Bacterial population and biodegradation potential in chronically crude oil-contaminated marine sediments are strongly linked to temperature

Abstract

Two of the largest crude oil-polluted areas in the world are the semi-enclosed Mediterranean and Red Seas, but the effect of chronic pollution remains incompletely understood on a large scale. We compared the influence of environmental and geographical constraints and anthropogenic forces (hydrocarbon input) on bacterial communities in eight geographically separated oil-polluted sites along the coastlines of the Mediterranean and Red Seas. The differences in community compositions and their biodegradation potential were primarily associated (P < 0.05) with both temperature and chemical diversity. Furthermore, we observed a link between temperature and chemical and biological diversity that was stronger in chronically polluted sites than in pristine ones where accidental oil spills occurred. We propose that low temperature increases bacterial richness while decreasing catabolic diversity and that chronic pollution promotes catabolic diversification. Our results further suggest that the bacterial populations in chronically polluted sites may respond more promptly in degrading petroleum after accidental oil spills.

Regional variations in the diversity and predicted metabolic potential of benthic prokaryotes in coastal northern Zhejiang, East China Sea

“…The high within-zone heterogeneity in community composition between samples from XSH and HZ likely reflected the large spatial scale of sampling in HZ and variations in hydrologic conditions in XSH comprising seven distinct hydrologic subzones48. The geophysical drivers, such as water depth, temperature, and sediment texture, were also reported in previous studies81112. Besides texture, porosity, as an important sedimentological parameter, was reported to be associated with microbial community structure in the coastal sediments4950.…”

“…Benthic prokaryotes play crucial roles in biogeochemical cycling within marine ecosystems123. The diversity of benthic prokaryotes has been investigated across various coastal marine ecosystems456789, demonstrating a wide range of environmental drivers shaping benthic prokaryotic communities such as sediment depth10, water depth11, temperature12, ocean currents5, sediment texture8, salinity6, nutrients13, organic matter quantity and availability14, heavy metals and organic pollutants7. Previous studies have suggested that geographic distance also drives variation in benthic prokaryotic communities1516.…”

Role of environmental factors and microorganisms in determining the fate of polycyclic aromatic hydrocarbons in the marine environment

“…A recent large-scale study in the Mediterranean Sea revealed that the microbial communities in pristine sites responded in a different way to those inhabiting chronically polluted sites (Bargiela et al. 2015). The latter showed a faster degradation response when an accidental oil spill occurred.…”

“…Bargiela et al. (2015), by comparing metagenomic-based pollutant-degrading networks of chronically polluted sites in the Mediterranean Sea with those of the Deepwater Horizon oil spill, demonstrated that chronic pollution promotes the diversification of PAH catabolic capacities. The study also revealed a correlation between temperature and microbial diversity, with low temperature increasing bacterial richness while decreasing catabolic diversity (Bargiela et al.…”

“…The study also revealed a correlation between temperature and microbial diversity, with low temperature increasing bacterial richness while decreasing catabolic diversity (Bargiela et al. 2015). …”