Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX

Abstract

In order to obtain insights in complexity shifts taking place in natural microbial communities under strong selective pressure, soils from a former air force base in the Czech Republic, highly contaminated with jet fuel and at different stages of a bioremediation air sparging treatment, were analyzed. By tracking phospholipid fatty acids and 16S rRNA genes, a detailed monitoring of the changes in quantities and composition of the microbial communities developed at different stages of the bioventing treatment progress was performed. Depending on the length of the air sparging treatment that led to a significant reduction in the contamination level, we observed a clear shift in the soil microbial community being dominated by Pseudomonads under the harsh conditions of high aromatic contamination to a status of low aromatic concentrations, increased biomass content, and a complex composition with diverse bacterial taxonomical branches.

Linking Microbial Community and Catabolic Gene Structures during the Adaptation of Three Contaminated Soils under Continuous Long-Term Pollutant Stress

“…In agreement, catabolic genes detected on the microarray are related to those observed in proteobacteria (Fig. 3), and signals were observed in the benzene/toluene/isopropylbenzene dioxygenase-encoding genes as well as those encoding enzymes of the EXDO-D branch of catechol 2,3-dioxygenases, as previously described (42)(43)(44). In addition, signals of probes indicating the presence of proteobacterial catechol 1,2-dioxygenases and soluble diiron monooxygenases supported the taxonomic results of a community dominated by Proteobacteria.…”

“…Phy8, indicating the presence of Pseudomonas strains related to Pseudomonas pseudoalcaligenes, was the most abundant phylotype and accounted for 49 and 32% of sequence reads after 10 and 20 days of treatment, respectively. Members of the Pseudomonas genus are in fact widespread in BTEX-contaminated sites (43,44), and different BTEX metabolic pathways have been previously described (9,56,57).…”

Strategizing Carbon-Neutral Mines: A Case for Pilot Projects

“…Carbonation could be further enhanced by circulation of air throughout tailings piles to increase the exposure of reactive phases to CO 2 [19]. This is similar to existing technologies for in situ aeration (i.e., air sparging), an established method for bioremediation of contaminated groundwater where increased O 2 concentrations stimulate growth of aerobic heterotrophs (e.g., [78,79]). Some considerations for enhanced passive carbonation are the abundance of highly reactive phases (e.g., oxides and hydroxides) that react more readily with atmospheric CO 2 , the availability of land to increase the areal footprint of a TSF, the permeability of tailings, the climate, and the economic viability of deploying the required infrastructure (Table 2).…”

Microbiology of Hydrocarbon-Degrading Pseudomonas

“…This is in accordance with culture-dependent studies on high solvent tolerance of Pseudomonas strains. It can thus be proposed that, at least at the site under study, Pseudomonas have paved the way for other bacteria to be capable to replicate, as shown by increased diversity observed after air sparging (Kabelitz et al, 2009). …”