Influence of low oxygen tensions and sorption to sediment black carbon on biodegradation of pyrene.
Sorption to sediment black carbon (BC) may limit the aerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) in resuspension events and intact sediment beds. We examined this hypothesis experimentally under conditions that were realistic in terms of oxygen concentrations and BC content. A new method, based on synchronous fluorescence observations of (14)C-pyrene, was developed for continuously measuring the uptake of dissolved pyrene by Mycobacterium gilvum VM552, a representative degrader of PAHs. The effect of oxygen and pyrene concentrations on pyrene uptake followed Michaelis-Menten kinetics, resulting in a dissolved oxygen half-saturation constant (K(om)) of 14.1 microM and a dissolved pyrene half-saturation constant (K(pm)) of 6 nM. The fluorescence of (14)C-pyrene in air-saturated suspensions of sediments and induced cells followed time courses that reflected simultaneous desorption and biodegradation of pyrene, ultimately causing a quasi-steady-state concentration of dissolved pyrene balancing desorptive inputs and biodegradation removals. The increasing concentrations of (14)CO(2) in these suspensions, as determined with liquid scintillation, evidenced the strong impact of sorption to BC-rich sediments on the biodegradation rate. Using the best-fit parameter values, we integrated oxygen and sorption effects and showed that oxygen tensions far below saturation levels in water are sufficient to enable significant decreases in the steady-state concentrations of aqueous-phase pyrene. These findings may be relevant for bioaccumulation scenarios that consider the effect of sediment resuspension events on exposure to water column and sediment pore water, as well as the direct uptake of PAHs from sediments.
Ortega-Calvo
José-Julio
JJ
Instituto de Recursos Naturales y Agrobiología (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville, Spain. jjortega@irnase.csic.es
Gschwend
Philip M
PM
D000327:Adsorption; D001673:Biodegradation, Environmental / Q000187:drug effects; D002250:Carbon Radioisotopes / Q000378:metabolism; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D009170:Nontuberculous Mycobacteria / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology; D011721:Pyrenes / Q000378:metabolism*; D053260:Soot; D014874:Water Pollutants, Chemical / Q000378:metabolism
D002250:Carbon Radioisotopes; D011721:Pyrenes; D053260:Soot; D014874:Water Pollutants, Chemical; C030984:pyrene; D010100:Oxygen
Environ Sci Technol. 2002 Jan 1;36(1):21-9
11811485
Environ Sci Technol. 2005 Jan 1;39(1):141-8
15667088
Appl Environ Microbiol. 1994 May;60(5):1687-9
8017949
Microb Ecol. 2005 Nov;50(4):488-95
16328660
Environ Sci Technol. 1995 Jun 1;29(6):1542-50
22276875
Biotechnol Bioeng. 2006 Feb 20;93(3):457-64
16224793
Environ Sci Technol. 2005 Nov 15;39(22):8776-83
16323776
Appl Environ Microbiol. 1998 Aug;64(8):3123-6
9687489
Environ Sci Technol. 2003 May 15;37(10):2209-17
12785527
Appl Environ Microbiol. 1998 Jul;64(7):2560-5
9647830
Environ Pollut. 2005 Mar;134(2):315-22
15589658
Environ Toxicol Chem. 2004 Nov;23(11):2551-62
15559268
Appl Environ Microbiol. 2001 Dec;67(12):5497-505
11722898
Environ Sci Technol. 2003 Jan 1;37(1):99-106
12542297
Environ Toxicol Chem. 2008 Jul;27(7):1526-32
18260699
Environ Sci Technol. 2007 Nov 15;41(22):7752-8
18075084
Appl Environ Microbiol. 1994 Jul;60(7):2643-6
8074534
Environ Pollut. 2008 Sep;155(2):366-74
18093711
Environ Sci Technol. 2002 Nov 15;36(22):4811-7
12487304
Microb Ecol. 2005 Feb;49(2):226-35
15965718
Appl Environ Microbiol. 2004 Jan;70(1):363-9
14711664
Environ Toxicol Chem. 2006 May;25(5):1239-45
16704054
Mar Environ Res. 2006 Mar;61(2):202-23
16309739
Environ Microbiol. 2006 Mar;8(3):535-45
16478459
Environ Sci Technol. 2008 Feb 1;42(3):740-5
18323096
Appl Environ Microbiol. 1996 Sep;62(9):3344-9
8795224