Characterization of Antifungal Chitinase from Bacillus licheniformis TCCC10016

Fungal plant diseases are one of urgent problems to agricultural production. With an increased attention of environmental issue, biological control using microorganisms or their secretions exhibited an excellent performance for preventing plant diseases. Chitinase could inhibit the growth of pathogenic fungi by lysing the cell wall. In this work, a chitinase-producing strain, Bacillus licheniformis TCCC10016 was screened from 16 bacteria strains using chitin as the sole carbon source. Enzyme activity analysis showed that the expression of the extracellular chitinase was induced by the substance chitin. This chitinase showed an obviously inhibitory effect on pathogen, Fusarium oxysporum. Chitinase was purified by ammonium sulfate salt fractionation from the culture supernatant. The optimal pH and temperature of enzyme-catalyzed reaction were 7.0 and 60 degrees C, respectively. It exhibited a good stability in a broad pH range 5-8 or at the temperature of 37 degrees C and 60 degrees C. Additionally, the activity could be improved by Na+ and Fe3+, however, Zn2+ and Co2+ showed an inhibited effect.