云芝产漆酶培养基优化及发酵液对玉米赤霉烯酮降解的研究

    Optimization of the culture medium for laccase production by Trametes versicolor and activity detection of fermentation broth in degrading zearalenone

    • 摘要: 粮食被玉米赤霉烯酮(Zearalenone,ZEN)污染不仅会造成巨大的经济损失,还会对人类和牲畜的健康构成重大威胁。为开发一种经济、绿色、高效且能直接降解ZEN的生物法,以云芝菌株Tv-1为试验菌株,碳源、氮源、漆酶诱导剂(Cu2+和粮油加工副产物)为影响因素,发酵液中的漆酶活力为指标,采用单因素和响应面试验确定云芝产漆酶的最适液体培养基以提高发酵液中漆酶的活力,然后用在最适培养基条件下制备的云芝发酵液直接降解ZEN,研究处理时间对ZEN降解率的影响。结果表明:云芝产漆酶的最适液体培养基为去皮马铃薯200 g/L、麦芽糖19.30 g/L、酵母浸粉2.00 g/L、小麦麸皮42.60 g/L、Cu2+ 0.48 mmol/L,在此条件下,漆酶活力达到5 611.56 U/L,较优化前提高了22.86倍;采用此发酵液直接降解ZEN,第96小时降解率可达92.45%。本研究确定了云芝Tv-1产漆酶的最适发酵液体培养基,且云芝发酵液能够有效降解ZEN,为消减粮食中的ZEN奠定了理论基础。

       

      Abstract: The contamination of grains with zearalenone (ZEN) not only causes huge economic losses, but also poses a significant threat to the health of humans and livestock. In order to develop an economical, green, efficient and direct biodegradation method for ZEN, the T. versicolor strain Tv-1 was used as the experimental strain, carbon sources, nitrogen sources, and laccase inducers (Cu2+ and by-products of grain and oil processing) were considered as influencing factors, and the activity of laccase in the fermentation broth served as the indicator. Single-factor experiments and response surface methodology were employed to determine the optimal liquid culture medium for laccase production by T. versicolor and enhance the activity of laccase in the fermentation broth. Then, the T. versicolor fermentation broth prepared under optimal medium conditions was used to directly degrade ZEN, and the effect of treatment time on the degradation rate of ZEN was investigated. The results showed that the optimal liquid culture medium for laccase production by the T. versicolor strain Tv-1 was found to have a peel potato concentration of 200 g/L,a maltose concentration of 19.30 g/L, a yeast extract concentration of 2.00 g/L, a wheat bran concentration of 42.60 g/L, and a Cu2+ concentration of 0.48 mmol/L. Under these conditions, the laccase activity reached 5 611.56 U/L, which was a 22.86-fold increase compared with the laccase activity in the non-optimized medium. This fermentation broth was directly used to degrade ZEN, achieving a degradation rate of 92.45% for ZEN at the 96th hour. Therefore, this study determined the optimal liquid culture medium for laccase production by the T. versicolor Tv-1 and the fermentation broth can efficiently degrade ZEN. This lays the theoretical foundation for reducing ZEN in grains.

       

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