Effects of polycyclic aromatic hydrocarbons on microbial community structure and PAH ring hydroxylating dioxygenase gene abundance in soil

• Published in: Biodegradation (Dordrecht) Vol. 25; no. 6; pp. 835 - 847
• Main Authors: Sawulski, Przemyslaw, Clipson, Nicholas, Doyle, Evelyn
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2014; Springer; Springer Nature B.V
• Subjects: Abundance; Actinobacteria; Analysis; Aquatic Pollution; Bacteria; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biomedical and Life Sciences; Bioremediation; Biotechnology; Communities; Community structure; Degradation; Dioxygenases - metabolism; Environment and pollution; Fundamental and applied biological sciences. Psychology; Genes; Geochemistry; Industrial applications and implications. Economical aspects; Life Sciences; Mediation; Microbial activity; Microbiology; Microorganisms; Original Paper; Phenanthrene; Phenanthrenes - metabolism; Pollutants; Pollution effects; Polyallylamine hydrochloride; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - metabolism; Pyrene; Soil (material); Soil amendment; Soil Microbiology; Soil microorganisms; Soil Pollutants - metabolism; Soil Science & Conservation; Terrestrial Pollution; Waste Management/Waste Technology; Waste Water Technology; Water Management; Water Pollution Control; Degradation; Polycyclic aromatic hydrocarbons; TRFLP; PAH ring hydroxylating dioxygenase; ARISA; Microbial community; PCR; Hydrocarbon; Abundance; Polycyclic aromatic compound; Soils; Gene; qPCR; Structure
• ISSN: 0923-9820; 1572-9729
• DOI: 10.1007/s10532-014-9703-4

Development of successful bioremediation strategies for environments contaminated with recalcitrant pollutants requires in-depth knowledge of the microorganisms and microbial processes involved in degradation. The response of soil microbial communities to three polycyclic aromatic hydrocarbons, phenanthrene (3-ring), fluoranthene (4-ring) and benzo(
a
)pyrene (5-ring), was examined. Profiles of bacterial, archaeal and fungal communities were generated using molecular fingerprinting techniques (TRFLP, ARISA) and multivariate statistical tools were employed to interpret the effect of PAHs on community dynamics and composition. The extent and rate of PAH removal was directly related to the chemical structure, with the 5-ring PAH benzo(
a
)pyrene degraded more slowly than phenathrene or fluoranthene. Bacterial, archaeal and fungal communities were all significantly affected by PAH amendment, time and their interaction. Based on analysis of clone libraries,
Actinobacteria
appeared to dominate in fluoranthene amended soil, although they also represented a significant portion of the diversity in phenanthrene amended and unamended soils. In addition there appeared to be more γ-
Proteobacteria
and less
Bacteroidetes
in soil amended with either PAH compared to the control. The soil bacterial community clearly possessed the potential to degrade PAHs as evidenced by the abundance of PAH ring hydroxylating (PAH-RHDα) genes from both gram negative (GN) and gram positive (GP) bacteria in PAH-amended and control soils. Although the dioxygenase gene from GP bacteria was less abundant in soil than the gene associated with GN bacteria, significant (
p
 < 0.001) increases in the abundance of the GP PAH-RHDα gene were observed during phenanthrene and fluoranthene degradation, whereas there was no significant difference in the abundance of the GN PAH-RHDα gene during the course of the experiment. Few studies to-date have examined the effect of pollutants on more than one microbial community in soil. The current study provides information on the response of soil bacterial, archaeal and fungal communities during the degradation of three priority pollutants and contributes to a knowledge base that can inform the development of effective bioremediation strategies for contaminated sites.