Effect of Sorption on the Biodegradation of Quinoline

Abstract

Quinoline is an N‐containing heterocyclic contaminant associated with creosote wastes and may be biologically degraded under aerobic and anaerobic conditions. Quinoline‐degrading bacteria were utilized to investigate the rate of quinoline desorption from smectite clay at low surface concentrations and its subsequent mineralization. Fluorescence spectroscopy and 14C‐quinoline mineralization techniques were used to compare the observed desorption rates to mineralization rates. Microbial utilization was desorption‐rate limiting. Desorption and microbial utilization may be modeled as pseudo‐first‐order reactions whose first‐order rate constant (kobs) is independent of surface concentration. The difference between quinoline disappearance from solution and from the clay surface as observed by fluorescence spectroscopy was comparable to the difference between microbial utilization of the solution and the surface‐bound species. The utilization of quinoline from solution was about 30 times more rapid than surface‐bound quinoline. The surface‐bound species appeared to be protected from microbial attack and, hence, desorption was required prior to utilization. The desorption process is suggested to be a chemical‐reaction‐controlled process rather than film diffusion controlled, as is typically suggested for an exchange process. The biotransformation of quinoline to 2‐hydroxyquinoline, observed in solution by fluorescence spectroscopy, was about five to eight times faster than the subsequent disappearance of 2‐hydroxyquinoline. When quinoline was sorbed, however, no 2‐hydroxyquinoline was observed in solution or on the surface of the clay. It is suggested that quinoline may be transformed to 2‐hydroxyquinoline at the cell surface and that 2‐hydroxyquinoline is the species that is transported into the cell prior to further degradation.

Assessment of Bioavailability of Soil-Sorbed Atrazine

“…Limited bioavailability may lead to unexpected pesticide persistence in soils, thereby increasing the likelihood of ground-or surfacewater contamination (J. J. Pignatello, B. L. Sawhney, and C. R. Frink, Letter, Science 236:898, 1987). Bioavailability of pesticides and organic contaminants has been identified as a potential limitation to the complete bioremediation of contaminated soils (60,62,67).…”

“…Generally, soil-sorbed organic contaminants and pesticides have been considered unavailable for biodegradation without prior desorption (52,62). However, some evidence suggests that sorbed contaminants can be degraded by microorganisms or at least that desorption into bulk solution is not a prerequisite for biodegradation.…”

Characterization of radionuclide-chelating agent complexes found in low-level radioactive decontamination waste. Literature review

“…Another factor that can influence the biodegradation of organic compounds in soils and sediments is their sorption to mineral and organic particles. For example, the rate of biodegradation of quinoline sorbed to smectite clay has been shown to be controlled by the rate of desorption from the clay (Smith et al 1992 the susceptibility of metal-picolinate complexes to enzymatic attack by aerobic or anaerobic microorganisms. We speculate, based on analogy to the synthetic chelating agents NTA and EDTA, that different metal-picolinate complexes will vary in the rate and extent to which they are degraded.…”

Influence of organic-mineral aggregates on microbial degradation of the dinoflagellate Scrippsiella trochoidea

“…Sorption to mineral surfaces results in decreased bioavailability of OM according to numerous studies of sediments and soils (Gordon and Millero, 1985;Smith et al, 1992;Nagata and Kirchman, 1996;Nam and Alexander, 1998). Reduced bioavailability is facilitated if sorption is not easily reversible (Henrichs, 1995;Ding and Henrichs, 2002) and sorbed molecules are less susceptible to microbial degradation than when they are in solution (Smith et al, 1992).…”

“…Reduced bioavailability is facilitated if sorption is not easily reversible (Henrichs, 1995;Ding and Henrichs, 2002) and sorbed molecules are less susceptible to microbial degradation than when they are in solution (Smith et al, 1992). Decreased bioavailability of sorbed OM thus leads to OM preservation in soils and sediments (e.g., Mayer, 1994b;Nam and Alexander, 2001).…”