Taxonomic and Predictive Functional Profile of Hydrocarbonoclastic Bacterial Consortia Developed at Three Different Temperatures.

Microbial community exhibit shift in composition in response to temperature variation. We report crude oil-degrading activity and high-throughput 16S rRNA gene sequencing (metagenome) profiles of four bacterial consortia enriched at three different temperatures in crude oil-amended Bushnell-Hass Medium from an oily sludge sediment. The consortia were referred to as O (4 ± 2 ℃ in 3% w/v crude oil), A (25 ± 2 ℃ in 1% w/v crude oil), H (25 ± 2 ℃ in 3% w/v crude oil), and X (45 ± 2 ℃ in 3% w/v crude oil). The hydrocarbon-degrading activity was highest for consortium A and H and lowest for consortium O. The metagenome profile revealed the predominance of Proteobacteria (62.12-1.25%) in each consortium, followed by Bacteroidota (18.94-37.77%) in the consortium O, A, and H. Contrarily, consortium X comprised 7.38% Actinomycetota, which was essentially low (< 0.09%) in other consortia, and only 0.41% Bacteroidota. The PICRUSt-based functional analysis predicted major functions associated with the metabolism and 5060 common KEGG Orthology (KOs). A total of 296 KOs were predicted exclusively in consortium X. Additionally, 247 KOs were predicted from xenobiotic biodegradation pathways. This study found that temperature had a stronger influence on the composition and function of the bacterial community than crude oil concentration.