Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
Environ Microbiol Rep. 2018 Aug;10(4):412-427. doi: 10.1111/1758-2229.12626. Epub 2018 Mar 25.
This review surveys the current state of knowledge of the concentrations, sources and sinks of reactive oxygen species (ROS) in the ocean. Both abiotic and biotic factors contribute to ROS dynamics in seawater, and ROS can feature prominently in marine microbe-microbe interactions. The sun plays a key role in the production of ROS in the ocean, and consequently ROS concentrations are typically maximal in the sun-exposed surface. However, microbes can also contribute significantly to extracellular ROS. Production of superoxide is widespread within the microbial community, and may benefit the producers as antimicrobial agents or perhaps more generally, as a means of nutrient scavenging. Decomposition of hydrogen peroxide is a community-wide activity, though some members may play less significant roles in this process. The more reactive forms of ROS, singlet oxygen and the hydroxyl radical, may be less important as microbial stressors, as they tend to react with the chemicals in seawater before they can contact the cells. However, exceptions may exist for microbes attached to singlet oxygen-generating sinking particulate matter. Extracellular ROS thus plays an important role in the ecology of marine microbes, the full extent to which we are only beginning to appreciate.
本综述调查了海洋中活性氧 (ROS) 的浓度、来源和汇的现有知识状况。非生物和生物因素都促成了海水中 ROS 的动态变化，ROS 在海洋微生物相互作用中可能占据重要地位。太阳在海洋中 ROS 的产生中起着关键作用，因此 ROS 浓度通常在阳光照射的表面达到最大值。然而，微生物也可以显著地向细胞外产生 ROS。超氧化物的产生在微生物群落中广泛存在，可能对生产者有利，作为抗菌剂，或者更普遍地，作为一种营养物质掠夺的手段。过氧化氢的分解是一种全社区范围的活动，尽管有些成员在这个过程中可能扮演的角色不那么重要。更具反应性的 ROS 形式，如单线态氧和羟基自由基，作为微生物胁迫物可能不太重要，因为它们在与细胞接触之前往往会与海水中的化学物质发生反应。然而，对于附着在产生单线态氧下沉颗粒物质上的微生物，可能存在例外情况。因此，细胞外 ROS 在海洋微生物的生态学中发挥着重要作用，而我们才刚刚开始认识到这一点。
