Kujur_2023_Int.Microbiol__

A Gram-negative, aerobic bacterial strain RR6(T) was isolated from the sea sand to produce lipase and proposed as a novel species of Halopseudomonas. The optimum growth occurred at 28-37 degreesC, and the pH was 6.0-8.0. The optimum growth occurred at 3.0 -6.5% (w/v) NaCl. The major cellular fatty acids were C10:0 3OH, C12:0, C16:1 omega7c/16:1 omega6c, 18:1 omega7c and/or 18:1 omega6c, and C16:0. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid, and unidentified lipids. The genome is 3.93 Mb, and the G + C content is 61.3%. The 16S rRNA gene sequences shared 99.73-99.87% sequence similarity with the closely related type strains of Halopseudomonas. The average nucleotide identity and average amino acid identity of strain RR6(T) with reference type strains were below 95-96%, and the corresponding in-silico DNA-DNA hybridization values were below 70%. Strain RR6(T) clustered with Halopseudomonas gallaeciensis V113(T) and Halopseudomonas pachastrellae CCUG 46540( T) in the phylogenetic tree. Further, lipase produced by this bacterium belongs to alpha/beta hydrolase lipase family and exhibits structural similarity to the lactonizing lipase. Based on the polyphasic analysis, the new isolates RR6(T) represent a novel species of Halopseudomonas for which Halopseudomonas maritima sp. nov. is proposed. The type strain is RR6(T) (= NBRC 115418( T) = TBRC 15628( T)).