分解玉米赤霉烯酮菌株的分离、鉴定及其产酶特征

Isolation, identification of a zearalenone degradated strain and the properties of its producing enzymes

摘要:

【目的】从发酵食品材料中筛选出对玉米赤霉烯酮(ZEN)有分解作用的微生物，研究其分解效率及产酶特征并进行菌种鉴定。【方法】利用添加ZEN毒素类似物(PL)的固体培养基对25 种发酵食品材料进行初筛，获得毒素类似物耐受菌株，经过用ZEN复筛，得到高效分解ZEN的细菌。用高效液相色谱法(HPLC)分析培养物残留ZEN，评价菌株对ZEN的分解效率。初步分析该菌株产纤维素酶、木聚糖酶及β-葡萄糖苷酶的特性。通过微生物形态学、分子生物学方法进行菌种鉴定，确定该菌的系统分类学地位。【结果】从发酵食品材料中筛选出一株分解ZEN的菌株BF-B-3，经初步鉴定该菌株为枯草芽孢杆菌(Bacillus subtilis)。其ZEN分解率达62.48%，测定该菌产纤维素酶、木聚糖酶及β-葡萄糖苷酶活力分别为160.38、84.51和4.14 U/mL。【结论】枯草芽孢杆菌属于饲用微生物，生物安全性高，所分离到的枯草芽孢杆菌疑似株(Bacillus subtilis) BF-B-3菌株，可作为具有分解ZEN功能的益生菌使用，具有较好的应用前景。

Abstract:

[Objective] To screen and identify a microorganism with zearalenone (ZEN) detoxification ability from fermented foods, and determine its decomposing efficiency and the properties of producing enzymes. [Methods] Solid media with toxin analogue (PL) were used to obtain toxin analogue resistant strains from 25 materials of fermented foods. Through the second screening of ZEN as the selective stress, a ZEN detoxified microorganism with high decomposition efficiency was confirmed. Its degradation efficiency was further evaluated in analysis of ZEN residue of bacteria suspension using high performance liquid chromatography (HPLC). Then we analysed the properties of producing cellulase, xylanase and β-glucosidase separately. The strain was identified for the taxonomical position using morphological observation and molecular identification. [Results] A ZEN detoxified strain BF-B-3 was screened and identified as Bacillus subtilis. Its degradation rate reached 62.48%. The cellulase, xylanase and β-glucosidase activity of Bacillus subtilis BF-B-3 reached 160.38 U/mL, 84.51 U/mL and 4.14 U/mL separately. [Conclusion] Bacillus subtilis is a kind of feed microorganism. Bacillus subtilis BF-B-3 has favorable security for detoxifying ZEN, and could grow under different carbon sources. Bacillus subtilis BF-B-3 has potential values for preventing mould pollution of crops and feed.