Previous Article | Next Article 
Applied and Environmental Microbiology, August 2000, p. 3616-3620, Vol. 66, No. 8
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Terminal Restriction Fragment Length Polymorphism
Analysis Program, a Web-Based Research Tool for Microbial
Community Analysis
Terence L.
Marsh,1,2,*
Paul
Saxman,1
James
Cole,1,3 and
James
Tiedje1,2,3
Center for Microbial
Ecology1 and Departments of
Microbiology2 and Crop and Soil
Science,3 Michigan State University, East
Lansing, Michigan 48824
Received 9 February 2000/Accepted 13 May 2000
 |
ABSTRACT |
Rapid analysis of microbial communities has proven to be a
difficult task. This is due, in part, to both the tremendous diversity of the microbial world and the high complexity of many microbial communities. Several techniques for community analysis have emerged over the past decade, and most take advantage of the molecular phylogeny derived from 16S rRNA comparative sequence analysis. We
describe a web-based research tool located at the Ribosomal Database
Project web site (http://www.cme.msu.edu/RDP/html/analyses.html) that
facilitates microbial community analysis using terminal restriction fragment length polymorphism of 16S ribosomal DNA. The analysis function (designated TAP T-RFLP) permits the user to perform in silico restriction digestions of the entire 16S sequence database and derive terminal restriction fragment sizes, measured in base pairs, from the 5' terminus of the user-specified primer to the 3'
terminus of the restriction endonuclease target site. The
output can be sorted and viewed either phylogenetically or by size. It is anticipated that the site will guide experimental design as well as
provide insight into interpreting results of community analysis with
terminal restriction fragment length polymorphisms.
 |
TEXT |
Many microbial communities have
proven to be complex assemblages of different phylotypes and
physiologies. For example, the number of species in soil is estimated
to be more than 4,000 species/30 g of soil (17), and
estimates of the number of bacterial species are enormous
(6). It has been only within the last 20 years that we have
begun to recognize the phylogenetic diversity of the microbial world.
During this time 16S rRNA has emerged as one of the premier
phylogenetic markers (7, 16, 19), providing a landmark for
comparative analyses of isolated and uncultured strains as well as
microbial communities.
Comparative community analysis provides an accelerated approach to
understanding community structure and function. It allows for the
identification of unique or numerically dominant strains or groups
under defined or controlled conditions. Thus, one can begin to dissect
the trophic complexity of a community by changing nutrient patterns and
observing the resulting changes in community structure. A number of
rapid techniques to screen communities have been developed (2, 3,
8, 9, 13, 14), and many of those described to date take advantage
of the 16S rRNA phylogenetic marker and are culture-independent
approaches (1). Preliminary steps include the isolation of
community DNA and the PCR amplification of a phylogenetic marker from
the community DNA template. It is at this point that the various
approaches differ in how the PCR products are separated. Terminal
restriction fragment length polymorphism (T-RFLP) takes advantage of
the high resolution and throughput of automated sequencing technologies to separate the polymorphic terminal fragments after restriction digestion. Because the polymorphism is based solely on the length of
the fragment, direct reference can be made to the sequence database
(9, 11).
The potential effectiveness of distinguishing phylotypes by T-RFLP is
presented in Fig. 1. The frequency
distribution of terminal fragment sizes derived from an in silico
digestion with TspEI (AATT) of all sequences in release 7 of
the Ribosomal Database Project (RDP) is plotted, with fragment size on
the abscissa. Of the 1,663 nearly complete sequences from release 7, 1,200 are recognized by both the 27F primer and restriction
endonuclease TspEI. Among the 1,200 restriction products,
there are 349 unique terminal fragment sizes. The ability to resolve
29% of the phylotypes from the current database is significant, given
the skewed composition (e.g., duplicated sequences and emphasis on
medically important organisms) of the database. The terminal fragment
sizes with the greatest frequency are indicated.

View larger version (31K):
[in this window]
[in a new window]
|
FIG. 1.
Frequency distribution profile of terminal fragments
derived from an in silico digestion of the RDP-II with the restriction
enzyme TspEI. The phylotypes with the highest frequency
found in the database are labeled.
|
|
To increase the effectiveness of T-RFLP as a tool for community
analysis, knowledge of the distribution of restriction sites on the 16S
ribosomal DNA (rDNA) and of the relationship of terminal fragment size
to phylogeny is required. To that end we have developed a web site that
integrates the most recent release of the Ribosomal Database Project
(10), including the phylogenetic tree, with a
pattern-searching algorithm. The site provides the investigator with a
rapid way to determine optimal primer and restriction enzyme combinations for community analysis. Moreover, it permits an approach to tentatively identify experimentally determined phylotypes from cognate phylotypes in the database.
Brief description of T-RFLP.
The initial steps of community
analysis protocols vary only in detail. Briefly, community DNA is
extracted directly from the environment by any of the techniques that
are efficient for the particular community (15, 20). The 16S
rDNAs from phylotypes present in the community are then PCR amplified
using primers targeted to conserved regions of the gene. Primers can be
designed to be nondiscriminating, amplifying nearly all 16S rDNAs, or
selective, targeting specific domains or groups. The 5' primer is
fluorescently labeled to tag the products. The amplification products
are then digested with restriction endonucleases, usually 4-base
cutters, and the primer-proximal products (hence, the use of the
descriptor "terminal") are sized on a sequencing gel (2, 3, 5,
9, 11). Three T-RFLP electrophoretic profiles from an
HhaI digestion are presented in Fig.
2. The two profiles from soil communities (Fig. 2A and B) are similar to one another and decidedly different from
the profile of activated sludge (Fig. 2C). Presented in Fig. 2 are
terminal fragments ranging from 35 to 600 bp long. The insert in Fig.
2A presents an expanded view of the soil community profile (with
terminal fragments from 35 to 120 base pairs long) as a demonstration
of the resolving power of the method. While longer fragments are
possible, they are not accurately sized by the combination of gel
parameters and size markers employed in this experiment.

View larger version (51K):
[in this window]
[in a new window]
|
FIG. 2.
T-RFLP profile of three bacterial communities. Terminal
fragments were generated from an HhaI digestion of 16S rDNAs
amplified from total community DNA using a fluorescently tagged 27F
primer and an unlabeled 1392R primer. The terminal fragments were sized
on an ABI 373 automated sequencer using internal size standards (ABI
TAMRA 2500). (A) Agricultural soil from Kellogg's Biological Station
(KBS), Michigan State University; (B) uncultivated soil from the upper
peninsula (UP) of Michigan; (C) activated sludge. The insert presents
an expanded view of the soil profile for fragments from 40 to 110 bp
long.
|
|
T-RFLP analysis program (TAP) web site.
We have developed a
web site (located at http://www.cme.msu.edu/RDP/trflp/#program) that
allows the investigator to answer the following initial questions in
community analysis using T-RFLP. (i) What restriction enzyme(s) will
provide the most discriminating activity for estimates of population
diversity? (ii) What enzyme(s) will provide the best resolution for the
phylogenetic group(s) of interest? (iii) What primer-enzyme combination
will be optimal for the community under investigation? In the final
analysis, each specific community may have its own set of optima that
are empirically defined. However, initial general directions regarding appropriate enzyme(s) to use, as well as phylogenetic insights, can be
gained by examining an in silico digestion of the 16S rRNA database
(4, 9).
TAP gives its users the ability to simulate the T-RFLP procedure with
the entire RDP as the surrogate community. The required
user input
includes a forward or reverse primer sequence that
may contain
non-Watson-Crick International Union of Biochemistry
(IUB) characters
and a restriction enzyme target sequence(s).
In addition, the maximum
number of base mismatches allowed within
a specified number of bases
from the 5' end of the primer can
be specified. In the event that more
than one restriction enzyme
is selected, the operator has the
additional option of performing
multiple single digests or a single
multiple enzyme
digest.
Upon submitting a digest request, the program accesses the most recent
release of the RDP prokaryote database, extracts a
name and a sequence,
and attempts to prime each sequence with
the supplied primer sequence
under the specified conditions. Each
sequence that is successfully
recognized by the primer sequence
is digested by the specified
enzyme(s). If the user selects multiple
single digestions, the program
will display each resulting terminal
fragment size and enzyme with the
organism's name and short ID
(SID) (Fig.
3). If the user selects a multienzyme
digestion, the
shortest fragment size and corresponding enzyme is
displayed with
the name and SID. In the event that a sequence is
successfully
primed but no restriction site is found, "NA" is
entered in the
data set at the appropriate site.

View larger version (71K):
[in this window]
[in a new window]
|
FIG. 3.
Phylogenetic and sorted display windows of TAP. (A)
Organism RDP identifiers, fragment sizes, selected restriction enzymes,
and organism names are displayed within the RDP-II phylogenetic
hierarchy. Organism names and RDP phylogenetic indices are displayed
adjacent to expansion status boxes. A plus image indicates the presence
of undisplayed subheadings, as with Archaea, and a minus
image indicates that the level is fully expanded. (B) Organisms are
displayed sorted in according to the selected column header buttons. In
this instance, the organisms are sorted alphabetically in ascending
order by their RDP sequence identifiers.
|
|
The resultant digest data, including the organism's name, its RDP
identifier, and one or more fragment sizes and enzyme pairs,
can be
displayed in two configurations. The default configuration
places the
data within the RDP's prokaryotic phylogenetic hierarchy
(Fig.
3). For
each phylogenetic group, the display shows the group's
level and name
and an image indicating whether any levels and/or
sequences are
collapsed underneath. If a phylogenetic group contains
subnodes, the
indicator can be selected to toggle the display
between expanded and
collapsed
forms.
In addition to the phylogenetic hierarchy display, TAP can display the
digest data in a sorted order. The user can sort the
data by sequence
name, by SID, or by a digest's restriction fragment
size. The data is
ordered alphabetically if sorted by the organism's
name or SID and is
ordered numerically if sorted by a digest's
restriction fragment size.
The program determines what information
to sort by the selection of a
header at the top of each column
of
data.
An additional function the program offers is the ability to highlight
specific organisms of interest. The highlight status
of an organism is
retained between the phylogenetic and sorted
displays. The user can
toggle the highlight status of an organism
by selecting it. In
addition, the highlight status can be toggled
by performing a search.
The program's search engine will examine
the column with the selected
header for the word, or set of fragment
sizes, supplied by the user. By
default, the search engine adds
to those already highlighted organisms
that meet the user-specified
criteria. This allows the user to perform
a Boolean "OR" search.
Alternately, the user can search only the
previously highlighted
organisms for the specified word or fragment
size(s), removing
the highlighting from any organisms that do not match
the search
parameters. This allows the user to construct a Boolean
"AND"
search. Furthermore, when searching a digest column for
particular
restriction fragment sizes, the user can specify a base-pair
tolerance.
TAP was developed for multiplatform usage through the web. The
priming and digest calculations and access to the Ribosomal
Database Project RDP-II database are handled by a web server using
common gateway interface programs at the RDP-II web site. The
user
interface is implemented as an applet in the Java 2 programming
language. Because browser support for Java is not uniform, we
have
designed the applet to work with a Java plug-in available
from
Sun Microsystem's web site (
http://java.sun.com/products/plugin)
for Solaris and Windows operating systems or from Mozilla
Organization's
web site
(
http://www.mozilla.org/oji/MRJPlugin.html) for the Macintosh
operating system. Some Macintosh users may also need to obtain
the most
recent version of the Macintosh Runtime for Java which
is available
from Apple Computer's web site (
http://www.apple.com/java).
All
aforementioned software packages are available free of charge.
Links to these packages can be found on the TAP web
page.
Fragment lengths and phylogeny.
The power of the technique
rests in the high throughput and resolution of terminal fragment
lengths with nucleic acid sequencing technology. The fact that in
silico digestions of the RDP indicate that a significant fraction of
the current database can be distinguished on the basis of terminal
restriction fragment length in no way is meant to imply that one can
positively identify phylogenetic groups or species based upon terminal
fragment length. However, the disposition of restriction sites along
the length of the 16S rDNA molecule does reflect phylogeny at some
level. Table 1 presents the terminal
fragments measured from 5' Escherichia coli position 8 of
three in silico digests (HhaI, MspI, and
RsaI) of the RDP. The fragments were sorted first by the
length of the HhaI fragment and then by the lengths of the
MspI and RsaI fragments, respectively. Only
HhaI digestion products between 1,098 and 1,105 bp long are presented, along with the subgroup affiliation from release 7.1 of the
RDP. Several points are revealed by the list in this table. First, note
that the table lists 26 members from group 2.28.3, 4 from group 2.30.8, and 1 from group 2.15.1. Hence, 84% of the sequences from this range
of HhaI terminal fragment sizes are from the gamma
subdivision of the Proteobacteria. Second, coherent groupings based upon one, two, or three digestions are indicated. All
nine of the phylogenetic subgroups represented can be resolved from the
remaining database with two or three digestions. Clusters of species
from subgroups 2.28.3.26.17, 2.28.3.26.18, 2.28.3.26.11, 2.28.3.26.12 cannot be distinguished with three enzymes. These are, of course,
phylogenetically quite close to one another, accounting for the
conservation of restriction site positions. The Buchnera subgroup is resolved below the species level. Third, the
HhaI fragments from these phylogenetic groups have terminal
fragment sizes greater than 1,000 bp. Terminal fragments of sizes
greater than 600 bp are resolved poorly, if at all, by gel systems.
While capillary electrophoresis systems offer longer sequence reads (up
to 1,000 bp under optimal conditions) and fewer electrophoretic anomalies, coverage of the entire molecule with one labeled primer is
still impossible. Hence a single-label profile, even under optimal
conditions, may not reveal or track all potentially resolvable populations of a community. An inspection of the digested database with
TAP will quickly reveal if there are any known phylogenetic groups that
would be out of range of a single labeled primer with a specified
enzyme. This underscores the need for several primer sets or
multiplexed fluorescently labeled primers when dissecting a complex
community by T-RFLP.
Pitfalls of T-RFLP.
T-RFLP analysis of microbial communities
is gaining increased usage in the scientific community because it is
rapid and has high resolution. It is, however, subject to all of the
caveats routinely applied to molecular approaches that are dependent on efficient extraction of community DNA and PCR amplification of a target
gene. These difficulties have been discussed previously in considerable
detail (15, 18, 20) and include, primarily, concerns
regarding preferential extraction of genomic DNAs and amplification
bias during PCR. In addition, care must be taken to assure that the
restriction digests are complete and specific. This can be monitored by
including the amplified product from a well-characterized isolate in
representative digestions. If this control product is amplified with a
primer labeled with a different fluor, it can easily be distinguished
from fragments derived from the community profile.
Inasmuch as the power of this technique lies in comparative community
analysis, considerable attention must be paid to standardizing
all
parameters during the processing of the samples. That having
been done,
any differences detected in community profiles can
be attributed to
differences in community structure rather than
to differences in sample
preparation. It should also be noted
that a terminal restriction
fragment profile is a quantitative
and detailed view of the PCR product
pool derived from a community.
It is not, however, a quantitative view
of the structure of the
native community, primarily because of possible
PCR bias during
amplification and the diversity of rRNA operon copy
numbers seen
within bacterial genomes (
18).
Evolving web site.
The future directions for this site will
depend in part upon suggestions from users. There are several new
features currently being considered. First, we will extend the analysis
function to the 18S and large subunit database. Second, we hope to
develop a data analysis function that would provide rapid
identification of species in the database that match a submitted T-RFLP
profile. Third, we will further enhance the methodologies for rapid
comparisons of T-RFLP profiles with an eye to identifying pandemic as
well as endemic populations among the communities being compared.
 |
ACKNOWLEDGMENTS |
This research was supported by the Center for Microbial Ecology
through NSF DEB-9120006 and funding from the DOE (DE-FG02-99ER62848) to
the Ribosomal Database Project. T.L. Marsh is supported, in part, by
the DOE (DE-FG02-97ER62477).
 |
FOOTNOTES |
*
Corresponding author. Mailing address: Center for
Microbial Ecology, Michigan State University, East Lansing, MI 48824. Phone: (517) 432-1365. Fax: (517) 432-3770. E-mail:
MARSHT{at}pilot.msu.edu.
 |
REFERENCES |
| 1.
|
Amann, R. I.,
W. Ludwig, and K. H. Schleifer.
1995.
Phylogenetic identification and in situ detection of individual microbial cells without cultivation.
Microbiol. Rev.
59:143-169[Abstract/Free Full Text].
|
| 2.
|
Avaniss-Aghajani, E.,
K. Jones,
D. Chapman, and C. Brunk.
1994.
A molecular technique for identification of bacteria using small subunit ribosomal RNA sequences.
BioTechniques
17(1):144-149[Medline].
|
| 3.
|
Bruce, K. D.
1997.
Analysis of mer gene subclasses within bacterial communities in soils and sediments resolved by fluorescent-PCR-restriction fragment length polymorphism profiling.
Appl. Environ. Microbiol.
63:4914-4919[Abstract].
|
| 4.
|
Brunk, C. F.,
E. Avaniss-Aghajani, and C. A. Brunk.
1996.
A computer analysis of primer and probe hybridization potential with bacterial small-subunit rRNA sequences.
Appl. Environ. Microbiol.
62:872-879[Abstract].
|
| 5.
|
Clement, B. G.,
L. E. Kehl,
K. L. DeBord, and C. L. Kitts.
1998.
Terminal restriction fragment patterns [TRFPs], a rapid, PCR-based method for the comparison of complex bacterial communities.
J. Microbiol. Methods
31:135-142.
|
| 6.
|
Dykhuizen, D. E.
1998.
Santa Rosalia revisited: why are there so many species of bacteria?
Antonie Leeuwenhoek
73:25-33[CrossRef][Medline].
|
| 7.
|
Hugenholtz, P.,
B. M. Goebel, and N. R. Pace.
1998.
Impact of culture-independent studies on the emerging phylogenetic view of bacterial diversity.
J. Bacteriol.
180:4765-4774[Free Full Text].
|
| 8.
|
Lee, D.-H.,
Y.-G. Zo, and S.-J. Kim.
1996.
Nonradioactive method to study genetic profiles of natural bacterial communities by PCR-single-strand-conformation polymorphism.
Appl. Environ. Microbiol.
62:3112-3120[Abstract].
|
| 9.
|
Liu, W.-T.,
T. L. Marsh,
H. Cheng, and L. J. Forney.
1997.
Characterization of microbial diversity by determining terminal restriction fragment length polymorphisms of genes encoding 16S rRNA.
Appl. Environ. Microbiol.
63:4516-4522[Abstract].
|
| 10.
|
Maidak, B. L.,
J. R. Cole,
C. T. Parker, Jr.,
G. M. Garrity,
N. Larsen,
B. Li,
T. G. Lilburn,
M. J. McCaughey,
G. J. Olsen,
R. Overbeek,
S. Pramanik,
T. M. Schmidt,
J. M. Tiedje, and C. R. Woese.
1999.
A new version of the RDP [Ribosomal Database Project].
Nucleic Acids Res.
27:171-173[Abstract/Free Full Text].
|
| 11.
|
Marsh, T. L.
1999.
Terminal restriction fragment length polymorphism (T-RFLP): an emerging method for characterizing diversity among homologous populations of amplicons.
Curr. Opin. Microbiol.
2:323-327[CrossRef][Medline].
|
| 12.
|
Marsh, T. L.,
W.-T. Liu,
L. J. Forney, and H. Cheng.
1998.
Beginning a molecular analysis of the eukaryal community in activated sludge.
Water Sci. Technol.
37:455-460[CrossRef].
|
| 13.
|
Massol-Deya, A. A.,
D. A. Odelson,
R. F. Hickey, and J. M. Tiedje.
1995.
Bacterial community fingerprinting of amplified 16S and 16-23S ribosomal DNA gene sequences and restriction endonuclease analysis [ARDRA], p. 1-8.
In
A. D. Akkermans, et al. (ed.), Molecular microbial ecology manual. Kluwer Academic Publishers, Dordrecht, The Netherlands.
|
| 14.
|
Muyzer, G. A.,
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].
|
| 15.
|
Ogram, A.
1998.
Isolation of nucleic acids from environmental samples.
In
R. S. Burlage, R. Atlas, D. Stahl, G. Geesey, and G. Sayler (ed.), Techniques in microbial ecology. Oxford University Press, New York, N.Y.
|
| 16.
|
Pace, N. R.,
D. A. Stahl,
D. J. Lane, and G. J. Olsen.
1986.
The analysis of natural microbial populations by ribosomal RNA sequences.
Adv. Microbial. Ecol.
9:1-55.
|
| 17.
|
Torsvik, V.,
J. Goksoyr, and F. L. Daae.
1990.
High diversity in DNA of soil bacteria.
Appl. Environ. Microbiol.
56:782-787[Abstract/Free Full Text].
|
| 18.
|
Wintzingerode, F. V.,
U. B. Göbel, and E. Satackebrandt.
1997.
Determination of microbial diversity in environmental samples: pitfalls of PCR-based rRNA analysis.
FEMS Microbiol. Rev.
21:213-229[CrossRef][Medline].
|
| 19.
|
Woese, C. R.
1987.
Bacterial evolution.
Microbiol. Rev.
51:221-271[Free Full Text].
|
| 20.
|
Zhou, J.,
M. A. Bruns, and J. M. Tiedje.
1996.
DNA recovery from soils of diverse composition.
Appl. Environ. Microbiol.
62:316-322[Abstract].
|
Applied and Environmental Microbiology, August 2000, p. 3616-3620, Vol. 66, No. 8
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Stres, B., Tiedje, J. M., Murovec, B.
(2009). BEsTRF: a tool for optimal resolution of terminal-restriction fragment length polymorphism analysis based on user-defined primer-enzyme-sequence databases. Bioinformatics
25: 1556-1558
[Abstract]
[Full Text]
-
Brugger, S. D., Hathaway, L. J., Muhlemann, K.
(2009). Detection of Streptococcus pneumoniae Strain Cocolonization in the Nasopharynx. J. Clin. Microbiol.
47: 1750-1756
[Abstract]
[Full Text]
-
Ramette, A.
(2009). Quantitative Community Fingerprinting Methods for Estimating the Abundance of Operational Taxonomic Units in Natural Microbial Communities. Appl. Environ. Microbiol.
75: 2495-2505
[Abstract]
[Full Text]
-
Junier, P., Junier, T., Witzel, K.-P.
(2008). TRiFLe, a Program for In Silico Terminal Restriction Fragment Length Polymorphism Analysis with User-Defined Sequence Sets. Appl. Environ. Microbiol.
74: 6452-6456
[Abstract]
[Full Text]
-
Gross, G., Wildner, J., Schonewille, A., Rademaker, J. L. W., van der Meer, R., Snel, J.
(2008). Probiotic Lactobacillus plantarum 299v Does Not Counteract Unfavorable Phytohemagglutinin-Induced Changes in the Rat Intestinal Microbiota. Appl. Environ. Microbiol.
74: 5244-5249
[Abstract]
[Full Text]
-
Collins, R. E., Rocap, G.
(2007). REPK: an analytical web server to select restriction endonucleases for terminal restriction fragment length polymorphism analysis. Nucleic Acids Res
35: W58-W62
[Abstract]
[Full Text]
-
Buckley, D. H., Huangyutitham, V., Hsu, S.-F., Nelson, T. A.
(2007). Stable Isotope Probing with 15N2 Reveals Novel Noncultivated Diazotrophs in Soil. Appl. Environ. Microbiol.
73: 3196-3204
[Abstract]
[Full Text]
-
Buckley, D. H., Huangyutitham, V., Hsu, S.-F., Nelson, T. A.
(2007). Stable Isotope Probing with 15N Achieved by Disentangling the Effects of Genome G+C Content and Isotope Enrichment on DNA Density. Appl. Environ. Microbiol.
73: 3189-3195
[Abstract]
[Full Text]
-
Thies, J. E.
(2007). Soil Microbial Community Analysis using Terminal Restriction Fragment Length Polymorphisms. Soil Sci.
71: 579-591
[Abstract]
[Full Text]
-
Jarman, S. N.
(2006). Cleaver: software for identifying taxon specific restriction endonuclease recognition sites. Bioinformatics
22: 2160-2161
[Abstract]
[Full Text]
-
Coolen, M. J. L., Post, E., Davis, C. C., Forney, L. J.
(2005). Characterization of Microbial Communities Found in the Human Vagina by Analysis of Terminal Restriction Fragment Length Polymorphisms of 16S rRNA Genes. Appl. Environ. Microbiol.
71: 8729-8737
[Abstract]
[Full Text]
-
Pett-Ridge, J., Firestone, M. K.
(2005). Redox Fluctuation Structures Microbial Communities in a Wet Tropical Soil. Appl. Environ. Microbiol.
71: 6998-7007
[Abstract]
[Full Text]
-
Yu, C.-P., Ahuja, R., Sayler, G., Chu, K.-H.
(2005). Quantitative Molecular Assay for Fingerprinting Microbial Communities of Wastewater and Estrogen-Degrading Consortia. Appl. Environ. Microbiol.
71: 1433-1444
[Abstract]
[Full Text]
-
Ricke, P., Kolb, S., Braker, G.
(2005). Application of a Newly Developed ARB Software-Integrated Tool for In Silico Terminal Restriction Fragment Length Polymorphism Analysis Reveals the Dominance of a Novel pmoA Cluster in a Forest Soil. Appl. Environ. Microbiol.
71: 1671-1673
[Abstract]
[Full Text]
-
Holt, J., Hothem, S., Howerton, H., Larson, R., Sanford, R.
(2005). 9,10-Phenanthrenequinone Photoautocatalyzes its Formation from Phenanthrene, and Inhibits Biodegradation of Naphthalene. J. Environ. Qual.
34: 462-468
[Abstract]
[Full Text]
-
Conn, V. M., Franco, C. M. M.
(2004). Effect of Microbial Inoculants on the Indigenous Actinobacterial Endophyte Population in the Roots of Wheat as Determined by Terminal Restriction Fragment Length Polymorphism. Appl. Environ. Microbiol.
70: 6407-6413
[Abstract]
[Full Text]
-
Holben, W. E., Feris, K. P., Kettunen, A., Apajalahti, J. H. A.
(2004). GC Fractionation Enhances Microbial Community Diversity Assessment and Detection of Minority Populations of Bacteria by Denaturing Gradient Gel Electrophoresis. Appl. Environ. Microbiol.
70: 2263-2270
[Abstract]
[Full Text]
-
Conn, V. M., Franco, C. M. M.
(2004). Analysis of the Endophytic Actinobacterial Population in the Roots of Wheat (Triticum aestivum L.) by Terminal Restriction Fragment Length Polymorphism and Sequencing of 16S rRNA Clones. Appl. Environ. Microbiol.
70: 1787-1794
[Abstract]
[Full Text]
-
Broderick, N. A., Raffa, K. F., Goodman, R. M., Handelsman, J.
(2004). Census of the Bacterial Community of the Gypsy Moth Larval Midgut by Using Culturing and Culture-Independent Methods. Appl. Environ. Microbiol.
70: 293-300
[Abstract]
[Full Text]
-
Kent, A. D., Smith, D. J., Benson, B. J., Triplett, E. W.
(2003). Web-Based Phylogenetic Assignment Tool for Analysis of Terminal Restriction Fragment Length Polymorphism Profiles of Microbial Communities. Appl. Environ. Microbiol.
69: 6768-6776
[Abstract]
[Full Text]
-
Engebretson, J. J., Moyer, C. L.
(2003). Fidelity of Select Restriction Endonucleases in Determining Microbial Diversity by Terminal-Restriction Fragment Length Polymorphism. Appl. Environ. Microbiol.
69: 4823-4829
[Abstract]
[Full Text]
-
Christensen, J. E., Stencil, J. A., Reed, K. D.
(2003). Rapid Identification of Bacteria from Positive Blood Cultures by Terminal Restriction Fragment Length Polymorphism Profile Analysis of the 16S rRNA Gene. J. Clin. Microbiol.
41: 3790-3800
[Abstract]
[Full Text]
-
Blackwood, C. B., Marsh, T., Kim, S.-H., Paul, E. A.
(2003). Terminal Restriction Fragment Length Polymorphism Data Analysis for Quantitative Comparison of Microbial Communities. Appl. Environ. Microbiol.
69: 926-932
[Abstract]
[Full Text]
-
Nagashima, K., Hisada, T., Sato, M., Mochizuki, J.
(2003). Application of New Primer-Enzyme Combinations to Terminal Restriction Fragment Length Polymorphism Profiling of Bacterial Populations in Human Feces. Appl. Environ. Microbiol.
69: 1251-1262
[Abstract]
[Full Text]
-
Lueders, T., Friedrich, M. W.
(2003). Evaluation of PCR Amplification Bias by Terminal Restriction Fragment Length Polymorphism Analysis of Small-Subunit rRNA and mcrA Genes by Using Defined Template Mixtures of Methanogenic Pure Cultures and Soil DNA Extracts. Appl. Environ. Microbiol.
69: 320-326
[Abstract]
[Full Text]
-
Sakamoto, M., Takeuchi, Y., Umeda, M., Ishikawa, I., Benno, Y.
(2003). Application of terminal RFLP analysis to characterize oral bacterial flora in saliva of healthy subjects and patients with periodontitis. J Med Microbiol
52: 79-89
[Abstract]
[Full Text]
-
McSpadden Gardener, B. B., Weller, D. M.
(2001). Changes in Populations of Rhizosphere Bacteria Associated with Take-All Disease of Wheat. Appl. Environ. Microbiol.
67: 4414-4425
[Abstract]
[Full Text]
-
Sessitsch, A., Weilharter, A., Gerzabek, M. H., Kirchmann, H., Kandeler, E.
(2001). Microbial Population Structures in Soil Particle Size Fractions of a Long-Term Fertilizer Field Experiment. Appl. Environ. Microbiol.
67: 4215-4224
[Abstract]
[Full Text]
-
Diez, B., Pedros-Alio, C., Marsh, T. L., Massana, R.
(2001). Application of Denaturing Gradient Gel Electrophoresis (DGGE) To Study the Diversity of Marine Picoeukaryotic Assemblages and Comparison of DGGE with Other Molecular Techniques. Appl. Environ. Microbiol.
67: 2942-2951
[Abstract]
[Full Text]
-
Kaplan, C. W., Astaire, J. C., Sanders, M. E., Reddy, B. S., Kitts, C. L.
(2001). 16S Ribosomal DNA Terminal Restriction Fragment Pattern Analysis of Bacterial Communities in Feces of Rats Fed Lactobacillus acidophilus NCFM. Appl. Environ. Microbiol.
67: 1935-1939
[Abstract]
[Full Text]
-
Maidak, B. L., Cole, J. R., Lilburn, T. G., Parker, C. T. Jr, Saxman, P. R., Farris, R. J., Garrity, G. M., Olsen, G. J., Schmidt, T. M., Tiedje, J. M.
(2001). The RDP-II (Ribosomal Database Project). Nucleic Acids Res
29: 173-174
[Abstract]
[Full Text]