title: Batch kinetics of Pseudomonas sp. growth on benzene. Modeling of product and substrate inhibitions.
abstract: Batch tests of benzene degradation were performed in liquid phase at 30 degrees C, pH 6.8 +/- 0.2, and 200 rpm in two 3-L stirred tank bioreactors, using the benzene-degrading bacterium Pseudomonas sp. NCIMB 9688. A relatively high starting biomass level (220-270 mg(X)/L) and starting benzene concentration ranging from 20 to 200 mg(S)/L were selected as conditions to investigate possible inhibition phenomena. Volumetric as well as specific rates of biomass formation and substrate consumption were calculated from experimental data of both growth and benzene degradation and used to propose and check a new overall kinetic model for cell growth simultaneously accounting for both product and substrate inhibitions. The results of the present study evidenced the occurrence of a competitive-type product inhibition due to 2-hydroxymuconic semialdehyde (K(iP)' = 0.902 mg(S)/L), which was stronger than the uncompetitive-type inhibition exerted by substrate (K(iS) = 7.69 mg(S)/L).
authors.affiliation: Department of Chemical and Process Engineering, University of Genova, via Opera Pia 15, I-16145 Genoa, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Monero
authors.forename: Luca
authors.initials: L
authors.lastname: Lanza
authors.forename: Mario
authors.initials: M
authors.lastname: Zilli
authors.forename: Luciane
authors.initials: L
authors.lastname: Sene
authors.forename: Attilio
authors.initials: A
authors.lastname: Converti
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D001554:Benzene / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division / Q000502:physiology; D003198:Computer Simulation; D004785:Environmental Pollutants / Q000378:metabolism; D007220:Industrial Waste / Q000517:prevention & control; D007700:Kinetics; D008954:Models, Biological; D011549:Pseudomonas / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D004785:Environmental Pollutants; D007220:Industrial Waste; D001554:Benzene