根结线虫卵寄生真菌蜡蚧菌(Lecanicillium lecanii)产生的几丁质酶活性

Chitinase Activity Produced by Egg-parasitic Fungus Lecanicillium lecanii from Root-kont Nematodes

卵寄生真菌产生的几丁质酶在卵孵化和寄生过程中发挥重要的作用,也是评价寄生线虫真菌生物防治潜力重要的生化指标之一。利用NAG法和pNP法分别测定蜡蚧菌(Lecanicillium lecanii)CFCC84957和CFCC80920菌系的几丁质降解酶系和外切酶活性,CFCC84957菌系接种4～6d含有0.2%胶体几丁质的培养滤液后,几丁质降解酶系到达活性高峰期,而CFCC80920菌系的培养滤液未检测到几丁质降解酶系。2个菌系的培养滤液从第2d开始均能检测到几丁质外切酶活性,CFCC84957和CFCC80920活性出现的最高峰分别在第12d和6d,但是CF-CC84957的活性值约是CFCC80920的4倍(分别为0.51μmol·h-1·ml-1、0.12μmol·h-1·ml-1)。含有0.01%糖基化几丁质的几丁质酶活性电泳检测到1条分子量为48.2kD的蛋白质谱带。

Chitinase produced by the nematode egg-parasitic fungi plays an important role in process of egg hatching and paratism ,and is one of the effective criteria for evaluation of the biocontrol potential of those fungi. The chitinolytic systems and exochitinase produced by Lecanicillium lecanii CFCC84957 and CFCC80920 were detected by means of NAG and pNP respectively,chitinolytic activity produced by CFCC84957 from 0. 2% swollen chitin broth medium reached the highest level between 4 ～ 6 days after inoculation,but no activity was found in CFCC80920 filtrates. The exochitinase activity was detected from 2 days in filtrates of 2 strains,maximum activity of CFCC84957 and CFCC80920 were found on the twelvth day and sixth day,but activity of CFCC84957 was about 4 times higher than these of CFCC80920 （0. 51 and 0. 12μmol·h-1·ml-1 respectively ）. On SDS-PAGE analysis with 0. 01% glycol chitin,one protein band of 48. 2 kD with chitinolytic activity was detected on the forth day filtrate inoculated by CFCC84957.