Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
Curr Microbiol. 2011 Feb;62(2):671-8. doi: 10.1007/s00284-010-9761-8. Epub 2010 Sep 25.
A mesophilic bacterium capable of utilizing acrylamide was isolated, AUM-01, from soil collected from leaf litter at Picnic Point on the UW-Madison campus. In minimal medium with acrylamide as the sole carbon and nitrogen source, a batch culture of AUM-01 completely converted 28.0 mM acrylamide to acrylic acid in 8 h and reached a cell density of 0.3 (A₆₀₀)). Afterward all the acrylic acid was degraded by 20 h with the cell density increasing to 1.9 (A₆₀₀). The acrylamide-utilizing bacterium was identified as Ralstonia eutropha based on morphological observations, the BiOLOG GN2 MicroPlate™ identification system for Gram-negative bacteria, and additional physiological tests. An acrylamidase that hydrolyzes acrylamide to acrylic acid was purified from the strain AUM-01. The molecular weight of the enzyme from AUM-01 was determined to be 38 kDa by SDS-PAGE. The enzyme had pH and temperature optima of 6.3 and 55°C, and the influence of different metals and amino acids on the ability of the purified protein to transform acrylamide to acrylic acid was evaluated. The enzyme from AUM-01 was totally inhibited by ZnSO₄ and AgNO₃.
从威斯康星大学麦迪逊分校野餐点采集的落叶土壤中分离到了一株能利用丙烯酰胺的嗜温细菌，命名为 AUM-01。在以丙烯酰胺为唯一碳源和氮源的基础培养基中，AUM-01 分批培养 8 小时后可将 28.0 mM 丙烯酰胺完全转化为丙烯酸，细胞密度达到 0.3（A₆₀₀）。20 小时后，所有的丙烯酸都被降解，细胞密度增加到 1.9（A₆₀₀）。根据形态学观察、BiOLOG GN2 MicroPlate™革兰氏阴性细菌鉴定系统以及其他生理测试，将利用丙烯酰胺的细菌鉴定为恶臭假单胞菌。从菌株 AUM-01 中纯化出了一种能水解丙烯酰胺生成丙烯酸的丙烯酰胺酶。SDS-PAGE 确定该酶的分子量为 38 kDa。该酶的最适 pH 和温度分别为 6.3 和 55°C，并评估了不同金属离子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。AUM-01 的酶被 ZnSO₄ 和 AgNO₃ 完全抑制。
