Crude oil as a microbial seed bank with unexpected functional potentials

Abstract

It was widely believed that oil is a harsh habitat for microbes because of its high toxicity and hydrophobicity. However, accumulating evidence has revealed the presence of live microbes in crude oil. Therefore, it’s of value to conduct an in-depth investigation on microbial communities in crude oil. To this end, microorganisms in oil and water phases were collected from four oil-well production mixtures in Qinghai Oilfield, China, and analyzed for their taxonomic and functional compositions via pyrosequencing and GeoChip, respectively. Hierarchical clustering of 16S rRNA gene sequences and functional genes clearly separated crude oil and water phases, suggestive of distinct taxonomic and functional gene compositions between crude oil and water phases. Unexpectedly, Pseudomonas dominated oil phase where diverse functional gene groups were identified, which significantly differed from those in the corresponding water phases. Meanwhile, most functional genes were significantly more abundant in oil phase, which was consistent with their important roles in facilitating survival of their host organisms in crude oil. These findings provide strong evidence that crude oil could be a “seed bank” of functional microorganisms with rich functional potentials. This offers novel insights for industrial applications of microbial-enhanced oil recovery and bioremediation of petroleum-polluted environments.

Integrated Comparative Genomic Analysis and Phenotypic Profiling of Pseudomonas aeruginosa Isolates From Crude Oil

“…However, growing evidence has revealed the presence of living microbes in crude oil (Yoshida et al, 2005). It has been reported that microbial communities in the crude oil phase were dominated by Pseudomonas, accounting for 96.84-98.87% of the total OTUs (Yamane et al, 2008;Cai et al, 2015), which exhibited significant survival advantages over other genera.…”

Divergent Responses of Forest Soil Microbial Communities under Elevated CO 2 in Different Depths of Upper Soil Layers

“…As a powerful high-throughput metagenomics technology, GeoChip 3.0 assesses 292 genes of key enzymes involved in C, N, S, and P cycling, key energy metabolism, metal resistance, organic contaminant degradation, antibiotic resistance, and a phylogenetic marker (gyrB) (39). Recently, many studies demonstrated that GeoChip is an ideal tool for analyzing microbial communities from complex environments, such as soil (17,19,30), contaminated water (40,41), oil fields (19,42), bioreactor systems (43,44), and other habitats (45). We hypothesized that the eCO 2 treatment would have significant effects on the functional diversity, composition, structure, and metabolic potential of soil microbial communities at different depths (0 to 5 cm and 5 to 15 cm) and that the plant and soil properties would have different impacts on soil microbial communities at different depths.…”

Isolation and Characterization of Biosurfactant-Producing Bacteria From Oil Well Batteries With Antimicrobial Activities Against Food-Borne and Plant Pathogens

“…However, in spite of its high toxicity and hydrophobicity, mounting evidence has revealed the presence of live microbes (mainly bacteria) in crude oil. A wide distribution of microbial diversity, including Pseudomonas, Bacillus, Streptomyces and Stenotrophomonas species, were associated with oil wells (Yoshida et al, 2005;Cai et al, 2015). These organisms have the potential to degrade numerous hydrocarbons for use as carbon sources and encapsulate heavy metals and/or hydrocarbons through the production of active surfactants (Varjani and Gnansounou, 2017).…”