【摘要】 从土壤中分离到1株能在55℃生长并分泌耐高温α-淀粉酶的菌株,其最适生长pH值为7.0～8.0,最适生长温度50℃。该菌株经初步鉴定为芽孢杆菌,疑似微地衣芽孢杆菌,命名为DG-1。对该菌株分泌的耐高温α-淀粉酶的性质研究表明,最适作用pH值为7.0,在pH6.0～7.5的范围内有较高酶活。最适反应温度为95℃,95℃保温60min处理后酶活仅损失4.73%。经紫外线诱变处理,得到菌株DG-4,酶活较出发菌株提高了104.6%。更多还原

【Abstract】 Thermostable α-amylase as a secretion from a thermophilic Bacillus DG-1 that was isolated from soil. The strain DG-1 can grow at a wide range of pH, from 5.0 to 11.0. The optimum pH for it is 7.0~8.0 and the optimum temperature is 50℃. The strain is bacillus by initial identification, and it most probably micro-bnfillus licheniformis, be named DG-1. The optimum temperature and pH for it were 95℃ and 7.0 after research the character of α-amylase. It has high activity in the range of pH 6.0~7.5. The enzyme activity was lost only 4.73% at 95℃ for 60 min. DG-1 was screened as the original strain and treated with ultraviolet radiation (UV) mutation. Comparisons to the original strain showed that the thermostable α-amylase producing ability of DG-4 increased 104.6% after the treatment with UV.更多还原