Batch nitrifying cultures in presence of mixtures of benzene, toluene, and m-xylene.
Benzene, toluene, and m-xylene compounds in individual (5.0 +/- 0.5 mg C l(-1)) and mixed solutions (2.5 +/- 0.2 mg C l(-1) for each one) in nitrifying batch cultures induced a decrease in the specific rates of NH4+ consumption (81 +/- 6%) and NO3- production (39-79%). However, after 24 h, ammonium consumption efficiency and conversion of consumed NH4+ -N into NO3- -N were close to 100% and there was no significant accumulation of nitrite in the medium. After 24 h, no aromatic intermediate was detected in the cultures and 50% of the mixed compounds was converted to acetate. The following order of biotransformation was found: m-xylene > toluene > benzene. Transformation rate of m-xylene was 0.051 +/- 0.005 g C (g protein-N h)(-1) in individual and mixed solutions. When m-xylene was added, benzene was oxidized at a faster rate (0.051 +/- 0.005 g C (g protein-N h)(-1)) whereas toluene at a slower rate (0.012 +/- 0.002 g C (g protein-N h)(-1)).
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Universidad Aut6noma Metropolitana-Iztapalapa, Div. CBS, Depto de Biotecnología, Av. San Rafael Atlixco 186, C.P. 09340, México DF, México.
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Gomez
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J
D001554:Benzene; D019149:Bioreactors; D001711:Biotransformation; D002849:Chromatography, Gas; D007700:Kinetics; D017672:Nitrogen Compounds / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D014050:Toluene; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D014992:Xylenes
D017672:Nitrogen Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; D014992:Xylenes; D014050:Toluene; D001554:Benzene; C031285:3-xylene