Abstract
A novel slightly halophilic Gram-stain-negative bacterial strain (MKS20(T)) was isolated from a brine sample collected from one of the Anderton brine springs in the Cheshire salt district, located in Northern England. Phylogenetic analysis of the 16S rRNA gene sequence revealed a close proximity to Motilimonas eburnea (98.30 %), followed by Motilimonas pumila (96.62 %), the two currently described species within the genus Motilimonas. Strain MKS20(T) forms white-beige-pigmented colonies and grows optimally at 28-30 °C, in 1-3 % (w/v) NaCl and at pH 7-7.5. The strain was facultatively anaerobic and showed a broader range of carbohydrate use than other species in the genus Motilimonas. Q-8 was the sole respiratory quinone and the major fatty acids (>10 %) were summed feature 3 (C(16 : 1) ω6c and/or C(16 : 1) ω7c) and C(16 : 0). The polar lipid profile included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyglycerol and several unidentified lipids. The G+C content of the genomic DNA was 44.2 mol%. Average nucleotide identity and DNA-DNA hybridization data were consistent with assignment to a separate species. Based on the phylogenetic and genomic-based analyses, as well as physiological and biochemical characteristics, we propose that strain MKS20(T) (=DSM 109936(T), MCCC 1K04071(T)) represents a new species of the genus Motilimonas, with the name Motilimonas cestriensis sp. nov.