Previous Article | Next Article 
Applied and Environmental Microbiology, December 2000, p. 5488-5491, Vol. 66, No. 12
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Rapid Method for Coextraction of DNA and RNA from
Natural Environments for Analysis of Ribosomal DNA- and rRNA-Based
Microbial Community Composition
Robert I.
Griffiths,1,2
Andrew S.
Whiteley,1
Anthony G.
O'Donnell,2 and
Mark
J.
Bailey1,*
Molecular Microbial Ecology Laboratory,
Institute of Virology and Environmental Microbiology, CEH-Oxford,
Oxford OX1 3SR,1 and Department of
Agricultural and Environmental Science, The University of Newcastle
Upon Tyne, Newcastle Upon Tyne NE1 7RU,2 United
Kingdom
Received 5 June 2000/Accepted 13 September 2000
 |
ABSTRACT |
A rapid protocol for the extraction of total nucleic acids from
environmental samples is described. The method facilitates concomitant
assessment of microbial 16S rRNA diversity by PCR and reverse
transcription-PCR amplification from a single extraction. Denaturing
gradient gel electrophoresis microbial community analysis differentiated the active component (rRNA derived) from the total bacterial diversity (ribosomal DNA derived) down the horizons of an
established grassland soil.
 |
TEXT |
The molecular analysis of 16S rRNA
is now central to studies examining the diversity of microorganisms in
the environment. Traditional methods based upon cultivation
underestimate diversity considerably, whereas modern molecular
methods (PCR, cloning, and sequencing) have provided a greater insight
into the extent of prokaryotic diversity (for a review see reference
6). Methodologies for the analyses of a DNA-based
phylogeny (using the 16S rRNA gene) are now well established but the
direct targeting of 16S rRNA, as a potential indicator of activity
(4), has received comparatively less attention, due
primarily to the lack of suitable protocols for extraction from natural environments.
Methods currently employed for DNA extraction vary widely, from direct
methods of in situ lysis to indirect methods of initial cell extraction
prior to lysis. In both cases, the methods used often include various
combinations of bead beating, detergents, enzymatic lysis, and solvent
extractions to obtain a crude preparation of nucleic acid (see, e.g.,
references 5 and 8). The utility of the published methods varies, particularly in soil systems, since
inhibitory compounds such as humic acids and clay minerals are often
coextracted. Therefore, additional purification procedures are required
for successful PCR amplification. These additional steps can prevent
the simultaneous extraction of the labile RNA (3) and reduce
DNA yield. Reliable extraction methods have been reported for isolation
of RNA from soils (2, 3, 11) and other environments
(10), but they typically involve multiple steps for
purification, rendering them impractical for processing large numbers
of samples. Here we describe the first direct method for the rapid
coextraction of RNA and DNA from soil for the comparison of bacterial
diversity by 16S rRNA reverse transcription-PCR (RT-PCR) and 16S
ribosomal DNA (rDNA)-PCR. To demonstrate the efficacy and
reproducibility of the method, we present the denaturing gradient gel
electrophoresis (DGGE) analysis of the diversity of bacterial populations in a humified upland soil based on 16S rDNA and 16S rRNA templates.
Sampling and extraction protocol.
Replicate cores of a
brown forest soil (pH 4.5 to 5.0) were collected from the
Sourhope Field Experiment Site in the Scottish Borders
(United Kingdom) to a depth of 20 to 25 cm. Each replicate core was
divided into four horizons characterized by standard nomenclature (Fh,
H, Ah upper, and Ah lower). Prior to nucleic acid extraction, all
solutions and glassware were rendered RNase free by diethyl
pyrocarbonate treatment (1), and only certified RNase- and
DNase-free plasticware was used. Nucleic acids were extracted from
0.5 g (wet weight) of soil using Bio-101 Multimix 2 Matrix tubes
in combination with the FastPrep FP120 bead beating system (Bio-101,
Vista, Calif.). Extractions were performed by the addition of 0.5 ml of
hexadecyltrimethylammonium bromide (CTAB) extraction buffer and 0.5 ml
of phenol-chloroform-isoamyl alcohol (25:24:1) (pH 8.0). CTAB
extraction buffer, modified from the method of Kowalchuk et al.
(7), was prepared by mixing equal volumes of 10% (wt/vol)
CTAB (Sigma, Poole, United Kingdom) in 0.7 M NaCl with 240 mM potassium
phosphate buffer, pH 8.0 (14). Samples were lysed for
30 s at a machine speed setting of 5.5 m/s, and the aqueous phase
containing nucleic acids were separated by centrifugation
(16,000 × g) for 5 min at 4°C. The aqueous phase was
then extracted, and phenol was removed by mixing with an equal volume
of chloroform-isoamyl alcohol (24:1) followed by repeated centrifugation (16,000 × g) for 5 min at 4°C. Total
nucleic acids were subsequently precipitated from the extracted aqueous
layer with 2 volumes of 30% (wt/vol) polyethelene glycol 6000 (Fluka BioChemika)-1.6 M NaCl for 2 h at room temperature, followed by centrifugation (18,000 × g) at 4°C for 10 min.
Pelleted nucleic acids were then washed in ice cold 70% (vol/vol)
ethanol and air dried prior to resuspension in 50 µl of RNase free
Tris-EDTA buffer (pH 7.4) (Severn Biotech, Kidderminster, United Kingdom).
In related studies, the method has been used to extract total nucleic
acids from environments such as activated sludge and limestone quarried
rock faces (data not shown). Nucleic acids from these samples were
precipitated directly using standard salt and alcohol methods
(14), as no darkly colored contaminants were coextracted.
Agarose gel analysis of nucleic acid extracts.
Extraction of
DNA and RNA was confirmed and quantified by gel electrophoresis (Fig.
1a). Typical yields of approximately 10 to 20 µg of DNA (~10 kb) and 2 to 5 µg of 16S rRNA per g (dry weight) of soil were observed in the total extracts from the uppermost horizons (Fh and H), which is consistent with results of other extraction methods (3, 8). Yields of nucleic acid typically decreased with depth. This may indicate a reduction in biological activity or, more likely, reflect the decreasing biomass relative to
the soil matrix down the soil profile. Plate count estimates of the
relative density of bacteria on R2A (Difco-Oxoid) supported this
conclusion: Fh = 7.9 × 107, H = 4.6 × 107, AhU = 4.7 × 107, and Ahl = 3.7 × 107 CFU/g (wet weight) of soil.

View larger version (24K):
[in this window]
[in a new window]
|
FIG. 1.
(a) Negative image of a 1% ethidium bromide-stained
agarose gel of the total nucleic extract. Lane 1, HyperLadder I
(Bioline, London, United Kingdom); lane 2, total nucleic extract from
0.5 g of Sourhope soil. (b) Ethidium bromide (1.5%)-stained
agarose gel showing PCR and RT-PCR amplification products from each
soil horizon (Fh, H, Ah upper [AhU], and Ah lower [AhL]). Lane 1, HyperLadder I; lanes 2 to 5 amplification products from 16S rDNA for
each soil horizon; lanes 6 to 9, amplification products from
reverse-transcribed 16S rRNA; lanes 10 to 13, amplified 16S rRNA
(controls without reverse transcriptase) for each horizon; lane 14, amplified bacterial 16S rDNA (positive control); lane 15, no-template
negative control.
|
|
PCR-based analyses of DNA and RNA extracts.
To demonstrate the
efficacy of the method, extracted nucleic acids were divided into two
aliquots for the preparation of pure DNA or RNA templates. To obtain
pure DNA, half of the sample was incubated at 37°C with RNase A
(Sigma) at a final concentration of 100 µg ml
1 for 10 min. RNA for RT-PCR analysis was obtained by treating the other 25 µl
of the sample with 3 U of RQ1 RNase-free DNase (Promega Corp.)
according to the manufacturer's instructions. Prior to reverse
transcription, the template secondary structure was melted by
incubating 0.5 µl of the universal 16S rRNA V3 region primer 530R
(100 pmol/µl) (12) with 2 µl of RNA and 12.75 µl of
nuclease-free water at 70°C for 5 min. Samples of annealed primer-template were then immediately placed on ice, and a reaction mixture was added, containing for each reaction 1.5 µl of
MgSO4 (25 mM), 5 µl of 5× reaction buffer (supplied with
the Access RT-PCR System [Promega Corp.]), 1.25 µl of
deoxynucleoside triphosphate mix (10 mM) (Promega Corp.), and 2 µl of
avian myeloblastosis virus reverse transcriptase (8 U/µl) (Promega
Corp.) (Note that the buffer supplied with the avian myeloblastosis
virus reverse transcriptase is not suitable for use in RT-PCR, as it
contains spermidine.) Reverse transcription was carried out at 48°C
for 45 min, and the enzyme was subsequently heat inactivated for 5 min
at 99°C. PCR amplification of both the DNA and cDNA templates was
performed in 100-µl volumes using 1 µl of DNA or cDNA template with
universal bacterial primers spanning the V3 region of the 16S rRNA and
incorporating a GC-clamped primer, as documented previously
(15). Efficient amplification of the 16S rDNA from the DNA
extract was occasionally variable when using 1 µl of undiluted template. However, 1/10 dilutions proved reliable and produced high
yields of PCR product (Fig. 1b). In contrast, RT-PCR consistently produced strong amplification from undiluted RNA samples. Particular attention was paid to ensure that DNA did not contaminate RNA preparations by always performing RT-PCR on RNA samples in the absence
of the reverse transcriptase enzyme.
DGGE fingerprinting of soil horizon communities by DNA and RNA
analyses.
DGGE analyses of PCR amplified products was performed as
described elsewhere (15). The DGGE profiles resulting from
either RNA or DNA templates confirmed the complex microbial diversity present in soils (Fig. 2). Silver
staining (SilverSequence; Promega Corp.) coupled with digital scanning
provided greater resolution of faint bands than Sybr Gold staining
(Molecular Probes, Eugene, Oreg.) and enabled more representative
profiling using Phoretix (Newcastle Upon Tyne, United Kingdom)
one-dimensional gel analysis software.

View larger version (142K):
[in this window]
[in a new window]
|
FIG. 2.
Scanned image of a silver-stained DGGE gel (10%
acrylamide, 30 to 60% denaturant) profiling the microbial communities
by soil horizon and nucleic acid template. For each horizon, two
replicate profiles from two independently extracted soil cores are
displayed.
|
|
Community composition and stratification in soil horizons.
The
presence or absence of bands in each community profile was analyzed by
the unweighted pairwise grouping method with mathematical averages
(utilizing the Dice coefficient of similarity). Analyses indicated
strong delineation of the profiles into clusters corresponding to the
nucleic acid template (DNA or RNA) (Fig.
3). This analysis clearly demonstrated
that differences existed between the profiles, presumably due to the
active or total diversity assessed by rRNA or rDNA, respectively.
Further, replicate Fh samples (top 5 cm) grouped separately from the
other horizons (for both the RNA- and DNA-derived profiles), indicative
of a different community structure in the near-rhizosphere environment
compared to soil depth profiles. Replicate homogeneity was also
demonstrated by the clustering of separately extracted and analyzed
replicate cores, indicating the consistency of the extraction and
analysis methods.

View larger version (27K):
[in this window]
[in a new window]
|
FIG. 3.
Dendrogram showing clustering analyses of the digitized
profiles from Fig. 2, using the unweighted pairwise grouping method
with mathematical averages (Dice coefficient of similarity). The
analyses takes into account the presence or absence of bands at certain
positions in each lane, standardized across the gel using
Rf values.
|
|
Community composition determined by sequence analyses.
In
order to assess any significant bias inherent to this extraction
method, full-length 16S rDNAs were cloned in pGEM-T Easy (Promega
Corp.). Sequence analyses of the gene library and DGGE bands confirmed
the clone dominance of the alpha-Proteobacteria and the
presence of the Acidobacterium-Holophaga group, including the recently described Sourhope 3 cluster (9). Therefore,
the sequences detected with the protocol described above were
consistent with those reported from an adjacent field site at Sourhope
(9) or a low-pH soil environment (13), which used
alternative primer sets to amplify cesium chloride-purified DNA.
Conclusions.
The study of 16S rRNA genes has provided a
greater knowledge of the diversity of bacteria in the environment and
has also revolutionized bacterial systematics. However, in order to
detect specific functional groups of microorganisms, different
techniques are required to differentiate the active components within a
sample. While the benefits of using an RNA directed approach are still to be fully realized, the use of the methodology described here will
allow examination of the correlation between an RNA-based phylogeny and
the activities of specific taxa. These data, when integrated with
measurements of biogeochemical processes, should permit a greater
understanding of microbial community structure and functionality in the environment.
 |
ACKNOWLEDGMENTS |
This work was supported as part of the Soil Biodiversity NERC
thematic program through grant GST/32/2136 to M.J.B., A.S.W., and
A.G.O. and an associated studentship (to R.I.G.).
We thank Sarah Buckland for help with sample collection.
 |
FOOTNOTES |
*
Corresponding author. Mailing address: IVEM,
CEH-Oxford, Mansfield Rd., Oxford OX1 3SR, United Kingdom. Phone: 44 (0)1865 281630. Fax: 44 (0)1865 281696. E-mail:
mbj{at}ceh.ac.uk.
 |
REFERENCES |
| 1.
|
Blumberg, D. D.
1987.
Creating a ribonuclease-free environment.
Methods Enzymol.
152:20-24[Medline].
|
| 2.
|
Duarte, G. F.,
A. S. Rosado,
L. Seldin,
A. C. KeijzerWolters, and J. D. van Elsas.
1998.
Extraction of ribosomal RNA and genomic DNA from soil for studying the diversity of the indigenous bacterial community.
J. Microb. Methods
32:21-29.
|
| 3.
|
Felske, A.,
B. Engelen,
U. Nubel, and H. Backhaus.
1996.
Direct ribosome isolation from soil to extract bacterial rRNA for community analysis.
Appl. Environ. Microbiol.
62:4162-4167[Abstract].
|
| 4.
|
Felske, A.,
A. Wolterink,
R. Van Lis, and A. D. L. Akkermans.
1998.
Phylogeny of the main bacterial 16S rRNA sequences in Drentse A grassland soils (The Netherlands).
Appl. Environ. Microbiol.
64:871-879[Abstract/Free Full Text].
|
| 5.
|
Frostegard, A.,
S. Courtois,
V. Ramisse,
S. Clerc,
D. Bernillon,
F. LeGall,
P. Jeannin,
X. Nesme, and P. Simonet.
1999.
Quantification of bias related to the extraction of DNA directly from soils.
Appl. Environ. Microbiol.
65:5409-5420[Abstract/Free Full Text].
|
| 6.
|
Head, I. M.,
J. R. Saunders, and R. W. Pickup.
1998.
Microbial evolution, diversity, and ecology: a decade of ribosomal RNA analysis of uncultivated micro-organisms.
Microb. Ecol.
35:1-21[CrossRef][Medline].
|
| 7.
|
Kowalchuk, G., A.,
P. L. E. Bodelier,
G. H. J. Heilig,
J. R. Stephen, and H. J. Laanbroek.
1998.
Community analysis of ammonia-oxidising bacteria, in relation to oxygen availability in soils and root-oxygenated sediments, using PCR, DGGE and oligonucleotide probe hybridisation.
FEMS Microbiol. Ecol.
27:339-350[CrossRef].
|
| 8.
|
Krsek, M., and E. M. H. Wellington.
1999.
Comparison of different methods for the isolation and purification of total community DNA from soil.
J. Microbiol. Methods
39:1-16[CrossRef][Medline].
|
| 9.
|
McCaig, A. E.,
L. A. Glover, and J. I. Prosser.
1999.
Molecular analysis of bacterial community structure and diversity in unimproved and improved upland grass pastures.
Appl. Environ. Microbiol.
65:1721-1730[Abstract/Free Full Text].
|
| 10.
|
Miskin, I. P.,
P. Farrimond, and I. M. Head.
1999.
Identification of novel bacterial lineages as active members of microbial populations in a freshwater sediment using a rapid RNA extraction procedure and RT-PCR.
Microbiology
145:1977-1987[Abstract/Free Full Text].
|
| 11.
|
Moran, M. A.,
V. L. Torsvik,
T. Torsvik, and R. E. Hodson.
1993.
Direct extraction and purification of rRNA for ecological studies.
Appl. Environ. Microbiol.
59:915-918[Abstract/Free Full Text].
|
| 12.
|
Muyzer, G.,
E. C. De Waal, and A. G. Uitterlinden.
1993.
Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16S rRNA.
Appl. Environ. Microbiol.
59:695-700[Abstract/Free Full Text].
|
| 13.
|
Radajewski, S.,
P. Ineson,
N. R. Parekh, and J. C. Murrell.
2000.
Stable-isotope probing as a tool in microbial ecology.
Nature
403:646-649[CrossRef][Medline].
|
| 14.
|
Sambrook, J.,
E. F. Fritsch, and T. Maniatis.
1989.
Molecular cloning: a laboratory manual, 2nd ed.
Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.
|
| 15.
|
Whiteley, A. S., and M. J. Bailey.
2000.
Bacterial community structure and physiological state within an industrial phenol bioremediation system.
Appl. Environ. Microbiol.
66:2400-2407[Abstract/Free Full Text].
|
Applied and Environmental Microbiology, December 2000, p. 5488-5491, Vol. 66, No. 12
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Wust, P. K., Horn, M. A., Henderson, G., Janssen, P. H., Rehm, B. H. A., Drake, H. L.
(2009). Gut-Associated Denitrification and In Vivo Emission of Nitrous Oxide by the Earthworm Families Megascolecidae and Lumbricidae in New Zealand. Appl. Environ. Microbiol.
75: 3430-3436
[Abstract]
[Full Text]
-
Miller, M.N., Zebarth, B.J., Dandie, C.E., Burton, D.L., Goyer, C., Trevors, J.T.
(2009). Influence of Liquid Manure on Soil Denitrifier Abundance, Denitrification, and Nitrous Oxide Emissions. Soil Sci.
73: 760-768
[Abstract]
[Full Text]
-
McIlroy, S., Porter, K., Seviour, R. J., Tillett, D.
(2008). Simple and Safe Method for Simultaneous Isolation of Microbial RNA and DNA from Problematic Populations. Appl. Environ. Microbiol.
74: 6806-6807
[Abstract]
[Full Text]
-
Pumphrey, G. M., Madsen, E. L.
(2008). Field-Based Stable Isotope Probing Reveals the Identities of Benzoic Acid-Metabolizing Microorganisms and Their In Situ Growth in Agricultural Soil. Appl. Environ. Microbiol.
74: 4111-4118
[Abstract]
[Full Text]
-
Hamberger, A., Horn, M. A., Dumont, M. G., Murrell, J. C., Drake, H. L.
(2008). Anaerobic Consumers of Monosaccharides in a Moderately Acidic Fen. Appl. Environ. Microbiol.
74: 3112-3120
[Abstract]
[Full Text]
-
Winderl, C., Anneser, B., Griebler, C., Meckenstock, R. U., Lueders, T.
(2008). Depth-Resolved Quantification of Anaerobic Toluene Degraders and Aquifer Microbial Community Patterns in Distinct Redox Zones of a Tar Oil Contaminant Plume. Appl. Environ. Microbiol.
74: 792-801
[Abstract]
[Full Text]
-
Dandie, C. E., Miller, M. N., Burton, D. L., Zebarth, B. J., Trevors, J. T., Goyer, C.
(2007). Nitric Oxide Reductase-Targeted Real-Time PCR Quantification of Denitrifier Populations in Soil. Appl. Environ. Microbiol.
73: 4250-4258
[Abstract]
[Full Text]
-
Nakatsu, C. H.
(2007). Soil Microbial Community Analysis Using Denaturing Gradient Gel Electrophoresis. Soil Sci.
71: 562-571
[Abstract]
[Full Text]
-
Lear, G., Song, B., Gault, A. G., Polya, D. A., Lloyd, J. R.
(2007). Molecular Analysis of Arsenate-Reducing Bacteria within Cambodian Sediments following Amendment with Acetate. Appl. Environ. Microbiol.
73: 1041-1048
[Abstract]
[Full Text]
-
Kourkoutas, Y., Kandylis, P., Panas, P., Dooley, J. S. G., Nigam, P., Koutinas, A. A.
(2006). Evaluation of Freeze-Dried Kefir Coculture as Starter in Feta-Type Cheese Production. Appl. Environ. Microbiol.
72: 6124-6135
[Abstract]
[Full Text]
-
Reischer, G. H., Kasper, D. C., Steinborn, R., Mach, R. L., Farnleitner, A. H.
(2006). Quantitative PCR Method for Sensitive Detection of Ruminant Fecal Pollution in Freshwater and Evaluation of This Method in Alpine Karstic Regions. Appl. Environ. Microbiol.
72: 5610-5614
[Abstract]
[Full Text]
-
Seidl, V., Druzhinina, I. S., Kubicek, C. P.
(2006). A screening system for carbon sources enhancing beta-N-acetylglucosaminidase formation in Hypocrea atroviridis (Trichoderma atroviride). Microbiology
152: 2003-2012
[Abstract]
[Full Text]
-
Sharma, S., Szele, Z., Schilling, R., Munch, J. C., Schloter, M.
(2006). Influence of freeze-thaw stress on the structure and function of microbial communities and denitrifying populations in soil.. Appl. Environ. Microbiol.
72: 2148-2154
[Abstract]
[Full Text]
-
Freitag, T. E., Chang, L., Clegg, C. D., Prosser, J. I.
(2005). Influence of Inorganic Nitrogen Management Regime on the Diversity of Nitrite-Oxidizing Bacteria in Agricultural Grassland Soils. Appl. Environ. Microbiol.
71: 8323-8334
[Abstract]
[Full Text]
-
Castaldini, M., Turrini, A., Sbrana, C., Benedetti, A., Marchionni, M., Mocali, S., Fabiani, A., Landi, S., Santomassimo, F., Pietrangeli, B., Nuti, M. P., Miclaus, N., Giovannetti, M.
(2005). Impact of Bt Corn on Rhizospheric and Soil Eubacterial Communities and on Beneficial Mycorrhizal Symbiosis in Experimental Microcosms. Appl. Environ. Microbiol.
71: 6719-6729
[Abstract]
[Full Text]
-
Nercessian, O., Noyes, E., Kalyuzhnaya, M. G., Lidstrom, M. E., Chistoserdova, L.
(2005). Bacterial Populations Active in Metabolism of C1 Compounds in the Sediment of Lake Washington, a Freshwater Lake. Appl. Environ. Microbiol.
71: 6885-6899
[Abstract]
[Full Text]
-
Johnson, D., IJdo, M., Genney, D. R., Anderson, I. C., Alexander, I. J.
(2005). How do plants regulate the function, community structure, and diversity of mycorrhizal fungi?. J Exp Bot
56: 1751-1760
[Abstract]
[Full Text]
-
Sharma, S., Aneja, M. K., Mayer, J., Munch, J. C., Schloter, M.
(2005). Diversity of Transcripts of Nitrite Reductase Genes (nirK and nirS) in Rhizospheres of Grain Legumes. Appl. Environ. Microbiol.
71: 2001-2007
[Abstract]
[Full Text]
-
Loy, A., Schulz, C., Lucker, S., Schopfer-Wendels, A., Stoecker, K., Baranyi, C., Lehner, A., Wagner, M.
(2005). 16S rRNA Gene-Based Oligonucleotide Microarray for Environmental Monitoring of the Betaproteobacterial Order "Rhodocyclales". Appl. Environ. Microbiol.
71: 1373-1386
[Abstract]
[Full Text]
-
Loy, A., Kusel, K., Lehner, A., Drake, H. L., Wagner, M.
(2004). Microarray and Functional Gene Analyses of Sulfate-Reducing Prokaryotes in Low-Sulfate, Acidic Fens Reveal Cooccurrence of Recognized Genera and Novel Lineages. Appl. Environ. Microbiol.
70: 6998-7009
[Abstract]
[Full Text]
-
Coyne, S. R., Craw, P. D., Norwood, D. A., Ulrich, M. P.
(2004). Comparative Analysis of the Schleicher and Schuell IsoCode Stix DNA Isolation Device and the Qiagen QIAamp DNA Mini Kit. J. Clin. Microbiol.
42: 4859-4862
[Abstract]
[Full Text]
-
Anukool, U., Gaze, W. H., Wellington, E. M. H.
(2004). In Situ Monitoring of Streptothricin Production by Streptomyces rochei F20 in Soil and Rhizosphere. Appl. Environ. Microbiol.
70: 5222-5228
[Abstract]
[Full Text]
-
Shaw, L. J., Burns, R. G.
(2004). Enhanced Mineralization of [U-14C]2,4-Dichlorophenoxyacetic Acid in Soil from the Rhizosphere of Trifolium pratense. Appl. Environ. Microbiol.
70: 4766-4774
[Abstract]
[Full Text]
-
Shigematsu, T., Tang, Y., Kobayashi, T., Kawaguchi, H., Morimura, S., Kida, K.
(2004). Effect of Dilution Rate on Metabolic Pathway Shift between Aceticlastic and Nonaceticlastic Methanogenesis in Chemostat Cultivation. Appl. Environ. Microbiol.
70: 4048-4052
[Abstract]
[Full Text]
-
Freitag, T. E., Prosser, J. I.
(2004). Differences between Betaproteobacterial Ammonia-Oxidizing Communities in Marine Sediments and Those in Overlying Water. Appl. Environ. Microbiol.
70: 3789-3793
[Abstract]
[Full Text]
-
Pesaro, M., Nicollier, G., Zeyer, J., Widmer, F.
(2004). Impact of Soil Drying-Rewetting Stress on Microbial Communities and Activities and on Degradation of Two Crop Protection Products. Appl. Environ. Microbiol.
70: 2577-2587
[Abstract]
[Full Text]
-
Yeager, C. M., Kornosky, J. L., Housman, D. C., Grote, E. E., Belnap, J., Kuske, C. R.
(2004). Diazotrophic Community Structure and Function in Two Successional Stages of Biological Soil Crusts from the Colorado Plateau and Chihuahuan Desert. Appl. Environ. Microbiol.
70: 973-983
[Abstract]
[Full Text]
-
Griffiths, R. I., Whiteley, A. S., O'Donnell, A. G., Bailey, M. J.
(2003). Physiological and Community Responses of Established Grassland Bacterial Populations to Water Stress. Appl. Environ. Microbiol.
69: 6961-6968
[Abstract]
[Full Text]
-
Nicol, G. W., Glover, L. A., Prosser, J. I.
(2003). Spatial Analysis of Archaeal Community Structure in Grassland Soil. Appl. Environ. Microbiol.
69: 7420-7429
[Abstract]
[Full Text]
-
Adamczyk, J., Hesselsoe, M., Iversen, N., Horn, M., Lehner, A., Nielsen, P. H., Schloter, M., Roslev, P., Wagner, M.
(2003). The Isotope Array, a New Tool That Employs Substrate-Mediated Labeling of rRNA for Determination of Microbial Community Structure and Function. Appl. Environ. Microbiol.
69: 6875-6887
[Abstract]
[Full Text]
-
Freitag, T. E., Prosser, J. I.
(2003). Community Structure of Ammonia-Oxidizing Bacteria within Anoxic Marine Sediments. Appl. Environ. Microbiol.
69: 1359-1371
[Abstract]
[Full Text]
-
Boon, N., Top, E. M., Verstraete, W., Siciliano, S. D.
(2003). Bioaugmentation as a Tool To Protect the Structure and Function of an Activated-Sludge Microbial Community against a 3-Chloroaniline Shock Load. Appl. Environ. Microbiol.
69: 1511-1520
[Abstract]
[Full Text]
-
Manefield, M., Whiteley, A. S., Griffiths, R. I., Bailey, M. J.
(2002). RNA Stable Isotope Probing, a Novel Means of Linking Microbial Community Function to Phylogeny. Appl. Environ. Microbiol.
68: 5367-5373
[Abstract]
[Full Text]
-
Metcalfe, A. C., Krsek, M., Gooday, G. W., Prosser, J. I., Wellington, E. M. H.
(2002). Molecular Analysis of a Bacterial Chitinolytic Community in an Upland Pasture. Appl. Environ. Microbiol.
68: 5042-5050
[Abstract]
[Full Text]
-
Loy, A., Lehner, A., Lee, N., Adamczyk, J., Meier, H., Ernst, J., Schleifer, K.-H., Wagner, M.
(2002). Oligonucleotide Microarray for 16S rRNA Gene-Based Detection of All Recognized Lineages of Sulfate-Reducing Prokaryotes in the Environment. Appl. Environ. Microbiol.
68: 5064-5081
[Abstract]
[Full Text]
-
Weinbauer, M. G., Fritz, I., Wenderoth, D. F., Hofle, M. G.
(2002). Simultaneous Extraction from Bacterioplankton of Total RNA and DNA Suitable for Quantitative Structure and Function Analyses. Appl. Environ. Microbiol.
68: 1082-1087
[Abstract]
[Full Text]