Oremland Ronald S, Saltikov Chad W, Stolz John F, Hollibaugh James T
U.S. Geological Survey, Menlo Park, CA 94025, USA.
Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, CA 95064, USA.
FEMS Microbiol Lett. 2017 Aug 15;364(15). doi: 10.1093/femsle/fnx146.
A number of prokaryotes are capable of employing arsenic oxy-anions as either electron acceptors [arsenate; As(V)] or electron donors [arsenite; As(III)] to sustain arsenic-dependent growth ('arsenotrophy'). A subset of these microorganisms function as either chemoautotrophs or photoautotrophs, whereby they gain sufficient energy from their redox metabolism of arsenic to completely satisfy their carbon needs for growth by autotrophy, that is the fixation of inorganic carbon (e.g. HCO3-) into their biomass. Here we review what has been learned of these processes by investigations we have undertaken in three soda lakes of the western USA and from the physiological characterizations of the relevant bacteria, which include the critical genes involved, such as respiratory arsenate reductase (arrA) and the discovery of its arsenite-oxidizing counterpart (arxA). When possible, we refer to instances of similar process occurring in other, less extreme ecosystems and by microbes other than haloalkaliphiles.
许多原核生物能够利用砷的含氧阴离子作为电子受体[砷酸盐；As(V)]或电子供体[亚砷酸盐；As(III)]来维持依赖砷的生长（“砷营养”）。这些微生物中的一部分作为化学自养生物或光合自养生物发挥作用，通过砷的氧化还原代谢获得足够的能量，以完全满足其自养生长的碳需求，即将无机碳（如HCO3-）固定到其生物量中。在这里，我们回顾了我们在美国西部的三个苏打湖所进行的研究以及相关细菌的生理学特征中所了解到的这些过程，其中包括所涉及的关键基因，如呼吸性砷酸盐还原酶（arrA）及其亚砷酸盐氧化对应物（arxA）的发现。在可能的情况下，我们还提及了在其他不太极端的生态系统以及除嗜盐碱菌以外的微生物中发生的类似过程的实例。
