Type genome is Methylosemipumilus turicensis MMS-10A-171 (GCF_000953015.1), that was initially proposed as ‘Candidatus Methylopumilus turicensis’ in Salcher et. al. 2015 and later changed to Methylosemipumilus turicensis in Salcher et al. 2019. The strain was isolated by dilution-to-extinction cultivation from the water column of Lake Zurich, Switzerland. MMS-10A-171 has a genome size of 1.76 Mb with a genomic GC content of 44.52%, contains 6 rRNA genes and 40 tRNAs. The genome is complete, consisting of 1 circular chromosome. Methylosemipumilus turicensis MMS-10A-171 has a relatively small genome size (1.76 Mb) but not as small as Methylopumilus (1.3-1.4 Mb), which – together with improved genomic analyses – led to the reclassification to Methylosemipumilus. The genome contains genes encoding proteorhodopsins and the biosynthetic pathway for retinal biosynthesis. Pathways for methanol oxidation (Xox), the ribulose monophosphate (RuMP) cycle and the tetrahydromethanopterin (H4MPT) pathway for formaldehyde oxidation were predicted. The closest cultivated relatives are Methylotenera sp. L2L1 (GCF_000744605.1) with an average amino acid identity of 67.45% and average nucleotide identity of 70.55% and Methylovorus sp. MP688 (GCF_000183115.1) with an AAI of 69.37% and an ANI of 69.42%, while the genus Methylopumilus is more distantly related (AAI of 61.5-62.2% and ANI of 66.4-66.9%).