粉红单端孢体外产毒条件的探讨及粗毒素活性测定

Inquire into the toxin production condition of Trichothecium roseum in vitro and toxicity bioassay

培养粉红单端孢(Trichothecium roseum)使其产生毒素,筛选出有利于该菌体外产毒的培养基和培养时间,并初步探讨毒素的活性大小。采用玉金香甜瓜种子发芽抑制实验测定了不同培养条件下粉红单端培养滤液对种子发芽的抑制率,用抑制率的大小表示培养滤液毒性的大小;对粉红单端孢体外产生的毒素用有机溶剂分别从菌丝和培养滤液中提取,经减压旋转蒸发浓缩,获得粗毒素。结果表明,PDA液体培养基,pH4.5时的培养滤液对玉金香甜瓜种子发芽抑制率最大;随着培养时间的延长,培养滤液对种子的抑制率呈现上升→下降→上升的趋势,17d时,培养滤液对玉金香种子的抑制率最大,并且抑制率与毒素浓度的大小也有关。

The purpose of this study was to pick out the suitable condition for toxin production of Trichotheclum roseum in vitro and discussion the toxicity. The toxin production condition of Trichothecium roseum was tested by using inhibiting germination rate of yujinxiang seeds. The toxin was extracted from the culture broth and mycelium of the fungus Trichothecium roseum by using organic solvent respectively. The date obtained suggests that the inhibiting germination rate of yujinxiang seeds is the biggest in the filter liquid of PDA liquid medium,pH4.5 than in PSC and Czapack containing 2% starch medium and it is bigger in 17 days than others. It showed the tendency of rise.drop,rise with increasing culture time. In conclusion we suggest that the optimum conditions were： PDA liquid medium, pH4.5; The concentration of toxin produced was maximum in 17days.