Thiopseudomonas acetoxidans sp. nov., an aerobic acetic and butyric acids oxidizer isolated from anaerobic fermentation liquid of food waste.

ABSTRACT

A Gram-stain-negative, oxidase-negative, rod-shaped, motile, facultatively anaerobic bacterial strain, designated as CY1220T, was isolated from an anaerobic fermentation liquid of food waste treatment plant. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain CY1220T belongs to the genus Thiopseudomonas, with the highest sequence similarity to Thiopseudomonas alkaliphila B4199T (95.91%), followed by Thiopseudomonas denitrificans X2T (95.56%). The genomic DNA G + C content of strain CY1220T was 48.6 mol%. The average nucleotide identity values and digital DNA-DNA hybridization values between strain CY1220T and the type species of T. alkaliphila and T. denitrificans were in the range of 70.8-71.6% and 19.2-20.0%, respectively, below the thresholds for species delineation. The strain was able to grow utilizing acetic acid and butyric acid (AABA) as the sole carbon source in aerobic conditions. Genomic analysis predicted that the strain could synthesize vitamin B12 and ectoine. The predominant cellular fatty acids were C181 ω7c and/or C181 ω6c, C160, C161 ω7c and/or C161 ω6c and C120. The polar lipids comprised diphosphatidylglycerol, unknown polar lipid, phosphatidylethanolamine, phosphatidylglycerol, and phospholipid. Q-8 (2.1%) and Q-9 (97.9%) were detected as the respiratory quinones. Based on its phenotypic, genotypic and genomic characteristics, strain CY1220T represents a novel species in the genus Thiopseudomonas, for which the name Thiopseudomonas acetoxidans sp. nov. is proposed. The type strain is CY1220T (= GDMCC 1.3503 T = JCM 35747 T).