Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands.
Biochem Soc Trans. 2011 Jan;39(1):230-5. doi: 10.1042/BST0390230.
The reduction of (per)chlorate and nitrate in (per)chlorate-reducing bacteria shows similarities and differences. (Per)chlorate reductase and nitrate reductase both belong to the type II DMSO family of enzymes and have a common bis(molybdopterin guanine dinucleotide)molybdenum cofactor. There are two types of dissimilatory nitrate reductases. With respect to their localization, (per)chlorate reductase is more similar to the dissimilatory periplasmic nitrate reductase. However, the periplasmic, unlike the membrane-bound, respiratory nitrate reductase, is not able to use chlorate. Structurally, (per)chlorate reductase is more similar to respiratory nitrate reductase, since these reductases have analogous subunits encoded by analogous genes. Both periplasmic (per)chlorate reductase and membrane-bound nitrate reductase activities are induced under anoxic conditions in the presence of (per)chlorate and nitrate respectively. During microbial (per)chlorate reduction, molecular oxygen is generated. This is not the case for nitrate reduction, although an atypical reaction in nitrite reduction linked to oxygen formation has been described recently. Microbial oxygen production during reduction of oxyanions may enhance biodegradation of pollutants under anoxic conditions.
在（过）氯酸盐还原菌中，（过）氯酸盐和硝酸盐的还原显示出相似和不同之处。（过）氯酸盐还原酶和硝酸盐还原酶都属于 II 型 DMSO 酶家族，具有共同的双（钼喋呤鸟嘌呤二核苷酸）钼辅因子。有两种类型的异化硝酸盐还原酶。就其定位而言，（过）氯酸盐还原酶更类似于异化周质硝酸盐还原酶。然而，周质的，不像膜结合的，呼吸硝酸盐还原酶，不能使用氯酸盐。结构上，（过）氯酸盐还原酶与呼吸硝酸盐还原酶更相似，因为这些还原酶具有类似的亚基，由类似的基因编码。在缺氧条件下，分别存在（过）氯酸盐和硝酸盐时，会诱导周质（过）氯酸盐还原酶和膜结合硝酸盐还原酶的活性。在微生物（过）氯酸盐还原过程中，会产生分子氧。硝酸盐还原则不是这样，尽管最近描述了一种与氧形成相关的亚硝酸盐还原的非典型反应。在缺氧条件下，氧阴离子还原过程中微生物产生的氧气可能会增强污染物的生物降解。
