Microbial stabilisation and kinetic enhancement of marine methane hydrates in both deionised- and sea-water

Abstract

The large quantity of marine methane hydrates has driven substantial interest in methane-gas-fuel potential, especially with the qualified success of Shensu (2017) and Nankai-Trough (2014 & 17) production trials via depressurisation (blighted ultimately by sanding out), building on an earlier Malik-2008 trial for permafrost-bound hydrate. In particular, obviating deep-water-drilling approaches, such as the MeBO production rig (without such a drill bit), together with blowout preventers, constitutes a tantalising cost-saving measure. Tailored means of addressing sand production by customised gravel packs, wellbore screens and slotted liners with from-seafloor drilling will be expected to lead to future production-trial success. However, despite these exciting engineering advances and a few marine-mimicking laboratory studies of methane-hydrate kinetics and stabilisation from microbial perspectives, relatively little is known about the thermogenic or microbial origin of marine hydrates, nor their possible formation kinetics or potential stabilisation by microbial sources as an exponent of Gaia's hypothesis, or within the context of “Gaia's breath” as regards global methane ‘exhalations’. Here, for the first time, we elucidate the methylotrophic-microbial basis for kinetic enhancement and stabilisation of marine-hydrate formation in both deionised- and sea-water, identifying the key protein at play, which has some similarity to porins in other methylotrophic communities. In so doing, we suggest such phenomena in marine hydrates as evidence of Gaia's hypothesis.