skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Attention:

The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 10:00 PM ET on Thursday, March 12 until 2:00 AM ET on Friday, March 13 due to maintenance. We apologize for the inconvenience.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Microbial production and consumption of hydrocarbons in the global ocean
Seeps, spills and other oil pollution introduce hydrocarbons into the ocean. Marine cyanobacteria also produce hydrocarbons from fatty acids, but little is known about the size and turnover of this cyanobacterial hydrocarbon cycle. We report that cyanobacteria in an oligotrophic gyre mainly produce n-pentadecane and that microbial hydrocarbon production exhibits stratification and diel cycling in the sunlit surface ocean. Using chemical and isotopic tracing we find that pentadecane production mainly occurs in the lower euphotic zone. Using a multifaceted approach, we estimate that the global flux of cyanobacteria-produced pentadecane exceeds total oil input in the ocean by 100- to 500-fold. We show that rapid pentadecane consumption sustains a population of pentadecane-degrading bacteria, and possibly archaea. Our findings characterize a microbial hydrocarbon cycle in the open ocean that dwarfs oil input. We hypothesize that cyanobacterial hydrocarbon production selectively primes the ocean’s microbiome with long-chain alkanes whereas degradation of other petroleum hydrocarbons is controlled by factors including proximity to petroleum seepage.  more » « less
Award ID(s):
1634478
PAR ID:
10231175
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Nature microbiology
Volume:
6
ISSN:
2058-5276
Page Range / eLocation ID:
489–49
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; ; et al (, ACS earth and space chemistry)
    null (Ed.)
    Aliphatic hydrocarbons in the surface ocean are derived from phytoplankton and oil, but the coexistence and cycling of these two sources is not well-defined. Moreover, phytoplankton and oil can create thin layers of a nonmiscible phase that appear as sheens on surface water and are visually difficult to distinguish. Here, we examine the co-occurrence of hydrocarbon compounds in surface water samples to determine the inputs from phytoplankton and oil using pentadecane (C15-n-alkane) and heptadecane (C17-n-alkane) as molecular markers. Surface water sheens collected from a 2015 field survey in the Northern Gulf of Mexico contained hydrocarbons from natural oil seepage, hytoplankton blooms (i.e., biogenic), and mixtures of the two. Microbial communities examined in surface water sheen samples were dominated by cyanobacteria of the Genus Trichodesmium. The hydrocarbon content of the field-collected surface sheens was used to inform the categorization of 2171 samples collected in 2010 during the Deepwater Horizon (DWH) oil spill. Of the water samples categorized, a small fraction (<1%) ontained only biogenic hydrocarbons, and ∼10% contained a biogenic-hydrocarbon input mixed with oil. This study provides a method for identifying biogenic inputs to oil slicks and surface sheens, and highlights a molecular approach to distinguish the two sources. KEYWORDS: Hydrocarbon, Pentadecane 
    more » « less
  2. ; ; (, Proceedings of the International Ocean Discovery Program Expedition reports)
    Sediment and pore water samples from all drill sites of International Ocean Discovery Program (IODP) Expedition 385 were analyzed quantitatively for aliphatic hydrocarbons, petroleum (C9–C44) hydrocarbons, and aromatic and polyaromatic compounds. All hydrocarbon classes showed concentration peaks in deep, hot sediments just above and below deeply buried sills (Sites U1545 and U1546), indicating that they were formed by thermal maturation of buried organic matter in the thermal aureole of sill intrusion and have, to a large extent, remained in situ. Plotting hydrocarbon concentrations against in situ temperature shows a pronounced increase in concentration between 65° and 80°C, the thermal limit of hydrocarbon-degrading microbial populations. A smaller hydrocarbon maximum is associated with surficial sediments: within the upper 4 m of the sediment column, the concentrations of total saturated hydrocarbons and of total petroleum hydrocarbons were almost always higher compared to the next sediment samples in downhole sequence, compatible with biogenic hydrocarbon input that reaches all drill sites in Guaymas Basin. The U-shaped hydrocarbon profiles suggest a biological filter that degrades surficial hydrocarbon input and deeply sourced hydrocarbons as soon as the temperature regime in gradually cooling, slowly accumulating sediments permits microbial activity. 
    more » « less
  3. ; ; ; ; ; ; (, The ISME Journal)
    Aqueous-soluble hydrocarbons dissolve into the ocean’s interior and structure deep-sea microbial populations influenced by natural oil seeps and spills. n-Pentane is a seawater-soluble, volatile compound abundant in petroleum products and reservoirs and will partially partition to the deep-water column following release from the seafloor. In this study, we explore the ecology and niche partitioning of two free-living Cycloclasticus strains recovered from seawater incubations with n-pentane and distinguish them as an open ocean variant and a seep-proximal variant, each with distinct capabilities for hydrocarbon catabolism. Comparative metagenomic analysis indicates the variant more frequently observed further from natural seeps encodes more general pathways for hydrocarbon consumption, including short-chain alkanes, aromatics, and long-chain alkanes, and also possesses redox versatility in the form of respiratory nitrate reduction and thiosulfate oxidation; in contrast, the seep variant specializes in short-chain alkanes and relies strictly on oxygen as the terminal electron acceptor. Both variants observed in our work were dominant ecotypes of Cycloclasticus observed during the Deepwater Horizon disaster, a conclusion supported by 16S rRNA gene analysis and read-recruitment of sequences collected from the submerged oil plume during active flow. A comparative genomic analysis of Cycloclasticus across various ecosystems suggests distinct strategies for hydrocarbon transformations among each clade. Our findings suggest Cycloclasticus is a versatile and opportunistic consumer of hydrocarbons and may have a greater role in the cycling of sulfur and nitrogen, thus contributing broad ecological impact to various ecosystems globally. 
    more » « less
  4. ; ; ; ; (, Microorganisms)
    Surfactants, both synthetic and natural, are used in a wide range of industrial applications, including the degradation of petroleum hydrocarbons. Organisms from extreme environments are well-adapted to the harsh conditions and represent an exciting avenue of discovery of naturally occurring biosurfactants, yet microorganisms from cold environments have been largely overlooked for their biotechnological potential as biosurfactant producers. In this study, four cold-adapted bacterial isolates from Antarctica are investigated for their ability to produce biosurfactants. Here we report on the physical properties and chemical structure of biosurfactants from the genera Janthinobacterium, Psychrobacter, and Serratia. These organisms were able to grow on diesel, motor oil, and crude oil at 4 °C. Putative identification showed the presence of sophorolipids and rhamnolipids. Emulsion index test (E24) activity ranged from 36.4–66.7%. Oil displacement tests were comparable to 0.1–1.0% sodium dodecyl sulfate (SDS) solutions. Data presented herein are the first report of organisms of the genus Janthinobacterium to produce biosurfactants and their metabolic capabilities to degrade diverse petroleum hydrocarbons. The organisms’ ability to produce biosurfactants and grow on different hydrocarbons as their sole carbon and energy source at low temperatures (4 °C) makes them suitable candidates for the exploration of hydrocarbon bioremediation in low-temperature environments. 
    more » « less
  5. ; ; ; ; ; ; (, mSystems)
    Mackelprang, Rachel (Ed.)
    Petroleum pollution in the ocean has increased because of rapid population growth and modernization, requiring urgent remediation. Our understanding of the metabolic response of native microbial communities to oil spills is not well understood. Here, we explored the baseline hydrocarbon-degrading communities of a subarctic Atlantic region to uncover the metabolic potential of the bacteria that inhabit the surface and subsurface water. We conducted enrichments with a 13 C-labeled hydrocarbon to capture the fraction of the community actively using the hydrocarbon. We then combined this approach with metagenomics to identify the metabolic potential of this hydrocarbon-degrading community. This revealed previously undescribed uncultured bacteria with unique metabolic mechanisms involved in aerobic hydrocarbon degradation, indicating that temperature may be pivotal in structuring hydrocarbon-degrading baseline communities. Our findings highlight gaps in our understanding of the metabolic complexity of hydrocarbon degradation by native marine microbial communities. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email