草莓表面典型微生物鉴定、16SrDNA同源性分析及附着能力研究(Ⅱ)

摘要

研究草莓表面微生物分布状况,分析其附着能力为草莓安全食用提供保障.按照草莓生长的3个阶段进行2年度连续抽样,对分离草莓的表面典型微生物进行生化分析及16SrDNA测序鉴定,对分离种最多的泛菌采用最大简约法(MP)进行系统进化分析,并观察沙雷菌和泛菌附着能力.结果表明,3种典型的沙雷菌属微生物在草莓表面均有检出,泛菌属微生物检出种类较多,且基因型差异较明显.在电镜下,能明显观察到泛菌属泛菌和粘质沙雷菌对草莓表皮的附着,含氯清洗剂和10％生理盐水可对其有效祛除.草莓表面附着多种属微生物,有效的清洗方法可以清除大部分微生物,此研究为草莓食用的风险评估提供理论依据.%The distribution of microorganisms on the surface of strawberry and their adhesion were studied to provide protection for the safe consumption of strawberry.Strawberry was continuously sampled within two years according to its three growing stages,the biochemical identification and 16SrDNA sequencing identification of the microorganisms on the surface of the sampled strawberry were conducted.Most isolated Pantoea by Maximum Parsimony (MP) phylogenetic analysis was conducted,and the adhesions of Serratia spp.and Pantoea spp.also were observed.The result showed that three typical Serratia spp.on the surface of strawberry were detected,and there were many kinds of Pantoea spp.with obviously different genotypes.Under the electron microscope,the adhesions of Pantoea spp.and Serratia marcescens on the surface of strawberry were clearly observed,which could be effectively eliminated by Chlorine-containing detergent and 10 ％ saline.Most of microorganisms existing on the surface of strawberry could be removed by effective cleaning methods.This research would provide theory basis for the risk assessment of the consumption of strawberry.