Department of Biochemistry and Biotechnology, Faculty of Enology, Rovira i Virgili University, Tarragona, Spain.
Int Microbiol. 2011 Dec;14(4):225-33. doi: 10.2436/20.1501.01.152.
Wine can contain trace amounts of ethyl carbamate (EC), a carcinogen formed when ethanol reacts with carbamyl compounds such as citrulline. EC is produced from arginine by lactic acid bacteria (LAB), e.g., Lactobacillus and Pediococcus. Although the amounts of EC in wine are usually negligible, over the last few years there has been a slight but steady increase, as climate change has increased temperatures and alcohol levels have become proportionately higher, both of which favor EC formation. In this study, resting cells of LAB were used to evaluate the effects of ethanol, glucose, malic acid, and low pH on the ability of non-oenococcal strains of these bacteria to degrade arginine and excrete citrulline. Malic acid was found to clearly inhibit arginine consumption in all strains. The relation between citrulline produced and arginine consumed was clearly higher in the presence of ethanol (10-12%) and at low pH (3.0), which is consistent with both the decreased amount of ornithine produced from arginine and the reduction in arginine degradation. In L. brevis and L. buchneri strains isolated from wine and beer, respectively, the synthesis of citrulline from arginine was highest.
葡萄酒中可能含有痕量的乙基卡巴肼（EC），这是乙醇与瓜氨酸等氨基甲酰化合物反应生成的一种致癌物质。EC 由精氨酸通过乳酸细菌（LAB）产生，例如，乳杆菌属和肠球菌属。尽管葡萄酒中的 EC 含量通常可以忽略不计，但近年来，由于气候变化导致温度升高，酒精含量相应升高，这两种情况都有利于 EC 的形成，因此含量略有稳步上升。在这项研究中，使用静止细胞的 LAB 来评估乙醇、葡萄糖、苹果酸和低 pH 值对这些细菌的非酿酒菌株降解精氨酸和排泄瓜氨酸的能力的影响。发现苹果酸明显抑制所有菌株对精氨酸的消耗。在存在乙醇（10-12%）和低 pH 值（3.0）的情况下，产生的瓜氨酸与消耗的精氨酸之间的关系明显更高，这与从精氨酸产生的鸟氨酸量减少以及精氨酸降解减少一致。在分别从葡萄酒和啤酒中分离出来的短乳杆菌和布赫纳乳杆菌菌株中，精氨酸合成瓜氨酸的能力最高。
