The preparation of low-molecular-weight chitosan using chitinolytic complex from Streptomyces kurssanovii

Streptomyces kurssanovii are Gram-positive mycelial bacteria ubiquitous in soil. They have a saprophytic way of life and produce many extracellular enzymes with polymer-degrading properties, for example, chitinase (EC 3.2.1.14) and N-acetyl-β--glucosaminidase (EC3.2.1.30). Biochemical aspects of chitosan degradation were presented. Low-molecular-weight (LMW) chitosans with molecular weight 4–8 kDa were prepared from commercial crab chitosan by means of chitinolytic a complex from S. kurssanovii. The optimum conditions of process in solution (temperature, pH, enzyme-substrate ratio) have been determined. Yields of LMW chitosan were 70–80%.