title: Soil type affects plant colonization, activity and catabolic gene expression of inoculated bacterial strains during phytoremediation of diesel.
abstract: The combined use of plants and associated microorganisms has great potential for cleaning up soils contaminated with petroleum hydrocarbons. Apart from environmental conditions the physicochemical properties of the soil are the main factors influencing the survival and activity of an inoculated strain as well as the growth of plants. This study examined the effect of different soil types (sandy, loamy sand and loam) on the survival, gene abundance and catabolic gene expression of two inoculated strains (Pseudomonas sp. strain ITRI53 and Pantoea sp. strain BTRH79) in the rhizosphere and shoot interior of Italian ryegrass vegetated in diesel contaminated soils. High colonization, gene abundance and expression in loamy soils were observed. By contrast, low colonization, gene abundance and absence of gene expression in sandy soil were found. The highest levels of genes expression and hydrocarbon degradation were seen in loamy soil that had been inoculated with BTRH79 and were significantly higher compared to those in other soils. A positive correlation was observed between gene expression and hydrocarbon degradation indicating that catabolic gene expression is necessary for contaminant degradation. These results suggest that soil type influences the bacterial colonization and microbial activities and subsequently the efficiency of contaminant degradation.
authors.affiliation: AIT Austrian Institute of Technology GmbH, Department of Health and Environment, A-2444 Seibersdorf, Austria.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Afzal
authors.forename: Sohail
authors.initials: S
authors.lastname: Yousaf
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Reichenauer
authors.forename: Melanie
authors.initials: M
authors.lastname: Kuffner
authors.forename: Angela
authors.initials: A
authors.lastname: Sessitsch
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000598:Amino Acids, Cyclic / Q000378:metabolism; D018533:Biomass; D019755:Carbon-Carbon Lyases / Q000235:genetics / Q000378:metabolism; D042926:Cytochrome P-450 CYP4A / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D052918:Environmental Restoration and Remediation; D005742:Gasoline / Q000032:analysis*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D006838:Hydrocarbons / Q000032:analysis; D020636:Pantoea / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D010316:Particle Size; D052638:Particulate Matter; D018520:Plant Shoots / Q000201:enzymology / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012987:Soil / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D000598:Amino Acids, Cyclic; D004269:DNA, Bacterial; D005742:Gasoline; D006838:Hydrocarbons; D052638:Particulate Matter; D012329:RNA, Bacterial; D012987:Soil; C023863:1-aminocyclopropane-1-carboxylic acid; D003577:Cytochrome P-450 Enzyme System; C435228:cytochrome P-450 CYP153 (Acinetobacter); D042926:Cytochrome P-450 CYP4A; C033634:1-aminocyclopropane-1-carboxylate deaminase; D019755:Carbon-Carbon Lyases