Effectiveness of Bacillus pumilus PDSLzg-1, an innovative Hydrocarbon-Degrading Bacterium conferring antifungal and plant growth-promoting function.

Genome of the hydrocarbon-degrading bacterium Bacillus pumilus PDSLzg-1 was analyzed. A group of gene clusters and pathways associated with nitrogen fixation, plant-bacterial interactions, plant growth-promoting hormone synthesis, antibiotics, secondary metabolite, and disease resistance were identified. In addition, 0.06 mg/L of 3-indoleacrylic acid (IAA) and 2 mg/L of gibberellin (GA) were, respectively, detected in PDSLzg-1 fermentation broth by high-performance liquid chromatography (HPLC). Up-regulated expression levels of 11 key genes related to GA and IAA biosynthesis pathways were detected after the induction of 0.2% n-hexadecane. Furthermore, bioassays showed that PDSLzg-1 fermentation could significantly promote the length and biomass of the stems and roots of Triticum aestivum L., while inhibited Colletotrichum truncatum colonization. Results indicated that B. pumilus PDSLzg-1 had plant growth-promoting and antifungal functions, besides its potential applications in phyto-microbial bioremediation combinations for oil-contaminated soil.