scholarly journals Stability and Change in Estuarine Biofilm Bacterial Community Diversity

2006 ◽  
Vol 72 (9) ◽  
pp. 5679-5688 ◽  
Author(s):  
Joseph A. Moss ◽  
Andreas Nocker ◽  
Joe E. Lepo ◽  
Richard A. Snyder
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
Temporal Stability ◽  
Community Diversity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phylogenetic Groups ◽  
Stability And Change ◽  
Community Profiling ◽  
Distribution Composition

ABSTRACT Biofouling communities contribute significantly to aquatic ecosystem productivity and biogeochemical cycling. Our knowledge of the distribution, composition, and activities of these microbially dominated communities is limited compared to other components of estuarine ecosystems. This study investigated the temporal stability and change of the dominant phylogenetic groups of the domain Bacteria in estuarine biofilm communities. Glass slides were deployed monthly over 1 year for 7-day incubations during peak tidal periods in East Sabine Bay, Fla. Community profiling was achieved by using 16S rRNA genes and terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA genes in combination with ribotyping, cloning, and sequencing to evaluate diversity and to identify dominant microorganisms. Bacterial community profiles from biofilms grown near the benthos showed distinct periods of constancy within winter and summer sampling periods. Similar periods of stability were also seen in T-RFLP patterns from floating biofilms. Alternating dominance of phylogenetic groups between seasons appeared to be associated with seasonal changes in temperature, nutrient availability, and light. The community structure appeared to be stable during these periods despite changes in salinity and in dissolved oxygen.

Levels of Bacterial Community Diversity in Four Arid Soils Compared by Cultivation and 16S rRNA Gene Cloning

1999 ◽  
Vol 65 (4) ◽  
pp. 1662-1669 ◽  
Author(s):  
John Dunbar ◽  
Shannon Takala ◽  
Susan M. Barns ◽  
Jody A. Davis ◽  
Cheryl R. Kuske
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Soil Samples ◽  
Community Diversity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Clone Libraries ◽  
Bacterial Community Diversity

ABSTRACT Techniques based on amplification of 16S rRNA genes for comparing bacterial communities are now widely used in microbial ecology, but calibration of these techniques with traditional tools, such as cultivation, has been conspicuously absent. In this study, we compared levels of bacterial community diversity in two pinyon rhizosphere soil samples and two between-tree (interspace) soil samples by analyzing 179 cultivated bacterial isolates and 801 16S rRNA genes amplified from extracted soil DNA. Phylotypes were defined by performing a restriction fragment length polymorphism analysis of 16S rRNA gene sequences with the enzymes RsaI and BstUI. The average level of 16S rRNA gene sequence similarity of members of a phylotype was 86.6% based on an analysis of partial sequences. A total of 498 phylotypes were identified among the 16S ribosomal DNA (rDNA) clones, while 34 phylotypes occurred among the cultivated isolates. Analysis of sequences from a subset of the phylotypes showed that at least seven bacterial divisions were represented in the clone libraries, whereas the isolates represented only three. The phylotype richness, frequency distribution (evenness), and composition of the four culture collections and the four clone libraries were investigated by using a variety of diversity indices. Although cultivation and 16S rRNA cloning analyses gave contradictory descriptions of the relative phylotype richness for one of the four environments, the two methods identified qualitatively consistent relationships when levels of evenness were compared. The levels of phylotype similarity between communities were uniformly low (15 to 31%). Both methods consistently indicated that one environment was distinct from the other three. Our data illustrate that while 16S rDNA cloning and cultivation generally describe similar relationships between soil microbial communities, significant discrepancies can occur.

scholarly journals Species-level bacterial community profiling of the healthy sinonasal microbiome using Pacific Biosciences sequencing of full-length 16S rRNA genes

Microbiome ◽  
2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Joshua P. Earl ◽  
Nithin D. Adappa ◽  
Jaroslaw Krol ◽  
Archana S. Bhat ◽  
Sergey Balashov ◽  
...  
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
Species Level ◽  
Full Length ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Pacific Biosciences ◽  
Community Profiling

scholarly journals Effects of Heavy Fuel Oil on the Bacterial Community Structure of a Pristine Microbial Mat

2007 ◽  
Vol 73 (19) ◽  
pp. 6089-6097 ◽  
Author(s):  
Sylvain Bordenave ◽  
María Soledad Goñi-Urriza ◽  
Pierre Caumette ◽  
Robert Duran
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
Oil Pollution ◽  
Microbial Mat ◽  
Fuel Oil ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Heavy Fuel Oil

ABSTRACT The effects of petroleum contamination on the bacterial community of a pristine microbial mat from Salins-de-Giraud (Camargue, France) have been investigated. Mats were maintained as microcosms and contaminated with no. 2 fuel oil from the wreck of the Erika. The evolution of the complex bacterial community was monitored by combining analyses based on 16S rRNA genes and their transcripts. 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) analyses clearly showed the effects of the heavy fuel oil after 60 days of incubation. At the end of the experiment, the initial community structure was recovered, illustrating the resilience of this microbial ecosystem. In addition, the responses of the metabolically active bacterial community were evaluated by T-RFLP and clone library analyses based on 16S rRNA. Immediately after the heavy fuel oil was added to the microcosms, the structure of the active bacterial community was modified, indicating a rapid microbial mat response. Members of the Gammaproteobacteria were initially dominant in the contaminated microcosms. Pseudomonas and Acinetobacter were the main genera representative of this class. After 90 days of incubation, the Gammaproteobacteria were superseded by “Bacilli” and Alphaproteobacteria. This study shows the major changes that occur in the microbial mat community at different time periods following contamination. At the conclusion of the experiment, the RNA approach also demonstrated the resilience of the microbial mat community in resisting environmental stress resulting from oil pollution.

scholarly journals Detection of Putatively Thermophilic Anaerobic Methanotrophs in Diffuse Hydrothermal Vent Fluids

2012 ◽  
Vol 79 (3) ◽  
pp. 915-923 ◽  
Author(s):  
Alexander Y. Merkel ◽  
Julie A. Huber ◽  
Nikolay A. Chernyh ◽  
Elizaveta A. Bonch-Osmolovskaya ◽  
Alexander V. Lebedinsky
Keyword(s):  
16S Rrna ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Optimal Growth ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Anaerobic Oxidation Of Methane ◽  
Phylogenetic Groups ◽  
Content Type

ABSTRACTThe anaerobic oxidation of methane (AOM) is carried out by a globally distributed group of uncultivatedEuryarchaeota, the anaerobic methanotrophic arachaea (ANME). In this work, we used G+C analysis of 16S rRNA genes to identify a putatively thermophilic ANME group and applied newly designed primers to study its distribution in low-temperature diffuse vent fluids from deep-sea hydrothermal vents. We found that the G+C content of the 16S rRNA genes (PGC) is significantly higher in the ANME-1GBa group than in other ANME groups. Based on the positive correlation between thePGCand optimal growth temperatures (Topt) of archaea, we hypothesize that the ANME-1GBa group is adapted to thrive at high temperatures. We designed specific 16S rRNA gene-targeted primers for the ANME-1 cluster to detect all phylogenetic groups within this cluster, including the deeply branching ANME-1GBa group. The primers were successfully tested bothin silicoand in experiments with sediment samples where ANME-1 phylotypes had previously been detected. The primers were further used to screen for the ANME-1 microorganisms in diffuse vent fluid samples from deep-sea hydrothermal vents in the Pacific Ocean, and sequences belonging to the ANME-1 cluster were detected in four individual vents. Phylotypes belonging to the ANME-1GBa group dominated in clone libraries from three of these vents. Our findings provide evidence of existence of a putatively extremely thermophilic group of methanotrophic archaea that occur in geographically and geologically distinct marine hydrothermal habitats.

scholarly journals Bacterial community structure in High-Arctic snow and freshwater as revealed by pyrosequencing of 16S rRNA genes and cultivation

2013 ◽  
Vol 32 (1) ◽  
pp. 17390 ◽  
Author(s):  
Annette K. Møller ◽  
Ditte A. Søborg ◽  
Waleed Abu Al-Soud ◽  
Søren J. Sørensen ◽  
Niels Kroer
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
Bacterial Community Structure ◽  
High Arctic ◽  
16S Rrna Genes ◽  
Rrna Genes

Abdominal setae and midgut bacteria of the mudshrimp Pestarella tyrrhena

2009 ◽  
Vol 4 (4) ◽  
pp. 558-566 ◽  
Author(s):  
Alexandra Demiri ◽  
Alexandra Meziti ◽  
Sokratis Papaspyrou ◽  
Maria Thessalou-Legaki ◽  
Konstantinos Kormas
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
Water Column ◽  
Redox Reactions ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Symbiotic Bacteria ◽  
Microbial Process

AbstractWe investigated the diversity of the bacterial 16S rRNA genes occurring on the abdominal setal tufts and in the emptied midgut of the marine mudshrimp Pestarella tyrrhena (Decapoda: Thalassinidea). There were no dominant phylotypes on the setal tufts. The majority of the phylotypes belonged to the phylum Bacteroidetes, frequently occurring in the water column. The rest of the phylotypes were related to anoxygenic photosynthetic α-Proteobacteria and to Actinobacteria. This bacterial profile seems more of a marine assemblage rather than a specific one suggesting that no specific microbial process can be inferred on the setal tufts. In the emptied midgut, 64 clones were attributed to 16 unique phylotypes with the majority (40.6%) belonging to the γ-Proteobacteria, specifically to the genus Vibrio, a marine group with known symbionts of decapods. The next most abundant group was the ɛ-Proteobacteria (28.1%), with members as likely symbionts related to the processes involving redox reactions occurring in the midgut. In addition, phylotypes related to the Spirochaetes (10.9%) were also present, with relatives capable of symbiosis conducting a nitrite associated metabolism. Entomoplasmatales, Bacteroidetes and Actinobacteria related phylotypes were also found. These results indicate a specific bacterial community dominated by putative symbiotic Bacteria within the P. tyrrhena’s midgut.

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