Ideonella oryzae sp. nov., isolated from soil, and Spirosoma liriopis sp. nov., isolated from fruits of Liriope platyphylla

Abstract

Gram-negative, aerobic, motile by means of two or more polar or subpolar flagella, rod-shaped strain NS12-5T and Gram-negative, facultatively anaerobic, yellow-coloured, rod-shaped strain RP8T were isolated from rice rhizosphere soil and fermented fruits of Liriope platyphylla in the Republic of Korea, respectively. The result of phylogenetic analyses based on 16S rRNA gene sequences showed that strain NS12-5T was most closely related to Ideonella aquatica 4Y11T with 99.79 % sequence similarity. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain NS12-5T and species of the genus Ideonella were 75.6–91.7 % and 20.3–43.9 %, respectively. Growth occurred at 15–40 °C and pH 5–11, and NaCl was not needed for growth. The major fatty acids of strain NS12-5T were summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0, and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content of strain NS12-5T was 69.03 mol%. The result of phylogenetic analyses based on 16S rRNA gene sequences revealed that strain RP8T was most closely related to Spirosoma aureum BT328T with 96.01 % sequence similarity. The ANI and dDDH values between strain RP8T and reference strains of the genus Spirosoma were 72.9–76.4 % and 18.6–20.0 %, respectively. Growth occurred at 15–37 °C and pH 5–11, and NaCl was not needed for growth. The major fatty acids of strain RP8T were summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 1 ω5c and iso-C15 : 0. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C contents of strain RP8T were 54.9 mol%. Based on phenotypic, genomic and phylogenetic results, strains NS12-5T and RP8T represent novel species in the genus Ideonella and Spirosoma , respectively, and the names Ideonella oryzae sp. nov. and Spirosoma liriopis sp. nov. are proposed. The type strain of I. oryzae sp. nov. is NS12-5T (=KACC 22691T=TBRC 16346T) and the type strain of S. liriopis is RP8T (=KACC 22688T=TBRC 16345T).