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Qi M, Zheng C, Wu W, Yu G, Wang P. Exopolysaccharides from Marine Microbes: Source, Structure and Application. Mar Drugs 2022; 20:md20080512. [PMID: 36005515 PMCID: PMC9409974 DOI: 10.3390/md20080512] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 12/03/2022] Open
Abstract
The unique living environment of marine microorganisms endows them with the potential to produce novel chemical compounds with various biological activities. Among them, the exopolysaccharides produced by marine microbes are an important factor for them to survive in these extreme environments. Up to now, exopolysaccharides from marine microbes, especially from extremophiles, have attracted more and more attention due to their structural complexity, biodegradability, biological activities, and biocompatibility. With the development of culture and separation methods, an increasing number of novel exopolysaccharides are being found and investigated. Here, the source, structure and biological activities of exopolysaccharides, as well as their potential applications in environmental restoration fields of the last decade are summarized, indicating the commercial potential of these versatile EPS in different areas, such as food, cosmetic, and biomedical industries, and also in environmental remediation.
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Affiliation(s)
- Mingxing Qi
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Caijuan Zheng
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, Haikou 571158, China
| | - Wenhui Wu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Correspondence: (W.W.); (G.Y.); (P.W.); Tel.: +86-021-61900388 (W.W.); +86-0532-8203-1609 (G.Y.); +86-021-61900388 (P.W.)
| | - Guangli Yu
- Key Laboratory of Marine Drugs, Ministry of Education, Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266237, China
- Laboratory for Marine Drugs and Bioproducts of Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Correspondence: (W.W.); (G.Y.); (P.W.); Tel.: +86-021-61900388 (W.W.); +86-0532-8203-1609 (G.Y.); +86-021-61900388 (P.W.)
| | - Peipei Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Correspondence: (W.W.); (G.Y.); (P.W.); Tel.: +86-021-61900388 (W.W.); +86-0532-8203-1609 (G.Y.); +86-021-61900388 (P.W.)
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Kamalanathan M, Schwehr KA, Labonté JM, Taylor C, Bergen C, Patterson N, Claflin N, Santschi PH, Quigg A. The Interplay of Phototrophic and Heterotrophic Microbes Under Oil Exposure: A Microcosm Study. Front Microbiol 2021; 12:675328. [PMID: 34408728 PMCID: PMC8366316 DOI: 10.3389/fmicb.2021.675328] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/28/2021] [Indexed: 11/18/2022] Open
Abstract
Microbial interactions influence nearly one-half of the global biogeochemical flux of major elements of the marine ecosystem. Despite their ecological importance, microbial interactions remain poorly understood and even less is known regarding the effects of anthropogenic perturbations on these microbial interactions. The Deepwater Horizon oil spill exposed the Gulf of Mexico to ∼4.9 million barrels of crude oil over 87 days. We determined the effects of oil exposure on microbial interactions using short- and long-term microcosm experiments with and without Macondo surrogate oil. Microbial activity determined using radiotracers revealed that oil exposure negatively affected substrate uptake by prokaryotes within 8 h and by eukaryotes over 72 h. Eukaryotic uptake of heterotrophic exopolymeric substances (EPS) was more severely affected than prokaryotic uptake of phototrophic EPS. In addition, our long-term exposure study showed severe effects on photosynthetic activity. Lastly, changes in microbial relative abundances and fewer co-occurrences among microbial species were mostly driven by photosynthetic activity, treatment (control vs. oil), and prokaryotic heterotrophic metabolism. Overall, oil exposure affected microbial co-occurrence and/or interactions possibly by direct reduction in abundance of one of the interacting community members and/or indirect by reduction in metabolism (substrate uptake or photosynthesis) of interacting members.
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Affiliation(s)
- Manoj Kamalanathan
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States
| | - Kathleen A Schwehr
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States
| | - Jessica M Labonté
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States
| | - Christian Taylor
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States
| | - Charles Bergen
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States
| | - Nicole Patterson
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States
| | - Noah Claflin
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States
| | - Peter H Santschi
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States.,Department of Oceanography, Texas A&M University, College Station, TX, United States
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States.,Department of Oceanography, Texas A&M University, College Station, TX, United States
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Marine Gel Interactions with Hydrophilic and Hydrophobic Pollutants. Gels 2021; 7:gels7030083. [PMID: 34287300 PMCID: PMC8293255 DOI: 10.3390/gels7030083] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/16/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
Microgels play critical roles in a variety of processes in the ocean, including element cycling, particle interactions, microbial ecology, food web dynamics, air-sea exchange, and pollutant distribution and transport. Exopolymeric substances (EPS) from various marine microbes are one of the major sources for marine microgels. Due to their amphiphilic nature, many types of pollutants, especially hydrophobic ones, have been found to preferentially associate with marine microgels. The interactions between pollutants and microgels can significantly impact the transport, sedimentation, distribution, and the ultimate fate of these pollutants in the ocean. This review on marine gels focuses on the discussion of the interactions between gel-forming EPS and pollutants, such as oil and other hydrophobic pollutants, nanoparticles, and metal ions.
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Ross J, Hollander D, Saupe S, Burd AB, Gilbert S, Quigg A. Integrating marine oil snow and MOSSFA into oil spill response and damage assessment. MARINE POLLUTION BULLETIN 2021; 165:112025. [PMID: 33571788 DOI: 10.1016/j.marpolbul.2021.112025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
Marine snow formation and vertical transport are naturally occurring processes that carry organic matter from the surface to deeper waters, providing food and sequestering carbon. During the Deepwater Horizon well blowout, oil was incorporated with marine snow aggregates, triggering a Marine Oil Snow (MOS) Sedimentation and Flocculent Accumulation (MOSSFA) event, that transferred a significant percentage of the total released oil to the seafloor. An improved understanding of processes controlling MOS formation and MOSSFA events is necessary for evaluating their impacts on the fate of spilled oil. Numerical models and predictive tools capable of providing scientific support for oil spill planning, response, and Natural Resource Damage Assessment are being developed to provide information for weighing the ecological trade-offs of response options. Here we offer considerations for oil spill response and recovery when assessing the potential for a MOSSFA event and provide tools to enhance decision-making.
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Affiliation(s)
- Jesse Ross
- Department of Civil and Environmental Engineering, University of New Hampshire, Durham, NH 03824, USA.
| | - David Hollander
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Susan Saupe
- Cook Inlet Regional Citizen's Advisory Council, Kenai, AK 99611, USA
| | - Adrian B Burd
- Department of Marine Sciences, University of Georgia, Athens, GA 30602, USA
| | - Sherryl Gilbert
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA
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Chen CS, Shiu RF, Hsieh YY, Xu C, Vazquez CI, Cui Y, Hsu IC, Quigg A, Santschi PH, Chin WC. Stickiness of extracellular polymeric substances on different surfaces via magnetic tweezers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143766. [PMID: 33243507 DOI: 10.1016/j.scitotenv.2020.143766] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/08/2020] [Accepted: 11/08/2020] [Indexed: 06/11/2023]
Abstract
Organic particle dynamics in the surface ocean plays a critical part in the marine carbon cycle. Aggregation of marine organic particles drives their downward transport to support various marine organisms on their transit to the sediments. Extracellular polymeric substances (EPS) from various microbes are a major contributor to the oceanic organic particle pool. The stickiness of EPS is expected to play a determining role in the aggregation process of particles; however, stickiness parameters are usually indirectly estimated through data fitting without direct assessment. Here a magnetic tweezer method was developed to quantitatively assess the stickiness of three model EPS produced by: Amphora sp., (diatom), Emiliania huxleyi (coccolithophore), and Sagittula stellata (bacteria), under different in vitro environmental conditions (salinity or EDTA complexed cations) and surface matrices (EPS-EPS and bare glass). Our results showed the stickiness of three microbial EPS decreasing for S. stellata > E. huxleyi > Amphora sp., in line with their decreasing protein-to-carbohydrate (P/C) ratios (related to their relative hydrophobicity). The data not only emphasize the importance of hydrophobicity on EPS stickiness, but also demonstrates that salinity and the nature of the substrate surface can influence the stickiness. Furthermore, we investigated stickiness between various types of EPS, and the observed selective stickiness of EPS between species may shed light on the interactions among heterogeneous marine microorganisms. Overall, this newly developed system provides a platform to assess the EPS stickiness to advance our understanding of the aggregation and sedimentation process of organic particles that are critical for the fate of organic carbon as well as for biofilm formation and microbial colonization of surfaces in the ocean.
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Affiliation(s)
- Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Yu-Ying Hsieh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chen Xu
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Carlos I Vazquez
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Yujia Cui
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ian C Hsu
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Peter H Santschi
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Wei-Chun Chin
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
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Faillettaz R, Paris CB, Vaz AC, Perlin N, Aman ZM, Schlüter M, Murawski SA. The choice of droplet size probability distribution function for oil spill modeling is not trivial. MARINE POLLUTION BULLETIN 2021; 163:111920. [PMID: 33340907 DOI: 10.1016/j.marpolbul.2020.111920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 09/07/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
The droplet size distribution (DSD) formed by gas-saturated oil jets is one of the most important characteristics of the flow to understand and model the fate of uncontrolled deep-sea oil spills. The shape of the DSD, generally modeled as a theoretical lognormal, Rosin-Rammler or non-fundamental distribution function, defines the size and the mass volume range of the droplets. Yet, the fundamental DSD shape has received much less attention than the volume median size (d50) and range of the DSD during ten years of research following the Deepwater Horizon (DWH) blowout. To better understand the importance of the distribution function of the droplet size we compare the oil rising time, surface oil mass, and sedimented and beached masses for different DSDs derived from the DWH literature in idealized and applied conditions, while keeping d50 constant. We highlight substantial differences, showing that the probability distribution function of the DSD for far-field modeling is, regardless of the d50, consequential for oil spill response.
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Affiliation(s)
- Robin Faillettaz
- University of Miami, Rosenstiel School of Marine and Atmospheric Science, FL 33149, Miami, USA; Ifremer, STH, F-56100 Lorient, France.
| | - Claire B Paris
- University of Miami, Rosenstiel School of Marine and Atmospheric Science, FL 33149, Miami, USA.
| | - Ana C Vaz
- University of Miami, Rosenstiel School of Marine and Atmospheric Science, FL 33149, Miami, USA
| | - Natalie Perlin
- University of Miami, Rosenstiel School of Marine and Atmospheric Science, FL 33149, Miami, USA
| | - Zachary M Aman
- Centre for Energy, School of Mechanical and Chemical Engineering, The University of Western Australia, Crawley 6009, WA, Australia
| | - Michael Schlüter
- Institute of Multiphase Flows, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
| | - Steven A Murawski
- University of South Florida, College of Marine Science, 140 7th Ave. S., St. Petersburg, FL 33701, USA
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Shiu RF, Vazquez CI, Chiang CY, Chiu MH, Chen CS, Ni CW, Gong GC, Quigg A, Santschi PH, Chin WC. Nano- and microplastics trigger secretion of protein-rich extracellular polymeric substances from phytoplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:141469. [PMID: 33113698 DOI: 10.1016/j.scitotenv.2020.141469] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/31/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
The substantial increase in plastic pollution in marine ecosystems raises concerns about its adverse impacts on the microbial community. Microorganisms (bacteria, phytoplankton) are important producers of exopolymeric substances (EPS), which govern the processes of marine organic aggregate formation, microbial colonization, and pollutant mobility. Until now, the effects of nano- and micro-plastics on characteristics of EPS composition have received little attention. This study investigated EPS secretion by four phytoplankton species following exposure to various concentrations of polystyrene nano- and microplastics (55 nm nanoparticles; 1 and 6 μm microparticles). The 55 nm nanoparticles induced less growth/survival (determined on a DNA basis) and produced EPS with higher protein-to-carbohydrate (P/C) ratios than the exposure to microplastic particles. The amount of DNA from the four marine phytoplankton showed a higher negative linear correlation with increasing P/C ratios, especially in response to nanoplastic exposure. These results provide evidence that marine phytoplankton are quite sensitive to smaller-sized plastics and actively modify their EPS chemical composition to cope with the stress from pollution. Furthermore, the release of protein-rich EPS was found to facilitate aggregate formation and surface modification of plastic particles, thereby affecting their fate and colonization. Overall, this work offers new insights into the potential harm of different-sized plastic particles and a better understanding of the responding mechanism of marine phytoplankton for plastic pollution. The data also provide needed information about the fate of marine plastics and biogenic aggregation and scavenging processes.
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Affiliation(s)
- Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Carlos I Vazquez
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Chang-Ying Chiang
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Meng-Hsuen Chiu
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA; National Life Science, Inc., Sacramento, CA 95660, USA; Kaiser Biotech, Inc., Sacramento, CA 95660, USA
| | - Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chih-Wen Ni
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Peter H Santschi
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA; Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Wei-Chun Chin
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
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Marine Snow Aggregates are Enriched in Polycyclic Aromatic Hydrocarbons (PAHs) in Oil Contaminated Waters: Insights from a Mesocosm Study. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8100781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Marine snow was implicated in the transport of oil to the seafloor during the Deepwater Horizon oil spill, but the exact processes remain controversial. In this study, we investigated the concentrations and distributions of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) in marine snow aggregates collected during a mesocosm experiment. Seawater only, oil in a water accommodated fraction (WAF), and Corexit-enhanced WAF (DCEWAF) were incubated for 16 d. Both WAF and DCEWAF aggregates were enriched in heavy molecular weight PAHs but depleted in naphthalene. DCEWAF aggregates had 2.6 times more total 16 PAHs than the WAF (20.5 vs. 7.8 µg/g). Aggregates in the WAF and DCEWAF incorporated 4.4% and 19.3%, respectively of the total PAHs in the mesocosm tanks. Our results revealed that marine snow sorbed and scavenged heavy molecular weight PAHs in the water column and the application of Corexit enhanced the incorporation of PAHs into the sinking aggregates.
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Niche Partitioning between Coastal and Offshore Shelf Waters Results in Differential Expression of Alkane and Polycyclic Aromatic Hydrocarbon Catabolic Pathways. mSystems 2020; 5:5/4/e00668-20. [PMID: 32843540 PMCID: PMC7449609 DOI: 10.1128/msystems.00668-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In the wake of the Deepwater Horizon oil spill, the taxonomic response of marine microbial communities to oil and dispersants has been extensively studied. However, relatively few studies on the functional response of these microbial communities have been reported, especially in a longitudinal fashion. Moreover, despite the fact that marine oil spills typically impact thousands of square kilometers of both coastal and offshore marine environments, little information is available on how the microbial response to oil and dispersants might differ between these biomes. The results of this study help fill this critical knowledge gap and provide valuable insight into how oil spill response efforts, such as chemically dispersing oil, may have differing effects in neighboring coastal and offshore marine environments. Marine oil spills can impact both coastal and offshore marine environments, but little information is available on how the microbial response to oil and dispersants might differ between these biomes. Here, we describe the compositional and functional response of microbial communities to different concentrations of oil and chemically dispersed oil in coastal and offshore surface waters from the Texas-Louisiana continental shelf. Using a combination of analytical chemistry and 16S rRNA amplicon and metatranscriptomic sequencing, we provide a broad, comparative overview of the ecological response of hydrocarbon-degrading bacteria and their expression of hydrocarbon-degrading genes in marine surface waters over time between two oceanic biomes. We found evidence for the existence of different ecotypes of several commonly described hydrocarbon-degrading bacterial taxa which behaved differentially in coastal and offshore shelf waters despite being exposed to similar concentrations of oil, dispersants, and nutrients. This resulted in the differential expression of catabolic pathways for n-alkanes and polycyclic aromatic hydrocarbons (PAHs)—the two major categories of compounds found in crude oil—with preferential expression of n-alkane degradation genes in coastal waters while offshore microbial communities trended more toward the expression of PAH degradation genes. This was unexpected as it contrasts with the generally held view that n-alkanes, being more labile, are attacked before the more refractory PAHs. Collectively, our results provide new insights into the existence and potential consequences of niche partitioning of hydrocarbon-degrading taxa between neighboring marine environments. IMPORTANCE In the wake of the Deepwater Horizon oil spill, the taxonomic response of marine microbial communities to oil and dispersants has been extensively studied. However, relatively few studies on the functional response of these microbial communities have been reported, especially in a longitudinal fashion. Moreover, despite the fact that marine oil spills typically impact thousands of square kilometers of both coastal and offshore marine environments, little information is available on how the microbial response to oil and dispersants might differ between these biomes. The results of this study help fill this critical knowledge gap and provide valuable insight into how oil spill response efforts, such as chemically dispersing oil, may have differing effects in neighboring coastal and offshore marine environments.
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Genzer JL, Kamalanathan M, Bretherton L, Hillhouse J, Xu C, Santschi PH, Quigg A. Diatom aggregation when exposed to crude oil and chemical dispersant: Potential impacts of ocean acidification. PLoS One 2020; 15:e0235473. [PMID: 32634146 PMCID: PMC7340286 DOI: 10.1371/journal.pone.0235473] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/17/2020] [Indexed: 01/14/2023] Open
Abstract
Diatoms play a key role in the marine carbon cycle with their high primary productivity and release of exudates such as extracellular polymeric substances (EPS) and transparent exopolymeric particles (TEP). These exudates contribute to aggregates (marine snow) that rapidly transport organic material to the seafloor, potentially capturing contaminants like petroleum components. Ocean acidification (OA) impacts marine organisms, especially those that utilize inorganic carbon for photosynthesis and EPS production. Here we investigated the response of the diatom Thalassiosira pseudonana grown to present day and future ocean conditions in the presence of a water accommodated fraction (WAF and OAWAF) of oil and a diluted chemically enhanced WAF (DCEWAF and OADCEWAF). T. pseudonana responded to WAF/DCEWAF but not OA and no multiplicative effect of the two factors (i.e., OA and oil/dispersant) was observed. T. pseudonana released more colloidal EPS (< 0.7 μm to > 3 kDa) in the presence of WAF/DCEWAF/OAWAF/OADCEWAF than in the corresponding Controls. Colloidal EPS and particulate EPS in the oil/dispersant treatments have higher protein-to-carbohydrate ratios than those in the control treatments, and thus are likely stickier and have a greater potential to form aggregates of marine oil snow. More TEP was produced in response to WAF than in Controls; OA did not influence its production. Polyaromatic hydrocarbon (PAH) concentrations and distributions were significantly impacted by the presence of dispersants but not OA. PAHs especially Phenanthrenes, Anthracenes, Chrysenes, Fluorenes, Fluoranthenes, Pyrenes, Dibenzothiophenes and 1-Methylphenanthrene show major variations in the aggregate and surrounding seawater fraction of oil and oil plus dispersant treatments. Studies like this add to the current knowledge of the combined effects of aggregation, marine snow formation, and the potential impacts of oil spills under ocean acidification scenarios.
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Affiliation(s)
- Jennifer L. Genzer
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
| | - Manoj Kamalanathan
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
| | - Laura Bretherton
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jessica Hillhouse
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
| | - Chen Xu
- Department of Marine Science, Texas A&M University at Galveston, Galveston, Texas, United States of America
| | - Peter H. Santschi
- Department of Marine Science, Texas A&M University at Galveston, Galveston, Texas, United States of America
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
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