Proposal for creation of a new genus Neomicrococcus gen. nov. to accommodate Zhihengliuella aestuarii Baik et al. 2011 and Micrococcus lactis Chittpurna et al. 2011 as Neomicrococcus aestuarii comb. nov. and Neomicrococcus lactis comb. nov.

Micrococcus lactis and Zhihengliuella aestuarii were described independently in 2011. Their type strains showed high levels of 16S rRNA gene sequence similarity (99.3 %). Phylogenetic analysis revealed that M. lactis MCC 2278T and Z. aestuarii JCM 16166T formed a monophyletic group and showed distant relationships to other members of closely related genera such as Micrococcus, Zhihengliuella, Arthrobacter and Citricoccus. The presence of large proportions of iso-C14 : 0 and iso-C16 : 0 with small amounts of iso-C15 : 0 distinguished M. lactis MCC 2278T and Z. aestuarii JCM 16166T from other members of the genera Micrococcus and Zhihengliuella. Unlike other members of the genera Zhihengliuella and Micrococcus, M. lactis MCC 2278T and Z. aestuarii JCM 16166T showed growth at low concentrations of NaCl. Thus, based on distinctive phylogenetic, chemotaxonomic and physiological features of these two organisms in comparison with other members of the genera Micrococcus and Zhihengliuella, it is clear that they do not fit within the existing classification and deserve separate status. DNA–DNA hybridization between the two type strains was 63 %, indicating that they represent separate species. In this study, we propose the creation of a novel genus, Neomicrococcus gen. nov., to accommodate the two species with Neomicrococcus aestuarii gen. nov., comb. nov. (type strain JCM 16166T = KCTC 19557T) as the type species. Neomicrococcus lactis comb. nov. (type strain MCC 2278T = DSM 23694T) is also proposed.

Zhihengliuella aestuarii sp. nov., isolated from tidal flat sediment

A Gram-stain-positive, ovoid to short rod-shaped, yellow-pigmented bacterium, designated strain DY66T, was isolated from tidal-flat sediment collected from Deukryang Bay (Republic of Korea), and its taxonomic position was investigated by using a polyphasic approach. Strain DY66T grew optimally at 30 °C and pH 8–9 and in 2 % (w/v) NaCl. The peptidoglycan type was A4α, l-Lys–l-Ala–d-Glu, and tyvelose and glucose were the major cell-wall sugars. The predominant menaquinones were MK-10 and MK-9. Major cellular fatty acids (>10 % of total) were anteiso-C15 : 0 and iso-C15 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, an unknown aminophospholipid and three unknown aminolipids. The DNA G+C content was 59.1 mol%. This chemotaxonomic profile supported the assignment of strain DY66T to the genus Zhihengliuella. Phylogenetic analysis based on 16S rRNA gene sequences also indicated that strain DY66T belonged to the family Micrococcaceae and was related to the genus Zhihengliuella. On the basis of the evidence presented in this study, strain DY66T represents a novel species of the genus Zhihengliuella, for which the name Zhihengliuella aestuarii sp. nov. is proposed. The type strain is strain DY66T ( = KCTC 19557T = JCM 16364T).