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Isolation, purification and characterization of an antifungal molecule produced by Bacillus licheniformis BC98, and its effect on phytopathogen Magnaporthe grisea
Author(s) -
Tendulkar S.R.,
Saikumari Y.K.,
Patel V.,
Raghotama S.,
Munshi T.K.,
Balaram P.,
Chattoo B.B.
Publication year - 2007
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2007.03501.x
Subject(s) - magnaporthe grisea , surfactin , bacillus licheniformis , biology , microbiology and biotechnology , hypha , fungus , magnaporthe , lipopeptide , fungicide , bacillus subtilis , bacteria , botany , biochemistry , oryza sativa , genetics , gene
Aims: Isolation of bacterial antagonist for use in the biological control of phytopathogenic fungi like rice blast fungus, Magnaporthe grisea , and to further purify and characterize the antifungal molecule produced by the antagonist. Methods and Results: Bacterial antagonist exhibiting highest antifungal activity against the rice blast fungus M. grisea was isolated from soil and identified as Bacillus licheniformis BC98. Besides M. grisea , the isolate also inhibited the growth of other phytopathogens such as Curvularia lunata and Rhizoctonia bataticola . Biologically active fractions were isolated from the culture filtrate and further fractionated by reverse‐phase high‐performance liquid chromatography (HPLC) enabling detailed structural characterization of a component of molecular mass 1035 Da. The active peptide was identified as surfactin after 500 MHz 1 H NMR analysis. Microscopic analysis of the effect of the antagonist on M. grisea revealed bulbous hyphae showing patchy and vacuolated cytoplasm when observed under the electron microscope. Conclusions: The antagonistic lipopeptide secreted by B. licheniformis BC98 and identified as surfactin, induced morphological changes in M. grisea , inhibiting its further growth, and thus exhibiting fungicidal activity. Significance and Impact of the Study: The antagonist inhibits germination of M. grisea , a potent rice phytopathogen, and therefore appears to be a potential candidate for control of rice blast disease.