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Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.

Bacosa HP, Liu Z, Erdner DL - Front Microbiol (2015)

Bottom Line: Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure.In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas.For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit.

View Article: PubMed Central - PubMed

Affiliation: Marine Science Institute, The University of Texas at Austin Port Aransas, TX, USA.

ABSTRACT
Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

No MeSH data available.


Related in: MedlinePlus

Non- metric multidimensional scaling (NMDS) of bacterial community structures in light and dark conditions. The ordination is based on Bray-Curtis coefficient matrix of relative abundances. The numbers indicate days of incubation.
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Figure 4: Non- metric multidimensional scaling (NMDS) of bacterial community structures in light and dark conditions. The ordination is based on Bray-Curtis coefficient matrix of relative abundances. The numbers indicate days of incubation.

Mentions: The overall similarity of the microbial communities was examined with non-metric multidimensional scaling (NMDS), and the significance among treatments was further tested with ANOSIM using the bacterial genus data. The NMDS plot shows that the bacterial community structure in the control (seawater only) exhibited the closest similarity with the initial community (Figure 4). The 5 and 10 days amended dark treatment clustered closely to the control and initial community. The dark treatments at 20 days and later clustered together, separated from the light treatments and the seawater/control communities. All light treatments, from 5 days through 36 days, were apart from the dark and control samples, and they were more scattered, showing a greater variability throughout the incubation period under the natural sunlight.


Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.

Bacosa HP, Liu Z, Erdner DL - Front Microbiol (2015)

Non- metric multidimensional scaling (NMDS) of bacterial community structures in light and dark conditions. The ordination is based on Bray-Curtis coefficient matrix of relative abundances. The numbers indicate days of incubation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664628&req=5

Figure 4: Non- metric multidimensional scaling (NMDS) of bacterial community structures in light and dark conditions. The ordination is based on Bray-Curtis coefficient matrix of relative abundances. The numbers indicate days of incubation.
Mentions: The overall similarity of the microbial communities was examined with non-metric multidimensional scaling (NMDS), and the significance among treatments was further tested with ANOSIM using the bacterial genus data. The NMDS plot shows that the bacterial community structure in the control (seawater only) exhibited the closest similarity with the initial community (Figure 4). The 5 and 10 days amended dark treatment clustered closely to the control and initial community. The dark treatments at 20 days and later clustered together, separated from the light treatments and the seawater/control communities. All light treatments, from 5 days through 36 days, were apart from the dark and control samples, and they were more scattered, showing a greater variability throughout the incubation period under the natural sunlight.

Bottom Line: Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure.In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas.For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit.

View Article: PubMed Central - PubMed

Affiliation: Marine Science Institute, The University of Texas at Austin Port Aransas, TX, USA.

ABSTRACT
Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

No MeSH data available.


Related in: MedlinePlus