Fusarium udum is resistant to the mycolytic activity of a biocontrol strain of Bacillus subtilis AF 1

• Published in: FEMS microbiology ecology Vol. 25; no. 4; pp. 385 - 390
• Main Authors: Harish, S. (Hyderabad Univ. (India). Dept. of Plant Sciences), Manjula, K, Podile, A.R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-1998; Blackwell; Oxford University Press
• Subjects: BACILLUS SUBTILIS; Biological and medical sciences; BIOLOGICAL CONTROL; Chitin; Chitinase; Chlamydospores; Control; CONTROL BIOLOGICO; Dextrose; Ecology; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungi; FUSARIUM; Fusarium udum; LUTTE BIOLOGIQUE; MICELIO; Microbiology; MYCELIUM; Mycolysis; Phytopathology. Animal pests. Plant and forest protection; Pigeonpeas; Potatoes; Proteins; Wilt; Mycolysis; Biological control; Chitinase; Plant pathogen; Enzyme; Bacillus subtilis; Fusarium udum; Bacillaceae; Fungi; Resistance; Antagonism; Bacillales; Enzymatic activity; Glycosidases; Bacteria; Hydrolases; Fungi Imperfecti; O-Glycosidases; Thallophyta
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.1998.tb00490.x

Abstract
In vitro interaction of the pigeonpea wilt pathogen Fusarium udum and a biocontrol strain of Bacillus subtilis AF 1 showed that the fungus forms chlamydospore-like structures and increases vacuolation, when both cultures are simultaneously inoculated into potato dextrose broth. If B. subtilis AF 1 was inoculated after 24 h of growth of F. udum, chlamydospores were not formed and regular conidiation was observed. The growth of F. udum was significantly affected in the presence of AF 1 in terms of dry weight. Extracellular proteins of B. subtilis AF 1 reduced the growth of F. udum in proportion to the concentration of the protein precipitate. Cell-free filtrates of B. subtilis AF 1 prepared from chitin-containing medium showed chitinase activity. The formation of chlamydospore-like structures and vacuolated portions in mycelium of F. udum in the presence of AF 1 suggests that F. udum has a mechanism to tolerate mycolytic activity and grows slowly with regular conidiation.