Anand Nagpure, Bharti and Rajinder K. Gupta. 2013
Journal of Basic Microbiology. DOI
10.1002/jobm.201200474
An extracellular mycolytic enzyme cocktail
produced by antagonist Streptomyces violaceusniger MTCC 3959 under submerged
fermentation was characterized. The strain MTCC 3959 produced higher amounts of
extracellular chitinase and protease during late exponential phase whereas
β-1,3-glucanase production was at peak in mid stationary phase. Cell-free
culture filtrate exhibited a broad range of antifungal activity against both
white and brown rot fungi. The inhibitory activity was completely lost after
the treatment with proteinase K and temperature, indicating that extracellular
antifungal metabolites are heat labile and proteinaceous in nature. Optimum pH
and temperature for chitinase was 9.0 and 60°C, for β-1,3-glucanase 6.0 and
60°C and for protease 9.0 and 70°C. Mycolytic enzymes were moderately
thermostable with a wide pH stability range from pH 5.0 to 10.0. The zymogram
analysis of cell-free culture filtrate revealed five chitinase and four
protease isoenzymes with approximate molecular weight of 20.8-114.8 and
22.8-120.5 kDa, respectively whereas β-1,3-glucanase appeared as a single band
of 131.8 kDa. S. violaceusniger MTCC 3959 produced mycolytic enzyme cocktail
that can be effectively used for suppression of phytopathogenic basidiomycetes
and can also evolve as a potential biofungicide.