The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils.
The ecological effect of earthworms on the fate of soil pentachlorophenol (PCP) differs with species. This study addressed the roles and mechanisms by which two earthworm species (epigeic Eisenia fetida and endogeic Amynthas robustus E. Perrier) affect the soil microbial community and enzyme activity during the bioremediation of PCP-contaminated soils. A. robustus removed more soil PCP than did E. foetida. A. robustus improved nitrogen utilisation efficiency and soil oxidation more than did E. foetida, whereas the latter promoted the organic matter cycle in the soil. Both earthworm species significantly increased the amount of cultivable bacteria and actinomyces in soils, enhancing the utilisation rate of the carbon source (i.e. carbohydrates, carboxyl acids, and amino acids) and improving the richness and evenness of the soil microbial community. Additionally, earthworm treatment optimized the soil microbial community and increased the amount of the PCP-4-monooxygenase gene. Phylogenic classification revealed stimulation of indigenous PCP bacterial degraders, as assigned to the families Flavobacteriaceae, Pseudomonadaceae and Sphingobacteriacea, by both earthworms. A. robustus and E. foetida specifically promoted Comamonadaceae and Moraxellaceae PCP degraders, respectively.
College of Agriculture, Guangdong Ocean University, Zhanjiang 524088, PR China; College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China.
Zhong
Z
Lin
College of Agriculture, Guangdong Ocean University, Zhanjiang 524088, PR China.
Zhen
Z
Zhen
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China.
Zhihao
Z
Wu
College of Agriculture, Guangdong Ocean University, Zhanjiang 524088, PR China.
Jiewen
J
Yang
College of Agriculture, Guangdong Ocean University, Zhanjiang 524088, PR China.
Laiyuan
L
Zhong
College of Agriculture, Guangdong Ocean University, Zhanjiang 524088, PR China.
Hanqiao
H
Hu
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China.
Chunling
C
Luo
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China.
Jing
J
Bai
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China. Electronic address: yongtao@scau.edu.cn.
Yongtao
Y
Li
Lancaster Environment Centre, Lancaster University, Lancaster LA1 2YW, UK. Electronic address: d.zhang@lancaster.ac.uk.
Dayi
D
Zhang
D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002374:Catalase / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism; D005658:Fungi / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000235:genetics*; D009835:Oligochaeta / Q000378:metabolism*; D010416:Pentachlorophenol / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D014510:Urease / Q000378:metabolism; D043324:beta-Fructofuranosidase / Q000378:metabolism
D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D010416:Pentachlorophenol; D006899:Mixed Function Oxygenases; D002374:Catalase; C069781:pentachlorophenol monooxygenase; D043324:beta-Fructofuranosidase; D002480:Cellulase; D014510:Urease