一起饮料微生物污染的鉴定报告The Identification Conclusion of a Drink Case with Microbial Contamination
史立敏, 李小曼, 王艳红, 宝福凯, 柳爱华
饮料, 黄曲霉菌, ITS区基因鉴定, 食品污染Drink, Aspergillus flavus, ITS Genotyping, Food Contamination
《Advances in Microbiology》, Vol.4 No.4, 2015-12-31
Objective: To isolate and identify the unknown microbes from the contaminated drink. Methods: With the naked eye observation of colony characteristics of isolated microorganisms inoculated in artificial culture medium, observation of colony morphology selected for staining in Medan under the microscope. The total DNA was extracted by DNA extraction kit, and used as the template, the PCR method was used to amplify the ITS gene fragment of this gene fragment, purified, sequenced by sequencing company, then the sequencing results were compared with the BLASTn tool, to find out the sequence of related strains, finally, the sequence of strains and sequence related strains in phylogenetic analysis based on the MEGA5.1 software. Result: The bacterial colony characteristics observed by naked-eye and the morphological characteristics observed microscopically show that the unknown microbe belongs to fungi; BLASTn comparison results of ITS sequence show that the unknown microbe is Aspergillus flavus, the similarity of them is 94% - 95%, and the phylogenetic tree reconstructed based on ITS shows that it is in the same clade as Aspergillus flavus. Conclusion: The unknown microbe in the drink is Aspergillus flavus.