An Extracellular Chitinase from Streptomyces sp. CS147 Releases N-acetyl- d -glucosamine (GlcNAc) as Principal Product

Streptomyces sp. CS147 grown on chitin liquid medium incorporating 0.5 % colloidal chitin as a sole carbon source produced an extracellular chitinase (Ch147). The enzyme (Ch147) was purified using Sepharose CL-6B column chromatography and biochemically characterized. The enzymatic reaction products, analyzed using high-performance liquid chromatography and thin layer chromatography clearly indicates the production of N-acetyl- d -glucosamine (GlcNAc) as principal product which can be further hydrolyzed for the production of alcohol, a second generation biofuel. Ch147 hydrolyzed colloidal chitin to 0.278, 0.817, and 1.058 mg/mL of (GlcNAc) as a major product, at retention time of 4.3, respectively, when incubated for 8, 16, and 24 h at 50 °C. GlcNAc is a monosaccharide that usually polymerize linearly through (1, 4) β linkage. The 41 kDa molecular mass chitinase, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), has the amino acid sequences DINGGGATLPQKLYL significantly different from other chitinase. Ch147 had K m and V max values of 2.05 ± 5.3 mg/mL and 467.2 ± 2.4 mmol/min, respectively. Further, the purified enzyme (5 U) inhibits the fungal phytopathogens belonging to the genera Fusarium and Aspergillus . We believe that Ch147 is a potential candidate for the conversion of waste materials into simple sugar for productions of biofuels and also can be used as an alternative option for biological control of plant pathogens being unfriendly to chemicals.