methanogenium boonei methanogenium boonei methanogenium boonei is a methanogenic archaean. cells are non-motile irregular cocci 1.0-2.5 μm in diameter. this mesophile grows optimally at 19.4 °c, ph6.4-7.8, salinity 0.3-0.5m na+. it was first isolated from skan bay, alaska. methanogenium boonei scientific classification domain: archaea kingdom: euryarchaeota phylum: euryarchaeota class: methanomicrobia order: methanomicrobiales family: methanomicrobiaceae genus: methanogenium species: m. boonei binomial name "methanogenium boonei"kendall et al. 2007 description and metabolism the cells are irregular and coccoid in shape, non-motile, approximately 1.0–2.5 μm in diameter. these mesophiles grow optimally at a temperature of 19.4 °c, ph 6.4–7.8 and salinity of 0.3–0.5 m na+. this is a strictly anaerobic species, and individuals can use carbon dioxide with hydrogen or formate as substrates to produce methane.