Chryseobacterium electrogenes sp. nov., an electrogenic bacterium isolated from the Mars-analogue Aiken Spring in the Qaidam Basin, Northwest China

A Gram-stain-negative, strictly aerobic, rod-shaped bacterium, designated strain T1ᵀ, was isolated from a water sample collected from Aiken Spring in the Qaidam Basin, Qinghai Province, PR China. Strain T1ᵀ grew optimally at 28-30 °C, pH 6.5 and with 0% NaCl (tolerating up to 1.5%). The predominant fatty acids were iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH, and the sole respiratory quinone was menaquinone-6. The major polar lipids included phosphatidylethanolamine, one aminolipid and two unidentified lipids. The genomic DNA G+C content was 34.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed strain T1ᵀ within the genus Chryseobacterium, showing the highest similarity to Chryseobacterium soldanellicola NBRC 100864ᵀ (95.5%). Average nucleotide identity (75.4%) and digital DNA-DNA hybridization (19.9%) values between strain T1ᵀ and its closest genomic relatives (Chryseobacterium buanense) were well below the thresholds for species delineation. The draft genome (3.2 Mb) contained multiple genes putatively involved in extracellular electron transfer, consistent with its ability to generate current in bioelectrochemical systems. On the basis of phenotypic, chemotaxonomic, phylogenetic and genomic data, strain T1ᵀ represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium electrogenes sp. nov. is proposed. The type strain is T1ᵀ (=KCTC 102478ᵀ=NBRC 117375ᵀ=MCCC 1K10085ᵀ).