Methanocalculus

Abstract

Me.tha.no.cal'cu.lus. N.L. neut. n. methanum methane; N.L. masc. n. calculus pebble; gravel; N.L. masc. n. Methanocalculus a methane‐producing pebble‐shaped bacterium. Euryarchaeota / Methanomicrobiales / Methanomicrobiales / Methanocalculaceae / Methanocalculus The genus Methanocalculus comprises six species with validly published names: Methanocalculus halotolerans, Methanocalculus pumilus, Methanocalculus taiwanensis , Methanocalculus chunghsingensis , Methanocalculus natronophilus , and Methanocalculus alkaliphilus . The members of the genus Methanocalculus belong to the Methanocalculaceae family. They have less than 90% 16S ribosomal RNA sequence identity to their closest phylogenetic relatives, Methanoculleus and Methanocorpusculum species. Methanocalculus spp. use only hydrogen and formate as electron donors for producing methane and require acetate as a carbon source. They are mesophilic and have a G + C content in the DNA ranging from 50.2 to 55.0 mol%. Some species tolerate NaCl at a concentration of 125 g/l (e.g., M. halotolerans ). They inhabit a wide range of environments including extreme ones (e.g., saline oil reservoirs and soda lakes) as confirmed by culture‐dependent and ‐independent techniques. While most Methanocalculus spp. are neutrophilic, two species, Methanocalculus natronophilus and M. alkaliphilus , are strictly alkaliphilic. DNA G + C content (mol%) : 50–55. Type species : Methanocalculus halotolerans Ollivier, Fardeau, Cayol, Magot, Patel, Prensier et al., 1998.

Draft Genomes of Methanocalculus taiwanensis P2F9704a T and Methanocalculus chunghsingensis K1F9705b T , Hydrogenotrophic Methanogens Belonging to the Family Methanocalculaceae

“…Methanocalculus spp. use only formate and hydrogen as electron donors for methanogenesis and require acetate as a carbon source ( 1 ). To date (August 2022), the genus Methanocalculus comprises six species with validly published names: Methanocalculus halotolerans ( 2 ), Methanocalculus pumilus ( 3 ), Methanocalculus taiwanensis ( 4 ), Methanocalculus chunghsingensis ( 5 ), Methanocalculus natronophilus ( 6 ), and Methanocalculus alkaliphilus ( 7 ).…”