Permian extinction possibly caused by microbes?

[Pmt111500]

Methanogenic microbes have been studied and this has given indications that they acquired a new set of enzymes about the time of Permian extinction. The enzymes provided these a new, third, pathway for producing methane, thus turning them the most efficient methanogens present. As there had been a lot of organic matter washing from the land during previous ages, the reserves of food for this archaea would have been abundant on the ocean floors. As they needed nickel for this pathway to work, the final piece of the hypothesis are the volcanic eruptions from Siberia that were large and rich of nickel.
http://www.reuters.com/article/2014/03/31/us-science-extinction-idUSBREA2U1KO20140331

Because of the day, I had to to check the claim of 13C/12C-ratio drop across the permian-triassic boundary. It appears the hypothesis is not some sick april fools.
http://gsabulletin.gsapubs.org/content/112/9/1459.short