Microbial degradation of gasoline in soil: Effect of season of sampling

Abstract

In cases where fire debris contains soil, microorganisms can rapidly and irreversibly alter the chemical composition of any ignitable liquid residue that may be present. In this study, differences in microbial degradation due to the season in which the sample is collected was examined. Soil samples were collected from the same site during Fall, Winter, Spring and Summer and the degradation of gasoline was monitored over 30 days. Predominant viable bacterial populations enumerated using real-time PCR and reverse transcriptase polymerase chain reaction (RT-PCR) enumeration revealed the predominant viable bacterial genera to be Alcaligenes, Bacillus, and Flavobacterium. Overall, the compounds most vulnerable to microbial degradation are the n-alkanes, followed by the mono-substituted alkylbenzenes (e.g., toluene, ethylbenzene, propylbenzene and isopropylbenzene). Benzaldehyde (a degradation product of toluene) was also identified as a marker for the extent of biodegradation.Ultimately, it was determined that soil collected during an unusually hot and dry summer exhibited the least degradation with little to no change in gasoline for up to 4 days, readily detectable n-alkanes for up to 7 days and relatively high levels of resilient compounds such as

Prevalence and risk factors for Bacillus cereus in raw milk in Inner Mongolia, Northern China

“…Beside these, there is low‐risk microbiological contamination in winter due to soils and gasoline was affected by microbial degradation during winter (Turner et al . ).…”

“…Moreover, reducing the exposure of cows to the natural environment by housing them in sheds where they are fed hay during late autumn and winter could be an important factor for the reduced B. cereus contamination levels in raw milk during this time of year (Bartoszewicz et al 2008). Beside these, there is low-risk microbiological contamination in winter due to soils and gasoline was affected by microbial degradation during winter (Turner et al 2015).…”

Bioremediation of Oil-Based Paint from Aqueous Media by Novel Indigenous Brevibacillus parabrevis Strain NAP3 and its Toxicity Assessment

“…Since the oil-based paints are made up of a wide range of hydrocarbons, media enriched with oil-based paints serve as a rich source of carbon and energy for several microbial species [17]. Although several factors affect bacterial numbers and activities in soil, including soil type and season [17], only a few studies in the literature have addressed the removal of oil-based paints and/or paintrelated waste materials from paint-polluted environments [1].…”

“…Although several factors affect bacterial numbers and activities in soil, including soil type and season [17], only a few studies in the literature have addressed the removal of oil-based paints and/or paintrelated waste materials from paint-polluted environments [1]. In the present study, an indigenous oil-based paint utilizing the bacterial strain of B. parabrevis was isolated and characterized from oil-based paint polluted soil samples and assessed for the biodegradation of oil-based paints in aqueous media using a shake flask experiment.…”

Using Alkylate Components for Classifying Gasoline in Fire Debris Samples

“…Unambiguous detection of reformate in fire debris samples can therefore be problematic, especially in cases of relative low amounts of gasoline, when other petroleum products are present and/or in the presence of pyrolysis products from certain polymers. Gasoline cannot be distinguished from aromatic solvents on the basis of the presence of aromatic compounds alone. The additional requirement that alkanes should be present is rather unspecific and cannot convincingly make the distinction in all cases . Studies on the microbial degradation of gasoline compounds in samples containing soil have shown that aromatic compounds are vulnerable to microbial degradation and that the monosubstituted benzenes in particular are the most vulnerable . Microbial degradation therefore leads to distorted aromatic profiles, which might not be recognized as originating from reformate. Reformate can be used as a source for specific aromatic compounds that can be extracted from it in the refinery , resulting in an altered composition that is used for gasoline blending, which might not be recognized as originating from reformate. Gasoline brands are sold that do not contain reformate, such as Aspen and Cleanlife.…”