Effect of Temperature on the Growth and Antifungal Activity of Fusarium-wilt-disease Biocontrol Bacterium Strain FJAT-4

To characterize the effect of temperature on the growth and antifungal activity of biological control strain Bacillus licheniformis FJAT-4, the growth response of strain FJAT-4at different temperature, the effect of concentration and temperature on the antifungal activity of the strain FJAT-4against Fusarium oxysporum strain FJAT-135were studied by culturing the strain on plate culture media, liquid media and culturing the strain FJAT135on the media contained strain FJAT-4.The results showed that the growth is inhibited and the growth curve is liner type under 20℃, but the growth return to normal and the growth curve is logarithmic type over 25℃, and the optimal temperature is 35-40℃.The cultured liquids of strain FJAT-4raised at different temperature and its 10 times serial dilution inhibited the growth of the strain FJAT-135effectively, and the differences among the inhibitions were far less than the differences among the concentrations of the cultured liquid.There were significant differences among effects of temperatures on the inhibitions of FJAT-4on FJAT-135, the inhibitory effect was the weakest at 15℃, and obvious at 20-30℃ and the highest at 35℃.Therefore, there were significant relationship between the temperatures and the growth and antifungal activity of strain FJAT-4, and the optimal temperature for the growth and antifungal activity was 35-40℃.