title: Screening of novel microorganisms for biosurfactant and biocontrol activity against Phytophthora infestans.
abstract: In the present study, 95 isolates of bacteria were tested for their biosurfactant as well as biocontrol activity against Phytophthora infestans. The results revealed that only 15.8% isolates showed biosurfactant activity. The emulsification index ranged from 0-68% and 24.2% isolates showed positive reaction for biosurfactant properties. In emulsification assay and oil spreading test, 18.95% and 5.26% isolates, respectively scored positive for biosurfactant production. Among all, only five isolates were found effective against P. infestans, for biocontrol properties. Pseudomonas aeruginosa-1 showed 62.22% inhibition zone after 72 hrs while P. aeruginosa-3 showed 46.42%. Forty-eight hrs old culture supernatants were highly effective in food-poisoning test, tuber slice test and detached leaf method against P. infestans. In whole potato plant test, bacterial cell based formulation, culture supernatant and bacterial cell suspension of P. aeruginosa-1 showed 10.42%, 9.94% and 17.96% diseases severity respectively, as against 53.96% in control. This isolate holds promise as biological control agent against P. infestans in field.
authors.forename: Sonica
authors.initials: S
authors.lastname: Tomar
authors.forename: B P
authors.initials: BP
authors.lastname: Singh
authors.forename: Mehi
authors.initials: M
authors.lastname: Lal
authors.forename: Khan
authors.initials: K
authors.lastname: Ma
authors.forename: Touseef
authors.initials: T
authors.lastname: Hussain
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sharma
authors.forename: S K
authors.initials: SK
authors.lastname: Kaushik
authors.forename: Satish
authors.initials: S
authors.lastname: Kumar
mesh_terms: D010572:Pest Control, Biological; D055750:Phytophthora infestans; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D011897:Random Allocation; D011198:Solanum tuberosum; D013501:Surface-Active Agents / Q000032:analysis
chemical_list: D013501:Surface-Active Agents