Abstract:

In the present study, the purification and characterization of a chitinase from the fermentation broth of
Brevibacillus brevis FM4B was investigated by centrifugation, ethanol precipitation and Sephadex G-100 chromatography.
Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to determine its molecular weight.
Purified chitinase with a purification factor of 7.19 and a recovery rate of 30.6% was obtained. The molecular weight of the
purified chitinase was approximately 66 kD. It had an optimum reaction temperature and pH of 50 ℃ and 6.0, respectively.
The enzyme also showed good stability in the pH range of 5.0–9.0. Its activity could be inhibited by Cu2+, Hg2+, Pb2+,
Co2+and Zn2+, but slightly activated by Mg2+ and Ca2+. In addition, the chitinase had obvious inhibitory effect on
different fungi. The chitinase, possessing high thermal stability, good pH adaptability and significant antifungal effect, has
great potential for practical applications.

Key words: Brevibacillus brevis, chitinase, purification, characterization, antibacterial activity