PETROX - Petroleum Alkane oxidation by Anaerobic Archaea

石油正构烷烃是原油中主要的一类化合物，其丰度决定了原油的流动性和可开发性。石油烷烃也是好氧和厌氧微生物的一种有吸引力的能量和碳源。本研究旨在利用最近获得的Candidatus Alkanophaga （ANME-1古菌的亲戚）和Candidatus Ca. Cerberiarchaeum（深分支hadarchae的一员）的独特培养物来解决厌氧石油烷烃氧化古菌的功能。这两种生物都与热脱硫菌一起生长，作为硫酸盐还原菌的伙伴。古细菌通过烷基辅酶M还原酶激活中至长链正构烷烃（C6-C20），烷基辅酶M还原酶是甲基辅酶M还原酶的不同变体，甲基辅酶M还原酶是已知的产生或捕获甲烷的酶。古细菌可能是地下石油转化的关键角色，并且具有有趣的未知生物化学。在PETROX项目中，我们将解决古细菌中石油烷烃降解的功能。围绕一个为期31年半的博士项目，我们将(1)优化两种培养物的生长条件，确定古菌及其伙伴适应溶剂样底物的策略；(2)利用天然结晶通过ACR分析石油烷烃活化的分子基础；(3)通过生理实验、稳定同位素探测实验和超微结构分析评估古菌与其细菌伙伴的相互作用。我们结合了我们在厌氧烃微生物学和生物化学方面的专业知识，并与可视化技术方面的专家合作。该项目将为地下微生物组成员的功能、激活长链烷烃的酶机制和共生相互作用提供基础知识。

Petroleum n-alkanes are a major compound class in crude oil, and their abundance determines the oils’ fluidity and exploitability. Petroleum alkanes are also an attractive energy and carbon source for aerobic and anaerobic microorganisms. This proposal aims at resolving the functioning of the anaerobic, petroleum-alkane oxidizing archaea using recently obtained, unique cultures of Candidatus Alkanophaga (a relative of the ANME-1 archaea) and Candidatus Ca. Cerberiarchaeum (a member of the deep-branching Hadarchaea). Both organisms grow with Thermodesulfobacteria as sulfate-reducing partners. The archaea activate mid- to long-chain n-alkanes (C6-C20) with alkyl coenzyme M reductases, divergent variants of methyl coenzyme M reductase, the enzyme known to generate or capture methane. The archaea are likely key players in subsurface oil transformations and have intriguing uncharted biochemistry. In the presented project PETROX, we will resolve the functioning of petroleum alkane degradation in archaea. Centralized around a 31/2-year PhD project, we will (I) optimize the growth conditions from both cultures and determine the strategies of the archaea and their partner to adapt to the solvent-like substrate (II) resolve the molecular basis of petroleum alkane activation via ACR using native crystallization (III) assess the interaction of the archaea with their bacterial partners in physiological experiments, stable isotope probing experiments and ultrastructural analyses. We combine our expertise in anaerobic hydrocarbon microbiology and biochemistry, and collaborate with experts in visualization techniques. This project will provide fundamental knowledge on the functioning of members from the subsurface microbiome, the enzyme mechanistic to activate long-chain alkanes and syntrophic interactions.