Journal of microbiology and biotechnology最新文献

The purpose of this study was to evaluate the safety and efficacy of fecal microbiota transplantation in patients with constipation due to parkinson's disease. Gut dysbiosis has long been associated with parkinson's and recent studies have shown that FMT can restore the normal flora of the gut. Therefore, this clinical trial aimed to test the therapeutic efficacy of FMT in 5 patients aged 55 to 71 diagnosed with PD who presented with constipation. The study was conducted as an open label, prospective trial and consisted of FMT performed every 3 days via nasojejunal tube placement followed by 8 weeks of patient follow-up to evaluate response to drug therapy and to assess neurological function using UPDRS-III OFF scores, and improvement in constipation assessed with Wexner scores. Samples taken before and after FMT were collected for shotgun metagenomic sequencing to analyze the composition of the microbial communities present in patients. Untargeted non-targeted metabolomic studies were performed to investigate the impact of FMT on metabolome changes due to FMT. The results indicate an improvement in constipation and neurological functioning following FMT, and significant alteration of the gut microbiota. Significant increases in Bifidobacteria bifidus, Alistipes shahi, Anaerotruncus coli, and uncharacterized Flavonifractor were found post-treatment compared to the baseline. Many of the other strains present prior to treatment, including Acinetobacter sp. and Proteobacteria sp., had significantly decreased after the FMT. The metabolomic studies found shifts in metabolic pathways involved with unsaturated fatty acid synthesis and amino acid metabolism due to FMT. FMT may be an effective treatment option for constipation and neurological symptoms associated with PD.

Several Lactobacillus strains isolated from fermented food are expected to possess digestion supporting function as potential probiotics. However, the safety of Lactobacillus as functional food and its stability until consumption are often overlooked. To prevent potential side effects and maximize probiotic efficacy, it is essential not only to demonstrate the beneficial properties of candidate strain but also verify their safety and stability through a stepwise method. In this study, Lactobacillus strains were isolated from various fermented food and sequentially evaluated for safety, stability, and probiotic properties with a focus on digestive activity. First, five safety tests were conducted in accordance with WHO/FAO guidelines-antibiotic minimum inhibitory concentrations (MICs), hemolytic activity, bile salt hydrolase (BSH) activity, D-/L-lactate production, and cytotoxicity based on lactate dehydrogenase (LDH) released from human epithelial cells. Next, four stability tests were performed, including tolerance to heat, oxygen, and gastric acid/bile salts. In addition, adhesion ability to intestinal epithelial cells was examined as an indicator of colonization potential. Finally, probiotic properties related to assistance of digestion-lipase activity, protease activity, lactose and xylan utilization ability—were evaluated. Through this three-step evaluation, Lacticaseibacillus paracasei JL32-5 was proven to be a safe and stable probiotic resource supporting digestion of lipid, protein, lactose, and non-digestible carbohydrate therefore enhancing human wellness.

Streptococcus iniae is a gram-positive, spherical- or ovoid-shaped, facultative anaerobic bacterium and is one of the major species causing streptococcosis, resulting in economic losses in aquaculture. Endolysins, peptidoglycan hydrolases produced by bacteriophages, are emerging as replacements for antibiotics due to their specific lytic activity against pathogens. This study aimed to develop a novel endolysin, SinLys1930, that specifically targets and kills S. iniae. The molecular and structural characteristics of SinLys1930 were predicted based on bioinformatic approaches. The lytic activity of SinLys1930 was evaluated against S. iniae KCTC 3657 under various conditions, including different dosages, pH levels, temperatures, NaCl concentrations, and metal ions, to identify the optimal conditions, and its effectiveness was further tested in sterilized seawater. The conserved domain analysis revealed that SinLys1930 possesses two enzymatically active domains (NlpC/P60 and glucosaminidase superfamilies) with two cell wall-binding domains (CW-7 superfamily) positioned between them. The lytic activity of SinLys1930 was highest at pH 6.0 to 6.5 and temperatures between 16 and 37°C, and it was maintained even under high NaCl concentration. SinLys1930 reduced the optical density of S. iniae in sterilized seawater by approximately 60% after incubation for 1 h. Therefore, SinLys1930 could potentially serve as an alternative to antibiotics for preventing streptococcosis caused by S. iniae in the aquaculture industry.

This study investigated the bone-protective effects of Maillard reaction products (MRPs) from isolated soy protein and their fermentation product (MRPF) using Lacticaseibacillus rhamnosus IM18. In lipopolysaccharide-induced RAW264.7 cells, MRP showed enhanced antioxidant and anti-inflammatory activities compared to isolated soy protein, which were further improved by MRPF. In ovariectomized mice and RANKL-stimulated RAW264.7 cells, MRPF demonstrated superior anti-osteoclastogenic and bone-protective effects by suppressing osteoclast differentiation and preventing bone resorption. These effects involved downregulation of pro-inflammatory cytokines (Tnfa, Il1b, Il6, and Tnfs11) and upregulation of osteoprotegerin (Tnfrsf11b), along with restoration of intestinal barrier genes (Ocln, Cldn1, and Tjp1). MRPF administration significantly modulated gut microbiota, reducing inflammation-associated taxa (Desulfovibrio) while enriching beneficial genera (Bifidobacterium, Ruminococcus, and Akkermansia). Peptide profiling identified 28 bioactive peptides contributing to observed effects. These findings indicate that MRPF alleviates inflammation and maintains gut homeostasis, supporting its potential as a functional food ingredient for postmenopausal osteoporosis.

This study investigated the protective effects of the ethanolic extract of Eisenia bicyclis (EB) against chronic pulmonary toxicity induced by particulate matter (PM_2.5) exposure in mice. EB contains phlorotannins, including dieckol and phlorofucofuroeckol A, sulfated polysaccharides, and lipid and amino acid derivatives. Male BALB/c mice were exposed to aerosolized PM_2.5 for 5 h daily over a repeated-dose period, and EB was administered orally. The administration of EB significantly ameliorated PM_2.5-induced lung damage by restoring antioxidant defense systems and decreasing serum levels of inflammatory cytokines. EB also suppressed mitochondrial dysfunction and apoptotic signaling. Furthermore, EB attenuated the expression of inflammatory markers, including TLR4, TNF-α, IL-1β, and COX-2, and attenuated the activation of fibrotic signaling pathways via the TGF-β/Smad axis. In vitro experiments using A549 cells further supported these findings, demonstrating that EB and its phlorotannin components (dieckol, 6,6'-bieckol, and 6,8'-bieckol) restored cell viability, reduced inflammatory cytokines, and modulated the Nrf2/HO-1 pathway together with fibrotic genes and proteins. These findings suggest that EB, which contains bioactive compounds, may be a promising functional material candidate for mitigating chronic lung injury caused by environmental toxicants such as PM_2.5.

Selenium is an essential micronutrient in aquaculture, with its efficacy and safety strongly dependent on the chemical form used for supplementation. In this study, we systematically compared the effects of three selenium sources-sodium selenite (SS), selenium-enriched Bacillus licheniformis fermentation broth (BlSe), and selenium-enriched Saccharomyces cerevisiae fermentation broth (ScSe)-on the growth performance and physiological parameters of largemouth bass (Micropterus salmoides). The SS group exhibited a survival rate of 90%, whereas both the BlSe and ScSe groups achieved 100% survival. Compared with the control, the ScSe group showed a significant increase in weight gain rate. In contrast, the BlSe group displayed markedly reduced serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phospholipase (ALP). All selenium-supplemented groups demonstrated substantially enhanced muscle selenium content-by 326% (SS), 455% (BlSe), and 88% (ScSe)-together with elevated activities of hepatic glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD), and reduced malondialdehyde (MDA) content. Intestinal microbiota analysis revealed a shift from Firmicutes dominance (50%) in the control to Proteobacteria dominance (60%) across all treatment groups at the phylum level. At the genus level, Mycoplasma was predominant in the control and BlSe groups (~20% abundance), while Sphingomonas and Chloroplast were enriched in the SS and ScSe groups, respectively. Moreover, KEGG pathway analysis indicated upregulation of taurine and hypotaurine metabolism, biosynthesis of unsaturated fatty acids, and fatty acid biosynthesis in all selenium-treated groups. These findings underscore the potential of B. licheniformis-derived nano-selenium as a highly effective selenium source for sustainable aquaculture.

Cannabis sativa L. has a long history of use and contains more than 80 cannabinoids. However, although cannabigerol (CBG), which acts as a biosynthetic precursor of its most abundant phytocannabinoids, has anti-inflammatory effects, the exact mechanism of action remains underexplored. In this study, we explored the anti-inflammatory potential of CBG to assess its potential for therapeutic and industrial applications. CBG was extracted from the cannabis cultivar 'Pink Pepper' In vitro assays were performed via RAW 264.7 mouse macrophages stimulated with lipopolysaccharide, and in vivo efficacy was evaluated through a carrageenan-induced paw edema mouse model to confirm the activity of CBG in acute inflammation. Nitric oxide production, mRNA, and protein expression of inflammatory mediators were suppressed by CBG treatment in a process downregulated through the MAPK and NF-κB pathways. Although paw edema was not statistically significantly reduced, oral administration of CBG suppressed the expression of COX-2, iNOS, TNF-α, IL-1β, and IL-6 in the carrageenan-induced mouse model. CBG has been demonstrated to exert significant anti-inflammatory effects via modulation of key inflammatory mediators and signaling pathways in both in vivo and in vitro models. Our findings further support the potential of CBG as a bioactive compound for further anti-inflammatory research.

In yeast, the mating pheromone α-factor triggers a signaling cascade in haploid "a" cells, leading to G1 cell cycle arrest, polarized growth ("shmoo" formation), cell wall remodeling, and ultimately cell fusion. While the physiological responses to α-factor are well established, a genome-wide analysis of transcriptional changes in response to α-factor has not been previously reported. Here, we performed RNA sequencing (RNA-seq) to profile gene expression changes in "a" mating type yeast cells treated with α-factor. We identified 957 differentially expressed genes (DEGs), including 448 upregulated and 509 downregulated genes. Gene ontology (GO) analysis revealed enrichment of upregulated genes in pheromone signaling, cell wall biogenesis, and cell shape regulation. In contrast, downregulated genes were mainly associated with cell cycle progression, chromatin remodeling, histone gene expression, and nucleosome organization. Our dataset validates known pheromone-responsive genes and identifies novel candidates potentially involved in mating responses. These findings provide a valuable resource for understanding how transcriptional regulation and chromatin dynamics are coordinated during pheromone signaling in yeast.

Gastritis is a common inflammatory gastrointestinal disease affecting approximately 40% of the global population. Alcohol abuse is a major contributor to gastritis, primarily acting through gastric mucosal injury and inflammation. Given the association between alcohol consumption and severe gastrointestinal complications, safe and effective strategies for the prevention and treatment of gastritis are urgently needed. This study investigated the pathophysiological effects of ethanol (EtOH) on gastric tissues using an EtOH-HCl-treated acute gastritis mouse model, EtOH-treated AGS gastric epithelial cells, and LPS-treated RAW 264.7 macrophages. We found that EtOH induces acute gastritis by damaging the gastric mucosa, elevating oxidative stress, and disrupting mitochondrial function. We identified Isochlorogenic acid C (ICAC) as a promising therapeutic candidate to counteract these detrimental effects. In the mouse model, oral administration of ICAC significantly alleviated acute gastritis by preserving mucosal integrity, preventing prostaglandin E₂ depletion, and enhancing Ptgs1 and Muc6 expression in mice, while suppressing inflammatory mediator production in gastric tissues. Mechanistically, ICAC's preventive effects in human cells manifested through PTGS1 upregulation and the inhibition of inflammatory pathways in AGS cells. Interestingly, ICAC mitigated mitochondrial dysfunction by modulating calcium-mediated mitochondrial fission, reducing mitochondrial reactive oxygen species production, stabilizing mitochondrial membrane potential, and maintaining mitochondrial morphology. Furthermore, the ethanol extract of Artemisia argyi, which is composed primarily of ICAC, exhibited comparable protective effects. These findings highlight the detrimental impacts of alcohol on gastric health and identify ICAC as a potential nutraceutical agent for the prevention and treatment of acute gastritis.

Strain HK10^T, previously isolated from saltern sediment and identified as a salternamides-producing bacterium, was taxonomically characterized in the present study. The strain is a Gram-stain-positive, aerobic, and filamentous actinobacterium. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HK10^T belongs to the genus Streptomyces and is most closely related to Streptomyces radiopugnans R97^T (99.4% sequence similarity), followed by other Streptomyces species with sequence similarities of ≤98.9%. The draft genome sequence of strain HK10^T was 6.69 Mbp and a DNA G+C content of 72.7%. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain HK10^T and type strains of the genus Streptomyces were ≤92.7% and ≤53.0%, respectively, which are below the thresholds for species delineation, indicating that strain HK10^T represents a novel species. The major cellular fatty acids were iso-C_16:0, anteiso-C_15:0, anteiso-C_17:0, and iso-C_14:0. The predominant menaquinone was menaquinone-9 (MK-9). The polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol dimannoside. Whole-cell hydrolysates of strain HK10^T contained _L,L-diaminopimelic acid and glycine. Based on phylogenetic, genomic, chemotaxonomic, and physiological evidence, strain HK10^T is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces shinuiensis sp. nov. is proposed. The type of strain is HK10^T (= NBRC 114904^T = KACC 22137^T).