Comparative metagenomics reveals different hydrocarbon degradative abilities from enriched oil-drilling waste

Abstract

The oil drilling process generates large volumes of waste with inadequate treatments. Here, oil drilling waste (ODW) microbial communities demonstrate different hydrocarbon degradative abilities when exposed to distinct nutrient enrichments as revealed by comparative metagenomics. The ODW was enriched in Luria Broth (LBE) and Potato Dextrose (PDE) media to examine the structure and functional variations of microbial consortia. Two metagenomes were sequenced on Ion Torrent platform and analyzed using MG-RAST. The STAMP software was used to analyze statistically significant differences amongst different attributes of metagenomes. The microbial diversity presented in the different enrichments was distinct and heterogeneous. The metabolic pathways and enzymes were mainly related to the aerobic hydrocarbons degradation. Moreover, our results showed efficient biodegradation after 15 days of treatment for aliphatic hydrocarbons (C8-C33) and polycyclic aromatic hydrocarbons (PAHs), with a total of about 50.5% and 46.4% for LBE and 44.6% and 37.9% for PDE, respectively. The results obtained suggest the idea that the enzymatic apparatus have the potential to degrade petroleum compounds.

Microbial community dynamics and functional responses that contribute to tolerance of high concentrations of petroleum hydrocarbon

“…Additionally, the greatest number of DAGs in genetic information processing was annotated to ribosomal function. Under the T7 condition, the PH stress was the main limiting factor in the development of the microbial community, and the osmotic pressure of the cells may also be changed by hc‐PH . Thus the carbon metabolism and amino acid metabolism were widely utilized to supply energy and balance the osmotic pressure, with the aim to enhance the reproduction of the microorganisms and maintain the structure of the microbial community in the hc‐PH environment.…”

“…Under the T7 condition, the PH stress was the main limiting factor in the development of the microbial community, and the osmotic pressure of the cells may also be changed by hc-PH. 49 Thus the carbon metabolism and amino acid metabolism were widely utilized to supply energy and balance the osmotic pressure, with the aim to enhance the reproduction of the microorganisms and maintain the structure of the microbial community in the hc-PH environment. Additionally, ABC transporters could have promoted the metabolism of hydrocarbons (particularly PAHs), 50 but the degradation ability of microorganisms was restricted by over-accumulation of PH, which resulted in a significant decrease of the PH degradation rate.…”

Microbial Culture in Minimal Medium With Oil Favors Enrichment of Biosurfactant Producing Genes

“…We performed comparative bioinformatics analyses between the consortia obtained from this study, microbial consortia obtained from drill cutting samples ( Guerra et al, 2018 ; Napp et al, 2018 ), and non-oil samples ( Leinonen et al, 2010 ). From drill cutting samples, Napp et al (2018) and Guerra et al (2018) obtained consortia only with enriched culture medium. Both authors obtained consortia from the Luria Broth culture medium, named LBE consortium in Napp et al (2018) and BHLBL consortium in Guerra et al (2018) .…”

“…From drill cutting samples, Napp et al (2018) and Guerra et al (2018) obtained consortia only with enriched culture medium. Both authors obtained consortia from the Luria Broth culture medium, named LBE consortium in Napp et al (2018) and BHLBL consortium in Guerra et al (2018) . Furthermore, Napp et al (2018) obtained a consortium in the Potato Dextrose medium (PDE consortium) and Guerra et al (2018) from the YPD medium (BHYPDL consortium).…”

“…Both authors obtained consortia from the Luria Broth culture medium, named LBE consortium in Napp et al (2018) and BHLBL consortium in Guerra et al (2018). Furthermore, Napp et al (2018) obtained a consortium in the Potato Dextrose medium (PDE consortium) and Guerra et al (2018) from the YPD medium (BHYPDL consortium). Two consortia obtained without oil as carbon source were used as control.…”