Department of Agricultural Chemistry, Faculty of Agriculture, Kobe University, Rokkodai, Nada-ku, Kobe 657, Japan.
Appl Environ Microbiol. 1987 Apr;53(4):768-71. doi: 10.1128/aem.53.4.768-771.1987.
Starting with a strain of Bacillus cereus excreting about 40-fold more beta-amylase than does the original wild-type strain, we isolated, after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine, a strain designated BQ10-S1 SpoIII which showed under optimal conditions a further 5.5-fold increase in beta-amylase activity. The amylase production of this strain was observed to increase in the presence of 0.5% glucose or 1% maltose and, more markedly, in the presence of 2% soluble starch in the culture medium. The enzyme produced by this strain was immunologically identical to the wild-type enzyme, suggesting that either the copy number of the gene or the efficiency of enzyme synthesis from it, or both, are altered in this strain.
从一株产β-淀粉酶比原始野生型菌株高出约 40 倍的蜡状芽孢杆菌出发，我们用 N-甲基-N′-硝基-N-亚硝基胍诱变后，分离到一株被命名为 BQ10-S1 SpoIII 的菌株，该菌株在最佳条件下β-淀粉酶活性进一步提高了 5.5 倍。该菌株的淀粉酶产量在培养基中存在 0.5%葡萄糖或 1%麦芽糖时增加，更显著的是，在存在 2%可溶性淀粉时增加。该菌株产生的酶与野生型酶免疫上相同，表明该菌株中基因的拷贝数或从其合成酶的效率，或两者都发生了改变。
