Bioremediation of diesel contamination at an underground storage tank site: a spatial analysis of the microbial community

Abstract

The present study reports on a real case of contamination due to the chronic leakage of diesel fuel from an underground tank at a dismissed service station. Speciation of the microbial community according to both lateral and vertical gradients from the origin of the contaminant release was analyzed by means of the PCR-DGGE technique. Moreover, the effects of a landfarming treatment on both the microbial community structure and the abatement of contamination were analyzed. The concentration of total petrol hydrocarbons (TPHs) decreased along the horizontal gradient (from 7042.2 ± 521.9 to 112.2 ± 24.3 mg kg(-1)), while increased downwards from the position of the tank (from 502.6 ± 43.7 to 4972.5 ± 275.3 mg kg(-1)). PCR-DGGE analyses and further statistical treatment of the data indicated a correlation between structure of the bacterial communities and amount of diesel fuel contamination. On the other hand, level of contamination, soil texture and depth were shown to affect the fungal community. Chloroflexi and Ascomycota were the most abundant microbes ascertained through culture-independent procedures. Landfarming promoted 91.6 % reduction of TPHs in 75 days. Furthermore, PCR-DGGE analyses evidenced that both bacterial and fungal communities of the treated soil were restored to the pristine conditions of uncontaminated topsoil. The present study demonstrated that bacterial and fungal communities were affected differently by soil factors such as level of hydrocarbon contamination as well as soil depth and texture. This report shows that a well-planned landfarming treatment can drive the restoration of the soil in terms of both abatement of the contaminants and resilience of the microbial community structure.

The Composition of Diesel Fuel Influences the Structure of Microbiological Assemblages in Contaminated Storage Tanks

“…The availability of different carbon substrates can influence microbial community composition and differences have been observed in diesel and biodiesel fuels as well (41–45). Correlations between both bacterial and fungal populations in contaminated fuels and the composition of FAME and alkanes in those fuels suggest that fuel composition influences the composition of contaminating microorganisms.…”

“…The availability of different carbon substrates can influence microbial community composition and differences have been observed in diesel and biodiesel fuels as well (41)(42)(43)(44)(45).…”

Mesocosm‐based simulations to optimize a bioremediation strategy for the effective restoration of wildfire‐impacted soils contaminated with high‐molecular‐weight hydrocarbons

“…Soil was collected in a deciduous forest area located within the jurisdiction of the 'Comunit a Montana della Val Trompia' in the Pezzaze municipality, north Italy. A wildfire swept the area on 2 April 2012 and the soil was collected 4 months later, according to the quartering procedure (Andreolli et al 2016a). To increase the quantity of HMW hydrocarbons, the soil was spiked with 5 g kg À1 of V-Power Diesel (Royal Dutch Shell; The Hague, Netherlands), then carefully homogenized, collected in triplicate following the quartering procedure and used for both chemical and microbiological analysis at experimental time zero (T 0 ).…”

Selective screening: isolation of fungal strains from contaminated soils in Austria

“…B: Anzahl der Pilzkolonien isoliert von jeder Probe, welche in Anwesenheit von Toluol (rot), PCB 126 (grün) und Hexadekan (blau) gewachsen sind. Ochroconis longiphorum (CBS 435.75) was isolated from the Canadian soil underneath the asphalt of a car park (Samerpitak et al, 2014), but also from the soil contaminated by a leaking diesel tank (Andreolli et al, 2016). Ochroconis longiphorum was formerly also described as Scolecobasidium longiphorum.…”