Novosphingobium oryzae sp. nov., a potential plant-promoting endophytic bacterium isolated from rice roots

Abstract

A novel endophytic bacterium, strain ZYY112T, isolated from rice roots, was characterized by a polyphasic approach. In phylogenetic analyses based on 16S rRNA gene sequences, ZYY112Tshowed highest sequence similarity to Novosphingobium sediminicola HU1-AH51T(97.2%) and less than 97% similarity with respect to other Novosphingobium species with validly published names. The DNA G+C content of strain ZYY112Twas 60.8 mol%. The level of DNA？DNA relatedness between strain ZYY112Tand N. sediminicola DSM 27057T was 33.7% (reciprocal 5.2%), which supported the suggestion that ZYY112Trepresented a novel species of the genus Novosphingobium. Ubiquinone Q-10 was the unique respiratory quinone (100%). The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, an unknown aminolipid and an unknown phospholipid. The major fatty acids of strain ZYY112Twere summed feature 8 (consisting of C18: 1ω7c and/or C18: 1ω6c), summed feature 3 (consisting of C16: 1ω7c and/or C16: 1ω6c), C14: 02-OH and C16: 0. The major polyamine of ZYY112Twas spermidine, which is a characteristic trait of the genus Novosphingobium. Characterization by genotypic, chemotaxonomic and phenotypic analysis indicated that strain ZYY112Trepresents a novel species of the genus Novosphingobium, for which the name Novosphingobium oryzae sp. nov. is proposed. The type strain is ZYY112T(=ACCC 06131T=JCM 30537T).