Microbial Consumption of Methanol in a Grassland

草原是甲醇的重要全球来源，甲醇是对流层中高度丰富和反应性的挥发性有机化合物（VOC）。然而，在陆地生态系统中，土壤微生物对甲醇通量的影响的环境生理学在很大程度上还没有得到研究。申请人先前的工作表明，迄今未知的土壤细菌参与通气土壤的环境甲醇氧化。拟议的项目将解决好氧和厌氧甲醇利用（包括。革兰氏阳性细菌和真菌）在温带草原。它将与四个丰富的草原植物物种进行测试，如果这些都与不同的土壤和叶圈甲醇利用社区采用稳定同位素探测（SIP）。在一个植被期，甲醇通量和转录的基因标记的积极甲醇利用者将在调查的草原进行评估，并在一个确证的实验室实验的地下和地上甲醇通量的比例将被解决。14C示踪实验将用于定位土壤和植物中的活动。活性厌氧甲醇利用者的身份将得到解决，他们对不寻常的微量营养素（稀土元素）的依赖将通过实验确定。与MPI Mainz的J.威廉姆斯和A. Held（拜罗伊特大学）将通过质子转移质谱法（PTR MS）测量甲醇的原位通量，目的是将通量数据与原位活性微生物相关联。拟议的工作将设置一个升级的单物种的生理和分布到生态系统水平的甲醇通量在草原阶段。

Grasslands are substantial global sources of methanol, which is a highly abundant and reactive volatile organic compound (VOC) in the troposphere. However, environmental physiology of soil microorganisms that impact on methanol flux in terrestrial ecosystems has largely not been investigated. Previous work of the applicant suggests that hitherto unknown soil bacteria are involved in ambient methanol oxidation of aerated soil. The proposed project will address aerobic and anaerobic methanol-utilizers (incl. Gram-positive bacteria and fungi) in temperate grassland. It will be tested with four abundant grassland plant species if those are associated with distinct soil and phyllosphere methanol utilizer communities employing stable isotope probing (SIP). Over a vegetation period, methanol flux and transcribed gene markers of active methanol utilizers will be assessed at the investigated grassland, and in a corroborative laboratory experiment the ratio of below-ground and above-ground methanol flux will be resolved. 14C tracer experiments will be used to localize activities in soil and plants. The identities of active anaerobic methanol utilizers will be resolved and their dependence on unusual trace nutrients (rare earth elements) will be experimentally determined. In collaboration with J. Williams (MPI Mainz) and A. Held (University Bayreuth) in situ fluxes of methanol will be measured by proton transfer mass spectrometry (PTR MS) aiming at correlation of flux data with in situ active microorganisms. The proposed work will set the stage for an upscaling of single-species physiology and distribution to ecosystem-level methanol flux in grassland.