Simplicispira limi sp. nov., isolated from activated sludge

Abstract

A Gram-negative, motile, rod-shaped bacterium, designated strain EMB325(T), was isolated from activated sludge that performed enhanced biological phosphorus removal in a sequencing batch reactor. The predominant fatty acids of strain EMB325(T) were summed feature 3 (C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH), C(16 : 0), C(18 : 1)omega7c and C(18 : 1)omega7c 11-methyl. The strain contained phosphatidylethanolamine and diphosphatidylglycerol as polar lipids. The G+C content of the genomic DNA was 63.3 mol%. The major quinone was Q-8. Phylogenetic analysis of 16S rRNA gene sequences showed that strain EMB325(T) formed a phyletic lineage with members of the genus Simplicispira and was most closely related to Simplicispira psychrophila LMG 5408(T) and Simplicispira metamorpha DSM 1837(T) with similarities of 98.1 and 97.9 %, respectively. Levels of DNA-DNA relatedness between strain EMB325(T) and S. psychrophila LMG 5408(T) and S. metamorpha DSM 1837(T) were 28 and 23 %, respectively. On the basis of chemotaxonomic data and molecular characteristics, strain EMB325(T) is considered to represent a novel species within the genus Simplicispira, for which the name Simplicispira limi sp. nov. is proposed. The type strain is EMB325(T) (=KCTC 12608(T)=DSM 17964(T)).