Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms

Abstract

BackgroundThe bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation) is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure) via enrichment (i.e., serial growth transfers) on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures) of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms.ResultsIn this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms) on Diesel (G1) and HiQ Diesel (G2), respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity.ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30°C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20°C for several months.ConclusionsENZ-G1 and ENZ-G2 are very similar highly enriched consortia of bacteria and a fungus capable of extensively degrading a broad range of the hydrocarbons mainly composing diesel fuels. Given their remarkable biodegradation potential, stability and resistance to cryopreservation, both consortia appear very interesting candidates for bioaugmentation operations on Diesel fuel impacted soils and sites.

Degradation of Diesel, a Component of the Explosive ANFO, By Bacteria Selected From an Open Cast Coal Mine in La Guajira, Colombia

“…Studies report that the mineralization of hydrocarbons is potentiated by the co-existence and cooperation of a group of microorganisms, as is the case in a consortium [5]. Research has shown that the biodegradation rate is high because these bacteria are dealing with simple molecules, such as n-alkanes (C10, C11), however, the rate might be lower for branched alkanes, n-alkyl aromatics, cyclic alkanes and polynuclear aromatics [6]. These results indicate that the Pseudomonas strains employed in this study were able to degrade diesel.…”

The Ecology, Biology and Pathogenesis of Acinetobacter spp.: An Overview

“…Recently, Acinetobacter spp. have demonstrated a hydrocarbon-degrading capability (74,75,122), that is of interest for soil bioremediation and a specific strain Acinetobacter baylyi ADP1 has shown remarkable competence for natural transformation irrespective of DNA source, thus making it a potentially important tool for biotechnology (2,19,111,112). Possible suggested applications of Acinetobacter spp.…”

Percularities of hydrocarbon degradation by bacteria isolated from drill sludge.

“…Деструктивная активность выделенных бактерий по отноше-нию к дизельному топливу и минеральному маслу была значительно ниже, что согласуется с литературными данными, так как известно, что, несмотря на мень-шее содержание ароматических углеводородов в своем составе, данные нефтепро-дукты обладают ограниченной биодоступностью для микроорганизмов-деструк-торов (Zanaroli et al, 2010).…”