Abstract：
BACKGROUND: Ethyl carbamate (EC) is a potential carcinogen existing in fermented foods such as Chinese rice wine (Huangjiu). Since urea is an important precursor of EC, the degradation of urea could be an effective way to reduce EC in foods.
RESULTS: In this study, an Enterobacter sp. R-SYB082 with acid urea degradation characteristics was obtained through microbial screening. Further research isolated a new acid urea-degrading enzyme from R-SYB082 strain - ureidoglycolate amidohydrolase (UAH) - which could degrade EC directly. The cloning and expression of UAH in Escherichia coli BL21 (DE3) suggested that the activity of urea-degrading enzyme reached 3560 U L-1 , while urethanase activity reached 2883 U L-1 in the optimal fermentation condition. The enzyme had the dual ability of degrading substrate urea and product EC. The removal rate of EC in Chinese rice wine could reach 90.7%.
CONCLUSIONS: This study provided a new method for the integrated control of EC in Chinese rice wine and other fermented foods. © 2022 Society of Chemical Industry.
RESULTS: In this study, an Enterobacter sp. R-SYB082 with acid urea degradation characteristics was obtained through microbial screening. Further research isolated a new acid urea-degrading enzyme from R-SYB082 strain - ureidoglycolate amidohydrolase (UAH) - which could degrade EC directly. The cloning and expression of UAH in Escherichia coli BL21 (DE3) suggested that the activity of urea-degrading enzyme reached 3560 U L-1 , while urethanase activity reached 2883 U L-1 in the optimal fermentation condition. The enzyme had the dual ability of degrading substrate urea and product EC. The removal rate of EC in Chinese rice wine could reach 90.7%.
CONCLUSIONS: This study provided a new method for the integrated control of EC in Chinese rice wine and other fermented foods. © 2022 Society of Chemical Industry.
摘要：
背景：氨基甲酸乙酯（EC）是一种潜在的致癌物质，存在于中国黄酒（黄酒）等发酵食品中。由于尿素是EC的重要前体，尿素的降解可能是降低食品中EC含量的有效途径。
结果：在这项研究中，肠杆菌。通过微生物筛选得到具有酸性尿素降解特性的R-SYB082。进一步研究从R-SYB082菌株中分离出一种新的酸性尿素降解酶-脲基乙醇酸酰胺水解酶（UAH）-可以直接降解EC。UAH在大肠杆菌BL21（DE3）中的克隆和表达表明，尿素降解酶的活性达到3560UL-1，在最佳发酵条件下，氨基甲酸酯酶活性达到2883UL-1。该酶具有降解底物尿素和产物EC的双重能力。黄酒中EC的去除率可达90.7%。
结论：本研究为黄酒和其他发酵食品中EC的综合控制提供了新的方法。©2022化学工业学会。
结果：在这项研究中，肠杆菌。通过微生物筛选得到具有酸性尿素降解特性的R-SYB082。进一步研究从R-SYB082菌株中分离出一种新的酸性尿素降解酶-脲基乙醇酸酰胺水解酶（UAH）-可以直接降解EC。UAH在大肠杆菌BL21（DE3）中的克隆和表达表明，尿素降解酶的活性达到3560UL-1，在最佳发酵条件下，氨基甲酸酯酶活性达到2883UL-1。该酶具有降解底物尿素和产物EC的双重能力。黄酒中EC的去除率可达90.7%。
结论：本研究为黄酒和其他发酵食品中EC的综合控制提供了新的方法。©2022化学工业学会。
