title: Degradation of para-hydroxybenzoic acid by means of mixed microbial cultures.
abstract: Olive mill wastewater contains some phenolic compounds that cause antibacterial activity of a kind that prevents biological treatment without previous dilution. Among these phenolic compounds, p-hydroxybenzoic acid (PHB) is considered to be one of the most representative. This work examines the biodegradation of PHB by aerobic microbial mixed cultures previously acclimatized to glucose, which was used as an easily biodegradable model compound. Microbial growth runs were carried out in a batch reactor in the PHB concentration range of 200-1000 mg/L. In all the runs the PHB proved to be completely degradable. The specific growth rates obtained were in the range of 0.16-0.35 l/h. Experimental runs showed that the functional relationship between the specific growth rate and PHB concentration was that proposed by Monod. The kinetic constants of the Monod equation (mu(max) and K(S)) and biomass yield coefficient (Y) were determined experimentally. With the parameter values thus obtained, a mathematical model that also takes account of the duration of the lag phase was employed to describe both the microbial growth and the consumption of PHB. The concentration values of the model fit well with the data obtained experimentally.
authors.affiliation: Dipartimento di Ingegneria Chimica e Materiali, Unità di Ricerca del Consorzio Interuniversitario Nazionale La Chimica per l'Ambiente, Università di Cagliari, Piazza d'Armi, I-09123 Cagliari, Italy. lallai@dicm.unica.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Lallai
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Mura
authors.forename: Simonetta
authors.initials: S
authors.lastname: Palmas
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Polcaro
authors.forename: Luca
authors.initials: L
authors.lastname: Baraccani
mesh_terms: D001420:Bacteria, Aerobic / Q000502:physiology; D001673:Biodegradation, Environmental; D019149:Bioreactors; D019649:Food Industry; D007220:Industrial Waste; D007700:Kinetics; D008962:Models, Theoretical; D031658:Olea; D010226:Parabens / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D007220:Industrial Waste; D010226:Parabens; D014874:Water Pollutants, Chemical; C038193:4-hydroxybenzoic acid