Chitinophaga costaii sp. nov., an endophyte of Pinus pinaster, and emended description of Chitinophaga niabensis.

Abstract

Bacterial strain A37T2(T) was isolated from the endophytic microbial community of a Pinus pinaster tree trunk and characterized. Strain A37T2(T) was Gram-stain-negative, formed rod-shaped cells, and grew optimally at 26-30 °C and at pH 5.5-7.5. The G+C content of the DNA was 46.6 mol%. The major respiratory quinone was menaquinone 7 (MK-7) and the major fatty acids were C16 : 1ω5c and iso-C15 : 0, representing 61.7 % of the total fatty acids. The polar lipids consisted of phosphatidylethanolamine, four unidentified aminophospholipids, one unidentified phospholipid, two unidentified aminolipids and three unidentified lipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain A37T2(T) belonged to the family Chitinophagaceae, forming a distinct branch with Chitinophaga niabensis JS13-10(T) within the genus Chitinophaga. Strain A37T2(T) shared between 92.7 and 95.1 % 16S rRNA gene sequence similarity with the type strains of species of the genus Chitinophaga. The phylogenetic, phenotypic and chemotaxonomic data presented indicate that strain A37T2(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga costaii sp. nov. is proposed. The type strain is A37T2(T) ( = CIP 110584(T) = LMG 27458(T)). An emended description of Chitinophaga niabensis JS13-10(T) is also proposed.