1. Indigenous microbial communities in heavy oil show a threshold response to salinity
- Author
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Lisa Voskuhl, Ali Akbari, Hubert Müller, Mark Pannekens, Darya Brusilova, Stefan Dyksma, Shirin Haque, Nadine Graupner, Micah Dunthorn, Rainer U Meckenstock, and Verena S Brauer
- Subjects
AcademicSubjects/SCI01150 ,Salinity ,0303 health sciences ,Bacteria ,Ecology ,030306 microbiology ,Microbiota ,microhabitat ,microbiome ,Pitch Lake ,Applied Microbiology and Biotechnology ,Microbiology ,6. Clean water ,diversity ,Lakes ,03 medical and health sciences ,RNA, Ribosomal, 16S ,salt ,microbial community assembly ,Biologie ,Research Article ,030304 developmental biology - Abstract
Microbial degradation influences the quality of oil resources. The environmental factors that shape the composition of oil microbial communities are largely unknown because most samples from oil fields are impacted by anthropogenic oil production, perturbing the native ecosystem with exogenous fluids and microorganisms. We investigated the relationship between formation water geochemistry and microbial community composition in undisturbed oil samples. We isolated 43 microliter-sized water droplets naturally enclosed in the heavy oil of the Pitch Lake, Trinidad and Tobago. The water chemistry and microbial community composition within the same water droplet were determined by ion chromatography and 16S rRNA gene amplicon sequencing, respectively. The results revealed a high variability in ion concentrations and community composition between water droplets. Microbial community composition was mostly affected by the chloride concentration, which ranged from freshwater to brackish-sea water. Remarkably, microbial communities did not respond gradually to increasing chloride concentration but showed a sudden change to less diverse and uneven communities when exceeding a chloride concentration of 57.3 mM. The results reveal a threshold-regulated response of microbial communities to salinity, offering new insights into the microbial ecology of oil reservoirs., Microbial communities from Pitch Lake oil show a sudden threshold-regulated response to salinity, leading to less diverse and uneven communities
- Published
- 2021