摘要
用淀粉平板透明圈法,从分离自腾冲热泉的高温菌中筛选到一株产胞外淀粉酶的菌株,经16sRNA序列比对,在Genbank中与Geobacillus sp.sbs4s有99%同源性,定名为Geobacillus sp.A27。该菌最适生长温度为60～65℃,在LB培养基上不生长,但能在以淀粉为唯一碳源的培养基上生长,并能将来自植物种子、根茎的淀粉质底物水解为以麦芽二糖为主的麦芽寡糖。Geobacillus sp.A27菌株产生的胞外α-淀粉酶最适pH5.6,最适温度70℃。金属离子Fe3+、Cu2+、EDTA对酶活有显著抑制作用,推测AmyA27可能属于金属酶。粗酶液经饱和硫酸胺沉淀、无水乙醇沉淀、8%分离胶的SDS-PAGE电泳和蛋白质复性,确定该淀粉酶分子量为67kD。
A strain with extracellular amylase was isolated by transparent circle in starch medium from Tengchong hot springs by 16sRNA sequence alignment in Genbank. It has 99% homology with Geobacillus sp. sbs4s, and blongs to Geobacillus sp.lt can grow up in culture medium in which starch was only one carbon source but can not in completely medium LB without starch.The amylase activity on solute starch was optimal at pH5.6 and 70℃The enzyme efficiently hydrolyzed various types of starch from plant seeds, roots and stems to yield a series of maltooligosaccharides by endo-cleavage mode.The enzyme had different reactions to varity metal ions,it was inhibited significantly by Fe3＋, EDTA and Cu2＋, it may belong to metal enzymes. The precipitate of the enzymes by ammonium sulfate and ethanol,d7kD for amylase molecular weight was determined by 8% separation glue SDSPAGE protein electropohoresis.
出处
《食品工业科技》
CAS
CSCD
北大核心
2011年第1期151-155,共5页
Science and Technology of Food Industry
基金
云南省应用基础研究计划重点项目(2006C0004Z)
