仓储稻米中产柄曲霉素菌的分离鉴定及其产毒条件研究

Isolation and identification of sterigmatocystin-producing strains from storage rice and research on toxin-producing conditions

中文关键词:  仓储稻米  真菌  分离鉴定  柄曲霉素

英文关键词:storage rice  fungi  isolation and identification  sterigmatocystin

中文摘要:

      目的 获得产柄曲霉素(sterigmatocystin, STC)的菌株并研究其最适产毒条件。方法 将1份来自广东省韶关市仓储霉变稻米的稀释液接种至马铃薯葡萄糖琼脂(potato dextrose agar, PDA)培养基上, 利用平板划线法分离获得菌株, 通过高效液相色谱-串联质谱法对获得菌株的产STC能力进行检测, 结合形态学观察和rDNA-ITS序列分析对产毒素菌鉴定, 并对其产STC菌株的产毒条件(培养基、培养天数、培养温度)进行考察。结果 该稻米中共分离到9种菌, 其中詹森曲霉(Aspergillus jensenii)可代谢合成STC, 其最佳产毒培养基为大米培养基, 最适温度为28℃, 且在培养的第28 d含量达到最大。结论 该研究从发霉稻米中分离获得1株可代谢产生STC的菌株, 可为我国针对性地防控粮食中产毒性真菌污染提供基础性实验菌株, 同时也有利于STC生物合成、代谢等工作的开展。

英文摘要:

      Objective To obtain the strains which can synthesis sterigmatocystin (STC) and study the optimum conditions for producing toxin. Methods A diluent of mildew rice from Shaoguan City, Guangdong Province was inoculated on potato dextrose agar (PDA) culture medium, and the strains were isolated by plate streak approach. High performance liquid chromatography-tandem mass spectrometry was used to analysis the ability of the obtained strain to produce STC. The species of the strains was identified respectively by morphologic observation and rDNA-ITS analysis, and the conditions (medium, incubation time and temperature) for the fungi to produce STC were investigated. Results A total of 9 strains were obtained, among which Aspergillus jensenii could metabolize STC, and the optimal medium was rice matrix, yield reached the maximum on the 28st day under 28℃. Conclusion This study obtains a fungus from the storage moldy rice that can synthesis STC, which provides a basic experimental strain for the prevention and control of food toxic fungal contamination in China, and is also conducive to the development of the biosynthesis and metabolism of STC.