title: Aerobic co-metabolism of sulfur, nitrogen and oxygen heterocycles by three marine bacterial consortia.
abstract: Bacterial samples were collected from three marine beaches in coastal Newfoundland, Canada, and enriched by growth on 1-methylnaphthalene. The most prominent bacterial cell type for each consortium was isolated in a serial dilutions test, and a substrate utilization profile was obtained for each using the Biolog MicroStation System. Each bacterial community was tested for its ability to co-metabolize sulfur heterocycles (benzothiophene: BT, 3-methylbenzothiophene: 3-MBT, and dibenzothiphene: DBT), a nitrogen heterocycle (carbazole: CARB), and an oxygen heterocycle (dibenzofuran: DBF). Co-metabolism of the starting material was determined using gas chromatography-mass spectroscopy (GC-MS), and formation of products was investigated by GC-MS and Fourier transform infrared (FTIR) spectroscopy. Bacterial growth was monitored turbidimetrically to determine the dry weight (microgram) of cells/ml. The 2-ringed heterocycles were co-metabolized faster and to a greater extent than the 3-ringed compounds. Co-metabolism of BT was not statistically different from that for 3-MBT and, likewise, a comparison of the 3-ringed heterocycles showed no significant differences in degradation rates. Statistical examination showed that no one culture demonstrated a significantly greater ability to co-metabolize the heterocycles studied. This study represents the first comprehensive investigation of the ability of local bacteria to co-metabolize a range of aromatic compounds and provides a preliminary understanding of their fate in sediments should contamination by these compounds occur.
authors.affiliation: Marine Environment and Habitat Management Division, Fisheries and Oceans Canada, P.O. Box 5667, St. John's, Newfoundland, Canada, A1C 5X1. meadej@dfo-mpo.gc.ca
authors.forename: James D
authors.initials: JD
authors.lastname: Meade
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Hellou
authors.forename: Thakor R
authors.initials: TR
authors.lastname: Patel
mesh_terms: D000332:Aerobiosis; D001572:Benzofurans / Q000378:metabolism; D001673:Biodegradation, Environmental; D002227:Carbazoles / Q000378:metabolism; D017753:Ecosystem; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D006571:Heterocyclic Compounds / Q000737:chemistry / Q000378:metabolism*; D009523:Newfoundland and Labrador; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D012623:Seawater / Q000382:microbiology*; D017550:Spectroscopy, Fourier Transform Infrared; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism*; D013876:Thiophenes / Q000737:chemistry / Q000378:metabolism
chemical_list: D001572:Benzofurans; D002227:Carbazoles; D006571:Heterocyclic Compounds; D013876:Thiophenes; C088015:benzothiophene; C041514:carbazole; D013455:Sulfur; C023614:dibenzofuran; D009584:Nitrogen; D010100:Oxygen