Open AccessInhibitory activity of Rhamnolipid produced by Pseudomonas aeruginosa NH22 against Rhizoctonia solani
Author(s) -
Nadhem H. Hayder Gumaa
Publication year - 2012
Publication title -
maǧallaẗ markaz buḥūṯ al-taqniyyaẗ al-aḥyāʾiyyaẗ
Language(s) - English
Resource type - Journals
eISSN - 2708-1370
pISSN - 1815-1140
DOI - 10.24126/jobrc.2012.6.1.196
Subject(s) - rhamnolipid , rhizoctonia solani , laccase , chemistry , critical micelle concentration , food science , pseudomonas aeruginosa , pseudomonas , microbiology and biotechnology , enzyme assay , micelle , enzyme , biology , horticulture , bacteria , biochemistry , organic chemistry , genetics , aqueous solution
In the present study, isolation and identification of microorganisms from rhizospher of garden soil with biosurfactant producing ability and characterization of biosurfactants were studied. The results exhibited capability of four isolates for biosurfactant production among six isolates. The isolate Pseudomonas aeruginosa NH22 showed a better emulsifier producer, therefore it selected for biosurfactant production and antifungal activity in the present study. Biochemical analysis of partially purified bioemulsifier demonstrated that the biosurfactant contains mono, and di- rhamnolipid with Rf values of 0.82 and 0.32 respectively. Rhamnolipid efficiency tested for antifungal activity by determination percentage reduction of radial growth, fresh and dry weight and laccase activity of fungus. Maximum reduction in radial growth 76%, and reduction of biomass obtained at rhamnolipid concentration of 1000 µg/ ml. Maximum laccase activity obtained 0.921 U/ml also at rhamnolipid concentration of 1000 µg/ ml, while reduction about 21% of the enzyme activity recorded at higher rhamnolipih concentration of 1500 µg/ ml. The critical micelle concentration estimated to be 200 mg/l, which led to reduce surface tension value of the culture to34 mN/m.