Title The effects of fluctuating culture temperature on stress tolerance and antioxidase expression in Esteya vermicola
Author Yun-bo Wang1, Wen-xing Pang2, Xiao-na Yv2, Jing-jie Li1, Yong-an Zhang3, and Chang-keun Sung1*
Address 1Department of Food Science and Technology, College of Agriculture and Biotechnology, Chungnam National University, Daejeon 305-764, Republic of Korea, 2Molecular Genetics and Genomics Lab, Department of Horticulture, Chungnam National University, Daejeon 305-764, Republic of Korea, 3Chinese Academy of Forestry, Beijing 100091, P. R. China
Bibliography Journal of Microbiology, 53(2),122-126, 2015,
DOI 10.1007/s12275-015-4529-2
Key Words Esteya vermicola, fluctuating temperature, stress tolerance, antioxidase expression
Abstract The endoparasitic nematophagous fungus, Esteya vermicola, has shown great potential as a biological control agent against the pine wood nematode, Bursaphelenchus xylophilus. Fluctuating culture temperatures can affect fungal yields and fungal tolerance to desiccation, UV radiation, H2O2, and heat stress, as well as antioxidase expression. To explore these effects, E. vermicola cultured under five temperature ranges, 26oC, 15-26oC, 26-35oC, 20-30oC, and 15-35oC, were compared. The cultures grown at lower temperatures showed better growth, stronger tolerance to desiccation, UV, and H2O2 stresses, and increased catalase expression, However, these cultures also showed weaker heat stress tolerance and lower superoxide dismutase expression than the higher-temperature cultures. In particular, the E. vermicola cultured at 20-30oC, i.e., fluctuating in a narrow range around the optimal temperature, showed the best performance. Therefore, for production in practical applications, this narrowly fluctuating, moderate temperature appears to be optimal for yield and stress tolerance in E. vermicola.