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The responses of indigenous oil-degrading bacteria to oil exposure in Phragmites australis-dominated marsh soil: a mesocosm study.
- Source :
- Hydrobiologia; Jan2019, Vol. 827 Issue 1, p65-74, 10p, 4 Charts, 1 Graph
- Publication Year :
- 2019
-
Abstract
- This study examined impacts of Macondo MC252 oil from the Deepwater Horizon spill on oil-degrading bacteria in fresh and oligohaline marshes dominated by the common reed Phragmites australis (Cav.) Trin. ex Steud. and correlated microbial changes to soil variables. We hypothesized that indigenous oil-degrading bacteria and soil characteristics in the marshes effectively respond to Macondo oil. We tested this hypothesis with a greenhouse mesocosm study. Weathered and emulsified Macondo oil was applied to P. australis sods at different rates (0, 4, 8, 12, and 16 L m<superscript>−2</superscript>). Populations of oil degrading bacteria containing alkane monooxygenase and PAH-ring hydroxylating dioxygenase alpha subunit (PAH-RHDα) genes, the expression of these genes, soil respiration rate, residual total petroleum hydrocarbon, redox potential (Eh), as well as dissolved organic carbon (DOC) and its aromaticity index of SUVA<subscript>254</subscript> were measured in soils 2 months after oil addition. Oil exposure generally increased oil-degrading bacterial populations, in particular Gram-positive (GP) PAH-degraders, soil respiration rate, DOC concentration, and aromaticity of DOC, but decreased Eh values. GP PAH-RHDα genes accounted for approximately 98% of total detected genes, and expression of these genes increased by a factor of 3 to 5 at various oil dosages. Both abundance and expression of GP PAH-RHDα genes significantly correlated to SUVA<subscript>254</subscript> (P < 0.05). The study revealed that indigenous oil-degrading bacteria effectively responded to weathered Macondo oil in the P. australis marsh soil wherein GP bacteria with PAH-RHDα genes played a major role in biodegradation of PAH-enriched petroleum hydrocarbons. [ABSTRACT FROM AUTHOR]
- Subjects :
- MARSH ecology
BACTERIA
PHRAGMITES australis
SOIL & civilization
PETROLEUM
Subjects
Details
- Language :
- English
- ISSN :
- 00188158
- Volume :
- 827
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Hydrobiologia
- Publication Type :
- Academic Journal
- Accession number :
- 133242844
- Full Text :
- https://doi.org/10.1007/s10750-017-3461-3