An alkalophilic Methanosarcina isolated from Lonar crater

Craters formed by hypervelocity meteoritic impact offer unique ecological environment. The Lonar crater situated on the outskirts of Lonar town in District Buldhana, Maharashtra is the only known crater formed by hypervelocity meteoritic impact in basaltic rock. The lake water is very salty and alkaline (pH 9.5–10.0). A methanogen isolated from this unique environment grows well with acetate, methanol, methylamine (mono-, di- and tri-), pyruvate and 1° propanol. It shows poor growth on H2 : CO2 (80:20 v/v). The isolate is a typical acetoclastic methanogen. The novelty of the isolate is its ability to grow at alkaline pH of 9.5. The isolate requires 0.5% (w/v) NaCl along with pH 9.0 for its optimum growth. Morphological and biochemical characteristics suggest that the isolate belongs to the genus Methanosarcina.