A potent biosurfactant producing bacterial endophyte isolated from root gall of lady's finger (Abelmoschus...

An endophytic bacterium having the capability to produce biosurfactant was isolated from the root gall of Lady's finger (Abelmoschus esculentus). The stain reduces the surface tension of the culture media from 50.8mN to 30.8mN in 24 h and produces 3.3 g/L of biosurfactant at 48 h of incubation using glucose as a carbon source. It was revealed from the characterization of the biosurfactant that the strain produces a lipopeptide type of biosurfactant and the main component of the lipopeptide was surfactin. The bacterial strain was further characterized through molecular technique and identified as Providencia vermicola which was designated as strain SCL1. The biosurfactant produced by the strain was found to exhibit efficient antifungal activities against phytopathogenic fungi Colletotrichum gleoisporoides, Sclerotinium sclerotiorum, and Corynespora cassicolla. This is the first report that an endophytic bacterium Providencia vermicola can produce lipopeptide biosurfactant having antifungal properties against certain phytopathogenic fungi.