Abundance of Three Bacterial Populations in Selected Streams

Olapade, Ola A.; Gao, Xueqing; Leff, Laura Gunn

doi:10.1007/s00248-004-0030-x

Cited by 16 publications

(13 citation statements)

References 25 publications

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“…Burkholderia spp. are found in a wide variety of niches ranging from freshwater streams and sediments to the soil rhizosphere (47,70,71). They also interact with various plants, fungi, insects, and animal pathogens (38).…”

Section: Discussionmentioning

confidence: 99%

Hopanoid Production Is Required for Low-pH Tolerance, Antimicrobial Resistance, and Motility in Burkholderia cenocepacia

2011

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Hopanoids are pentacyclic triterpenoids that are thought to be bacterial surrogates for eukaryotic sterols, such as cholesterol, acting to stabilize membranes and to regulate their fluidity and permeability. To date, very few studies have evaluated the role of hopanoids in bacterial physiology. The synthesis of hopanoids depends on the enzyme squalene-hopene cyclase (Shc), which converts the linear squalene into the basic hopene structure. Deletion of the 2 genes encoding Shc enzymes in Burkholderia cenocepacia K56-2, BCAM2831 and BCAS0167, resulted in a strain that was unable to produce hopanoids, as demonstrated by gas chromatography and mass spectrometry. Complementation of the ⌬shc mutant with only BCAM2831 was sufficient to restore hopanoid production to wild-type levels, while introducing a copy of BCAS0167 alone into the ⌬shc mutant produced only very small amounts of the hopanoid peak. The ⌬shc mutant grew as well as the wild type in medium buffered to pH 7 and demonstrated no defect in its ability to survive and replicate within macrophages, despite transmission electron microscopy (TEM) revealing defects in the organization of the cell envelope. The ⌬shc mutant displayed increased sensitivity to low pH, detergent, and various antibiotics, including polymyxin B and erythromycin. Loss of hopanoid production also resulted in severe defects in both swimming and swarming motility. This suggests that hopanoid production plays an important role in the physiology of B. cenocepacia.

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Section: Discussionmentioning

confidence: 99%

Hopanoid Production Is Required for Low-pH Tolerance, Antimicrobial Resistance, and Motility in Burkholderia cenocepacia

2011

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“…These two sampling sites are separated by 5.2 km, which establishes the ability of water flow to partially homogenize microbial communities over at least this distance. A study of the Ipswich River (Massachusetts) demonstrated a similar degree of variability among unconnected primary stream communities (Levine and Crump 2002), and on a broader spatial scale the abundance of bacterioplankton taxa were shown to be variable among nine streams in the eastern Unites States (Olapade et al 2005(Olapade et al , 2006.…”

Section: Stream Communities and Processesmentioning

confidence: 99%

Biogeography of Bacterioplankton in Lakes and Streams of an Arctic Tundra Catchment

Crump

Adams

Hobbie

et al. 2007

Ecology

175

207

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Abstract. Bacterioplankton community composition was compared across 10 lakes and 14 streams within the catchment of Toolik Lake, a tundra lake in Arctic Alaska, during seven surveys conducted over three years using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified rDNA. Bacterioplankton communities in streams draining tundra were very different than those in streams draining lakes. Communities in streams draining lakes were similar to communities in lakes. In a connected series of lakes and streams, the stream communities changed with distance from the upstream lake and with changes in water chemistry, suggesting inoculation and dilution with bacteria from soil waters or hyporheic zones. In the same system, lakes shared similar bacterioplankton communities (78% similar) that shifted gradually down the catchment. In contrast, unconnected lakes contained somewhat different communities (67% similar). We found evidence that dispersal influences bacterioplankton communities via advection and dilution (mass effects) in streams, and via inoculation and subsequent growth in lakes. The spatial pattern of bacterioplankton community composition was strongly influenced by interactions among soil water, stream, and lake environments. Our results reveal large differences in lake-specific and stream-specific bacterial community composition over restricted spatial scales (,10 km) and suggest that geographic distance and connectivity influence the distribution of bacterioplankton communities across a landscape.

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“…Nucleotide sequences of these bacteria have been detected in lakes and rivers but, so far, not in headwater streams. While substantial information on the compositions of bacterial communities in rivers and estuaries has been accumulated using fluorescence in situ hybridization (FISH) (e.g., references 7, 8, 32, 34, and 65), as well as denaturing gradient gel electrophoresis and sequence analysis (e.g., references 6, 14, 19, 33, 64, 65, and 72), fewer reports of studies of headwaters have been published, and these studies have used mainly FISH (5,12,18,22,30,49,57,56).…”

mentioning

confidence: 99%

Bacterial Community Composition in Central European Running Waters Examined by Temperature Gradient Gel Electrophoresis and Sequence Analysis of 16S rRNA Genes

Beier

Witzel

Marxsen

2008

Appl Environ Microbiol

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The bacterial community composition in small streams and a river in central Germany was examined by temperature gradient gel electrophoresis (TGGE) with PCR products of 16S rRNA gene fragments and sequence analysis. Complex TGGE band patterns suggested high levels of diversity of bacterial species in all habitats of these environments. Cluster analyses demonstrated distinct differences among the communities in stream and spring water, sandy sediments, biofilms on stones, degrading leaves, and soil. The differences between stream water and sediment were more significant than those between sites within the same habitat along the stretch from the stream source to the mouth. TGGE data from an entire stream course suggest that, in the upper reach of the stream, a special suspended bacterial community is already established and changes only slightly downstream. The bacterial communities in water and sediment in an acidic headwater with a pH below 5 were highly similar to each other but deviated distinctly from the communities at the other sites. As ascertained by nucleotide sequence analysis, stream water communities were dominated by Betaproteobacteria (one-third of the total bacteria), whereas sediment communities were composed mainly of Betaproteobacteria and members of the Fibrobacteres/Acidobacteria group (each accounting for about 25% of bacteria). Sequences obtained from bacteria from water samples indicated the presence of typical cosmopolitan freshwater organisms. TGGE bands shared between stream and soil samples, as well as sequences found in bacteria from stream samples that were related to those of soil bacteria, demonstrated the occurrence of some species in both stream and soil habitats. Changes in bacterial community composition were correlated with geographic distance along a stream, but in comparisons of different streams and rivers, community composition was correlated only with environmental conditions.

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Abundance of Three Bacterial Populations in Selected Streams

Cited by 16 publications

References 25 publications

Hopanoid Production Is Required for Low-pH Tolerance, Antimicrobial Resistance, and Motility in Burkholderia cenocepacia

Hopanoid Production Is Required for Low-pH Tolerance, Antimicrobial Resistance, and Motility in Burkholderia cenocepacia

Biogeography of Bacterioplankton in Lakes and Streams of an Arctic Tundra Catchment

Bacterial Community Composition in Central European Running Waters Examined by Temperature Gradient Gel Electrophoresis and Sequence Analysis of 16S rRNA Genes

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