Chryseobacterium oryctis sp. nov., isolated from the gut of the beetle Oryctes rhinoceros, and Chryseobacterium kimseyorum sp. nov., isolated from a stick insect rearing cage

Abstract

Two strains of Chryseobacterium identified from different experiments are proposed to represent new species. Strain WLa1L2M3T was isolated from the digestive tract of an Oryctes rhinoceros beetle larva. Strain 09-1422T was isolated from a cage housing the stick insect Eurycantha calcarata. Sequence analysis of the 16S rRNA and rpoB genes found both strains to be similar but not identical to other Chryseobacterium species. Whole-genome sequencing suggested the isolates represent new species, with average nucleotide identity values ranging from 74.6 to 80.5 %. Genome-to-genome distance calculations produced values below 25.3 %, and digital DNA–DNA hybridization values were 13.7–29.9 %, all suggesting they are distinct species. The genomic DNA G+C content of WLa1L2M3T is approximately 32.53 %, and of 09-1422T is approximately 35.89 %. The predominant cellular fatty acids of strain WLa1L2M3T are C15 : 0 iso, summed feature 9 (C16 : 0 10OH or C17 : 1 iso ω6c), C17 : 0 iso 3OH, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0 iso 3OH, C15 : 0 anteiso and C13 : 0 iso, and those of strain 09-1422T are C15 : 0 iso, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C17 : 0 iso 3OH, C15 : 0 anteiso, C15 : 0 iso 3OH, C16 : 1 ω7c, C17 : 0 2OH and C18 : 0. In addition, physiological and biochemical tests revealed phenotypic differences from related Chryseobacterium type strains. These cumulative data indicate that the two strains represent novel species of the genus Chryseobacterium for which the names Chryseobacterium oryctis sp. nov. and Chryseobacterium kimseyorum sp. nov. are proposed with WLa1L2M3T (=BCRC 81350T=JCM 35215T=CIP 112035T) and 09-1422T (=UCDFST 09-1422T=BCRC 81359T=CIP 112165T), as type strains, respectively.