Bioconversion of shellfish chitin wastes for the production of Bacillus subtilis W-118 chitinase.
Bacillus subtilis W-118, a strain that produces antifungal materials, excreted a chitinase when cultured in a medium containing shrimp- and crab-shell powder as the major carbon source. This chitinase, purified by sequential chromatography, had a molecular mass of 20,600 Da and a pI of 6. The optimum pH, optimum temperature, and pH stability of the chitinase were pH 6, 37 degrees C, and pH 5-7, respectively. The unique characteristics of the purified chitinase include low molecular mass and acidic pI. In the investigation of the inhibitory activity, it was found that the growth of Fusarium oxysporum was 100% inhibited after incubation for 1 day with sterilized W-118 chitinase solution (5.6 units/mL). The chitinase hydrolyzates of chitin with low degrees of polymerization (DP 1-6) were analyzed by HPLC. Longer reaction times led to the generation of chitin oligosaccharides with lower DP. The chitin oligosaccharides were examined for their inhibitory effects on F. oxysporum and human leukemia cell lines.
Wang
San-Lang
SL
Graduate Institute of Life Sciences, Tamkang University, Tamsui 251, Taiwan. sabulo@mail.tku.edu.tw
Lin
Tzu-Yin
TY
Yen
Yue-Horng
YH
Liao
Hui-Fen
HF
Chen
Yu-Jen
YJ
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000096:biosynthesis; D002455:Cell Division; D002688:Chitinases / Q000096:biosynthesis* / Q000737:chemistry; D003445:Crustacea; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020014:K562 Cells; D007700:Kinetics; D014866:Waste Products
D000935:Antifungal Agents; D001426:Bacterial Proteins; D014866:Waste Products; D002688:Chitinases