一株产柚苷酶的罗伦隐球酵母的鉴定及柚苷酶表达

Characterization of Cryptococcus sp. Jmudeb008 and regulation of naringinase activity by glucose

摘要:

摘要：【目的】对一株新分离的、产生柚苷酶的疑似酵母菌株Jmudeb008进行鉴定，确定其分类的种属关系，阐明葡萄糖对该菌株表达柚苷酶的影响。【方法】利用形态观察、核酸分析及生理生化实验对Jmudeb008进行种属鉴定；用含有0.5 g/L柚皮苷及不同浓度葡萄糖的培养基培养Jmudeb008，通过检测培养过程柚皮苷、柚皮素及葡萄糖浓度的变化研究葡萄糖对Jmudeb008表达柚苷酶的影响。【结果】Jmudeb008的菌落形态及个体形态都与典型的酵母相似，其26S rDNA D1/D2区域和5.8S rDNA-

Abstract:

Abstract: [Objective] We identified a new isolated naringinase-producing yeast strain named as Jmudeb008, and analyzed its naringinase-producing ability cultured with different composition and concentration of carbon sources. [Methods] The strain was identified based on conventional phenotypic methods and sequences of the D1/D2 region of 26S rDNA and 5.8S-ITS. Media with different composition and concentration of carbon sources were used in shaking culture of Jmudeb008. The activity of naringinase was evaluated by analyzing the concentration of naringin, naringenin and glucose during 48 h culture. [Results] The Jmudeb008’s sequences of the D1/D2 region of 26S rDNA and 5.8S-ITS were 99% identical with Cryptococcus laurentii. Further glucose fermentation test, urease test, DBB (diazotization based blue）test and nitrate reduction test were coincided with results of DNA sequencing. Therefore, Jmudeb008 was identified as Cryptococcus laurentii. When Jmudeb008 was cultured in the medium with naringin as the only carbon source, it could synthesize naringinase. However, when glucose was available, the synthesis of naringinase was repressed. [Conclusion] The new isolated naringinase-producing yeast strain Jmudeb008 was identified as Cryptococcus laurentii. The glucose in medium repressed naringinase expression.