Wang Yun-bo, Pang Wen-xing, Yv Xiao-na, Li Jing-jie, Zhang Yong-an, Sung Chang-keun
Department of Food Science and Technology, College of Agriculture and Biotechnology, Chungnam National University, Daejeon, 305-764, Republic of Korea.
J Microbiol. 2015 Feb;53(2):122-6. doi: 10.1007/s12275-015-4529-2. Epub 2015 Jan 28.
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, 26°C, 15-26°C, 26-35°C, 20-30°C, and 15-35°C, 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 20-30°C, 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.
内寄生线虫捕食真菌——埃斯氏线虫真菌（Esteya vermicola）已显示出作为防治松材线虫（Bursaphelenchus xylophilus）生物防治剂的巨大潜力。培养温度的波动会影响真菌产量以及真菌对干燥、紫外线辐射、过氧化氢和热胁迫的耐受性，以及抗氧化酶的表达。为了探究这些影响，对在26°C、15 - 26°C、26 - 35°C、20 - 30°C和15 - 35°C五个温度范围内培养的埃斯氏线虫真菌进行了比较。在较低温度下培养的菌株生长更好，对干燥、紫外线和过氧化氢胁迫的耐受性更强，过氧化氢酶表达增加，然而，与较高温度培养的菌株相比，这些菌株对热胁迫的耐受性较弱，超氧化物歧化酶表达较低。特别是，在20 - 30°C下培养的埃斯氏线虫真菌，即在最适温度附近的窄范围内波动，表现出最佳性能。因此，在实际应用生产中，这种窄范围波动的适度温度似乎对埃斯氏线虫真菌的产量和胁迫耐受性最为适宜。
