关于链格孢的毒性及其产毒条件的研究

本文报告了从食管癌高发区林县分离的具有强烈毒性和致突变性的链格孢(Alternariaalternata)“D_(10)-A_2”菌株粗提物半数致死量的测定,结果为71.25g 培养物/kg 体重;7个菌株粗提物的程序外 DNA 合成(UDS)试验,6个菌株粗提物的 DNA 合成抑制(DSI)试验。结果 UDS 试验6个菌株为阳性,DSI 试验5个菌株为阳性。说明互隔交链孢提取物可致人体细胞 DNA 的损伤。本文还报道了链格孢适宜的产毒条件。链格孢在一般粮食上均能生长繁殖产毒,适温为25℃,适宜的湿度根据粮食品种不同而为33—50％含水量。在北方侵染的主要粮食为小麦,当麦粒灌浆成熟期遇到较长时间的阴雨天气,或在收割脱粒时遇到连阴雨,麦粒被雨水浸泡。污染非发生于贮存期。

THE STUDY OF TOTICITY AND CONDITION OF TOXIN PRODUTION OF ALTERNARIA ALTERNATA

The LD_(50) of Alternaria alternata D_(10-a_2) strain which was isolated from the corn of area of the high incidence of esophageal cancer is 71,85 g culture/kg weight of mouse. The result of UDS test of the extracts of seven strains indicated that the six extracts of them were positive.The DSI test of six extracts indicted that the five were weaker positive,but the result showed that the extracts of A.alternata could damage DNA of human cells.Resea- ching the condition of the toxin production provided that A.alternata could produce toxin was 25℃,and the suitable humidity was 33.3—50%.The results suggest that the wheat is con- taminated by A.alternata in its fruitful period when it is growing in the field or in the period of harvesting crops in which the wheat is immersed in rain water for a long time rather than in the period of its store.