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

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.

2001 ◽  
Vol 67 (6) ◽  
pp. 2395-2403 ◽  
Author(s):  
Gundula Eller ◽  
Peter Frenzel

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.


2003 ◽  
Vol 69 (1) ◽  
pp. 177-185 ◽  
Author(s):  
Andrew J. McBain ◽  
Robert G. Bartolo ◽  
Carl E. Catrenich ◽  
Duane Charbonneau ◽  
Ruth G. Ledder ◽  
...  

ABSTRACT We have used heterotrophic plate counts, together with live-dead direct staining and denaturing gradient gel electrophoresis (DGGE), to characterize the eubacterial communities that had formed as biofilms within domestic sink drain outlets. Laboratory microcosms of these environments were established using excised biofilms from two separate drain biofilm samples to inoculate constant-depth film fermentors (CDFFs). Drain biofilms harbored 9.8 to 11.3 log10 cells of viable enteric species and pseudomonads/g, while CDFF-grown biofilms harbored 10.6 to 11.4 log10 cells/g. Since live-dead direct staining revealed various efficiencies of recovery by culture, samples were analyzed by DGGE, utilizing primers specific for the V2-V3 region of eubacterial 16S rDNA. These analyses showed that the major PCR amplicons from in situ material were represented in the microcosms and maintained there over extended periods. Sequencing of amplicons resolved by DGGE revealed that the biofilms were dominated by a small number of genera, which were also isolated by culture. One drain sample harbored the protozoan Colpoda maupasi, together with rhabtidid nematodes and bdelloid rotifers. The microcosm enables the maintenance of stable drain-type bacterial communities and represents a useful tool for the modeling of this ecosystem.


2000 ◽  
Vol 41 (10-11) ◽  
pp. 259-268 ◽  
Author(s):  
B.S. Luxmy ◽  
F. Nakajima ◽  
Kazuo Yamamoto

The bacterial communities of membrane-separation bioreactors (MBR) fed with raw sewage were analyzed by a pilot scale study. The community was analyzed by both Fluorescent in Situ Hybridization (FISH) and PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) techniques. Five rRNA targeted group specific oligonucleotide probes showed that the alpha- and beta- subclasses of proteobacteria were the most dominant groups among them. The identification of ammonia-oxidizing bacteria in MBR was confirmed by three probes: NEU, Nsv 443 and Nso 190. Mostly the ammonia-oxidizers were found in groups and present in the form of clusters or aggregates. The ratio of NEU/EUB was estimated by double hybridization and image analysis techniques as 6%. The Nitrobacter sp. was also identified inside the MBR with the help of a NIT3 probe and they were also found to be present in the form of a cluster. Usually the clusters formed by the Nitrobacter sp. were smaller than those of ammonia-oxidizing groups. After numerical analysis on the band pattern of DGGE, it was found that the MBR bacterial communities were different from that of conventional activated sludge (CAS) communities with dissimilarity indexes more than 0.6. The diversity of the microbial community was estimated by the Shannon-Weaver index of general diversity. It was found that the value of the diversity index for the CAS process was 1.61 while those for two MBR processes were 1.68 and 1.59.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.


2000 ◽  
Vol 66 (7) ◽  
pp. 2703-2710 ◽  
Author(s):  
M. Friedrich ◽  
R. J. Grosser ◽  
E. A. Kern ◽  
W. P. Inskeep ◽  
D. M. Ward

ABSTRACT Reduced bioavailability of nonpolar contaminants due to sorption to natural organic matter is an important factor controlling biodegradation of pollutants in the environment. We established enrichment cultures in which solid organic phases were used to reduce phenanthrene bioavailability to different degrees (R. J. Grosser, M. Friedrich, D. M. Ward, and W. P. Inskeep, Appl. Environ. Microbiol. 66:2695–2702, 2000). Bacteria enriched and isolated from contaminated soils under these conditions were analyzed by denaturing gradient gel electrophoresis (DGGE) and sequencing of PCR-amplified 16S ribosomal DNA segments. Compared to DGGE patterns obtained with enrichment cultures containing sand or no sorptive solid phase, different DGGE patterns were obtained with enrichment cultures containing phenanthrene sorbed to beads of Amberlite IRC-50 (AMB), a weak cation-exchange resin, and especially Biobead SM7 (SM7), a polyacrylic resin that sorbed phenanthrene more strongly. SM7 enrichments selected for mycobacterial phenanthrene mineralizers, whereas AMB enrichments selected for a Burkholderia sp. that degrades phenanthrene. Identical mycobacterial andBurkholderia 16S rRNA sequence segments were found in SM7 and AMB enrichment cultures inoculated with contaminated soil from two geographically distant sites. Other closely relatedBurkholderia sp. populations, some of which utilized phenanthrene, were detected in sand and control enrichment cultures. Our results are consistent with the hypothesis that different phenanthrene-utilizing bacteria inhabiting the same soils may be adapted to different phenanthrene bioavailabilities.


2009 ◽  
Vol 75 (7) ◽  
pp. 1979-1989 ◽  
Author(s):  
F. G. Hidde Boersma ◽  
Jan A. Warmink ◽  
Fernando A. Andreote ◽  
Jan Dirk van Elsas

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vanessa Oliveira ◽  
Patrícia Martins ◽  
Bruna Marques ◽  
Daniel F. R. Cleary ◽  
Ana I. Lillebø ◽  
...  

AbstractThe intensification of marine aquaculture raises multiple sustainability issues, namely the handling of nutrient-rich effluents that can adversely impact ecosystems. As integrated multi-trophic aquaculture (IMTA) gains momentum, the use of halophyte plants to phytoremediate aquaculture effluents has received growing attention, particularly in aquaponics. It is, therefore, important to obtain a more in-depth knowledge of the microbial communities present in the root systems of these plants, both in their natural environment (sediment) and in aquaponics, in order to understand their nutrient removal potential. The present study used denaturing gradient gel electrophoresis (DGGE) and barcoded pyrosequencing to assess the bacterial community present in the endosphere and rhizosphere of three halophyte plants: Halimione portulacoides, Salicornia ramosissima and Sarcocornia perennis. Species-specific effects were recorded in the profile and diversity of the bacterial communities present in halophyte roots, with significant differences also recorded for the same halophyte species grown in contrasting environments (sediment vs. aquaponics). In aquaponics the most abundant groups belonged to the orders Rhodocyclales, Campylobacterales, Rhodobacterales and Desulfobacterales, while in the natural environment (sediment) the most abundant groups belonged to the orders Rhizobiales, Sphingomonadales and Alteromonadales. An overall enrichment in bacterial taxa involved in nutrient cycling was recorded in the roots of halophytes grown in aquaponics (such as Denitromonas, Mesorhizobium, Colwellia, Dokdonella and Arcobacter), thereby highlighting their potential to reduce the nutrient loads from aquaculture effluents.


2019 ◽  
Vol 7 (8) ◽  
pp. 236
Author(s):  
Karampoula ◽  
Doulgeraki ◽  
Fotiadis ◽  
Tampakaki ◽  
Nychas

The present study aims to monitor the ability of Salmonella to colonize and compete as a member of the mixed species biofilm within key points at a water bottling plant, in case of a contamination incident with this major foodborne pathogen. To achieve this goal, bacterial communities throughout the production line were collected and their identities were investigated by microbial counts and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). These bacterial communities alone or along with constructed Salmonella enterica serovar Typhimurium (ST) fluorescence-based bioreporters were left to form a biofilm on stainless steel for 6 days at 20 °C. ST bioreporters were constructed by introducing plasmids expressing EYFP (enhanced yellow fluorescent protein) fusions of the genes csgB, csrA, sspH2, and fliD into ST 14028S. The bead vortexing-plate counting method was applied for the enumeration of the biofilm population, while the behavior of the bioreporters was evaluated by fluorescence microscopy. From a set of 16 samples that were collected from the plant, species of Citrobacter, Staphylococcus, Pseudomonas, Bacillus, and Exiguobacterium were identified. The presence of these indigenous bacteria neither inhibited nor enhanced the biofilm formation of ST in mixed bacterial communities (p > 0.05). Furthermore, the csrA-based bioreporter was shown to be induced in multispecies biofilms with Citrobacter. In conclusion, this study enhanced our knowledge of bacterial interactions occurring within a biofilm in a water bottling plant.


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