Kinetics of competitive inhibition and cometabolism in the biodegradation of benzene, toluene, and p-xylene by two Pseudomonas isolates
- Michigan State Univ., East Lansing (United States)
Two Pseudomonas species (designated strains B1 and X1) were isolated from an aerobic pilot-scale fluidized-bed reactor treating groundwater containing benzene, toluene, and p-xylene (BTX). Strain B1 grew with benzene and toluene as the sole sources of carbon and energy, and it cometabolized p-xylene in the presence of toluene. Strain X1 grew on toluene and p-xylene, but not benzene. In single substrate experiments, the appearance of biomass lagged the consumption of growth substrates, suggesting that substrate uptake may not be growth-rate limiting for these substrates. Batch tests using paired substrates (BT, TX, or BX) revealed competitive inhibition and cometabolic degradation patterns. Competitive inhibition was modeled by adding a competitive inhibition term to the Monod expression. Cometabolic transformation of nongrowth substrate (p-xylene) by strain B1 was quantified by coupling xylene transformation to consumption of growth substrate (toluene) during growth and to loss of biomass during the decay phase. Coupling was achieved by defining two transformation capacity terms for the cometabolizing culture: one that relates consumption of biomass to the consumption of nongrowth substrate. Cometabolism increased decay rates, and the observed yield for strain B1 decreased in the presence of p-xylene.
- OSTI ID:
- 6773683
- Journal Information:
- Biotechnology and Bioengineering; (United States), Journal Name: Biotechnology and Bioengineering; (United States) Vol. 41:11; ISSN BIBIAU; ISSN 0006-3592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROBIC CONDITIONS
ALKYLATED AROMATICS
AROMATICS
BACTERIA
BENZENE
BIODEGRADATION
BIOLOGICAL VARIABILITY
BIOREACTORS
CHEMICAL REACTIONS
CLEANING
DECOMPOSITION
DECONTAMINATION
GENETIC VARIABILITY
GROUND WATER
GROWTH
HYDROCARBONS
HYDROGEN COMPOUNDS
MATHEMATICAL MODELS
MICROORGANISMS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PSEUDOMONAS
TOLUENE
WATER
XYLENES