title: Traceability of polychlorinated dibenzo-dioxins/furans pollutants in soil and their ecotoxicological effects on genetics, functions and composition of bacterial community.
abstract: Dioxins (PCDD/Fs) are persistent organic pollutants. Their accumulation in soil is a crucial step in their transmission through the ecosystem. Traceability of dioxin in soil was evaluated in four sites A, B, C and D considered as potential industrial PCDD/Fs sources in Syria. Our results showed that the highest pollution with dioxin (⩾50 ppt) was found in site C (vicinity of Homs refinery). In parallel, analysis of physicochemical proprieties and bacterial density of soil samples were carried out. Bacterial density differed significantly among samples between 68×10(4) and 64×10(6) CFU g(-1)DW. Analysis of 16S rRNA encoding sequences showed that the genus Bacillus was the most abundant (74.7%) in all samples, followed by the genera Arthrobacter and Klebsiella with 5.2% and 4.7%, respectively. The genera Microbacterium, Pantoea, Pseudomonas, Enterobacter and Exiguobacterium formed between 2.1% and 2.6%. Cellulomonas, Kocuria, Lysinibacillus, Staphylococcus and Streptomyces were in a minority (0.5-1%). The bacterial richness and biodiversity, estimated by DMg and H' index, were highest in the heavily polluted site. Molecular screening for angular dioxygenase (AD α-subunit) and the cytochrome P450 (CYPBM3) genes, led to identification of 41 strains as AD-positive and 31 strains as CYPBM3-positive. RT-real-time PCR analysis showed a significant abundance of AD α-subunit transcript in the heavily dioxin-polluted soils, while the expression of CYPBM3 was highest in the moderately polluted soils. Our results illustrate the microbial diversity and functionality in soil exposed to dioxin pollution. Identification of dioxin-degrading bacteria from polluted sites should allow bioremediation to be carried out.
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria. Electronic address: ashanano@aec.org.sy.
authors.forename: Abdulsamie
authors.initials: A
authors.lastname: Hanano
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Hassan
authors.initials: H
authors.lastname: Ammouneh
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Ibrahem
authors.initials: I
authors.lastname: Almousally
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Abdulfattah
authors.initials: A
authors.lastname: Alorr
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Mouhnad
authors.initials: M
authors.lastname: Shaban
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Amer Abu
authors.initials: AA
authors.lastname: Alnaser
authors.affiliation: Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), B.P. Box 6091, Damascus, Syria.
authors.forename: Iyad
authors.initials: I
authors.lastname: Ghanem
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D001673:Biodegradation, Environmental; D044822:Biodiversity; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D054750:Ecotoxicology; D005663:Furans / Q000032:analysis / Q000633:toxicity*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*
chemical_list: D001426:Bacterial Proteins; D005663:Furans; D000072317:Polychlorinated Dibenzodioxins; D012987:Soil; D012989:Soil Pollutants; D003577:Cytochrome P-450 Enzyme System
keywords: Angular dioxygenase (AD); Biodegradation; Biodiversity; Cytochrome P450 (CYPBM3); Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs); Soil bacterial community