Xanthomonas chitinilytica sp. nov., a novel chitinolytic bacterium isolated from a microbial fermentation bed material.

ABSTRACT

A Gram-stain-negative bacterium, H13-6T, was isolated from a microbial fermentation bed material collected from a pig farm located in Yan'an, Shaanxi, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain H13-6T was affiliated with the genus Xanthomonas and showed highest similarity to strain Xanthomonas maliensis M97T (98.38%), Xanthomonas prunicola CFBP 8353T (98.26%) and Xanthomonas oryzae ATCC 35933T (98.11%). The pairwise ortho Average Nucleotide Identity values and the digital DNA-DNA hybridization values between strain H13-6T and the other Xanthomonas species were all below their respective cut-offs. Two genes encoding for chitinase were found and the strain showed a strong chitin-degrading activity. The major fatty acids were Iso-C150 (55.9%), Antesio-C150 (7.4%) and Iso-C110 (5.5%) and the major polar lipids were diphosphatidylglycerol, phosphatidyglycerol and phosphatidylethanolamine. Based on the phenotypic properties and phylogenetic distinctiveness, Xanthomonas chitinilytica was proposed as a novel species of the genus Xanthomonas, with strain H13-6T (= CGMCC 1.61317T = NBRC 115641T) as type strain.