Characterization and degradation potential of diesel-degrading bacterial strains for application in bioremediation

Abstract

Bioremediation of polluted soils is a promising technique with low environmental impact, which uses soil organisms to degrade soil contaminants. In this study, 19 bacterial strains isolated from a diesel-contaminated soil were screened for their diesel-degrading potential, biosurfactant (BS) production, and biofilm formation abilities, all desirable characteristics when selecting strains for re-inoculation into hydrocarbon-contaminated soils. Diesel-degradation rates were determined in vitro in minimal medium with diesel as the sole carbon source. The capacity to degrade diesel range organics (DROs) of strains SPG23 (Arthobacter sp.) and PF1 (Acinetobacter oleivorans) reached 17-26% of total DROs after 10 days, and 90% for strain GK2 (Acinetobacter calcoaceticus). The amount and rate of alkane degradation decreased significantly with increasing carbon number for strains SPG23 and PF1. Strain GK2, which produced BSs and biofilms, exhibited a greater extent, and faster rate of alkane degradation compared to SPG23 and PF1. Based on the outcomes of degradation experiments, in addition to BS production, biofilm formation capacities, and previous genome characterizations, strain GK2 is a promising candidate for microbial-assisted phytoremediation of diesel-contaminated soils. These results are of particular interest to select suitable strains for bioremediation, not only presenting high diesel-degradation rates, but also other characteristics which could improve rhizosphere colonization.

Bioaugmentation-Enhanced Remediation of Crude Oil Polluted Water in Pilot-Scale Floating Treatment Wetlands

“…These observations are in line with previous studies on the positive effect of the combined application of plants and bacterial inoculation on water treatment [4,21,34,51,56,57]. This effect was likely a result of the removal of toxic compounds via specific catabolic activities of the inoculated bacterial strains [29,58,59], and the improvement of plant fitness by the bacteria due to multiple plant growth promoting activities such as production of siderophores, IAA, and ACC deaminase [46]. The four bacterial strains used for bioaugmentation exhibited successful colonization of the rhizoplane and plant tissues (Figure 3).…”

Exploring the Diversity and Aromatic Hydrocarbon Degrading Potential of Epiphytic Fungi on Hornbeams from Chronically Polluted Areas

“…® Fungal DNA Mini Kit (Omega Bio-Tek, Inc., Norcross, GA, USA), according the manufacturer's recommendations. Subsequently, a PCR reaction was performed using the primer pair ITS1F (5 -CTTGGTCATTTAGAGGTAA-3 ) and ITS4R (5 -TCCTCC GCTTATTGATATGC-3 ) to span the entire ITS1-5.8S-ITS2 region in the genome of the fungi [39,40]. Additionally, the primer pair TEF1-108F (5 -GAYTTCATCAAGAACATGAT-3 ) and TEF1-1620R (5 -GACGTTGAADCCRACRTTGTC-3 ) was also used to allow deeper taxonomic resolution of the clades Fusarium and Penicillium [41].…”

In-Depth Characterization of Plant Growth Promotion Potentials of Selected Alkanes-Degrading Plant Growth-Promoting Bacterial Isolates

“…Hexadecane (C 16 H 34 ) is present in the aliphatic fraction of crude oil and is a main component of diesel fuel ( Chénier et al, 2003 ). Hexadecane has been used as a model compound to study alkane biodegradation because of its presence in many diesel-contaminated soils and its well-characterized biodegradability ( Chénier et al, 2003 ; Tara et al, 2014 ; Shiri et al, 2015 ; Balseiro-Romero et al, 2017a ; Garrido-Sanz et al, 2019 ). The presence of these compounds in the environment adversely affects plant, animal, and human health ( Arslan et al, 2014 ).…”