Degradation of diesel with microorganisms in rhizosphere of Carex phacota Spr.

摘要

Because of widespread use of petroleum, the Huangpu-Yangtze River estuary (HYRE) wetland has been polluted by accidental spills. The technology to degrade these compounds is a major goal of environmental research. This study isolated oil-degrading microorganisms from oil contaminated wetland in the HYRE. Three bacterial strains were discovered, and identified by sequencing their 16S rDNA genes. Two of them were Pseudomonas and the other one was Alcaligenes. Diesel biodegradation potential of these indigenous oil-degrading microorganisms(HPM) and HPM co-metabolize with the native plant Carex phacota Spr.(CPS) were assessed. During the 60-day experiment, soil samples were collected and analyzed periodically to determine the residual diesel content and microbial populations. The results showed that the oil-degrading microorganisms isolated from the HYRE wetland had a certain degradation effect on diesel. Within 60 days, the relative degradation rates of microorganisms were 8.05-36.59%; and under the combined effects of microorganisms and plants, the degradation rates of diesel could reach 28.28-52.94% at different concentration of diesel. They all play a good role on the n-alkanes within the range of C_(18)~C_(24) components of diesel. Results indicated that the oil-degrading bacteria isolated from the HYRE wetland have a certain degradation effect on diesel. The co-metabolize of plants and microbes would increase the diesel biodegradation rate. The plants and the oil-degraders in wetland could be reasonably matched to control the diesel pollution of wetland sediment.