Novel alkaline proteases from alkaliphilic bacteria grown on chicken feather
Novel alkaline proteases from alkaliphilic bacteria grown on chicken feather
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DOI：
10.1016/s0141-0229(02)00324-1
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发表时间：
2003-04-08
影响因子：
3.4
通讯作者：
Mattiasson, B
中科院分区：
文献类型：
--
作者：
Gessesse, A;Hatti-Kaul, R;Mattiasson, B
从天然碱性环境中分离到两株产碱性蛋白酶的嗜碱细菌，命名为AL-20和AL-89。经鉴定，这两株菌分别为Nesternkonia sp.和Bacillus pseudofirmus。这两种菌株生长和生产碱性蛋白酶使用羽毛作为唯一的碳和氮源。在羽毛培养基中添加0.5%葡萄糖可增加B的蛋白酶产量。pseudofirmus AL-89和Nesternkonia sp. AL-20的抑制酶产生。硫酸铵沉淀、离子交换、疏水相互作用和凝胶过滤层析后，将两种生物体的酶纯化至电泳均一。使用SDS-PAGE测定的蛋白酶AL-20的分子量为23 kDa，蛋白酶AL-89的分子量为24 kDa。蛋白酶AL-20在较宽的pH范围内有活性，在pH 7.5至11.5之间显示其最大活性的90%以上，在pH 10处具有峰。该酶的独特之处在于，与迄今为止已知的所有其他微生物丝氨酸蛋白酶不同，它不需要Ca 2+来获得活性和热稳定性。该酶的最适反应温度为70 ℃，在65 ℃下孵育1h后，在有Ca ~（2+）存在和无Ca ~（2+）存在的条件下均保持稳定。这些特性使蛋白酶AL-20成为洗涤剂应用的理想候选者。另一方面，蛋白酶AL-89在高于50 ℃的温度值下需要Ca 2+来保持活性和稳定性。其最佳活性分别为60 ℃和70 ℃，无Ca ~（2+）存在。它显示出最适pH值为11，并在pH 6.5和11之间保留约70%或更多的其原始活性。B。pseudofirmus AL-89，其产生的蛋白酶为羽毛的酶促和/或微生物水解提供了有趣的潜力，以用作动物饲料补充剂。(C)2002年爱思唯尔科技有限公司All rights reserved.
Two alkaline protease producing alkaliphilic bacterial strains, designated as AL-20 and AL-89, were isolated from a naturally occurring alkaline habitat. The two strains were identified as Nesternkonia sp. and Bacillus pseudofirmus, respectively. Both strains grew and produced alkaline protease using feather as the sole source of carbon and nitrogen. Addition of 0.5% glucose to the feather medium increased protease production by B. pseudofirmus AL-89 and suppressed enzyme production by Nesternkonia sp. AL-20. The enzymes from both organisms were purified to electrophoretic homogeneity following ammonium sulphate precipitation, ion exchange, hydrophobic interaction, and gel filtration chromatography. The molecular weight, determined using SDS-PAGE, was 23 kDa for protease AL-20 and 24 kDa for protease AL-89. Protease AL-20 was active in a broad pH range displaying over 90% of its maximum activity between pH 7.5 and 11.5 with a peak at pH 10. The enzyme is unique in that unlike all other microbial serine proteases known so far, it did not require Ca2+ for activity and thermal stability. Its optimum temperature for activity was at 70 degreesC and was stable after 1 h incubation at 65 degreesC both in the presence and absence of Ca2+. These properties make protease AL-20 an ideal candidate for detergent application. Protease AL-89 on the other hand require Ca2+ for activity and stability at temperature values above 50 degreesC. Its optimum activity was at 60 and 70 degreesC in the absence and presence of Ca2+, respectively. It displayed a pH optimum of 11 and retained about 70% or more of its original activity between pH 6.5 and 11. B. pseudofirmus AL-89, and the protease it produce offers an interesting potential for the enzymatic and/or microbiological hydrolysis of feather to be used as animal feed supplement. (C) 2002 Elsevier Science Inc. All rights reserved.