State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China.
Environ Sci Technol. 2011 Nov 15;45(22):9531-7. doi: 10.1021/es2020132. Epub 2011 Oct 20.
Methane (CH(4)) may be generated via microbial and nonmicrobial mechanisms. Nonmicrobial CH(4) is also ubiquitous in nature, such as in biomass burning, the Earth's crust, plants, and animals. Relative to microbial CH(4), nonmicrobial CH(4) is less understood. Using fresh (living) and dried (dead) leaves and commercial structural compounds (dead) of plants, a series of laboratory experiments have been conducted to investigate CH(4) emissions under aerobic and anaerobic conditions. CH(4) emissions from fresh leaves incubated at ambient temperatures were nonmicrobial and enhanced by anaerobic conditions. CH(4) emissions from dried leaves incubated at rising temperature ruled out a microbial-mediated formation pathway and were plant-species-dependent with three categories of response to oxygen levels: enhanced by aerobic conditions, similar under aerobic and anaerobic conditions, and enhanced by anaerobic conditions. CH(4) emissions in plant structural compounds may help to fully understand nonmicrobial CH(4) formation in plant leaves. Experiments of reactive oxygen species (ROS) generator and scavengers indicate that ROS had a significant role in nonmicrobial CH(4) formation in plant material under aerobic and anaerobic conditions. However, the detailed mechanisms of the ROS were uncertain.
甲烷（CH(4)）可能通过微生物和非微生物机制产生。非微生物 CH(4)在自然界中也很普遍，如生物质燃烧、地壳、植物和动物。与微生物 CH(4)相比，非微生物 CH(4)的了解较少。使用新鲜（活）和干燥（死）的叶子和植物的商业结构化合物（死），进行了一系列实验室实验，以研究有氧和厌氧条件下的 CH(4)排放。在环境温度下孵育的新鲜叶子的 CH(4)排放是非微生物的，并受到厌氧条件的增强。在升温条件下孵育的干燥叶子的 CH(4)排放排除了微生物介导的形成途径，并且与氧气水平的三种反应类别有关：有氧条件下增强，有氧和厌氧条件下相似，以及厌氧条件下增强。植物结构化合物中的 CH(4)排放可能有助于全面了解植物叶子中非微生物 CH(4)的形成。活性氧（ROS）发生器和清除剂的实验表明，ROS 在有氧和厌氧条件下的植物材料中非微生物 CH(4)形成中起重要作用。然而，ROS 的详细机制尚不确定。
