Description of Luteithermobacter gelatinilyticus gen. nov., sp. nov., and Paremcibacter congregatus gen. nov., comb. nov. via reclassification of the genus Emcibacter

Abstract

Strain MEBiC09520(T), which was isolated from a tidal sediment in Incheon, Korea, is a pale yellow, rod-shaped bacterium, cells of which are 0.4-0.5 mu m in width and 1.5-2 mu m in length. Strain MEBiC09520(T) shared 95.17 and 92.57% 165 rRNA gene sequence similarity with Emcibacter nanhaiensis and E. congregatus, respectively. It grew optimally at pH 6.0, at 55 degrees C and with 2.5-3.5% (w/v) NaCl. Its polar lipid components included phosphatidylethanolamine (PE). diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), an unidentified phospholipid (PL), three unidentified aminolipids (ALs) and two unidentified lipids (L). The fatty acids C-16:0, C-19(:0) cyclo omega 8c, C(1)(4:0)2-OH and summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) were predominantly present in its cell wall. Strain MEBiC09520(T) was thermophilic, while E. nanhaiensis and E. congregatus were mesophilic. Although E. nanhaiensis showed no nitrate reduction activity, MEBiC09520(T) and E. congregatus showed a positive reaction. These strains differed in carbohydrate utilization. In particular, E. congregatus was able to thrive on various carbohydrate substrates as compared to the other strains. The average nucleotide identity value was 69.92% between strain MEBiC09520(T) and E. congregatus 70.38% between E. congregatus ZYL(T) and E. nanhaiensis HTCJW17(T), and 72.83% between strain MEBiC09520 and E. nanhaiensis HTCJW17(T). Considering these differences, strain MEBiC09520(T) (=KCCM 43320(T)=MCCC 1K03920(T)) is suggested to represent and novel species of a new genus, Luteithermobacter gelatinilyticus gen. nov., sp. nov., and E. congregatus should be reclassified as Paremcibacter congregatus gen. nov., comb. nov.