Current Microbiology最新文献

The production of high-quality Prunus seedling rootstocks in soilless systems requires optimizing the interaction between genetics, nutrient availability, and rhizosphere microbiology. This study evaluated the morphophysiological response of four peach rootstock genotypes ('Capdeboscq', "Okinawa Roxo", "NR0060408", and "NR0160305") to inoculation with Trichoderma asperellum and a microbial consortium (Bacillus amyloliquefaciens + Trichoderma harzianum), under contrasting doses of controlled-release fertilizer (0 and 4 g dm^- 3 of CRF). Longitudinal analysis (0-120 days) demonstrated that nutrient availability is the primary limiting factor; microbial bioinputs did not compensate for the absence of fertilization due to the metabolic cost of symbiosis. However, under nutrient sufficiency (4 g dm^- 3), strong synergism was observed. The new selections ("NR0060408" and "NR0160305") exhibited high phenotypic plasticity, maximizing the conversion of biostimulation into shoot biomass and outperforming the "Okinawa Roxo" genotype, which displayed a conservative growth strategy. The Bacillus-Trichoderma consortium was superior to single inoculation in responsive genotypes, potentiating seedling leaf area and height. Furthermore, inoculation promoted the "stay-green" effect, maintaining chlorophyll index stability until the end of the cycle. It is concluded that the use of bioinputs, especially in a consortium, acts as a metabolic catalyst in responsive genotypes, but their efficacy depends on adequate basal nutritional management.

In recent years, gut microbiota has been recognized to participate in gallstone formation via the gut-liver axis, yet the specific changes and roles of ileal microbiota remain unclear. This study aims to investigate the effects of microbial communities in different digestive tract segments on the formation of gallstones and the underlying mechanisms. Six-week-old C57BL/6J mice were randomly divided into a lithogenic diet group and a normal diet group. Ileal and colonic contents were collected separately for metagenomic sequencing.The Lactobacillus taiwanensis gavage model was constructed to compare its effects on gallstone formation and ileal metabolism. An intraperitoneal injection model of Lipoxin A4 (LXA4) was established to investigate the mechanisms by which Lactobacillus taiwanensis and LXA4 inhibit gallstone through Western blot analysis and ELISA methods. We found that there were significant differences in the intestinal microbiota between the group with gallstone formation and the control group in the small intestine and colon. Species-level analysis indicated that the lithogenic diet reduced the abundance of Lactobacillus taiwanensis in the small intestine. When Lactobacillus taiwanensis was administered intragastrically to mice, the incidence of gallstones decreased. Through metabolomics analysis and experimental verification, we demonstrated that Lactobacillus taiwanensis could down-regulate the expression of NETs in the liver and bile by increasing the level of LXA4, thereby reducing gallstone. The ileal and colonic microbiota exert site-specific effects in gallstone formation. Lactobacillus taiwanensis may inhibit gallstone formation by regulating ileal metabolism, may contribute to prevention and treatment of gallstones.

The gut microbiota of the western honey bee Apis mellifera plays a vital role in host nutrition, digestion, immunity, and overall colony health. Although the functional and enzymatic capabilities of bee-associated microbes are increasingly recognized, studies integrating culture-dependent screening with metagenomic functional profiling remain scarce. This study characterizes the gut bacterial communities of forager and hive bees from the Indian subcontinent using cultivation, 16S rRNA gene sequencing, enzyme assays, and metagenomic analysis. A total of 165 isolates were obtained, yielding 85 unique strains deposited in GenBank. Metagenomic assembly generated 7.78 million non-redundant genes, including 11,050 KEGG-annotated and 2.43 million CAZy-annotated genes. Forager bees showed pronounced enrichment of carbohydrate-processing pathways such as glycolysis/gluconeogenesis (22.9%), galactose metabolism (4.42%), starch and sucrose metabolism, and ABC transporters (9.80%), consistent with their nectar- and pollen-rich diet. Culture-based biochemical assays revealed substantial enzymatic diversity among isolates belonging to Bacillus, Enterobacter, Serratia, Cedecea, Clostridium, Lysinibacillus, and Aneurinibacillus. High invertase activities were recorded in Xanthomonas sp. HAmf44 (2.509 U/mg), Clostridium argentinense HAmf20 (2.470 U/mg), Lysinibacillus fusiformis HAmh15 (2.509 U/mg), and Bacillus paralicheniformis HAmh05 (2.333 U/mg). Strong lipolytic activities were observed in Cedecea davisae HAmf19 (6.062 U/mg), Pseudomonas aeruginosa HAmh21 (5.927 U/mg), and Enterobacter cloacae HAmf26 (3.349 U/mg). Significant variation among isolates (p = 0.001) underscored the functional diversity of the gut microbiota. Integrating KEGG orthologs with species abundance revealed that dominant taxa-including Gilliamella, Snodgrassella, Lactobacillus, and Bifidobacterium-drive key metabolic pathways. Overall, this study provides the first combined enzymatic and metagenomic assessment of A. mellifera gut microbiota from India and identifies high-performing strains with probiotic potential to enhance honey bee nutrition and colony productivity.

Tunnel excavation generates large amounts of oligotrophic waste slag, posing ecological and environmental challenges. Enhancing its fertility is critical for sustainable utilization. This study evaluated a fertilization strategy combining phosphate-solubilizing bacteria (PSB), Bacillus subtilis 2 C (NCBI GenBank accession no. PX700567), with a reduced phosphorus fertilizer rate in oligotrophic tunnel waste slag. Lolium multiflorum Lam. was consecutively cultivated for three years with four treatments: sufficient phosphorus fertilizer (PF), reduced phosphorus plus PSB (PSBF), PSB alone, and a control without amendments. Plant growth and nutrient dynamics were monitored, while bacterial communities and phosphorus-related functional genes (phoD and gcd) were analyzed using high-throughput sequencing and quantitative PCR, respectively. Results showed that both PF and PSBF treatments significantly improved plant biomass compared with the control, and fresh weight under PSBF exceeded PF by the third year. Available phosphorus in slag increased with consecutive plantings, reaching the highest level under PSBF, despite overall declines in total nitrogen and phosphorus. Bacterial community analysis revealed that available phosphorus and total phosphorus were the main drivers of community composition. The abundance of phoD was strongly and positively correlated with AP (R² = 0.92, P < 0.01), while gcd abundance correlated with total nitrogen. Taxa such as Bacteroidota, Cyanobacteria, and the genus Devosia were closely associated with phosphorus transformation. These findings demonstrate that halving phosphorus fertilizer input combined with PSB inoculation sustains plant growth and enhances phosphorus availability through bacterially mediated processes. This strategy offers a practical approach for improving the ecological function of tunnel waste slag while reducing fertilizer dependence.

Two Gram-stain positive, motile, aerobic, yellowish rod-shaped bacterial strains sgz301303 and sgz301304^T were isolated from the paddy soils. The 16S rRNA gene phylogenetic analysis revealed that both strains belong to the genus Sphingobium, and exhibited the highest sequence similarity (98.3%) with reference strain Sphingobium amiense JCM 11777^T. The draft genome of sgz301304^T has a size of 4.3 Mbp, with DNA G + C content of 64.5%. Whole-genome relatedness analyses showed that the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain sgz301304^T and S. amiense JCM 11777^T were 82.3% and 25.7%, respectively, both below the accepted species delineation thresholds. The main quinone was Q-10, and the main fatty acids included C_14:0 2-OH (11.3%), and Summed Features 8 (46.6%). Phylogenetic, genomic and phenotypic analyses suggest that strain sgz301304^T belongs to a novel species within the genus of Sphingobium. Therefore, it is recommended to be named as Sphingobium agrisoil sp. nov. The type strain is sgz301304^T (= MCCC 1K09180^T = JCM 37704^T), respectively.