Final Report: Resistance of Communities to Chronic Haloaromatic Contamination from Biogenic and Anthropogenic Sources

EPA Grant Number: R824776
Title: Resistance of Communities to Chronic Haloaromatic Contamination from Biogenic and Anthropogenic Sources
Investigators: Lincoln, David E. , Lewis, V. Pernell , Lovell, Charles R. , Woodin, Sarah A.
Institution: University of South Carolina at Columbia
EPA Project Officer: Hiscock, Michael
Project Period: January 1, 1996 through December 1, 1998
Project Amount: $470,000
RFA: Water and Watersheds (1995) Recipients Lists
Research Category: Water and Watersheds , Water

Objective:

Halogenated aromatic compounds are important pollutants characterized by their toxicity, persistence and accumulation in the environment, and their abundant production and frequent use in a variety of industrial processes. This project examines the extent to which the capacity to degrade naturally occurring halogenated aromatic compounds may determine the biological impact of halophenol pollutants on marine benthic communities. Despite the global prevalence of marine sedimentary habitats, the responses of biota in benthic assemblages to haloorganic compounds is poorly understood. Our conceptual model describing the role of biogenic haloorganics as structuring agents in marine sedimentary assemblages proposes that haloorganics act by decreasing rates of predation in and increasing emigration from contaminated habitats, but that taxa that naturally contain or degrade haloorganics are not affected deleteriously by these compounds. Further, tolerance of biogenic haloorganics is proposed as a basis for responses to analogous compounds of anthropogenic origin and that dehalogenase activity may be a mechanistic basis for the occurrence of indicator species.

Summary/Accomplishments (Outputs/Outcomes):

Our findings highlight the abundance and broad distribution of benthic macro- and micro-organisms capable of production and/or degradation of halometabolites. A large number of invertebrate worm taxa are halometabolite producers and have enzymatic dehalogenation activity; this is particularly true of the polychaetes and the hemichordates. Interestingly, extensive areas of temperate marine soft-bottom benthic communities are contaminated by infauna, which produce noxious, toxic, volatile halocompounds. Using GC/MS, we examined the abundant worm, mollusc, and crustacean macroinfauna from two intertidal sandflat communities for volatile organohalogens. Halogenated compounds were newly identified from 11 common polychaete species. The represented chemical classes included aromatic mono- and dibrominated hydroxyphenylpropanoids, nitrogen-containing bromoalkylpyrroles, as well as brominated and chlorinated hydrocarbons and sulfides. Among the molluscs, only one contained an organohalogen compound, which is likely derived from its diet of hemichordate worms. Volatile haloorganics were not found in amphipod and nemertean taxa. Possession of these compounds was not a function of any particular phylum, size categorization, or trophic mode, although hemichordates and all capitellid and spionid polychaetes collected at these sites invariably contained halocompounds. Most (40 of ca. 54 taxa) of the numerically dominant macroinfaunal taxa at these two sites were examined in this survey; of these, 43% contained halometabolites, including several broadly distributed species. Thus, the potential for widespread occurrence of halogenated compounds among infauna is great.

The polychaetes are the dominant macrofauna at our study sites and appear to be segregated among sites with regard to their dehalogenation capacity and production of haloorganics. Species with high levels of dehalogenation capacity or production of haloorganics comprise over 80 percent of the macrofauna at sites with larger producers of haloaromatic compounds. At sites without such large producers of haloaromatic compounds, typically less than 40 percent of the smaller macrofauna are producers themselves (Fielman et al., 1999). This striking difference may be related to the presence of halophenols in their environment; the sediments in beds of large producers are significantly contaminated by haloaromatics (Steward and Lovell, 1997; Lincoln et al., submitted). Intolerance, measured as a very low rate of debromination, was more common among taxa at uncontaminated sites. A chemical refuge hypothesis was tested by comparisons among three sites: a known physical refuge (polychaete tube clumps), a proposed chemical refuge (sediment contaminated by a halophenol-producing hemichordate), and an area lacking either refuge type. During the low predation/high recruitment winter period, overall producer and nonproducer densities were not significantly different among sites, although the distributions of the dominant species differed. In contrast, during summer's high predation period, nonproducer species were significantly less abundant at the chemical refuge compared to the physical refuge, and the species composition between refugia was different. Significantly, the overall density of haloorganic-containing infauna was equivalent between the physical and chemical refuges. Similar to winter's results, halophenol-intolerant polychaetes and bivalves were least abundant in the proposed chemical refuge. Our results suggest that chemical refugia based on the presence of bromophenols in animals and sediments exist, but that their use is limited to taxa tolerant of chronic haloorganic exposure. Predation and tolerance to bromophenols appear to strongly influence the spatial and temporal distribution of numerous species and thus, are principal structuring factors in these assemblages.

As one would expect given such sediment contamination, the bacterial assemblage includes active dehalogenators. Twelve reductively dechlorinating anaerobic bacterial strains have been isolated from the burrows of a bromphenol producing and a nonproducing macrofaunal species within the contaminated site. These strains reductively dechlorinate 2,4,6-trichlorophenol as well as 2,4,6-tribromophenol (Watson et al., 2000). In addition, a benthic microalgal species (Thallasiosira sp.) has been found to have dehalogenase activity. This organism can dechlorinate 2,4,6-trichlorophenol and can cleave the aromatic ring using protocatechuate 4,5-dioxygenase (Lovell et al., 2000).

This striking difference in dehalogenase activity between members of the benthic communities at the contaminated and the uncontaminated sites is consistent with our previous findings on recruitment, which indicated that halophenols in sediments can act as a recruitment filter (Woodin et al., 1997). To determine whether this difference in dehalogenase activity would translate into differences in bioaccumulation of halophenols, we experimentally contaminated a site with 2,6-dibromophenol for 2 weeks and looked for changes in body burden between species with active dehalogenases and those without (Fielman et al., 2000). In parallel with the macrofaunal sampling, the bacterial community in sites with and without experimental addition of halophenol was examined by phospholipid fatty acid analysis (PLFA). We predicted that the presence of halometabolites in infauna and sediments would affect marine communities by excluding haloorganic-intolerant taxa over time, much like the deleterious impact of halogenated environmental pollutants. Body burden of polychaetes was 10-fold greater in intolerant than in tolerant taxa. Dehalogenase activity in intolerant taxa decreased by approximately 50 percent or showed no significant increase. This biochemical stress response was corroborated by the induction of stress proteins (heat-shock proteins). A PLFA biomarker specific for the genus Desulfovibrio, recently observed to have members with dehalogenation activity, increased within treatment plots, although microbial biomass and overall assemblage composition did not change. Individuals of the polychaete, Diopatra cuprea, were transplanted to sites with and without chronic biogenic bromophenol input and their survivorship monitored for a minimum of 2 months. D. cuprea exposed to chronic biogenic bromophenol input exhibited reduced survivorship relative to control transplants. The short-term microbial response, the rapid biochemical stress response of macroinfauna, the absence of an immediate change in macroinfaunal community structure, but a long-term decrease in D. cuprea survivorship, were consistent with our expectations. Based on their inherent abilities to detoxify or otherwise tolerate native halocompounds, microbial and macroinfaunal members of these benthic communities, including pollution indicator species, may show similar tolerance to halogenated anthropogenic xenobiotics.

To further examine the reponses of sediment bacterial communities, we have developed a new method, based on neural networks, for analyzing PLFA profiles. The neural computing method is more sensitive than conventional cluster and principal component analyses and yields greater resolution of community composition (Noble et al., 2000).

The halophenols produced by many marine infaunal hemichordates and polychaetes have been suggested to have antimicrobial activity. Intact sediment cores were collected from a site inhabited by the bromophenol producing polychaete Notomastus lobatus and from a similar site having no bromometabolite producing infauna. No significant inhibition of respiration or assimilation by 4-bromophenol was observed even at bromophenol levels 100X the ambient concentration in wormbed sediments (Steward and Lovell, 1997; Lovell et al., 1999). These data show that this naturally occurring bromoaromatic compound has no significant effect on community activity of sediment bacteria.

We have substantially increased our understanding of the dehalogenase/tolerance mechanism through molecular and biochemical approaches to the structure and function of the enzyme and gene for the dehaloperoxidase (DHP), as well as the haloperoxidase invoved in the production of halophenols (Roach et al., 1997; Lebioda et al., 1999). We constructed a cDNA library from RNA isolated from the polychaete Amphitrite ornata. A. ornata occurs in sites with high sediment halophenol concentrations and has a high dehalogenase activity. A partial amino acid sequence was obtained from the purified enzyme and used to construct oligonucleotide probes for the cDNA library. We obtained a full-length clone and sequence for the dehalogenase. Translating the newly found nucleic acid sequence into an amino acid sequence allowed us to use crystallographic analysis of the protein to evaluate the functional structure of the dehalogenase enzyme. DHP has structural (and sequence) homology to the globin family of proteins and is the first example of an enzymatic globin (Lebioda et al., 1999). The elucidation of the RNA sequence and enzyme structure may well form the basis for new developments in dehalogenation technology.


Journal Articles on this Report : 16 Displayed | Download in RIS Format

Other project views: All 27 publications 16 publications in selected types All 16 journal articles
Type Citation Project Document Sources
Journal Article Cowart JD, Fielman KT, Woodin SA, Lincoln DE. Halogenated metabolites in two marine polychaetes and their planktotrophic and lecithotrophic larvae. Marine Biology 2000;136(6):993-1002. R824776 (1999)
R824776 (Final)
not available
Journal Article Fielman KT, Woodin SA, Walla MD, Lincoln DE. Widespread occurrence of natural halogenated organics among temperate marine infauna. Marine Ecology Progress Series 1999;181:1-12. R824776 (1999)
R824776 (Final)
not available
Journal Article Fielman KT, Woodin SA, Lincoln DE. Polychaete indicator species as a source of natural halogenated organic compounds in marine sediments. Environmental Toxicology and Chemistry 2001;20(4):738-747. R824776 (1999)
R824776 (Final)
not available
Journal Article Kihslinger RL, Woodin SA. Food patches and a surface deposit feeding spionid polychaete. Marine Ecology: Progress Series 2000;201:233-239. R824776 (1999)
R824776 (Final)
not available
Journal Article Lebioda L, LaCount MW, Zhang E, Chen YP, Han K, Whitton MM, Lincoln DE, Woodin SA. An enzymatic globin from a marine worm -- Brief communications. Nature 1999;401(6752):445. R824776 (1999)
R824776 (Final)
R827612E01 (Final)
R827612E02 (Final)
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  • Journal Article Lincoln DE, Fielman KT, Marinelli RL, Woodin SA. Bromophenol accumulation and sediment contamination by the polychaetes Notomastus lobatus (Capitellidae) and Thelepus crispus (Terebellidae). Biochemical Systematics and Ecology 2005;33:559-570. R824776 (1999)
    R824776 (Final)
    not available
    Journal Article Lovell CR, Steward CC, Phillips T. Activity of marine sediment bacterial communities exposed to 4-bromophenol, a polychaete secondary metabolite. Marine Ecology Progress Series 1999;179:241-246. R824776 (1999)
    R824776 (Final)
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    Journal Article Lovell CR, Eriksen NT, Lewitus AJ, Chen YP. Resistance of the marine diatom Thalassiosira sp to toxicity of phenolic compounds. Marine Ecology Progress Series 2002;229:11-18. R824776 (Final)
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    Journal Article Noble PA, Almeida JS, Lovell CR. Application of neural computing methods for interpreting phospholipid fatty acid profiles of natural microbial communities. Applied and Environmental Microbiology 2000;66(2):694-699. R824776 (Final)
    R826944 (1999)
    R826944 (2000)
    R826944 (2001)
    R826944 (Final)
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  • Full-text: AEM-Full Text HTML
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  • Abstract: AEM-Abstract
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  • Journal Article Phillips TM, Lovell CR. Distributions of total and active bacteria in biofilms lining tubes of the onuphid polychaete Diopatra cuprea. Marine Ecology Progress Series 1999;183:169-178. R824776 (Final)
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    Journal Article Roach MP, Chen YP, Woodin SA, Lincoln DE, Lovell CR, Dawson JH. Notomastus lobatus chloroperoxidase and Amphitrite ornata dehaloperoxidase both contain histidine as their proximal heme iron ligand. Biochemistry 1997;36:2197-2202. R824776 (Final)
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    Journal Article Steward CC, Lovell CR. Respiration and assimilation of 4-bromophenol by estuarine sediment bacteria. Microbial Ecology 1997;33:198-205. R824776 (Final)
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    Journal Article Watson J, Matsui GY, Leaphart A, Wiegel J, Rainey FA, Lovell CR. Reductively debrominating strains of Propionigenium maris from burrows of bromophenol-producing marine infauna. International Journal of Systematic and Evolutionary Microbiology 2000;50:1035-1042. R824776 (Final)
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    Journal Article Woodin SA, Lindsay SM, Lincoln DE. Biogenic bromophenols as negative recruitment cues. Marine Ecology Progress Series 1997;157:303-306. R824776 (Final)
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    Journal Article Woodin SA. Biogenic determinants of marine benthic community composition: structures and smells. American Zoologist 1999;39. R824776 (1999)
    R824776 (Final)
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    Journal Article Woodin SA. Shallow water benthic ecology: A North American perspective of sedimentary habitats. Australian Journal of Ecology 1999;24(4):291-301. R824776 (1999)
    R824776 (Final)
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    Supplemental Keywords:

    water, sediments, marine, estuary, ecological effects, population, enzymes, chemicals, toxics, PAHs, organics, ecosystem, restoration, aquatic, habitat, environmental chemistry, biology, ecology, genetics, zoology, survey, southeast, South Carolina, SC, EPA Region 4., RFA, Scientific Discipline, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Water & Watershed, Contaminated Sediments, exploratory research environmental biology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Chemical Mixtures - Environmental Exposure & Risk, Ecosystem Protection, Chemistry, State, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Wet Weather Flows, Agronomy, Biology, EPA Region, Watersheds, Ecological Indicators, anthropogenic stresses, ecological exposure, region 4, anthropogenic processes, urbanization, anthropogenic stress, aquatic ecosystem, contaminant transport, agricultural discharges, biological condition, contaminated sediment, agricultural watershed, runoff, sediment, urban runoff, enzyme assays, citizen perceptions, industrial chemicals, bromophenol producing marine worms, ecological impacts, biogenic haloaromatic contamination, gene probes, aquatic ecosystems, water quality, South Carolina (SC), ecosystem response , haloaromatic contamination, anthropogenic haloaromatic contamination, chronic haloaromatic contamination, ecological response

    Progress and Final Reports:

    Original Abstract
  • 1996
  • 1997