Utilization of mixtures of polycyclic aromatic hydrocarbons by bacteria isolated from contaminated sediment

Abstract

The ability of sediment bacteria to utilize polycyclic aromatic hydrocarbons (PAHs) when present as components of mixtures was investigated. One strain, identified as Mycobacterium flavescens, could utilize fluoranthene in the presence of pyrene, although utilization of pyrene was slower in the presence of fluoranthene than in its absence. The second strain, a Rhodococcus species, could utilize fluoranthene in the presence of anthracene, although the presence of fluoranthene slowed the rate of utilization of anthracene. Cometabolism of fluoranthene in these strains was confirmed by the isolation of metabolites of fluoranthene and by kinetic analysis of the rate of utilization of the growth substrate in the presence of fluoranthene. In both strains, metabolism of fluoranthene occurred on the fused ring of the fluoranthene molecule, producing 9-fluorenone-1-carboxylic acid. In the Rhodococcus sp., a second metabolite, a-(carboxymethylene)fluorene-1-carboxylic acid, was identified, indicating that this strain has the capacity to metabolize fluoranthene via ortho as well as meta cleavage. The presence of PAHs in a mixture produces interactive effects which can either increase or decrease the rate of utilization of individual PAHs, results which need to be taken into account when estimating rates of degradation in contaminated environments.

Molecular Characterization of Fusarium Solani Degrades a Mixture of Low and High Molecular Weight Polycyclic Aromatic Hydrocarbons

“…Microorganisms offer an enormous field of environment friendly options for mineralization of contaminants or their transformation into less harmful non-hazardous compounds. Recently, researchers have been focusing on the degradation of HMW-PAH which has resulted in the isolation of a number of indigenous microorganisms that can mineralize and grow on four or five-ringed PAHs as the sole carbon and energy source [14,15,32,33]. Enrichment technique is a way to obtain the promising indigenous microorganisms that could utilize PAHs as the sole carbon source [14].…”

Bacterial metabolism of polycyclic aromatic hydrocarbons: strategies for bioremediation

“…strain LB501T do not produce biosurfactant but still have a strong ability to degrade low concentrations of aqueous-phase anthracene. The specifi c affi nity of strain LB501T cells for aqueous anthracene was found to be higher than the specifi c affi nities of other cultures reported elsewhere [91][92][93]. Wick et al [91] proposed the presence of a high-affi nity uptake system in strain LB501T to account for these observations.…”

Simultaneous Biodegradation of Polyaromatic Hydrocarbons by a Stenotrophomonas sp: Characterization of nid Genes and Effect of Surfactants on Degradation

“…IITR87 was found to degrade three major PAHs as sole carbon sources under aerobic conditions. Few more bacteria have been reported previously that are able to metabolize multiple PAHs [12]. Gene involved in pyrene degradation was identified from strain IITR87 and were found to be homologous to the naphthalene dioxygenase large subunit (nidA), small subunit (nidB) and aldehyde dehydrogenase (nidD).…”

“…Gram positive bacteria such as Mycobacterium [6,10,11], Rhodococcus sp. were also reported to degrade PAHs [12]. The initial degradation reactions are catalyzed by multi-component dioxygenase to produce dihydrodiols [6,13].…”