Chitinolytic activity of an endophytic strain of Bacillus cereus

Bacillus cereus strain 65, previously isolated as an endophyte of Sinapis, was shown to produce and excrete a chitinase with an apparent molecular mass of 36 kDa. The enzyme was classified as a chitobiosidase because it was able to cleave diacetylchitobiose (GlcNAc)2 from the non-reducing end of trimeric chitin derivatives. The chitinase exhibited activity over the pH range 4.5-7.5 and was stable between pH 4.0 and 8.5. The enzyme had an isoelectric point of 6.4. Application of B. cereus 65 directly to soil significantly protected cotton seedlings from root rot disease caused by Rhizoctonia solani.