Production of an antifungal chitinase from Enterobacter sp. NRG4 and its application in protoplast production.

摘要

Suitability of flake chitin, crab shell chitin, mushroom stalk, fungal cell wall, wheat bran and rice bran as substrates for chitinase production by Enterobacter sp. NRG4 under submerged and solid state fermentation (SSF) conditions was investigated. Results show that Enterobacter sp. NRG4 produced chitinase at 72 and 49.7 U/ml in submerged fermentation in the presence of cell walls of Candida albicans and Fusarium moniliforme, respectively. In SSF, max. chitinase production was 965 U/g solid substrate using flake chitin and wheat bran (1:3 ratio) at 75% moisture level after 144 h. The purified chitinase inhibited hyphal extension of F. moniliforme, Aspergillus niger, Mucor rouxi and Rhizopus nigricans. The chitinase was effective in release of protoplasts from Trichoderma ressei, Pleurotus florida, Agaricus bisporus and A. niger. Max. protoplasts yield was achieved with 60 mg of a 24-h-old fungal mycelium incubated with 60 U of chitinase and 60 U of cellulase.