Three novel Luteimonas species from faeces of Cygnus atratus: Luteimonas changyuni sp. nov., Luteimonas yanweni sp. nov. and Luteimonas qiangzhengi sp. nov

Abstract

Six Gram-stain-negative, aerobic and rod-shaped bacterial strains, designated as MJ145^T, MJ204, MJ174^T, MJ246, MJ146^T and MJ293, were isolated from faeces of Cygnus atratus, in Qinghai, PR China. The six strains grew at pH 7.0-9.0, 4-37 °C; strains MJ145^T, MJ204, MJ174^T and MJ246 grew at 0-6.0% NaCl; MJ146^T and MJ293 grew at 0-5.0% NaCl. The 16S rRNA gene sequence analysis revealed that strains MJ145^T and MJ204 exhibited the highest similarity (98.21% and 98.03 %, respectively) to Luteimonas terricola BZ92r^T, strains MJ174^T and MJ246 showed the highest similarity (98.36% and 98.16 %, respectively) to 'Luteimonas granuli' Gr-4 and strains MJ146^T and MJ293 showed the highest similarity (96.36% and 96.38 %, respectively) to 'Luteimonas dalianensis' OB44-3. Combined with the phylogenomic tree, it showed that strain pairs MJ145^T/MJ204 and MJ174^T/MJ246 were most closely related to L. terricola BZ92r^T, while strain pair MJ146^T/MJ293 was most closely related to 'L. dalianensis' OB44-3, Luteimonas suaedae LNNU 24178^T, Luteimonas salinilitoris C3-2-a3^T, Luteimonas endophytica RD2P54^T and Luteimonas salinisoli SJ-92^T. The average nt identity and digital DNA-DNA hybridization values between the strains and the other members of the genus Luteimonas were below the established thresholds of 95-96% and 70 %, respectively. The respiratory ubiquinone-8 was detected in the strains MJ145^T, MJ174^T and MJ146^T. The major fatty acids of all three strains (MJ145^T, MJ174^T and MJ146^T) were iso-C_{15 : 0} and summed feature 9 (C_{16 : 0} 10-methyl and/or iso-C_{17 : 1} ω9c). All three strains contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. Based on polyphasic characterization, these six strains should be considered to be three novel species within genus Luteimonas, for which the names Luteimonas changyuni sp. nov. (MJ145^T/MJ204, type strain MJ145^T=GDMCC 1.4700^T=JCM 37394^T), Luteimonas yanweni sp. nov. (MJ174^T/MJ246, type strain MJ174^T=GDMCC 1.4862^T=JCM 37396^T) and Luteimonas qiangzhengi sp. nov. (MJ146^T/MJ293, type strain MJ146^T=GDMCC 1.4701^T=JCM 37395^T) are proposed, respectively.

Keywords: Cygnus atratus; Luteimonas; faeces; novel species.