It is demonstrated that Bacillus subtilis Y61 promoted the growth of Weissella paramesenteroides (CWP) through cross-feeding via the extracellular secretion of the key metabolites arginine and isovaleric acid.
Abstract
Elucidating the interactions among microbial communities in the Sichuan paocai fermentation system is of great significance for ensuring the safety and quality of paocai. In this study, the interaction between Bacillus subtilis Y61 and Weissella paramesenteroides (CWP) was preliminarily verified through the culture of CWP using the cell-free supernatant derived from Y61. Building on this, a transwell chamber was employed to spatially isolate the two bacteria. Combined with transcriptomic and metabolomic profiling, the underlying interaction mechanism was revealed. Weissella paramesenteroides (CWP) exhibited enhanced growth in the cell-free supernatant of Bacillus subtilis Y61, confirming a cross-feeding relationship between the two strains. In the transwell chamber, the promoting effect was most significant when Weissella paramesenteroides (CWP) was in the upper compartment and Bacillus subtilis Y61 in the lower compartment. Transcriptomic analysis showed that Weissella paramesenteroides (CWP) significantly upregulated genes involved in fatty acid synthesis and metabolism while downregulating those related to amino acid anabolism (p < 0.05). Metabolomic analysis further revealed that metabolites secreted by Bacillus subtilis Y61, including the key metabolites arginine and isovaleric acid, were markedly depleted during co-culture. Exogenous supplementation assays revealed that the combination of 0.1 g arginine and 2 mg isovaleric acid exhibited the strongest growth-promoting effect on Weissella paramesenteroides (CWP). Collectively, these results demonstrated that Bacillus subtilis Y61 promoted the growth of Weissella paramesenteroides (CWP) through cross-feeding via the extracellular secretion of the key metabolites arginine and isovaleric acid.
New insights are provided into the physiological role of azurin in environmental bacteria and its involvement in bacterium–eukaryote interactions is suggested, thereby opening new perspectives for biotechnological and biomedical applications.
The results suggest that facing continuously increased environmental stress over time, GHZJ-1 undergoes global transcriptional reprogramming and resource reallocation, downregulating basal metabolism to construct a synergistic antagonistic system coupling chemical defense with nutritional competition.
Wen-Ji Chen, Yu Ni, Yuan-Yuan Bai et al.· Microorganisms· 0 citations
Pseudomonas sp. MUP55, isolated from rainfall water in Western Australia, was characterized by polyphasic taxonomy and functional assays. Whole-genome and 16S rRNA phylogeny placed Pseudomonas sp. MUP55 in the Pseudomonas fluorescens species group. Massetolide A/D was identified as the leading candidate bioactive compound(s), consistent with its biosynthetic gene cluster, GNPS library matching, and loss of activity in regulatory mutants. The strain showed broad-spectrum antimicrobial activity against bacterial (Escherichia coli and Xanthomonas campestris) and fungal (Fusarium oxysporum and Rhizoctonia solani) plant pathogens. GacA regulates Massetolide production: a P58L mutation abolished synthesis and reduced biocontrol efficacy. Metabolomic and transcriptomic analysis of a ΔpvfC mutant revealed that the pvf cluster regulates specialized metabolism while also contributing to secreted growth-inhibitory activity. The pvf cluster differentially regulates dual siderophore systems and uncouples the co-regulated small RNAs rsmY and rsmZ in the Gac/Rsm cascade. Deletion of pvfC partially reduced the growth-inhibitory activity of Pseudomonas sp. MUP55 supernatants against bacterial pathogens, indicating that pvfC also influences secreted antimicrobial activity beyond its global regulatory role. These findings establish Pseudomonas sp. MUP55 as a taxonomically novel, mechanistically characterized biocontrol agent with potential for sustainable agriculture.
Hussain Alattas, Samuele Sala, Joseph Boctor et al.· International Journal of Mol...· 0 citations
Soil-occupy Brevibacillus parabrevius PS12 species are known for their metabolically versatile and it is being discovered as source of natural enzymes valuable to industry. Arginase catalyzes the processing of L-arginine to L-ornithine and urea, it is the one that plays a significant role in nitrogen metabolism Finding novel bacterial strains from environmental sources that are capable of producing the arginase enzyme is crucial for expanding microbial resources for industrial and pharmaceutical use. Among the 20 isolates, one isolate was identified as Brevibacillus parabrevis PS12 (97% 16S rRNA similarity, GenBank accession no. (PX118439.1), representing the first report from Iraqi soil. Arginase activity reached 8.3 U/mg protein a peak in nutritional source with maltose as a arbone source and casein as a Nitrogen source, the physical parameters also effect on enzyme specific activity at 7.0 pH, 37°C, and 48 hours of incubation time with shaker incubator 150 rpm to ensure the homogeneity of all medium components and continuous aeration all these factors contributed to an increase in bacterial biomass which led to a rise in the specific activity of arginase.
Ayah Muwafaq Hussein, Aqeel Mohammed Majeed Al-Ezee, Zaid Raad Abbas· Journal of the College of B...· 0 citations
This study systematically elucidates the dual inhibitory mechanisms of thermosonication against Bacillus subtilis spores through integrated transcriptomic-proteomic analysis, identifying critical genes at the regulatory level and clarifying indirect suppression through metabolic network disruption.
Lisha Song, Kairu He, Wang Han et al.· Food and Bioprocess Technolo...· 0 citations
This study demonstrates that Bacillus velezensis SPE2, a low-abundance isolate from the phycosphere of dinoflagellate, exhibits a wide degree of antagonistic activity against multiple marine Flavobacteriaceae strains, a dominant taxonomic group across the phycosphere of diverse phytoplankton species.
Runlin Cai, Hao Feng, Yang Liu et al.· Environmental Microbiome· 0 citations