中文摘要：

从高温环境土壤中分离到1株能在75℃生长并产生α-淀粉酶的菌株（POT5）,扩增了其16Sr DNA核苷酸序列,序列分析表明该菌属于Geobacillus属.根据该属全基因序列测定数据中推定的α-淀粉酶基因,利用PCR方法从G.sp.POT5基因组中扩增得到该菌α-淀粉酶基因（amyP）.序列分析表明该基因全长1.545 kb、G＋C含量51.33%,编码514个氨基酸.构建重组表达质粒pET22b（＋）-amyP,转化Escherichia coliBL21系统,表达产物经SDS-PAGE分析、活性染色及淀粉酶活力分析,表明amyP基因得到了表达,且产物具有生物学活性.

英文摘要：

A strain of bacterium which can grow at the temperature of 75℃ and secrete a-amylases was isolated from soil of thermal environment. It was identified as Geobacillus sp. according to the analysis of 16S rDNA nucleotide sequence. The gene of a-amylases（amyP）was amplified from the genome of G. sp. POT5 by PCR. Sequence analysis indicated that the gene was 1 545 bp in full size with 51. 33% content of G＋C, encoding 514 amino acids. The recombinant expression vector pET22b （＋）--amyP was constructed and transformed into Escherichia coli BL21, the expressed product was detected through SDS- PAGE, active-staining and activity analysis of a-amylase.