Crude Oil Treatment Leads to Shift of Bacterial Communities in Soils from the Deep Active Layer and Upper Permafrost along the China-Russia Crude Oil Pipeline Route

Abstract

The buried China-Russia Crude Oil Pipeline (CRCOP) across the permafrost-associated cold ecosystem in northeastern China carries a risk of contamination to the deep active layers and upper permafrost in case of accidental rupture of the embedded pipeline or migration of oil spills. As many soil microbes are capable of degrading petroleum, knowledge about the intrinsic degraders and the microbial dynamics in the deep subsurface could extend our understanding of the application of in-situ bioremediation. In this study, an experiment was conducted to investigate the bacterial communities in response to simulated contamination to deep soil samples by using 454 pyrosequencing amplicons. The result showed that bacterial diversity was reduced after 8-weeks contamination. A shift in bacterial community composition was apparent in crude oil-amended soils with Proteobacteria (esp. α-subdivision) being the dominant phylum, together with Actinobacteria and Firmicutes. The contamination led to enrichment of indigenous bacterial taxa like Novosphingobium, Sphingobium, Caulobacter, Phenylobacterium, Alicylobacillus and Arthrobacter, which are generally capable of degrading polycyclic aromatic hydrocarbons (PAHs). The community shift highlighted the resilience of PAH degraders and their potential for in-situ degradation of crude oil under favorable conditions in the deep soils.

Responses of microbial community from tropical pristine coastal soil to crude oil contamination

“…We found that crude oil 318 had a deleterious effect on microbial alpha-diversity (Tables 2 and 3). This result is 319 similar to that obtained by Yang (2014), as crude oil was thought to have an eco-320 toxicological effect. The higher amount of CO 2 evolved in the crude oil treated-soil 321 (Figure 2) is related to the oil stressing effect (Franco et al, 2004), and the further peaks 322 observed in the Figure 2, might be related to different fractions of oil being degraded 323 according to its bioavailability.…”

Efficiency of Indigenous Filamentous Fungi for Biodegradation of Petroleum Hydrocarbons in Medium and Soil: Laboratory Study from Ecuador

“…For instance, the percentages of oil degradation by Penicillium chrysogenum at 26, 28, 31 and 37°C were 30.3 %, 43.8 %, 43.2 % and 15 %, respectively (Goddy and Dami 2013). However, the biodegradation of hydrocarbons in psychrophilic environments have been also reported (Sizhong et al 2014).…”

From Rare to Dominant: a Fine-Tuned Soil Bacterial Bloom during Petroleum Hydrocarbon Bioremediation

“…Sphingomonadaceae, Caulobacteraceae, and Rhodospirillaceae (Alphaproteobacteria), Alcaligenaceae, Comamonadaceae, and Burkholderiaceae (Betaproteobacteria), Pseudomonadaceae and Xanthomonadaceae (Gammaproteobacteria), and Nocardiaceae (Actinobacteria), among others, have been reported to be enriched during hydrocarbon degradation (5,55,56). Bacteroidetes may become enriched in creosote-contaminated soils, in which PAHs are main pollutants (7).…”