| Title |
Effects of Nutritional Input and Diesel Contamination on Soil Enzyme Activities and Microbial Communities in Antarctic Soils |
| Author |
Jiwon Han1, Jaejoon Jung1, Seunghun Hyun1, Hyun Park2, and Woojun Park1* |
| Address |
1Department of Environmental Science and Ecological Engineering, Korea University, Seoul 136-713, Republic of Korea, 2Korea Polar Research Institute, Incheon 406-840, Republic of Korea |
| Bibliography |
Journal of Microbiology, 50(6),916-924, 2012,
|
| DOI |
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| Key Words |
soil, enzyme, biogeochemical cycle, community analysis, Actinobacteria, Proteobacteria |
| Abstract |
Pollution of Antarctic soils may be attributable to increased nutritional input and diesel contamination via anthropogenic activities. To investigate the effect of these environmental changes on the Antarctic terrestrial ecosystem, soil enzyme activities and microbial communities in 3 types of Antarctic soils were evaluated. The activities of alkaline phosphomonoesterase and dehydrogenase were dramatically increased, whereas the activities of β-glucosidase, urease, arylsulfatase, and fluorescein diacetate hydrolysis were negligible. Alkaline phosphomonoesterase and dehydrogenase activities in the 3 types of soils increased 3- to 10-fold in response to nutritional input, but did not increase in the presence of diesel
contamination. Consistent with the enzymatic activity data, increased copy numbers of the phoA gene, encoding an alkaline phosphomonoesterase, and the 16S rRNA gene were verified using quantitative real-time polymerase chain reaction.
Interestingly, dehydrogenase activity and 16S rRNA gene copy number increased slightly after 30 days, even under diesel contamination, probably because of adaptation of the bacterial population. Intact Antarctic soils showed a predominance
of Actinobacteria phylum (mostly Pseudonorcarida species) and other phyla such as Proteobacteria, Chloroflexi, Planctomycetes, Firmicutes, and Verrucomicrobia were present in successively lower proportions. Nutrient addition might act
as a selective pressure on the bacterial community, resulting in the prevalence of Actinobacteria phylum (mostly Arthrobacter species). Soils contaminated by diesel showed a predominance of Proteobacteria phylum (mostly Phyllobacterium species), and other phyla such as Actinobacteria, Bacteroidetes, Planctomycetes, and Gemmatimonadetes were present in successively lower proportions. Our data reveal that nutritional input has a dramatic impact on bacterial communities in Antarctic soils and that diesel contamination is likely toxic to enzymes in this population. |
