中华散尾鬼笔的液体培养条件优化及生物安全性测定

以中华散尾鬼笔为对象，以菌丝生物量为指标，通过单因素试验筛选了接种量、pH、温度、装液量等4种非营养因子对中华散尾鬼笔液体发酵的影响，优化了培养条件，并测定了中华散尾鬼笔正丁醇提取物水溶液对绿豆的他感作用及对斑马鱼的急性毒性。结果表明，中华散尾鬼笔液体发酵的优化培养条件为:培养温度25℃、pH中性、接种菌饼3片、装液量220 mL·瓶^-1，在此培养条件下，中华散尾鬼笔菌丝干重为0.66 g，较未优化之前增加了1倍。同时，中华散尾鬼笔正丁醇提取物水溶液对绿豆种子的发芽和胚轴芽的伸长均产生抑制效果，且随着提取物浓度的升高，绿豆发芽率和胚轴芽长均趋于下降，抑芽率显著升高（P<0.05）；对斑马鱼的急性毒性试验结果表明，中华散尾鬼笔正丁醇提取物水溶液对斑马鱼96 h的致死中浓度LC₅₀为426.54 mg·L^-1，属于低毒。研究为中华散尾鬼笔的进一步研究和利用提供了参考和依据，为其作为微生物源农药提供了可能。

Optimization of Liquid Culture Conditions and Biosafety Determination of Lysurus mokusin

Taking Lysurus mokusin as the research object and using the mycelial biomass as an indicator,the effects of inoculum size,pH,temperature and liquid volume on the liquid fermentation were screened by single factor test,and the culture conditions were optimized.Then the allelopathic effect of L.mokusin n-butanol extract on mung bean and its acute toxicity to zebrafish were determined.The results showed that the optimal culture conditions for L.mokusin liquid fermentation were as followings:culture temperature:25℃,pH:7,number of inoculum fungus plugs:3,and liquid volume:220 mL per bottle.Under these culture conditions,the dry weight of biomass was 0.66 g,which was doubled compared with that before optimization.The n-butanol extract of L.mokusin hadpresented inhibitory effects on the germination of mung bean seeds and the growth of bean sprouts.The inhibitory effects increased with the increase of concentration.The acute toxicity test on zebrafish showed that the LC₅₀ of the extract to the zebrafish at 96 h was 426.54 mg/L,belonging to low toxicity.The results of this study would provide references for the further research and utilization of L.mokusin,as a microbial source fungicide.