scholarly journals Selection of Sphingomonadaceae at the Base of Laccaria proxima and Russula exalbicans Fruiting Bodies

2009 ◽  
Vol 75 (7) ◽  
pp. 1979-1989 ◽  
Author(s):  
F. G. Hidde Boersma ◽  
Jan A. Warmink ◽  
Fernando A. Andreote ◽  
Jan Dirk van Elsas
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Bulk Soil ◽  
Fruiting Bodies ◽  
Community Structures ◽  
Specific Pcr ◽  
Laccaria Proxima ◽  
The Family ◽  
Gradient Gel Electrophoresis ◽  
Selection Of

ABSTRACT The dense hyphal network directly underneath the fruiting bodies of ectomycorrhizal fungi might exert strong influences on the bacterial community of soil. Such fruiting bodies might serve as hot spots for bacterial activity, for instance by providing nutrients and colonization sites in soil. Here, we assessed the putative selection of specific members of the Sphingomonadaceae family at the bases of the fruiting bodies of the ectomycorrhizal fungi Laccaria proxima and Russula exalbicans in comparison to the adjacent bulk soil. To do so, we used a previously designed Sphingomonadaceae-specific PCR-denaturing gradient gel electrophoresis (DGGE) system and complemented this with analyses of sequences from a Sphingomonadaceae-specific clone library. The analyses showed clear selective effects of the fruiting bodies of both fungi on the Sphingomonadaceae community structures. The effect was especially prevalent with R. exalbicans. Strikingly, similar fungi sampled approximately 100 m apart showed similar DGGE patterns, while corresponding bulk soil-derived patterns differed from each other. However, the mycospheres of L. proxima and R. exalbicans still revealed divergent community structures, indicating that different fungi select for different members of the Sphingomonadaceae family. Excision of specific bands from the DGGE patterns, as well as analyses of the clone libraries generated from both habitats, revealed fruiting body-specific Sphingomonadaceae types. It further showed that major groups from the mycospheres of R. exalbicans and L. proxima did not cluster with known bacteria from the database, indicating new groups within the family of Sphingomonadaceae present in these environments.

scholarly journals Succession of Bacterial Communities during Early Plant Development: Transition from Seed to Root and Effect of Compost Amendment

2006 ◽  
Vol 72 (6) ◽  
pp. 3975-3983 ◽  
Author(s):  
Stefan J. Green ◽  
Ehud Inbar ◽  
Frederick C. Michel ◽  
Yitzhak Hadar ◽  
Dror Minz
Keyword(s):  
Bacterial Community ◽  
Plant Growth ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Bacterial Community Composition ◽  
Bacterial Populations ◽  
Specific Pcr ◽  
Compost Amendment ◽  
The Family ◽  
Gradient Gel Electrophoresis ◽  
Root Surfaces

ABSTRACT Compost amendments to soils and potting mixes are routinely applied to improve soil fertility and plant growth and health. These amendments, which contain high levels of organic matter and microbial cells, can influence microbial communities associated with plants grown in such soils. The purpose of this study was to follow the bacterial community compositions of seed and subsequent root surfaces in the presence and absence of compost in the potting mix. The bacterial community compositions of potting mixes, seed, and root surfaces sampled at three stages of plant growth were analyzed via general and newly developed Bacteroidetes-specific, PCR-denaturing gradient gel electrophoresis methodologies. These analyses revealed that seed surfaces were colonized primarily by populations detected in the initial potting mixes, many of which were not detected in subsequent root analyses. The most persistent bacterial populations detected in this study belonged to the genus Chryseobacterium (Bacteroidetes) and the family Oxalobacteraceae (Betaproteobacteria). The patterns of colonization by populations within these taxa differed significantly and may reflect differences in the physiology of these organisms. Overall, analyses of bacterial community composition revealed a surprising prevalence and diversity of Bacteroidetes in all treatments.

scholarly journals Development and Validation of a Nested-PCR-Denaturing Gradient Gel Electrophoresis Method for Taxonomic Characterization of Bifidobacterial Communities

2003 ◽  
Vol 69 (11) ◽  
pp. 6380-6385 ◽  
Author(s):  
R. Temmerman ◽  
L. Masco ◽  
T. Vanhoutte ◽  
G. Huys ◽  
J. Swings
Keyword(s):  
Nested Pcr ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Temporal Changes ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Gradient Gel Electrophoresis ◽  
Species Specific ◽  
Taxonomic Characterization

ABSTRACT The taxonomic characterization of a bacterial community is difficult to combine with the monitoring of its temporal changes. None of the currently available identification techniques are able to visualize a “complete” community, whereas techniques designed for analyzing bacterial ecosystems generally display limited or labor-intensive identification potential. This paper describes the optimization and validation of a nested-PCR-denaturing gradient gel electrophoresis (DGGE) approach for the species-specific analysis of bifidobacterial communities from any ecosystem. The method comprises a Bifidobacterium-specific PCR step, followed by purification of the amplicons that serve as template DNA in a second PCR step that amplifies the V3 and V6-V8 regions of the 16S rRNA gene. A mix of both amplicons is analyzed on a DGGE gel, after which the band positions are compared with a previously constructed database of reference strains. The method was validated through the analysis of four artificial mixtures, mimicking the possible bifidobacterial microbiota of the human and chicken intestine, a rumen, and the environment, and of two fecal samples. Except for the species Bifidobacterium coryneforme and B. indicum, all currently known bifidobacteria originating from various ecosystems can be identified in a highly reproducible manner. Because no further cloning and sequencing of the DGGE bands is necessary, this nested-PCR-DGGE technique can be completed within a 24-h span, allowing the species-specific monitoring of temporal changes in the bifidobacterial community.

scholarly journals Molecular Analysis of Ammonia-Oxidizing Bacteria of the β Subdivision of the Class Proteobacteria in Compost and Composted Materials

1999 ◽  
Vol 65 (2) ◽  
pp. 396-403 ◽  
Author(s):  
George A. Kowalchuk ◽  
Zinaida S. Naoumenko ◽  
Piet J. L. Derikx ◽  
Andreas Felske ◽  
John R. Stephen ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Ammonia Oxidizer ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrogen Transformations ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Specific Pcr ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Almost All

ABSTRACT Although the practice of composting animal wastes for use as biofertilizers has increased in recent years, little is known about the microorganisms responsible for the nitrogen transformations which occur in compost and during the composting process. Ammonia is the principle available nitrogenous compound in composting material, and the conversion of this compound to nitrite in the environment by chemolithotrophic ammonia-oxidizing bacteria is an essential step in nitrogen cycling. Therefore, the distribution of ammonia-oxidizing members of the β subdivision of the class Proteobacteriain a variety of composting materials was assessed by amplifying 16S ribosomal DNA (rDNA) and 16S rRNA by PCR and reverse transcriptase PCR (RT-PCR), respectively. The PCR and RT-PCR products were separated by denaturing gradient gel electrophoresis (DGGE) and were identified by hybridization with a hierarchical set of oligonucleotide probes designed to detect ammonia oxidizer-like sequence clusters in the genera Nitrosospira and Nitrosomonas. Ammonia oxidizer-like 16S rDNA was detected in almost all of the materials tested, including industrial and experimental composts, manure, and commercial biofertilizers. A comparison of the DGGE and hybridization results after specific PCR and RT-PCR suggested that not all of the different ammonia oxidizer groups detected in compost are equally active. amoA, the gene encoding the active-site-containing subunit of ammonia monooxygenase, was also targeted by PCR, and template concentrations were estimated by competitive PCR. Detection of ammonia-oxidizing bacteria in the composts tested suggested that such materials may not be biologically inert with respect to nitrification and that the fate of nitrogen during composting and compost storage may be affected by the presence of these organisms.

scholarly journals Microbial Diversity Associated with Odor Modification for Production of Fertilizers from Chicken Litter

2006 ◽  
Vol 72 (6) ◽  
pp. 4105-4114 ◽  
Author(s):  
Julie J. Enticknap ◽  
Hirofumi Nonogaki ◽  
Allen R. Place ◽  
Russell T. Hill
Keyword(s):  
Microbial Diversity ◽  
Agricultural Soil ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Viable Solution ◽  
Soil Actinomycetes ◽  
Chicken Litter ◽  
Gradient Gel Electrophoresis ◽  
Total Community ◽  
Processing Steps ◽  
Selection Of

ABSTRACT Litter from the chicken industry can present several environmental challenges, including offensive odors and runoff into waterways leading to eutrophication. An economically viable solution to the disposal of waste from chicken houses is treatment to produce a natural, granulated fertilizer that can be commercially marketed for garden and commercial use. Odor of the final product is important in consumer acceptance, and an earthy odor is desirable. By understanding and manipulating the microbial processes occurring during this process, it may be possible to modify the odors produced. Geosmin and related volatiles produced by soil actinomycetes are responsible for earthy odors, and actinomycetes are likely to be present in the composting manure. Bacterial communities at each stage of the process were analyzed by culturing studies and denaturing gradient gel electrophoresis (DGGE). The processing steps changed the culturable bacterial community, but the total community was shown by DGGE to be stable throughout the process. A local agricultural soil was analyzed in parallel as a potential source of geosmin-producing actinomycetes. This agricultural soil had higher microbial diversity than the compost at both the culturable and the molecular levels. Actinomycete bacteria were isolated and analyzed by AromaTrax, a gas chromatography-olfactometry system. This system enables the odor production of individual isolates to be monitored, allowing for rational selection of strains for augmentation experiments to improve the odor of the final fertilizer product.

scholarly journals Bifidobacterial Diversity in Human Feces Detected by Genus-Specific PCR and Denaturing Gradient Gel Electrophoresis

2001 ◽  
Vol 67 (2) ◽  
pp. 504-513 ◽  
Author(s):  
Reetta M. Satokari ◽  
Elaine E. Vaughan ◽  
Antoon D. L. Akkermans ◽  
Maria Saarela ◽  
Willem M. de Vos
Keyword(s):  
16S Rdna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Methodological Approach ◽  
Common Species ◽  
Bifidobacterium Adolescentis ◽  
Specific Pcr ◽  
Rdna Sequences ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis

ABSTRACT We describe the development and validation of a method for the qualitative analysis of complex bifidobacterial communities based on PCR and denaturing gradient gel electrophoresis (DGGE).Bifidobacterium genus-specific primers were used to amplify an approximately 520-bp fragment from the 16S ribosomal DNA (rDNA), and the fragments were separated in a sequence-specific manner in DGGE. PCR products of the same length from different bifidobacterial species showed good separation upon DGGE. DGGE of fecal 16S rDNA amplicons from five adult individuals showed host-specific populations of bifidobacteria that were stable over a period of 4 weeks. Sequencing of fecal amplicons resulted in Bifidobacterium-like sequences, confirming that the profiles indeed represent the bifidobacterial population of feces. Bifidobacterium adolescentis was found to be the most common species in feces of the human adult subjects in this study. The methodological approach revealed intragenomic 16S rDNA heterogeneity in the type strain of B. adolescentis, E-981074. The strain was found to harbor five copies of 16S rDNA, two of which were sequenced. The two 16S rDNA sequences of B. adolescentis E-981074T exhibited microheterogeneity differing in eight positions over almost the total length of the gene.

scholarly journals Changes in Activity and Community Structure of Methane-Oxidizing Bacteria over the Growth Period of Rice

2001 ◽  
Vol 67 (6) ◽  
pp. 2395-2403 ◽  
Author(s):  
Gundula Eller ◽  
Peter Frenzel
Keyword(s):  
Community Structure ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Growth Period ◽  
Fish Analysis ◽  
Rice Plants ◽  
Cell Counts ◽  
Methane Oxidizing Bacteria ◽  
The Family ◽  
Gradient Gel Electrophoresis

ABSTRACT The activity and community structure of methanotrophs in compartmented microcosms were investigated over the growth period of rice plants. In situ methane oxidation was important only during the vegetative growth phase of the plants and later became negligible. The in situ activity was not directly correlated with methanotrophic cell counts, which increased even after the decrease in in situ activity, possibly due to the presence of both vegetative cells and resting stages. By dividing the microcosms into two soil and two root compartments it was possible to locate methanotrophic growth and activity, which was greatest in the rhizoplane of the rice plants. Molecular analysis by denaturing gradient gel electrophoresis and fluorescent in situ hybridization (FISH) with family-specific probes revealed the presence of both families of methanotrophs in soil and root compartments over the whole season. Changes in community structure were detected only for members of the Methylococcaceae and could be associated only with changes in the genusMethylobacter and not with changes in the dominance of different genera in the family Methylococcaceae. For the family Methylocystaceae stable communities in all compartments for the whole season were observed. FISH analysis revealed evidence of in situ dominance of the Methylocystaceae in all compartments. The numbers of Methylococcaceae cells were relatively high only in the rhizoplane, demonstrating the importance of rice roots for growth and maintenance of methanotrophic diversity in the soil.

scholarly journals Composition of Bacterial Communities Associated with Natural and Laboratory Populations of Asobara tabida Infected with Wolbachia

2009 ◽  
Vol 75 (11) ◽  
pp. 3755-3764 ◽  
Author(s):  
Karima Zouache ◽  
Denis Voronin ◽  
Van Tran-Van ◽  
Patrick Mavingui
Keyword(s):  
Bacterial Communities ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Culture Methods ◽  
Asobara Tabida ◽  
The Family ◽  
Laboratory Populations ◽  
Gradient Gel Electrophoresis ◽  
Laboratory Colonies ◽  
And Control

ABSTRACT Asobara tabida wasps are fly endoparasitoids that naturally harbor three Wolbachia strains, which induce cytoplasmic incompatibility and control oogenesis. To investigate whether other bacteria play a role in wasp biology, we surveyed the bacterial communities of wild A. tabida populations originating from different regions of France and of laboratory colonies using PCR-denaturing gradient gel electrophoresis and culture methods. Proteobacteria and Firmicutes were found to be the main phyla represented in these populations. Among these were several cultured and uncultured representatives of the genera Acetobacter, Acidomonas, Bacillus, Brevibacillus, Duganella, Herbaspirillum, Pseudomonas, Staphylococcus, and Streptococcus. In addition to Wolbachia, wild individuals harbored Rickettsia, which tended to be lost when insects were reared in the laboratory. The antibiotic treatment used to generate wasp sublines singly infected with Wolbachia also affected the overall bacterial composition, with most fingerprint sequences being characteristic of the family Enterobacteriaceae. We also screened for potentially heritable endosymbionts by PCR and fluorescence in situ hybridization in stable laboratory lines, with only Wolbachia being consistently found in wasp ovaries.

scholarly journals Molecular Profiling of the Clostridium leptum Subgroup in Human Fecal Microflora by PCR-Denaturing Gradient Gel Electrophoresis and Clone Library Analysis

2006 ◽  
Vol 72 (8) ◽  
pp. 5232-5238 ◽  
Author(s):  
Jian Shen ◽  
Baorang Zhang ◽  
Guifang Wei ◽  
Xiaoyan Pang ◽  
Hua Wei ◽  
...  
Keyword(s):  
Clone Library ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Clone Library Analysis ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Universal Bacterial Primer ◽  
Group Specific Primer

ABSTRACT A group-specific PCR-based denaturing gradient gel electrophoresis (DGGE) method was developed and combined with group-specific clone library analysis to investigate the diversity of the Clostridium leptum subgroup in human feces. PCR products (length, 239 bp) were amplified using C. leptum cluster-specific primers and were well separated by DGGE. The DGGE patterns of fecal amplicons from 11 human individuals revealed host-specific profiles; the patterns for fecal samples collected from a child for 3 years demonstrated the structural succession of the population in the first 2 years and its stability in the third year. A clone library was constructed with 100 clones consisting of 1,143-bp inserts of 16S rRNA gene fragments that were amplified from one adult fecal DNA with one forward universal bacterial primer and one reverse group-specific primer. Eighty-six of the clones produced the 239-bp C. leptum cluster-specific amplicons, and the remaining 14 clones did not produce these amplicons but still phylogenetically belong to the subgroup. Sixty-four percent of the clones were related to Faecalibacterium prausnitzii (similarity, 97 to 99%), 6% were related to Subdoligranulum variabile (similarity, ∼99%), 2% were related to butyrate-producing bacterium A2-207 (similarity, 99%), and 28% were not identified at the species level. The identities of most bands in the DGGE profiles for the same adult were determined by comigration analysis with the 86 clones that harbored the 239-bp group-specific fragments. Our results suggest that DGGE combined with clone library analysis is an effective technique for monitoring and analyzing the composition of this important population in the human gut flora.

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