Department of Bacteriology and Department of Food Science, University of Wisconsin-Madison, 1550 Linden Dr., Microbial Sciences Building, Madison, WI 53706, USA.
Biodegradation. 2013 Feb;24(1):57-67. doi: 10.1007/s10532-012-9557-6. Epub 2012 May 26.
A thermophilic bacterium capable of degrading acrylamide, AUT-01, was isolated from soil collected from a hot spring area in Montana, USA. The thermophilic strain grew with 0.2 % glucose as the sole carbon source and 1.4 mM acrylamide as the sole nitrogen source. The isolate AUT-01 was identified as Geobacillus thermoglucosidasius based on 16S rDNA sequence. An enzyme from the strain capable of transforming acrylamide to acrylic acid was purified by a series of chromatographic columns. The molecular weight of the enzyme was estimated to be 38 kDa by SDS-PAGE. The enzyme activity had pH and temperature optima of 6.2 and 70 ºC, respectively. The influence of different metals and amino acids on the ability of the purified protein to transform acrylamide to acrylic acid was evaluated. The gene from G. thermoglucosidasius encoding the acrylamidase was cloned, sequenced, and compared to aliphatic amidases from other bacterial strains. The G. thermoglucosidasius gene, amiE, encoded a 38 kDa, monomeric, heat-stable amidase that catalysed the cleavage of carbon-nitrogen bonds in acrylamide. Comparison of the amino acid sequence to other bacterial amidases revealed 99 and 82 % similarity to the amino acid sequences of Bacillus stearothermophilus and Pseudomonas aeruginosa, respectively.
从美国蒙大拿州温泉地区采集的土壤中分离到了一种能够降解丙烯酰胺的嗜热菌 AUT-01。该嗜热菌株以 0.2%葡萄糖为唯一碳源和 1.4mM 丙烯酰胺为唯一氮源生长。根据 16S rDNA 序列，分离株 AUT-01 被鉴定为解糖热杆菌。通过一系列色谱柱对该菌株中能够将丙烯酰胺转化为丙烯酸的酶进行了纯化。SDS-PAGE 估计该酶的分子量为 38kDa。酶活性的 pH 和温度最适值分别为 6.2 和 70°C。评估了不同金属和氨基酸对纯化蛋白将丙烯酰胺转化为丙烯酸能力的影响。克隆、测序并比较了来自解糖热杆菌的编码丙烯酰胺酶的基因与来自其他细菌菌株的脂肪酰胺酶。解糖热杆菌基因 amiE 编码一个 38kDa、单体、耐热的酰胺酶，它催化丙烯酰胺中碳-氮键的断裂。将氨基酸序列与其他细菌酰胺酶进行比较，发现与嗜热脂肪芽孢杆菌和铜绿假单胞菌的氨基酸序列分别具有 99%和 82%的相似性。
