Multisubstrate biodegradation kinetics of naphthalene, phenanthrene, and pyrene mixtures

Abstract

Biodegradation kinetics of naphthalene, phenanthrene and pyrene were studied in sole‐substrate systems, and in binary and ternary mixtures to examine substrate interactions. The experiments were conducted in aerobic batch aqueous systems inoculated with a mixed culture that had been isolated from soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Monod kinetic parameters and yield coefficients for the individual compounds were estimated from substrate depletion and CO2 evolution rate data in sole‐substrate experiments. In all three binary mixture experiments, biodegradation kinetics were comparable to the sole‐substrate kinetics. In the ternary mixture, biodegradation of naphthalene was inhibited and the biodegradation rates of phenanthrene and pyrene were enhanced. A multisubstrate form of the Monod kinetic model was found to adequately predict substrate interactions in the binary and ternary mixtures using only the parameters derived from sole‐substrate experiments. Numerical simulations of biomass growth kinetics explain the observed range of behaviors in PAH mixtures. In general, the biodegradation rates of the more degradable and abundant compounds are reduced due to competitive inhibition, but enhanced biodegradation of the more recalcitrant PAHs occurs due to simultaneous biomass growth on multiple substrates. In PAH‐contaminated environments, substrate interactions may be very large due to additive effects from the large number of compounds present. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 65:491–499, 1999.

Biodegradation kinetics of aromatic hydrocarbon mixtures by pure and mixed bacterial cultures.

“…Although these kinetics can in some cases be described by relatively simple no-interaction (16) or competitive inhibition (9,18,20) models, we have demonstrated that such models are inadequate for P. putida F1 growing on mixtures of toluene, benzene, and phenol and for Burkholderia sp. JS150 growing on mixtures of toluene and phenol.…”

“…More recently, models have been proposed and tested for larger mixtures. Examples include the growth of Escherichia coli on six sugars (16), the growth of a mixed culture on benzene, toluene, ethylbenzene, and o-and p-xylene (BTEX compounds) (11), and the biodegradation of three polycyclic aromatic hydrocarbons (20).…”

Saturable, Energy-Dependent Uptake of Phenanthrene in Aqueous Phase by Mycobacterium sp. Strain RJGII-135

“…The specific affinity (calculated as maximum degradation rate [V max ]/Michaelis-Menten half-saturation constant [K m ]) of LB501T cells for aqueous anthracene was found to be higher than the specific affinities of other cultures reported elsewhere (41). A diverse range of K m values for PAH degradation have been obtained with pure cultures (1,12,18,27,36) and mixed cultures (19). Wick et al have proposed the presence of a high-affinity uptake system in LB501T (41), which would account for the facile degradation of aqueous-phase PAHs occurring at extremely low concentrations in the environment.…”

Federal Integrated Biotreatment Research Consortium (FIBRC): Flask to Field Initiative

“…In the presence of surfactant, Boonchan et al (2000) found that Stenotrophomonas maltophilia VUN 1,0010s degraded mixtures of PAHs faster in the presence of surfactant than in the absence of surfactant, and the maximum specific degradation rate of each component from the mixture was smaller than when it was degraded alone. Similar decreases in the degradation rate of individual PAHs due to the presence of other PAHs have been found in the absence of surfactants for mixed cultures (Guha et al, 1999) and for pseudomonads (Stringfellow and Aitken, 1995a;Bouchez et al, 1995). Further work in this area is necessary to provide a greater understanding of how surfactants influence the microbial degradation of mixtures and to make the application of surfactants a standard engineering tool in biological soil remediation (Volkering et al, 1998).…”