A NOVEL MICROBIAL HYDROCARBON DEGRADATION PATHWAY REVEALED BY HOPANE DEMETHYLATION IN A PETROLEUM RESERVOIR

Abstract

The origin of 25-norhopanes is controversial, despite their abundance in many biodegraded oils. In a biodegraded oil reservoir, we found concomitant and directionally opposite changes with depth in the concentrations of certain 17α-hopanes and their 17α,25-norhopane counterparts, demonstrating microbially induced demethylation of hopanes. These observations suggest a hitherto unknown biodegradation mechanism and provide insight into the poorly understood process of natural petroleum biodegradation.