Aerobic and oxygen-limited naphthalene-amended enrichments induced the dominance of Pseudomonas spp. from a groundwater bacterial biofilm

Tibor Benedek (1) , Flóra Szentgyörgyi (1) , Istvan Szabo (2) , Milán Farkas (1) , Robert Duran (3) , Balázs Kriszt (1) , András Táncsics (1)

1 Szent István University
2 Federal Institute for Risk Assesment
3 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

In this study, we aimed at determining the impact of naphthalene and different oxygen levels on a biofilm bacterial community originated from a petroleum hydrocarbon-contaminated groundwater. By using cultivation-dependent and cultivation-independent approaches, the enrichment, identification, and isolation of aerobic and oxygen-limited naphthalene degraders was possible. Results indicated that, regardless of the oxygenation conditions, Pseudomonas spp. became the most dominant in the naphthalene-amended selective enrichment cultures. Under low-oxygen conditions, P. veronii/P. extremaustralis lineage affiliating bacteria, and under full aerobic conditions P. laurentiana-related isolates were most probably capable of naphthalene biodegradation. A molecular biological tool has been developed for the detection of naphthalene 1,2-dioxygenase-related 2Fe-2S reductase genes of Gram-negative bacteria. The newly developed COnsensus DEgenerate Hybrid Oligonucleotide Primers (CODEHOP-PCR) technique may be used in the monitoring of the natural attenuation capacity of PAH-contaminated sites. A bacterial strain collection with prolific biofilm-producing and effective naphthalene-degrading organisms was established. The obtained strain collection may be applicable in the future for the development of biofilm-based bioremediation systems for the elimination of PAHs from groundwater (e.g., biofilm-based biobarriers).

Mots clés: Biofilm; PAH; Naphthalene; Bioremediation; Oxygen-limited; Biobarrier

Domaines: Biotechnologies; Bactériologie; Ingénierie de l'environnement

Tibor Benedek, Flóra Szentgyörgyi, Istvan Szabo, Milán Farkas, Robert Duran, et al.. Aerobic and oxygen-limited naphthalene-amended enrichments induced the dominance of Pseudomonas spp. from a groundwater bacterial biofilm. Applied Microbiology and Biotechnology, 2020, 104 (13), pp.6023-6043. ⟨10.1007/s00253-020-10668-y⟩. ⟨hal-02734344⟩