[Chitinase production by a strain of Streptomyces griseoruber isolated from the rhizosphere of sugar cane].

Twenty nine mesophilic and 19 thermophilic actinomycetes from sugar cane phyllosphere, rhizosphere and root-free soil were isolated. Twelve mesophilic and 7 thermophilic strains produced clear zones of hydrolyses on colloidal chitin agar and hydrolysed a chitin colloidal suspension. The rhizosphere strains were significantly more chitinolytic (p < 0.05) than the root-free soil strains. Streptomyces griseoruber 202 produced chitinase in colloidal chitin liquid medium with an activity of 108 micrograms of colloidal chitin hydrolysed/mg protein/hour, at pH 4.6 and 40 degrees C. This strain also produced chitinase in a medium with insect exoskeleton powder.