Methanotrophic community Raw sequence reads

Methane (CH4) is an important greenhouse gas and one strategy for methane mitigation could rely on the use of methanotrophic bacteria (MOB). Recently, accumulating evidence demonstrated that methane oxidation is stimulated when MOB are interacting with non-methanotrophic microbes. Dissecting such an “interactome” can be done in a multitude of ways, of which stable-isotope probing (SIP) of the DNA is a valuable technique to track carbon flow through all partners actively involved. While most studies employing DNA-SIP to the methanotrophic interactome focused on the MOB that form the basis of the interactome, here a short-term time-resolved SIP incubation was performed in order to identify the non-methanotrophic microbes most actively involved in the interactome. A MOB (Methylomonas sp.) was found to be the primary producer supplying organic carbon to the interactome, and having a restricted trophic interaction with Methylotenera spp. as primary consumers. The relationship with secondary consumers was more promiscuous. Our findings provide insight into the methane-derived carbon flow through a methanotrophic interactome by focusing on the most intricately involved non-MOB community members. While confirming the previously reported link between Methylococcaceae and Methylophilaceae the diversity of secondary consumers (with Flavobacteria, Hydrogenophaga and Chitinophagaceae among the most prominent of them) is an interesting connection within the interactome, indicating the importance of specific biotic interactions to aerobic methane oxidation.