Ecotoxicity monitoring and bioindicator screening of oil-contaminated soil during bioremediation.
A series of toxicity bioassays was conducted to monitor the ecotoxicity of soils in the different phases of bioremediation. Artificially oil-contaminated soil was inoculated with a petroleum hydrocarbon-degrading bacterial consortium containing Burkholderia cepacia GS3C, Sphingomonas GY2B and Pandoraea pnomenusa GP3B strains adapted to crude oil. Soil ecotoxicity in different phases of bioremediation was examined by monitoring total petroleum hydrocarbons, soil enzyme activities, phytotoxicity (inhibition of seed germination and plant growth), malonaldehyde content, superoxide dismutase activity and bacterial luminescence. Although the total petroleum hydrocarbon (TPH) concentration in soil was reduced by 64.4%, forty days after bioremediation, the phytotoxicity and Photobacterium phosphoreum ecotoxicity test results indicated an initial increase in ecotoxicity, suggesting the formation of intermediate metabolites characterized by high toxicity and low bioavailability during bioremediation. The ecotoxicity values are a more valid indicator for evaluating the effectiveness of bioremediation techniques compared with only using the total petroleum hydrocarbon concentrations. Among all of the potential indicators that could be used to evaluate the effectiveness of bioremediation techniques, soil enzyme activities, phytotoxicity (inhibition of plant height, shoot weight and root fresh weight), malonaldehyde content, superoxide dismutase activity and luminescence of P. phosphoreum were the most sensitive.
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Weihang
W
Shen
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China. Electronic address: nwzhu@scut.edu.cn.
Nengwu
N
Zhu
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Jiaying
J
Cui
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Huajin
H
Wang
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
Zhi
Z
Dang
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
Pingxiao
P
Wu
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Yidan
Y
Luo
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Chaohong
C
Shi
D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D001673:Biodegradation, Environmental; D018525:Germination / Q000187:drug effects; D006838:Hydrocarbons / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D019684:Magnoliopsida / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D010578:Petroleum / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D063245:Plant Development / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D013482:Superoxide Dismutase / Q000378:metabolism
D006838:Hydrocarbons; D010578:Petroleum; D012989:Soil Pollutants; D008315:Malondialdehyde; D013482:Superoxide Dismutase
Bioindicator; Bioremediation; Ecotoxicity; Oil-contaminated soil