1株产单宁酶嗜热真菌的鉴定、酶学性质分析及碳水化合物活性酶表达  

Identification, Properties and Carbohydrate-Active Eenzymes(CAZymes) Expression Analysis of a Thermophilic Fungal Strain Producing Tannase

作　　者：谷新晰[1,2] 卢海强[1] 刘亚娟[3] 陈赛娟[3] 谷子林[4] 孟祥晨[2] 陈宝江[4] GU Xinxi;LU Haiqiang;LIU Yajuan;CHEN Saijuan;GU Zilin;MENG Xiangchen;CHEN Baojiang(College of Food Science and Technology,Hebei Agricultural University,Baoding 071000,China;Key Laboratory of Dairy Science,Ministry of Education,Northeast Agricultural University,Harbin 150030,China;Mountain Area Research Institute,Hebei Agricultural University,Baoding 071000,China;College of Animal Science and Technology,Hebei Agricultural University,Baoding 071000,China)

机构地区：[1]河北农业大学食品科技学院,河北保定071000 [2]东北农业大学乳品科学教育部重点实验室,黑龙江哈尔滨150030 [3]河北农业大学山区研究所,河北保定071000 [4]河北农业大学动物科技学院,河北保定071000

出　　处：《食品科学》2018年第18期88-93,共6页Food Science

基　　金：国家自然科学基金青年科学基金项目(31501417);河北省食品科学与工程学科"双一流"建设资金项目(2016SPGCA18)

摘　　要：对产单宁酶的1株嗜热真菌HBHF5进行鉴定,开展单宁酶酶学性质的分析及碳水化合物活性酶(carbohydrate-active enzymes,CAZymes)的转录组学研究,探究嗜热真菌HBHF5在食品酶制剂开发中的潜力。经对菌株的菌落、孢子形态观察及ITS序列比对分析,最终鉴定嗜热真菌HBHF5为烟曲霉(Aspergillus fumigatus)。经分析,菌株HBHF5在固态发酵培养时不产单宁酶,而液态诱导培养时,菌株HBHF5胞内和胞外均检测到单宁酶活性,且以胞外酶为主(94%),酶活力最高达136 U/m L。单宁酶最适反应温度为60℃,在60℃处理30 min,能够维持酶原活力的90%以上。该酶最适反应pH值为6.0,在p H 5.0~9.0范围内,能够维持60%以上的酶活力。不同金属离子对酶活力的影响存在差异,Cu^(2+)、Fe^(3+)、Mn^(2+)和Zn^(2+)对该单宁酶活性抑制较强。经转录组学分析,该菌以麸皮为唯一碳源时,共有淀粉酶、纤维素酶和果胶酶等239个CAZymes基因表达,其中糖苷水解酶类最为丰富,约占CAZymes表达总数的70%。A.fumigatus HBHF5是1株优良产酶菌株,为具有食品酶制剂开发潜力的嗜热真菌。In this study,a thermophilic fungal strain(HBHF5)producing tannase was identified.Also,the enzymatic properties of tannase from strain HBHF5 were evaluated and transcriptomic analysis of its carbohydrate-active enzymes(CAZymes)was carried out.We aimed to explore the potential of strain HBHF5 for use in the development of food enzyme preparations.Based on its morphology and ITS sequence alignment analysis,strain HBHF5 was identified as Aspergillus fumigatus.A.fumigatus HBHF5 did not produce tannase under solid-state fermentation(SSF),but it produced both extracellular and intracellular tannase when cultured under submerged fermentation conditions.The extracellular enzyme was found to be dominant(94%)and its activity was as high as 136 U/mL.Tannase activity was optimal at pH 6.0 and 60℃.After treatment at 60℃for 30 min,more than 90%of the initial activity was retained,and the residual activity was over 60%in the pH range of 5.0 to 9.0.The tannase activity was inhibited by some metal ions,such as Cu2+,Fe3+,Mn2+and Zn2+.Transcriptomic analysis showed that 239 CAZymes genes including those encoding amylase,cellulase and pectinase were expressed when wheat bran was used as the sole carbon source.Among these the most abundant was glycoside hydrolase,accounting for about 70%of the total CAZymes.It has been demonstrated that A.fumigatus HBHF5 is a good producer of tannase and has the potential to be used to develop food enzyme preparations.

关 键 词：单宁酶 嗜热酶 脱涩 转录组 碳水化合物活性酶 

分 类 号：Q939.97[生物学—微生物学]