title: Change in gene abundance in the nitrogen biogeochemical cycle with temperature and nitrogen addition in Antarctic soils.
abstract: The microbial community (bacterial, archaeal, and fungi) and eight genes involved in the nitrogen biogeochemical cycle (nifH, nitrogen fixation; bacterial and archaeal amoA, ammonia oxidation; narG, nitrate reduction; nirS, nirK, nitrite reduction; norB, nitric oxide reduction; and nosZ, nitrous oxide reduction) were quantitatively assessed in this study, via real-time PCR with DNA extracted from three Antarctic soils. Interestingly, AOB amoA was found to be more abundant than AOA amoA in Antarctic soils. The results of microcosm studies revealed that the fungal and archaeal communities were diminished in response to warming temperatures (10 °C) and that the archaeal community was less sensitive to nitrogen addition, which suggests that those two communities are well-adapted to colder temperatures. AOA amoA and norB genes were reduced with warming temperatures. The abundance of only the nifH and nirK genes increased with both warming and the addition of nitrogen. NirS-type denitrifying bacteria outnumbered NirK-type denitrifiers regardless of the treatment used. Interestingly, dramatic increases in both NirS and NirK-types denitrifiers were observed with nitrogen addition. NirK types increase with warming, but NirS-type denitrifiers tend to be less sensitive to warming. Our findings indicated that the Antarctic microbial nitrogen cycle could be dramatically altered by temperature and nitrogen, and that warming may be detrimental to the ammonia-oxidizing archaeal community. To the best of our knowledge, this is the first report to investigate genes associated with each process of the nitrogen biogeochemical cycle in an Antarctic terrestrial soil environment.
authors.affiliation: Department of Environmental Science and Ecological Engineering, Korea University, Anam-Dong 5Ga, Seungbuk-Ku, Seoul 136-713, Republic of Korea.
authors.forename: Jaejoon
authors.initials: J
authors.lastname: Jung
authors.forename: Jinki
authors.initials: J
authors.lastname: Yeom
authors.forename: Jisun
authors.initials: J
authors.lastname: Kim
authors.forename: Jiwon
authors.initials: J
authors.lastname: Han
authors.forename: Hyoun Soo
authors.initials: HS
authors.lastname: Lim
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.forename: Seunghun
authors.initials: S
authors.lastname: Hyun
authors.forename: Woojun
authors.initials: W
authors.lastname: Park
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000864:Antarctic Regions; D001105:Archaea / Q000235:genetics; D001419:Bacteria / Q000235:genetics; D057231:Climate Change; D003080:Cold Temperature; D005658:Fungi / Q000235:genetics; D019766:Genes, Archaeal; D005798:Genes, Bacterial; D005800:Genes, Fungal; D019015:Geologic Sediments / Q000382:microbiology; D009584:Nitrogen / Q000378:metabolism*; D058458:Nitrogen Cycle / Q000235:genetics*; D009586:Nitrogen Fixation; D009609:Nitrous Oxide / Q000032:analysis; D010084:Oxidation-Reduction; D060888:Real-Time Polymerase Chain Reaction; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D000641:Ammonia; D009609:Nitrous Oxide; D009584:Nitrogen