Integrated Genomics and Transcriptomics Provide Insights into Salt Stress Response in Bacillus subtilis ACP81 from Moso Bamboo Shoot (Phyllostachys praecox) Processing Waste

Abstract

Salt stress is detrimental to the survival of microorganisms, and only a few bacterial species produce hydrolytic enzymes. In this study, we investigated the expression of salt stress-related genes in the salt-tolerant bacterial strain Bacillus subtilis ACP81, isolated from bamboo shoot processing waste, at the transcription level. The results indicate that the strain could grow in 20% NaCl, and the sub-lethal concentration was 6% NaCl. Less neutral protease and higher cellulase and β-amylase activities were observed for B. subtilis ACP81 under sub-lethal concentrations than under the control concentration (0% NaCl). Transcriptome analysis showed that the strain adapted to high-salt conditions by upregulating the expression of genes involved in cellular processes (membrane synthesis) and defense systems (flagellar assembly, compatible solute transport, glucose metabolism, and the phosphotransferase system). Interestingly, genes encoding cellulase and β-amylase-related (malL, celB, and celC) were significantly upregulated and were involved in starch and sucrose metabolic pathways, and the accumulated glucose was effective in mitigating salt stress. RT-qPCR was performed to confirm the sequencing data. This study emphasizes that, under salt stress conditions, ACP81 exhibits enhanced cellulase and β-amylase activities, providing an important germplasm resource for saline soil reclamation and enzyme development.

The Effect of Two Siderophore-Producing Bacillus Strains on the Growth Promotion of Perennial Ryegrass under Cadmium Stress

“…By secreting siderophores, Bacillus can convert iron in the soil into a form that can be absorbed by plants, thus increasing the utilization of iron by plants. In addition, siderophores can also form stable chelates with heavy metal ions in the soil, thus reducing the bioavailability of these toxic metals and their toxic effects on plants [ 13 ]. For example, Wang et al [ 14 ] observed that inoculating the Bacillus strains T1 and Y2 that produce siderophores into Solanum nigrum L. soils significantly promoted ( p < 0.05) Cd absorption in soils and strengthened the ability of Solanum nigrum L. to remediate soils polluted by Cd.…”