Sphingomonas colocasiae sp. nov., isolated from taro (Colocasia esculanta)

A polyphasic approach was used to characterize an aerobic, Gram-stain-negative, rod-shaped bacterium (designed as strain CC-MHH0539^T) isolated from the chopped tuber of taro (Colocasia esculanta) in Taiwan. Strain CC-MHH0539^T was able to grow at 15-30 °C (optimum, 25 °C), at pH 6.0-9.0 (optimum, 7.0) and with 0-1 % (w/v) NaCl. Strain CC-MHH0539^T showed highest 16S rRNA gene sequence similarity to Sphingomonas laterariae LNB2^T (96.8 %), Sphingobium boeckii 469^T (96.5 %), Sphingomonas faucium E62-3^T (96.4 %) and Sphingosinicella vermicomposti YC7378^T (96.2 %) and <96.1 % similarity to other sphingomonads. Strain CC-MHH0539^T was found to cluster mainly with the clade that accommodated members of the genus Sphingomonas. The dominant cellular fatty acids were C16 : 0, C16 : 1ω5c, C14 : 0 2-OH, C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, two sphingoglycolipids and two unidentified phospholipids were detected in strain CC-MHH0539^T. The DNA G+C content was 69.5 mol%. The respiratory quinone system and predominant polyamine was ubiquinone 10 (Q-10) and sym-homospermidine, respectively, which is in line with Sphingomonas representatives. Based on the distinct phylogenetic, phenotypic and chemotaxonomic traits, strain CC-MHH0539^T is considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas colocasiae sp. nov. is proposed. The type strain is CC-MHH0539^T (=BCRC 80933^T=JCM 31229^T).