一株產低溫堿性淀粉酶蕈狀芽孢桿菌的分離篩選和發酵優化

劉佳慧 呂紅 林娟

本研究的目的是從生態環境獨特而復雜的西藏林芝地區的土壤樣品中挖掘所蘊藏的特殊淀粉酶微生物資源.采用淀粉酶功能篩選的方法獲得一株低溫堿性淀粉酶生產菌株，編號為3F1.其酶活最適條件為10 ℃、pH 10.2.通過16S rDNA序列分析法鑒定該菌株為蕈狀芽孢桿菌（Bacillus mycoides），并將其命名為Bm3F1.通過發酵條件的逐步優化，最終確定其最佳發酵條件為：發酵培養基中添加1.5%可溶性淀粉，培養基初始pH 7.2，裝液量10 mL/250 mL，菌體接種量9.0%，發酵溫度30 ℃，發酵時間18 h，經優化后可將菌株的酶活提升至13.58 U/mL. 表明從西藏林芝地區分離的Bm3F1具有在低溫和堿性條件下產較高酶活淀粉酶的特性.

低溫堿性淀粉酶; 蕈狀芽孢桿菌; 分離篩選; 發酵條件優化

Q93A2023.026001

收稿日期： 2022-05-09

基金項目： 上海市科技攻關項目 （19DZ2282100）; 西藏大學-復旦大學生物多樣性與全球變化聯合實驗室資助項目

作者簡介： 劉佳慧 （1997- ）， 女， 上海人， 碩士研究生， 研究方向為微生物活性物質挖掘. E-mail： 19210700068@fudan.edu.cn

通訊作者： 林娟. E-mail： linjuan@fudan.edu.cn; 呂紅. E-mail： honglv@fudan.edu.cn

Isolation and screening of psychrophilic and alkaline amylase-producing Bacillus mycoides strain 3F1 and the optimum fermentation for enzyme production

LIU Jia-Hui， L Hong， LIN Juan

（School of Life Science， State Key Laboratory of Genetic Engineering， Tibet University-Fudan University Joint Laboratory for Biodiversity and Global Change， Fudan University， Shanghai 200438， China）

This study is intended to explore the microbial resource contained in the soil samples of Nyingchi， Tibet， which has a unique and complex ecological environment. A psychrophilic and alkaline amylase-producing strain was obtained by the amylase functional screening method， numbered 3F1. The optimum conditions of amylase activity were 10 ℃ and pH 10.2. According to the 16S rDNA sequencing and phylogenetic analysis result， this strain was classified as Bacillus mycoides and named Bm3F1. Through the gradual optimization of fermentation conditions， the optimum fermentation condition for Bm3F1 was determined as follows： fermentation medium was supplemented with 1.5% soluble starch， the initial pH was 7.2， the liquid volume was 10 mL/250 mL， the bacterial inoculum was 9.0%， and the fermentation temperature and time were 30 ℃ and 18 hours， respectively. Under the optimum conditions， the amylase activity from Bm3F1 could be increased to 13.58 U/mL. The results showed that Bm3F1 isolated from Nyingchi， Tibet， has the characteristics of producing high activity amylase under low temperature and alkaline conditions.

Psychrophilic and alkaline amylase; Bacillus mycoides; Isolation and screening; Fermentation condition optimization

1 引 言

淀粉酶全稱為葡聚糖水解酶，屬于一種水解酶類，能催化淀粉、糖原和糊精等多糖化合物中的糖苷鍵，將其水解轉化成葡萄糖、麥芽糖及其他低聚糖.在淀粉為原料的工業生產中，淀粉酶作為最重要的一種水解酶，可參與液化（liquefaction）和糖化（saccharification）等加工過程.例如生淀粉降解酶（Raw starch degrading enzymes， RSDE）在淀粉糊化階段可直接用于降解生淀粉顆粒，具有顯著的節省能源和簡化工序等效益［1］.目前淀粉酶已經成為用途最廣、產量最大的一種酶制劑，占整個酶制劑……