Isolation and Identification of Spoilage Organism in Strawberry and Screening of Antagonistic Yeast

To isolate,purify and identify the main spoilage organisms in the stawberry and screen the yeast with good antagonistic ability to bacteria and large biological control potential. The main spoilage organisms were screened by colony morphology and microscopic morphology,and the genus was identified by 28S rDNA sequence analysis. The yeast with obvious antagonism were selected,and which were identified by the 26S rDNA sequence similarity analysis. The wounded winter jujubes were inoculated with selected yeast and the spoilage organism at the same time. In this way to verify the yeast antagonistic ability and analyze the application effect of yeast as a biocontrol bacteria. This study showed that the main spoilage organisms carried by strawberries were 5 kinds of common molds in the air which were Cladosporium sp. Botrytis cinereal Alternaria sp.,Mucor sp.,and Geotrichum candidum. Twenty-three strains of antagonistic strains against spoilage organisms were screened from 191 strains of yeast,belonging to 17 genera. Metschnikowia pulcherrima S4-1 showed good antagonistic effects in experiments.