Insights into hydrocarbons cycling in the subsurface from isotopologue analysis

我们在新泻县Tokamachi泥火山的新气体渗漏处取样。我们测量了这些新渗漏处碳氢化合物的体积和特定位置的同位素组成。多亏了博士后张乃中博士，我们可以有效地测量来自这些不同渗漏层的甲烷的双取代同位素。数据显示，降解率从极低的生物降解率到bb0 - 90%的生物降解率。这使得Tokamachi成为研究碳氢化合物生物降解对其他分子影响的一个非常有趣的地方。我们注意到丙烷的生物降解与甲烷的双取代同位素丰度相关，表明甲烷生成与生物降解有关。

We sampled at Tokamachi mud volcano (Niigata prefecture) at new gas seeps. We measured bulk and position-specific isotope composition of hydrocarbons at these new seeps. Thanks to the post-doc employed (Dr Naizhong Zhang), we could measure efficiently the doubly-substituted isotopologues of methane from these different seeps.The data shows a full range of degradation rate from very low biodegradation to >90% biodegradation. This makes Tokamachi a very interesting place to study the impact of hydrocarbons biodegradation on other molecules.We notably showed that the biodegradation of propane is correlated with the abundance of the doubly-substituted isotopologues of methane,suggesting an involvement of methanogenesis associated with biodegradation.