterases, which release the final product from the biosynthetic complex, and type II thioesterases, which ensure biosynthetic fidelity by editing aberrant acyl carrier protein intermediates. In this study, we analyzed the structure and kinetic feature of SgnI, a type II thioesterase from the modular polyketide synthase natamycin biosynthetic cluster. Steady-state kinetic results revealed that SgnI preferentially hydrolyzes malonyl-CoA, with kcat/Km values that are 17.7-fold, 5.08-fold, and 1.30-fold higher compared to those for ethylmalonyl-CoA, acetyl-CoA, and methylmalonyl-CoA, respectively. This confirms that SgnI functions as an editing thioesterase. Furthermore, SgnI was shown to hydrolyze malonyl units from the phosphopantetheine arm of various acyl carrier domains. Structural modeling of SgnI revealed a wedge-shaped hydrophobic substrate-binding cleft, which restricts substrate size. To elucidate the molecular mechanisms underlying SgnI’s substrate specificity, molecular dynamics simulations were conducted on the SgnI-malonyl-CoA and SgnI-ethylmalonyl-CoA complexes. The smaller active site pocket of the SgnI-malonyl-CoA complex, coupled with enhanced interactions between active site residues and malonyl-CoA, likely contributes to its higher catalytic efficiency in hydrolyzing malonyl-CoA. These findings advance our understanding of thioesterase specificity and pave the way for engineering trans-acting thioesterases for use in biosynthetic assembly lines.
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.
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.
Sophorolipids (SLs), a class of glycolipid biosurfactants, are naturally synthesized by Starmerella bombicola. Composed of sophorose and fatty acids, SLs exhibit excellent emulsification, reduced surface tension, low toxicity, and high biodegradability, making them promising for applications in food, detergent, and agricultural industries. In this study, we screened a S. bombicola capable of efficiently and stably synthesizing SLs through multiple rounds of rejuvenation as the wild-type strain. First, we knocked out PXA1, a gene critical for fatty acid β-oxidation (a competing pathway for SLs production). This weakened β-oxidation and generated the P1 strain. The SLs titer of the P1 strain reached 66.96 ± 4.29 g/L, representing a 50.5% increase compared to the wild-type strain (48.11 ± 3.50 g/L). Subsequently, by enhancing the expression of CYP52M1, a key enzyme in the fatty acid ω-oxidation pathway, we constructed the PC1 strain, which achieved an SLs titer of 88.50 ± 4.91 g/L, a 98.8% improvement over the wild-type strain. Finally, we scaled up the fermentation of the PC1 strain in a 5 L fermenter, and through fed-batch fermentation, the SLs titer reached 232.27 ± 13.83 g/L on the 7th day. This study shows that engineered S. bombicola strains can efficiently produce high SLs titers, making large-scale biosynthesis feasible.