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| Titel |
Characterization of primary biogenic aerosol particles in urban, rural, and high-alpine air by DNA sequence and restriction fragment analysis of ribosomal RNA genes |
| VerfasserIn |
V. R. Després, J. F. Nowoisky, M. Klose, R. Conrad, M. O. Andreae, U. Pöschl |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 4, no. 6 ; Nr. 4, no. 6 (2007-12-20), S.1127-1141 |
| Datensatznummer |
250002003
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| Publikation (Nr.) |
 copernicus.org/bg-4-1127-2007.pdf |
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| Zusammenfassung |
This study explores the applicability of DNA analyses for the
characterization of primary biogenic aerosol (PBA) particles in the
atmosphere. Samples of fine particulate matter (PM2.5) and total suspended
particulates (TSP) have been collected on different types of filter
materials at urban, rural, and high-alpine locations along an altitude
transect in the south of Germany (Munich, Hohenpeissenberg, Mt. Zugspitze).
From filter segments loaded with about one milligram of air particulate
matter, DNA could be extracted and DNA sequences could be determined for
bacteria, fungi, plants and animals. Sequence analyses were used to
determine the identity of biological organisms, and terminal restriction
fragment length polymorphism analyses (T-RFLP) were applied to estimate
diversities and relative abundances of bacteria. Investigations of blank and
background samples showed that filter materials have to be decontaminated
prior to use, and that the sampling and handling procedures have to be
carefully controlled to avoid artifacts in the analyses.
Mass fractions of DNA in PM2.5 were found to be around 0.05% in urban,
rural, and high-alpine aerosols. The average concentration of DNA determined
for urban air was on the order of ~7 ng m−3, indicating that
human adults may inhale about one microgram of DNA per day (corresponding to
~108 haploid bacterial genomes or ~105 haploid human
genomes, respectively).
Most of the bacterial sequences found in PM2.5 were from Proteobacteria (42) and some from
Actinobacteria (10) and Firmicutes (1). The fungal sequences were characteristic for Ascomycota (3) and
Basidiomycota (1), which are known to actively discharge spores into the atmosphere. The
plant sequences could be attributed to green plants (2) and moss spores (2),
while animal DNA was found only for one unicellular eukaryote (protist).
Over 80% of the 53 bacterial sequences could be matched to one of the 19
T-RF peaks found in the PM2.5 samples, but only 40% of the T-RF peaks did
correspond to one of the detected bacterial sequences. The results
demonstrate that the T-RFLP analysis covered more of the bacterial diversity
than the sequence analysis. Shannon-Weaver indices calculated from both
sequence and T-RFLP data indicate that the bacterial diversity in the rural
samples was higher than in the urban and alpine samples. Two of the
bacterial sequences (Gammaproteobacteria) and five of the T-RF peaks were found at all
sampling locations. |
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