啤酒酵母呼吸缺陷型诱变形成机制初探

本文以两株不同的啤酒酵母(S.cerevisiae)作出发菌株,用溴化乙锭(10—100μg/ml)作诱变剂,诱变呼吸缺陷型。发现在非生长条件下,EB诱变呼吸缺陷型过程中出现回复现象。这一现象可被咖啡碱有一定程度的抑制,而在生长条件下EB诱变过程中未发现此现象。但当用KCN处理时,则得到了类似于非生长条件下的诱变结果。因而,推测呼吸缺陷型形成过程中可能存在一中间态过程ρ~-]~*。呼吸缺陷型的形成过程可用ρ~ ρ~-]~*→ρ~-表示。这是一动态过程。加入一定量的放线菌酮、氯霉素处理时,对诱变动力学曲线没有发现有影响,但培养酵母所用葡萄糖浓度不同时,对其诱变结果有一定的影响。

A Preliminary Study on Mechanism of Respiratory Deficiency of Mutagenesis in S. Cerevisiae

The results of ethidium bromide treatment for two different strains of S.eerevlsiae were reported here.The recovery of respiratory competence was discovered when cells were treated with EB under non-growing condition.However,this recovery can be inhibited by caffine.It was not observed when cells were treated with EB under growing condition.Similar results were obtained when cells were treated with EB during their exposure to KCN.The formation of at least one intermediate state p-] was proposed.The process of formation of respiratory deficiency could be expressed by The different concentrations of sucrose supplemented to the culture of 5.eerevlsiae resulted in certain influence in the experiment.