周明炀^1,2，曾美端¹，成立文¹，肖余俊¹，叶婷娥¹，余超凡¹，郑 毅^1,2*

（1.福建师范大学生命科学学院，福建福州 350117；

2.福建师范大学工业微生物教育部工程研究中心，福建福州 350117）

摘要：食品工业上果糖基转移酶（FTase）是以蔗糖为底物酶法生产低聚果糖（FOS）的重要酶种，真菌是FTase主要微生物来源。以蔗糖为唯一碳源，通过检测发酵液FOS含量（初筛）和胞外、胞内的FTase酶活水平（复筛），成功筛选获得1株高产FTase的真菌菌株FS054，经ITS分子鉴定该菌株为黑曲霉，24 h胞内酶活达558.3 U/g。该FTase酶学特性研究表明：最适反应温度为55 ℃，最适反应pH为5.5，在30～35 ℃和pH 4.0～5.5的范围内酶活稳定性良好，0.5 mmol/L的Fe³⁺和Al³⁺具有激活效应，酶活性分别提高121.59%和110.26%，而Cu²⁺则严重抑制酶活力，相对酶活降至37.74%。本研究为后续全细胞生物合成FOS提供新酶源及前期基础。

关键词：真菌；果糖基转移酶；筛选；鉴定；酶学特性

中图分类号：TS201.3        文献标识码：A        文章编号：1674-506X（2023）03-0030-0006

Studies on Screening,Identification and Enzymatic Properties of

a Fungal Strain Producing Fructosyltransferase

ZHOU Mingyang^1,2, ZENG Meiduan¹, CHENG Liwen¹, XIAO Yujun¹, Ye Tinge¹, YU Chaofan¹, ZHENG Yi^1,2*

(1.College of Life Sciences, Fujian Normal University, Fuzhou Fujian 350117, China;

2.Fujian Engineering Research Center of Industrial Microbiology, Ministry of Education, Fujian Normal University, Fuzhou Fujian 350117, China)

Abstract: In the food industry,fructosyltransferase (FTase) is an important enzyme for the enzymatic production of fructooligosaccharides (FOS) based on sucrose,and fungi are the main microbial source of FTase. Using sucrose as the only carbon source,a fungal strain FS054 with high FTase production was successfully screened by detecting the FOS content in the fermentation broth (primary screening) and the FTase activity in the extracellular and intracellular enzyme (secondary screening).The strain was identified as Aspergillus niger by ITS molecules,and the intracellular enzyme activity reached 558.3 U/g within 24 h. The study on the enzymatic properties of FTase showed that the optimal reaction temperature was 55 ℃,the optimal reaction pH was 5.5,and the enzyme activity was stable in the range of 30～35 ℃ and pH 4.0～5.5,  0.5 mmol/L Fe³⁺ and Al³⁺ had an activation effect,and the enzyme activity was increased by 121.59% and 110.26% respectively,while Cu²⁺severely inhibited the enzyme activity,and the relative enzyme activity was reduced to 37.74%. This study provides a new enzyme source and preliminary basis for the subsequent whole cell biosynthesis of FOS.

Keywords: fungi; fructosyltransferase; screening; identification; enzymatic properties

doi: 10.3969/j.issn.1674-506X.2023.03-005

收稿日期：2022-11-09

基金项目：财政部与农业农村部国家现代农业产业技术体系资助项目（CARA-170501）

作者简介：周明炀（1999-），男，硕士。研究方向：微生物工程。

*通信作者；郑毅（1970-），男，副教授。研究方向：微生物工程研究。

引用格式:周明炀,曾美端,成立文,等.1株真菌果糖基转移酶高产菌的筛选、鉴定及其酶学特性的研究[J].食品与发酵科技,2023,59(3):30-35.