碳源及阻遏蛋白CreA对黑曲霉产α-L-鼠李糖苷酶的影响  

Effect of Carbon Sources and Repressor Protein CreA on α-L-Rhamnosidase Production of Aspergillus niger

作　　者：张霞[1] 李利君[1,2,3] 倪辉[1,2,3] 肖安风[1,2,3] 陈峰[1,4] 苏文金[1,2,3] 

机构地区：[1]集美大学食品与生物工程学院,福建厦门361021 [2]福建省食品微生物与酶工程重点实验室,福建厦门361021 [3]福建省高校食品微生物与酶工程技术研究中心,福建厦门361021 [4]美国克莱姆森大学食品科学、营养与包装科学系,美国南卡罗琳娜州29634

出　　处：《中国食品学报》2016年第1期54-60,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31371751);福建省自然科学基金项目(2011J01225);厦门科技计划项目(3502Z20153008)

摘　　要：【目的】研究碳源对黑曲霉JMU-TS528发酵α-L-鼠李糖苷酶的影响,并探讨葡萄糖阻遏黑曲霉合成α-L-鼠李糖苷酶的分子机制。【方法】分别用5种单一碳源进行摇瓶发酵,高效液相色谱法测定经黑曲霉发酵后产物中的α-L-鼠李糖苷酶活性;通过在培养基中添加葡萄糖进行液态发酵,研究葡萄糖对黑曲霉JMU-TS528产α-L-鼠李糖苷酶的影响,并用实时定量PCR技术检测α-L-鼠李糖苷酶基因rha和葡萄糖抑制基因Cre A的相对表达量。【结果】黑曲霉JMU-TS528在以柚皮苷、橘皮苷、芸香苷和鼠李糖为唯一碳源时可分泌α-L-鼠李糖苷酶,以葡萄糖为唯一碳源时不能合成α-L-鼠李糖苷酶;培养基中添加葡萄糖后,黑曲霉发酵产物中α-L-鼠李糖苷酶活性降低,黑曲霉α-L-鼠李糖苷酶基因rha表达量降低,而葡萄糖抑制基因Cre A表达量上升。【结论】黑曲霉JMU-TS528菌株液态发酵条件下合成α-L-鼠李糖苷酶需要诱导物作为碳源,该菌株合成α-L-鼠李糖苷酶的能力受到葡萄糖的调节作用,此调控过程可能通过一个依赖阻遏蛋白Cre A的机制实现。[Objective] The aim of this work was to investigate the effects of different carbon sources on the production of α-L-rhamnosidase by Aspergillus niger, and to explore the molecular mechanism of glucose repression on the synthesis of α-L-rhamnosidase. [Methods] The A. niger JMU-TS528 strain was cultured in the medium contained naringin, hesperidin, rutin, rhamnose and glucose as sole carbon sources in shake flask, respectively. Then the α-L-rhamnosidase activity was measured by High Performance Liquid Chromatography（HPLC）. Further to study the effect of glucose on α-L-rhamnosidase production, the relative expression of the α-L-rhamnosidase gene rha and glucose repression gene CreA was examined by Real Time PCR（RT-PCR）to compare the different expression level with or without adding glucose during culture. [Results] α-L-rhamnosidase can be induced when naringin, hesperidin, rutin and rhamnose were used as the sole carbon source; while no activity of α-L-rhamnosidase was detected when glucose was used as the sole carbon source. Furthermore, a lower enzymatic activity was observed by adding of glucose, and the expression of α-L-rhamnosidase gene（rha） was decreased also. In the same time, it was found that the expression level of glucose repression gene CreA was increased greatly. [Conclusion] L-rhamnose or L-rhamnose-containing flavonoid glycosides（rutin, hesperidin, and naringin） can be used as specific inducers for α-L-rhamnosidase production. L-Rhamnose induction of A. niger JMU-TS528 α-L-rhamnosidase genes is glucose repressed and may function via a Cre A-dependent mechanism.

关 键 词：α-L-鼠李糖苷酶 葡萄糖抑制基因CreA 实时定量多聚核苷酸链式反应 黑曲霉 

分 类 号：TQ925[轻工技术与工程—发酵工程]