Microbial biodegradation

About: Microbial biodegradation is a research topic. Over the lifetime, 1647 publications have been published within this topic receiving 75473 citations.

Microbial Degradation of Phenanthrene in Pristine and Contaminated Sandy Soils

Abstract: Phenanthrene mineralisation studies in both pristine and contaminated sandy soils were undertaken through detailed assessment of the activity and diversity of the microbial community. Stable isotope probing (SIP) was used to assess and identify active 13C-labelled phenanthrene degraders. Baseline profiling indicated that there was little difference in fungal diversity but a significant difference in bacterial diversity dependent on contamination history. Identification of dominant fungal and bacterial species highlighted the presence of organisms capable of degrading various petroleum-based compounds together with other anthropogenic compounds, regardless of contamination history. Community response following a simulated contamination event (14C-phenanthrene) showed that the microbial community in deep pristine and shallow contaminated soils adapted most to the presence of phenanthrene. The similarity in microbial community structure of well-adapted soils demonstrated that a highly adaptable fungal community in these soils enabled a rapid response to the introduction of a contaminant. Ten fungal and 15 bacterial species were identified as active degraders of phenanthrene. The fungal degraders were dominated by the phylum Basidiomycota including the genus Crypotococcus, Cladosporium and Tremellales. Bacterial degraders included the genera Alcanivorax, Marinobacter and Enterococcus. There was little synergy between dominant baseline microbes, predicted degraders and those that were determined to be actually degrading the contaminant. Overall, assessment of baseline microbial community in contaminated soils provides useful information; however, additional laboratory assessment of the microbial community's ability to degrade pollutants allows for better prediction of the bioremediation potential of a soil.

Organic Solvents Improve Hydrocarbon Desorption and Biodegradation in Highly Contaminated Weathered Soils

Abstract: Slurry phase laboratory microcosms were used to investigate the effect of selected solvents (hexane, benzene, toluene, n-butanol, acetone, and methanol) on desorption and the resulting microbial biodegradation of hydrocarbons in highly contaminated weathered soils. For nonpolar solvents, solubility and desorption of hydrocarbons increased linearly as polarity increased. In desorption and biodegradation assays, toluene significantly increased hydrocarbon consumption by twice as much, in comparison to the control without solvent. After 30 culture days, the initial hydrocarbon concentration in soil (Soxhlet method), 237.2 g kg–1 of dry soil, diminished 21% when toluene was initially added. Saturated and aromatic fractions became degraded to a greater extent in the presence of toluene, 11% and 50%, respectively. The results in this research indicated that the use of solvents is effective in improving both hydrocarbons desorption and biodegradation in highly polluted weathered soils. Key words: slurry phase, o...