In-vitro assessment of plant growth promoting traits integrated with antagonistic activity of biosurfactant producing Bacillus species of oil contaminated soil

Ratan Singh; Dheeraj Rathore

Abstract

Researchers are in search of microbial tools having plant growth promoting activity integrated to biosurfactant production potential to develop eco-friendly technique for sustainable agricultural. Presented study was undertaken to characterize the plant growth promoting activity of biosurfactant producing Bacillus species isolated from oil contaminated soil. Bacterial strains were identified as Bacillus licheniformis P1 and Bacillus velezensis P2, on the basis of morphological, biochemical and 16SrDNA gene sequence homology. Biosurfactant producing capability of isolates was screened by oil displacement activity, CTAB methylene blue agar test, emulsification activity and reduction of surface tension. Screening of direct plant growth promoting activity of isolates was included synthesis of IAA, phosphate solubilisation and siderophore production. Indirect plant growth promoting activity of isolates was screened by antagonistic property against Fusarium oxysporum and Aspergillus niger. Both the strains tested positive for oil displacement, emulsification and reduction of surface tension except CTAB methylene blue agar test. Both the strains also showed a positive result for IAA synthesis, phosphate solubilisation, siderophore production as well as antagonisms of fungal pathogens. Study concluded that the Bacillus species isolated from oil contaminated site having plant growth promoting traits integrated with antagonistic activity and biosurfactant production ability.

Abstract

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