Limits...
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

Relative abundances of bacteria at class level in seawater alone, seawater with dispersant Corexit, crude oil, and both oil and dispersant incubated under the dark and light conditions for 36 days. The numbers on the horizontal axis indicate the days of incubation.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664628&req=5

Figure 2: Relative abundances of bacteria at class level in seawater alone, seawater with dispersant Corexit, crude oil, and both oil and dispersant incubated under the dark and light conditions for 36 days. The numbers on the horizontal axis indicate the days of incubation.

Mentions: Pyrosequencing of 16S rRNA gene amplicons from the 41 samples resulted in a total of 289, 066 quality-filtered sequences for an average of 7050 sequences per sample. At the class level, Flavobacteria, Gammaproteobacteria, Alphaproteobacteria, and Cyanobacteria dominated at almost all time points (Figure 2). The original surface seawater at the beginning of the experiment comprised roughly equal proportions of Alpha- (33%) and Gammaproteobacteria (31%), along with Cyanobacteria (22%) and Flavobacteria (8%). In controls with seawater alone, Cyanobacteria were greatly reduced in the dark, and Sphingobacteria increased by about 20-fold at the later stage of incubation under the light. The sequences were submitted to the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) and are available in the URL http://data.gulfresearchinitiative.org/data/R1.x140.126:0005 and doi: 10.7266/N7H70CRW. The data were also submitted to NCBI Sequence Read Archive (SRA) under the Accession SAMN04054215. The relative abundances of bacteria genera is also available under doi: 10.7266/N7CF9N11.


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

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

Relative abundances of bacteria at class level in seawater alone, seawater with dispersant Corexit, crude oil, and both oil and dispersant incubated under the dark and light conditions for 36 days. The numbers on the horizontal axis indicate the days of incubation.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: Relative abundances of bacteria at class level in seawater alone, seawater with dispersant Corexit, crude oil, and both oil and dispersant incubated under the dark and light conditions for 36 days. The numbers on the horizontal axis indicate the days of incubation.
Mentions: Pyrosequencing of 16S rRNA gene amplicons from the 41 samples resulted in a total of 289, 066 quality-filtered sequences for an average of 7050 sequences per sample. At the class level, Flavobacteria, Gammaproteobacteria, Alphaproteobacteria, and Cyanobacteria dominated at almost all time points (Figure 2). The original surface seawater at the beginning of the experiment comprised roughly equal proportions of Alpha- (33%) and Gammaproteobacteria (31%), along with Cyanobacteria (22%) and Flavobacteria (8%). In controls with seawater alone, Cyanobacteria were greatly reduced in the dark, and Sphingobacteria increased by about 20-fold at the later stage of incubation under the light. The sequences were submitted to the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) and are available in the URL http://data.gulfresearchinitiative.org/data/R1.x140.126:0005 and doi: 10.7266/N7H70CRW. The data were also submitted to NCBI Sequence Read Archive (SRA) under the Accession SAMN04054215. The relative abundances of bacteria genera is also available under doi: 10.7266/N7CF9N11.

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