Larkinella humicola sp. nov., a gamma radiation-resistant bacterium isolated from soil

A Gram-negative, short rod-shaped, and pink-pigmented bacterial strain, designated MA1(T), was isolated from a soil sample from Gijang-gun, Busan in Republic of Korea. The 16S rRNA gene sequence analysis showed that strain MA1(T) belonged to the genus Larkinella and was closely related to Larkinella punicea (97.5% similarity), Larkinella rosea 15J16-1T3A(T) (96.5%), and Larkinella knui 15J6-3T6(T) (96.2%). Polar lipid profile of strain MA1(T) contained phosphatidylethanolamine, two unidentified aminolipids, and three unidentified lipids. Menaquinone-7 was the only quinone and the main fatty acids were C-16:1 omega 5c (36.7%), iso-C-15:0 (30.0%), iso-C-17:0 3-OH (7.7%), and summed feature 3 (C-16:1 omega 6c and/or C-16:1 omega 7c and/or iso-C-15:0 2-OH) (7.3%). The genomic DNA G + C content was 52.3 mol% based on the whole-genome analysis. Strain MA1(T) exhibited a relatively low level of ANI and in silico DDH values with Larkinella punicea (91.9 and 47.1%, respectively), Larkinella rosea (79.7 and 23.3%), and Larkinella knui(81.9 and 25.7%). Based on its phenotypic properties and phylogenetic distinctiveness, strain MA1(T) should be classified in the genus Larkinella as a representative of a novel species, for which the name Larkinella humicola sp. nov. is proposed. The type strain is MA1(T) (= KCTC 72629(T) = NBRC 114191(T)).

Automated summary

A new bacterial strain, designated Larkinella humicola sp. nov., was isolated from a soil sample in Gijang-gun, Busan, Republic of Korea. This strain belongs to the genus Larkinella and exhibits Gram-negative, short rod-shaped morphology with pink pigmentation. Genetic and biochemical analysis revealed its close relationship with other species in the Larkinella genus.