食品科学

• 生物工程 • 上一篇    下一篇

降解赭曲霉毒素A菌株的筛选及其鉴定

王峻峻,张红印*,杨其亚   

  1. 江苏大学食品与生物工程学院,江苏 镇江 212013
  • 出版日期:2014-11-15 发布日期:2014-11-06

Screening and Identification of Microorganisms for Ochratoxin A Degradation

WANG Jun-jun, ZHANG Hong-yin*, YANG Qi-ya   

  1. School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
  • Online:2014-11-15 Published:2014-11-06

摘要:

为了提供筛选生物降解赭曲霉毒素A(ochratoxin A,OTA)的便利条件,优化水系中OTA的测定方法。通过在水系中添加甲醇或乙醇的方法,使得水系中OTA回收率超过了90%,此外通过对比,当甲醇或乙醇与样液体积比为1∶1时,足以准确测定水系中OTA含量。利用以上方法对降解OTA的菌株进行筛选,发现细菌B-1和酵母Y-2均能够降解OTA,且细菌B-1在2 d时能降解87%的OTA,3 d将OTA全部降解,而酵母Y-2在2 d时就能够降解84%的OTA,在后续的培养中维持降解率不变。此外,利用液质联用法进一步确定了菌株B-1和Y-2的降解作用,并分析了降解产物。最后,通过分别分析细菌B-1和酵母Y-2的16S rDNA和ITS rDNA序列,菌株B-1鉴定为泡囊短波单胞菌,菌株Y-2鉴定为耶罗维亚酵母。

关键词: 赭曲霉毒素A, 回收率, 降解, 微生物, 筛选, 鉴定

Abstract:

An optimized method for determining of ochratoxin A (OTA) in aqueous solution was proposed, and screening
of six strains isolated from vineyard soil for microbial OTA degradation was performed using the developed method. By
adding either methanol or ethanol, the recovery rate of OTA in aqueous solution was increased to more than 90%, and its
concentration could accurately determined at an addition ratio of 1:1 by volume. It was demonstrated that B-1 (bacterium)
and Y-2 (yeast) were able to degrade OTA. After incubation for two days, B-1 reduced 87% of OTA, and it was thoroughly
degraded another day later. Y-2 showed similar ability to degrade OTA, with a degradation rate of 84% after two-day
cultivation, and the concentration of residual OTA was stable in the following days. Moreover, LC-MS was used to detect
OTA byproducts. Finally, through sequence analysis of the 16S rDNA and 5.8S internal transcribed spacer (ITS) ribosomal
DNA (rDNA) regions, respectively, B-1 was identified as Brevundimonas vesicularis, while Y-2 as Yarrowia lipolytica.

Key words: ochratoxin A (OTA), recovery, degradation, microorganisms, screening, identification

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