ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Molecular analysis of methanogenic archaeal communities in managed and natural upland pasture soils (2003)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 9 (2003), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Grassland management influences soil archaeal communities, which appear to be dominated by nonthermophilic crenarchaeotes. To determine whether methanogenic Archaea associated with the Euryarchaeota lineage are also present in grassland soils, anaerobic microcosms containing both managed (improved) and natural (unimproved) grassland rhizosphere soils were incubated for 28 days to encourage the growth of anaerobic Archaea. The contribution of potential methanogenic organisms to the archaeal community was assessed by the molecular analysis of RNA extracted from soil, using primers targeting all Archaea and Euryarchaeota. Archaeal RT-PCR products were obtained from all anaerobic microcosms. However, euryarchaeal RT-PCR products (of putative methanogen origin) were obtained only from anaerobic microcosms of improved soil, their presence coinciding with detectable methane production. Sequence analysis of excised denaturing gradient gel electrophoresis (DGGE) bands revealed the presence of euryarchaeal organisms that could not be detected before anaerobic enrichment. These data indicate that nonmethanogenic Crenarchaeota dominate archaeal communities in grassland soil and suggest that management practices encourage euryarchaeal methanogenic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.2003.00673.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Effect of anoxia and high sulphide concentrations on heterotrophic microbial communities in reduced surface sediments (Black Spots) in sandy intertidal flats of the German Wadden Sea (2003)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 44 (2003), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Black reduced sediment surfaces (Black Spots) in sandy intertidal flats of the German Wadden Sea (southern North Sea) are characterised by elevated sulphide concentrations (up to 20 mM) and low redox potentials. It is assumed that the appearance of Black Spots is linked to elevated levels of organic matter content within the sediments. In order to establish the effect of high substrate and sulphide concentrations on the heterotrophic microbial communities in Black Spot sediments, bacterial abundances and the potential C-source utilisation patterns of microbial communities were compared in natural and artificially induced Black Spots and unaffected control sites. Bacterial numbers were estimated by direct counts and the most probable number technique for different physiological groups, while patterns of C-substrate utilisation of entire aerobic microbial communities were assessed using the Biolog™ sole-carbon-source-catabolism assay. Bacterial abundances at Black Spot sites were increased, with increases in mean cell numbers, more disperse data distributions and more extreme values. Substrate utilisation patterns of aerobic microbial communities were significantly different in Black Spot sediment slurries, showing diminished richness (number of C-sources catabolised) and substrate diversity (Shannon diversity index) in comparison to unaffected sites. Principal component analysis clearly discriminated Black Spot utilisation patterns from controls and indicated that microbial communities in individual Black Spot sites are functionally diverse and differ from communities in oxidised surface sediments and reduced subsurface sediments at control sites. This work suggests that potentially negative effects on microbial communities in Black Spot sediments, through anoxia and high sulphide concentrations, are balanced by the stimulating influence of substrate availability, leading to comparable or higher bacterial numbers, but lower functional microbial diversity of aerobic microbial communities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0168-6496(03)00076-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Impact of cultivation on characterisation of species composition of soil bacterial communities (2001)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 35 (2001), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The species composition of culturable bacteria in Scottish grassland soils was investigated using a combination of Biolog and 16S rDNA analysis for characterisation of isolates. The inclusion of a molecular approach allowed direct comparison of sequences from culturable bacteria with sequences obtained during analysis of DNA extracted directly from the same soil samples. Bacterial strains were isolated on Pseudomonas isolation agar (PIA), a selective medium, and on tryptone soya agar (TSA), a general laboratory medium. In total, 12 and 21 morphologically different bacterial cultures were isolated on PIA and TSA, respectively. Biolog and sequencing placed PIA isolates in the same taxonomic groups, the majority of cultures belonging to the Pseudomonas (sensu stricto) group. However, analysis of 16S rDNA sequences proved more efficient than Biolog for characterising TSA isolates due to limitations of the Microlog database for identifying environmental bacteria. In general, 16S rDNA sequences from TSA isolates showed high similarities to cultured species represented in sequence databases, although TSA-8 showed only 92.5% similarity to the nearest relative, Bacillus insolitus. In general, there was very little overlap between the culturable and uncultured bacterial communities, although two sequences, PIA-2 and TSA-13, showed 〉99% similarity to soil clones. A cloning step was included prior to sequence analysis of two isolates, TSA-5 and TSA-14, and analysis of several clones confirmed that these cultures comprised at least four and three sequence types, respectively. All isolate clones were most closely related to uncultured bacteria, with clone TSA-5.1 showing 99.8% similarity to a sequence amplified directly from the same soil sample. Interestingly, one clone, TSA-5.4, clustered within a novel group comprising only uncultured sequences. This group, which is associated with the novel, deep-branching Acidobacterium capsulatum lineage, also included clones isolated during direct analysis of the same soil and from a wide range of other sample types studied elsewhere. The study demonstrates the value of fine-scale molecular analysis for identification of laboratory isolates and indicates the culturability of approximately 1% of the total population but under a restricted range of media and cultivation conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6941.2001.tb00786.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Quantitative analysis of ammonia oxidising bacteria using competitive PCR (2000)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 32 (2000), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Culture-based methods for enumeration, such as most probable number (MPN) methodologies, have proved inefficient due to difficulties in the isolation and cultivation of ammonia oxidising bacteria in the laboratory. Biases are associated with the isolation of bacteria in selective media and organisms cultivated in the laboratory may not be truly representative of those in the environment. In this study, we developed a competitive PCR (cPCR)-based method based on the amplification of 16S rRNA genes specific for the β-subgroup proteobacterial ammonia oxidising bacteria for enumeration of these organisms. Populations in both agricultural soils and estuarine sediments were quantified by traditional MPN and by cPCR. The numbers of ammonia oxidisers for both sample types were significantly underestimated by conventional MPN and were 1–3 orders of magnitude lower than those obtained by cPCR. Higher numbers of ammonia oxidisers found in fertilised plots in agricultural soils by the cPCR technique were not observed in MPN estimates. It was necessary to construct a separate standard curve for each sample type as differences in DNA extraction, quantity and purity had a significant bearing on the ease of PCR of both competitor and target DNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6941.2000.tb00710.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Effect of temperature and plasmid carriage on nonculturability in organisms targeted for release (1995)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 17 (1995), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract: The ability to track genetically modified bacteria released into the environment is essential for assessing their persistence and dispersal. Some bacteria can enter a ‘viable but nonculturable’ (VBNC) state in which the cells remain viable while losing the ability to grow on routine culture media. Thus, VBNC cells are not detectable by standard plating methods. In order to determine what conditions, if any, induce this state in Pseudomonas fluorescens, Pseudomonas syringae, and Escherichia coli, cells were ‘marked’ with lux genes, either chromosomally or on one of two different plasmids. Variations in temperature, but not nutrient or NaCl concentrations, affected culturability of these strains and induced the VBNC state. The temperature which induced the VBNC state in the two pseudomonads depended on whether or not the cell carried one of the two lux-marked plasmids. This effect was shown not to be due to the presence of the lux genes, as their removal from the plasmid had no effect on entry into the VBNC state. Instead, the effect appeared to depend on the location of the plasmid DNA, as a strain of P. fluorescens with the same plasmid integrated into the chromosome behaved identically to the parent strain. The fact that plasmids may have such a dramatic effect on culturability has significant implications for the monitoring of genetically modified bacteria intended for environmental release.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6941.1995.tb00147.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Characterisation of bacterial communities associated with toxic and non-toxic dinoflagellates: Alexandrium spp. and Scrippsiella trochoidea (2001)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 37 (2001), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Several dinoflagellate species have been shown to produce potent neurotoxins known as paralytic shellfish toxins. Evidence is also accumulating that marine bacteria associated with dinoflagellates play a role in the accumulation of paralytic shellfish toxins. In this study, the diversity of bacteria in cultures of both toxic and non-toxic dinoflagellates, Alexandrium spp. and Scrippsiella trochoidea, were compared using colony morphology, restriction fragment length polymorphisms, denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA genes and, ultimately, sequence determination of the 16S rRNA genes. The results suggest that a number of different bacterial species are associated with dinoflagellates, some of which are common to each of the dinoflagellate cultures examined, whereas others appear to be unique to a particular dinoflagellate. The phylogenetic diversity of the bacteria observed was limited to two bacterial phyla, the Proteobacteria and the Cytophaga-Flavobacter-Bacteroides (CFB). Although phylum level diversity was limited, many distinct phylogenetic clades were recovered, including members of both the α- and γ-subclasses of the Proteobacteria. Additionally, several of the bacterial phylotypes isolated were not closely related to any published bacterial species but, rather, were identical to isolates characterised from Alexandrium cultures 4 years earlier. Finally, many of the bacteria isolated from the dinoflagellate cultures were related to microorganisms with known surface-associated life histories (e.g. the CFB phylum, Hyphomonas, Caulobacter and some members of the Roseobacter clade including Ruegeria algicola).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6941.2001.tb00864.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The role of the earthworm Lumbricus terrestris in the transport of bacterial inocula through soil (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 132-139 
    Details
    ISSN: 1432-0789
    Keywords: Key words Bacterial inocula lux modified ; Pseudomonas fluorescens ; Repacked soil microcosms ; Earthworms ; Lumbricus terrestris ; Leaching patterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two laboratory experiments were used to investigate the effect of the earthworm Lumbricus terrestris on transport of genetically marked Pseudomonas fluorescens inocula through soil microcosms. The microcosms comprised cylindrical cores of repacked soil with or without earthworms. Late log-phase cells of P. fluorescens, chromosomally marked with lux genes encoding bioluminescence, were applied to the surface of soil cores as inoculated filter paper discs. In one experiment, 5 and 10 days after inoculation, cores were destructively harvested to determine concentrations of marked pseudomonads with depth relative to the initial inoculum applied. Transport of the bacteria occurred only in the presence of earthworms. In a second experiment cores were subjected to simulated rainfall events 18 h after inoculation with lux-marked bacteria at 3-day intervals over a 24-day period. Resulting leachates were analysed for the appearance of the marked bacteria, and after 28 days cores were destructively harvested. Although some marked cells (less than 0.1% of the inoculum applied) were leached through soil in percolating water, particularly in the presence of earthworms, the most important effect of earthworms on cell transport was through burial of inoculated litter rather than an increase in bypass flow due to earthworm channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336053
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The role of the earthworm Lumbricus terrestris in the transport of bacterial inocula through soil (1996)
    Springer
    Biology and fertility of soils 23 (1996), S. 132-139 
    Details
    ISSN: 1432-0789
    Keywords: Bacterial inocula lux modified ; Pseudomonas fluorescens ; Repacked soil microcosms ; Earthworms ; Lumbricus terrestris ; Leaching patterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two laboratory experiments were used to investigate the effect of the earthworm Lumbricus terrestris on transport of genetically marked Pseudomonas fluorescens inocula through soil microcosms. The microcosms comprised cylindrical cores of repacked soil with or without earthworms. Late log-phase cells of P. fluorescens, chromosomally marked with lux genes encoding bioluminescence, were applied to the surface of soil cores as inoculated filter paper discs. In one experiment, 5 and 10 days after inoculation, cores were destructively harvested to determine concentrations of marked pseudomonads with depth relative to the initial inoculum applied. Transport of the bacteria occurred only in the presence of earthworms. In a second experiment cores were subjected to simulated rainfall events 18 h after inoculation with lux-marked bacteria at 3-day intervals over a 24-day period. Resulting leachates were analysed for the appearance of the marked bacteria, and after 28 days cores were destructively harvested. Although some marked cells (less than 0.1% of the inoculum applied) were leached through soil in percolating water, particularly in the presence of earthworms, the most important effect of earthworms on cell transport was through burial of inoculated litter rather than an increase in bypass flow due to earthworm channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336053
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Novel method for the study of the population dynamics of a genetically modified microorganism in the gut of the earthworm Lumbricus terrestris (1993)
    Springer
    Biology and fertility of soils 15 (1993), S. 55-59 
    Details
    ISSN: 1432-0789
    Keywords: Genetically modified microorganisms ; Population dynamics ; Earthworm gut ; Pseudomonas fluorescens ; Lumbricus terrestris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A laboratory microcosm study was used to investigate the survival and population dynamics of genetically modified microorganisms (GMM) in the gut of Lumbricus terrestris. Three methods of axenic earthworm production were investigated. An antibiotic mixture of streptomycin and cycloheximide was introduced either passively, mixed with sterile soil or cellulose, or actively, by teflon catheter. Worms treated by all methods lost weight but this was least for the catheter method which was also the only method to produce axenic earthworms. Axenic earthworms were used to determine the effect of competition with indigenous gut bacteria on ingested GMM. The GMM used was Pseudomonas fluorescens, strain 10586/FAC510, with chromosomally inserted Lux genes for bioluminescence, and chromosomal resistance to rifampicin. The bacteria were grown up to the mid-exponential phase before inoculation into earthworms. Bacteria in faecal material were enumerated by dilution plate counting using selective agar. The GMM were re-isolated from the casts of both antibiotic-treated and untreated earthworms. Lower concentrations of GMM and higher concentrations of indigenous bacteria in the casts of untreated compared to antibiotic-treated earthworms suggested that competition is a fundamental control on population dynamics of the introduced bacterial inocula ingested by earthworms. The catheter method, developed in this study, is proposed as a technique to contribute to the risk assessment of environmental release of GMM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336289
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A partial chloroform-fumigation technique to characterise the spatial location of bacteria introduced into soil (1994)
    Springer
    Biology and fertility of soils 17 (1994), S. 191-195 
    Details
    ISSN: 1432-0789
    Keywords: Pseudomonas fluorescens ; Chloroform ; Fumigation ; Spatial location ; Pore location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Bioluminescence-marked cells of Pseudomonas fluorescens were inoculated into soil by introduction into pores of two different size classes (〈 6 and 30–60 μm neck diameter). Partial chloroform fumigation resulted in a differential killing of cells depending on the placement of the inoculum within the soil pore network and on the period of fumigation. Reduced survival was associated with increasing periods (30–120 min) of fumigation, and with inoculum placement into larger rather than smaller pores. Comparison of the effects of partial fumigation on cells introduced into four soils of contrasting pore-size distribution highlighted the need to calibrate the method on the basis of air/water-filled pore space and chloroform diffusion dynamics for different soil types. It is proposed that partial fumigation facilitates spatial characterisation of the distribution of bacterial cells introduced into soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336321
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...