title: Influences of polycyclic aromatic hydrocarbons (PAHs) on soil microbial community composition with or without vegetation.
abstract: Uptake of three polycyclic aromatic hydrocarbons (PAHs), naphthalene (NAP), phenanthrene (PHN), and pyrene (PYR), from soils by ryegrass, white clover and soybean were investigated in an 8-week pot experiment. The microbial phospholipid-fatty-acid (PLFA) patterns in PAHs-contaminated soil were analyzed. Contamination with PAHs inhibited the soil microbial activity. In non-vegetated soils, the total PLFA showed 87% reduction on the addition of PAHs after an 8-week incubation compared to the PAH-free soil; the concentrations of NAP, PHN, and PYR in soils showed 19.4%, 25.5% and 24.3% reduction, respectively, due mainly to the evaporative loss and microbial degradation. In vegetated soils, the reduction of added NAP and PHN levels was not related to the plant biomass nor to the total PLFA. However, the reduction in PYR concentrations in soil mediated by soybean growth was much pronounced than those by ryegrass or white clover growth, but thisis not related to the total microbial biomass as revealed by PLFAs. The principal-component analysis (PCA) of the PLFA signatures revealed significant changes in the PLFA pattern in PAH-spiked soils when different vegetations were planted. Using the PLFA as a biomarker, it was found that the Gram-negative bacteria were more sensitive to PAHs than Gram-positive bacteria and fungi.
authors.affiliation: Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Yu H
authors.initials: YH
authors.lastname: Su
authors.forename: Yong G
authors.initials: YG
authors.lastname: Zhu
authors.forename: Mei M
authors.initials: MM
authors.lastname: Chen
authors.forename: B D
authors.initials: BD
authors.lastname: Chen
authors.forename: Yun X
authors.initials: YX
authors.lastname: Liu
mesh_terms: D063245:Plant Development; D010944:Plants / Q000187:drug effects*; D011084:Polycyclic Aromatic Hydrocarbons / Q000494:pharmacology*; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants