脱氧雪腐镰刀菌烯醇(DON)降解菌Devosia sp.A8和Paracoccus yeei A9的生理生化及生长特性

Physiological and growth characteristics of DON degrading consortium comprising Devosia sp.A8 and Paracoccus yeei A9

由菌株A8和A9组成的人工混菌能够有效地降解脱氧雪腐镰刀菌烯醇(DON)毒素。为了对双菌降解系统进行深入了解,对这2株菌进行严格的生理生化试验,并通过单因素设计,探究不同培养条件(时间、培养基、温度、pH、NaCl质量浓度、抗生素及摇床转速)对其生长状况的影响。通过生理生化试验,进一步确认了菌株A8和A9分别为Devosia sp.和Paracoccus yeei。生长特性研究结果表明:Devosia sp.A8最适宜生长的培养基为多价蛋白胨-酵母粉(PY)培养基,最适pH为8.0,最适培养温度为30℃,最适NaCl质量浓度为5 g/L;而P.yeei A9的最适培养基则为超优肉汤(SOC)培养基,最适pH为7.0~8.0,最适培养温度为35℃,最适NaCl质量浓度为2 g/L。Devosia sp.A8和P.yeei A9的培养条件较为温和,为以后大规模发酵生产以开发DON降解菌剂或酶制剂提供了有利条件。

An artificial bacterial consortium comprising two strains,A8 and A9,was constructed to degrade deoxynivalenol(DON).To identify the strain A8 and A9,physiological and biochemical analysis was performed.Then,the effects of culture conditions(time,medium,NaCl,temperature,pH,shaker speed and antibiotics) on the growth of A8 and A9 were studied.According to the physiological and biochemical characteristics,strain A8 and A9 were identified as Devosia sp.and Paracoccus yeei,respectively.Devosia sp.A8 and P.yeei A9 were sensitive to most antibiotics.The most suitable medium for Devosia sp.A8 was poly peptone-yeast extract(PY) medium(pH 8.0),the optimal NaCl concentration in medium was 5 g/L and the optimal temperature wass 30 ℃.The most suitable medium for P.yeei A9 was Super Optimal Broth with Catabolic Repression(SOC) medium(pH 7.0-8.0),the optimal NaCl concentration in medium was 2 g/L and the optimal temperature was 35 ℃.In conclusion,the optimal conditions for the growth of Devosia sp.A8 and P.yeei A9 were relatively mild,that is beneficial to obtain DON degrading bacteria or enzyme through large-scale fermentation in the future.