Mucilaginibacter endophyticus sp. nov., an endophytic polysaccharide-producing bacterium isolated from a stem of Miscanthus sinensis

摘要

In this study, a Gram-negative, rod-shaped, endophytic bacterial strain (RS1(T)) capable of producing large amounts of exopolysaccharides was isolated from a stem of Miscanthus sinensis. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RS1(T) is closely related to Mucilaginibacter kameinonensis NBRC 102645(T) (98.72%), followed by Mucilaginibacter gossypiicola Gh-48(T) (97.56%) and Mucilaginibacter oryzae DSM 19975(T) (97.36%). The DNA G+C content of strain RS1(T) was determined to be 42.80mol%. ANIb and GGDC values from genomic comparison between the genomes of strain RS1(T) and the related reference species were less than 95% and 70%, respectively. The major cellular fatty acids (more than 10% of total fatty acids) were identified as iso-C15: 0, C16:0, iso-C17:0-3OH and summed feature 3 (C16: 17c and/or iso-C15:02-OH). The only isoprenoid quinone detected was MK-7. Based on the physiological, genotypic and genomic characteristics, strain RS1(T) is concluded to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter endophyticus sp. nov. is proposed (type strain RS1(T)=KCTC 62785(T)=GDMCC 1.1414(T)).