DEGRADATION OF PLANT PATHOGENIC FUNGI BY Streptomycetes

Document Type : Original Article

Author

Microbial Chemistry Department National Research Center, Dokki, Egypt

Abstract

 
An isolate of Strep < /em>tomyces sp. excreted chitinase, cellulase and protease
activities into the medium when grown on chitin, carboxymethylcellulose and
casein ,respectively, or on cell walls of the fungal pathogen Sclerotium rolfsii or
Rhizoctonia solni, as sole carbon source. This isolate of Streptomyces sp. gave
highest lytic enzymes ( chitinase , cellulase, protease ), when grown at28 °C. Factors
involved in the production of enzymes were investigated. The lytic activities were
produced optimally in the medium at' pH range between 6.5-7.0 for the three
enzymes . The lytic activities of culture on autoclaved mycelium of S. rolfsii and R ..
solani took place at different pH values .The effect of mycelium concentration as
substrate on the extent on mycelium lysis and lytic activities were also studied. The
level of hydrolytic enzymes, produced by Streptomyces sp. depended on the source
of mycelium attacked i. e. S. rolfsii or R. so/ani in soil.

Keywords