Affiliation:
1. Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse, 35043 Marburg, Germany
Abstract
ABSTRACT
The effect of ammonium addition (6.5, 58, and 395 μg of NH
4
+
-N g [dry weight] of soil
−1
) on soil microbial communities was explored. For medium and high ammonium concentrations, increased N
2
O release rates and a shift toward a higher contribution of nitrification to N
2
O release occurred after incubation for 5 days at 4°C. Communities of ammonia oxidizers were assayed after 4 weeks of incubation by denaturant gradient gel electrophoresis (DGGE) of the
amoA
gene coding for the small subunit of ammonia monooxygenase. The DGGE fingerprints were invariably the same whether the soil was untreated or incubated with low, medium, or high ammonium concentrations. Phylogenetic analysis of cloned PCR products from excised DGGE bands detected
amoA
sequences which probably belonged to
Nitrosospira
16S rRNA clusters 3 and 4. Additional clones clustered with
Nitrosospira
sp. strains Ka3 and Ka4 and within an
amoA
cluster from unknown species. A
Nitrosomonas-
like
amoA
gene was detected in only one clone. In agreement with the
amoA
results, community profiles of total bacteria analyzed by terminal restriction fragment length polymorphism (T-RFLP) showed only minor differences. However, a community shift occurred for denitrifier populations based on T-RFLP analysis of
nirK
genes encoding copper-containing nitrite reductase with incubation at medium and high ammonia concentrations. Major terminal restriction fragments observed in environmental samples were further described by correspondence to cloned
nirK
genes from the same soil. Phylogenetic analysis grouped these clones into clusters of soil
nirK
genes. However, some clones were also closely related to genes from known denitrifiers. The shift in the denitrifier community was probably the consequence of the increased supply of oxidized nitrogen through nitrification. Nitrification activity increased upon addition of ammonium, but the community structure of ammonium oxidizers did not change.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference40 articles.
1. Aakra, A., J. B. Utaker, and I. F. Nes. 2001. Comparative phylogeny of the ammonia monooxygenase subunit A and 16S rRNA genes of ammonia-oxidizing bacteria. FEMS Microbiol. Lett.205:237-242.
2. Aakra, A., J. B. Utaker, A. Pommerening-Roser, H. P. Koops, and I. F. Nes. 2001. Detailed phylogeny of ammonia-oxidizing bacteria determined by rDNA sequences and DNA homology values. Int. J. Syst. Evol. Microbiol. 51:2021-2030.
3. Phylogenetic identification and in situ detection of individual microbial cells without cultivation
4. Community Structure of Denitrifiers,
Bacteria
, and
Archaea
along Redox Gradients in Pacific Northwest Marine Sediments by Terminal Restriction Fragment Length Polymorphism Analysis of Amplified Nitrite Reductase (
nirS
) and 16S rRNA Genes
5. Development of PCR Primer Systems for Amplification of Nitrite Reductase Genes (
nirK
and
nirS
) To Detect Denitrifying Bacteria in Environmental Samples
Cited by
248 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献