橙汁中两株条件致病酵母的形态及分子鉴定

目的：为建立更加完善的橙汁酵母菌检测体系，进一步精确监控市售橙汁质量，对市售橙汁中分离的两株酵母菌Y25、Y32进行菌落动态发育和细胞特征的观察。方法：以NL1和NL4为引物，对分离到的两株酵母菌基因组进行26S rDNA D1/D2区域序列扩增。结果：酵母菌的菌落形态随培养时间延长发生变化，菌落发育形态和菌体细胞特征对菌株鉴定具有直观、简洁的优点；PCR扩增后的基因碱基序列经GeneBank公布的同源基因碱基序列比对后，相似度在99%以上。结论：把分离到的Y25、Y32鉴定为汉逊德巴利酵母(Debaryomyces hansenii)和近平滑假丝酵母(Candida parapsilosis)。形态学与分子技术的结合使鉴定结果更为准确可靠，将为橙汁中其他腐败微生物的鉴定与监控提供有价值的借鉴。

Morphological and Molecular Identification of Two Opportunistic Pathogenic Yeast Strains in Orange Juice

In order to establish a complete detection system for spoilage yeasts and to monitor the quality of orange juice in market, the colony dynamic development and cell characteristics of yeast strains Y25 and Y32 isolated from orange juice were examined. The domain sequences 26S rDNA D1/D2 from Y25 and Y32 were amplified with NL1 and NL4 primers, respectively. The results showed that the morphological features of colonies for the same strain changed with culture time and were clear and concise and could therefore be used to identify the yeast strains isolated. Through comparison with the homologous gene sequences published in GeneBank, Y25 was identified as Debaryomyces hansenii, and Y32 as Candida parapsilosis. Their similarity degrees to the homologous gene sequences were both higher than 99%. The combination of morphology and molecular technology can allow to more accurately and reliably identify yeast strains and will provide valuable references for the identification and monitoring of other spoilage microorganisms in orange juice.