Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
Type of Medium
Language
Year
  • 1
    Language: English
    In: Research in Microbiology, 2011, Vol.162(9), pp.858-868
    Description: Coastal photosynthetic microbial mats are highly structured microbial communities that populate a variety of shallow environments such as estuaries, sheltered sandy beaches, intertidal flats, salt marshes and hypersaline salterns. In soft sediments, most of these microbial mats are formed of vertically stratified, multicolored cohesive thin layers, of several functional groups of microorganisms, such as cyanobacteria, colorless sulfur bacteria, purple sulfur bacteria and sulfate-reducing bacteria, distributed along vertical microgradients of oxygen, sulfide and light. These microbial communities are highly productive and significant contributors to carbon, nitrogen and sulfur cycles and to sediment stability in shallow-water habitats. Many examples of these communities have been cited in the past, but comparatively few microbial mats have been presented for which mass developments of anoxygenic purple bacteria have been observed. Yet, application of molecular approaches has provided fresh insight into the ecology, diversity and evolution of microbial mats. In situ measurements using electrochemical and optical microprobes led to detailed characterization of their physical and chemical environment, whereas reflectance measurements revealed the spatial and temporal heterogeneity of microbial mat surfaces. We hereby report the main discoveries due to introduction of these powerful techniques and we point out the potential insight to be gained from the study of anoxygenic purple bacterial mats.
    Keywords: Microbial Mats ; Anoxygenic Phototrophs ; Purple Sulfur Bacteria ; Diversity ; Photosynthesis ; Spectral Reflectance ; Biology
    ISSN: 0923-2508
    E-ISSN: 1769-7123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Journal of Experimental Marine Biology and Ecology, Dec 30, 2012, Vol.438, p.52(9)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jembe.2012.10.005 Byline: Claire Passarelli, Cedric Hubas, Audrey Nicolas Segui, Julie Grange, Tarik Meziane Keywords: Diatoms; Extracellular polymeric substances (EPS); Fatty acids; H. diversicolor; Microphytobenthos; Sediment stability Abstract: In soft-bottom tidal flats, sediment stability is one of the crucial parameters modulating the abundance and composition of benthic assemblages. It is dependent on a wide range of variables, both abiotic and biotic. Investigating how these variables and their interactions influence sediment stability is therefore essential to understand how benthic assemblages are distributed in their environment. In this context, we designed a microcosm study to examine how microorganisms and macrofauna interact to alter sediment stability. We cultured a natural microbial community, enriched with diatoms, both alone and together with the common ragworm Hediste diversicolor, and monitored their effects on photosynthetic biomasses, bacterial abundances, exopolymer secretions and sediment stability. We also assessed the consumption of biofilm by worms using fatty acid biomarkers. Our results demonstrate that even if H. diversicolor fed on diatoms, they stimulated biofilm development, in terms of photosynthetic biomass and exopolymer production. Also, sediment cohesiveness was enhanced when both diatoms and H. diversicolor were cultured together; this result was unexpected since macrofauna, through consumption of microorganisms and modification of sediment properties, is often considered to have a destabilising effect on sediment. Predicting the effect of macrofauna on microphytobenthic biofilms and their associated influence of sediment stability is therefore not straightforward. Similar experiments including different types of organisms or more complex assemblages might help to further characterise the effect of biota on sediment stability. Article History: Received 16 July 2012; Revised 1 October 2012; Accepted 7 October 2012
    Keywords: Fatty Acids ; Sediments (Geology)
    ISSN: 0022-0981
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Marine Ecology Progress Series, 2012, Vol.465, pp.85-97
    Description: ABSTRACT: Species that modify their surroundings are known as ecosystem engineers. For example, patches of polychaete tubes enhance soft-bottom intertidal habitat complexity, modifying water flow, promoting sediment accretion and affecting nutrient fluxes at the water–sediment interface. Understanding how such structures affect the benthic ecosystem’s functioning requires the assessment of their influence on all benthic components and how the related ecosystem services may be modified. We performed an in situ experimental study, involving the use of artificial mimics of polychaete tubes, to investigate the purely physical impacts of the structures without the complexity of worm activity. Benthic chambers of different mimic densities were used, and their effect on the recolonisation of defaunated natural sandy sediments by microorganisms, meiofauna and macrofauna was monitored. We also measured air–sediment CO₂ fluxes and sediment stability as they constitute crucial ecosystem services provided by benthic habitats. We showed that the biogenic structures stimulated the development of diatom biofilms (microphytobenthos) and their associated extracellular polymeric substances (EPS). Impacts of tubes on meiofaunal and macrofaunal assemblages were significant; in most cases, species and groups were more abundant in treatments with few or no tubes. In response to the tube density increase, the whole system tended towards heterotrophy and higher sediment stability, probably as a consequence of the development of the diatom biofilm. Biogenic structures are, therefore, of critical importance for soft-bottom intertidal communities in terms of both structure and function.
    ISSN: 01718630
    E-ISSN: 16161599
    Source: JSTOR Sustainability
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: PLoS ONE, 2012, Vol.7(4), p.e31183
    Description: The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS) in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition – isolated from sediments of the Eden Estuary (Scotland, UK) – on non-cohesive glass beads (〈63 µm) and exposed to a range of triclosan concentrations (control, 2 – 100 µg L −1 ) was monitored over time by Magnetic Particle Induction (MagPI). In parallel, bacterial cell numbers, division rate, community composition (DGGE) and EPS (extracellular polymeric substances: carbohydrates and proteins) secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI) of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality) were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of ecosystem effects.
    Keywords: Research Article ; Biology ; Chemistry ; Earth Sciences ; Engineering ; Genetics And Genomics ; Chemistry ; Microbiology ; Ecology ; Marine And Aquatic Sciences ; Developmental Biology ; Biochemistry
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Science of the Total Environment, 15 April 2015, Vol.512-513, pp.296-307
    Description: In order to investigate spatio-temporal variations in the composition and origin of the benthic organic matter (OM) at the sediment surface in mangrove receiving shrimp farm effluents, fatty acid (FA) biomarkers, natural stable isotopes (δ C and δ N), C:N ratios and chlorophyll- (chl- ) concentrations were determined during the active and the non-active period of the farm. Fatty acid compositions in surface sediments within the mangrove forest indicated that organic matter inputs varied along the year as a result of farm activity. Effluents were the source of fresh particulate organic matter for the mangrove, as evidenced by the unsaturated fatty acid (UFA) distribution. The anthropogenic MUFA 18:1ω9 was not only accumulated at the sediment surface in some parts of the mangrove, but was also exported to the seafront. Direct release of bacteria and enhanced in situ production of fungi, as revealed by specific FAs, stimulated mangrove litter decomposition under effluent runoff condition. Also, microalgae released from ponds contributed to maintain high benthic chl- concentrations in mangrove sediments in winter and to a shift in microphytobenthic community assemblage. Primary production was high whether the farm released effluent or not which questioned the temporary effect of shrimp farm effluent on benthic microalgae dynamic. This study outlined that mangrove benthic organic matter was qualitatively and quantitatively affected by shrimp farm effluent release and that responses to environmental condition changes likely depended on mangrove stand characteristics.
    Keywords: Mangrove ; Organic Matter ; Shrimp Farming ; Fatty Acids ; Chlorophyll-a ; Stable Isotopes ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: The Science of the Total Environment, April 15, Vol.512-513, p.296(12)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.scitotenv.2014.12.082 Byline: Adelaide Aschenbroich, Cyril Marchand, Nathalie Molnar, Jonathan Deborde, Cedric Hubas, Herve Rybarczyk, Tarik Meziane Abstract: In order to investigate spatio-temporal variations in the composition and origin of the benthic organic matter (OM) at the sediment surface in mangrove receiving shrimp farm effluents, fatty acid (FA) biomarkers, natural stable isotopes ([delta].sup.13C and [delta].sup.15N), C:N ratios and chlorophyll-a (chl-a) concentrations were determined during the active and the non-active period of the farm. Fatty acid compositions in surface sediments within the mangrove forest indicated that organic matter inputs varied along the year as a result of farm activity. Effluents were the source of fresh particulate organic matter for the mangrove, as evidenced by the unsaturated fatty acid (UFA) distribution. The anthropogenic MUFA 18:1[omega]9 was not only accumulated at the sediment surface in some parts of the mangrove, but was also exported to the seafront. Direct release of bacteria and enhanced in situ production of fungi, as revealed by specific FAs, stimulated mangrove litter decomposition under effluent runoff condition. Also, microalgae released from ponds contributed to maintain high benthic chl-a concentrations in mangrove sediments in winter and to a shift in microphytobenthic community assemblage. Primary production was high whether the farm released effluent or not which questioned the temporary effect of shrimp farm effluent on benthic microalgae dynamic. This study outlined that mangrove benthic organic matter was qualitatively and quantitatively affected by shrimp farm effluent release and that responses to environmental condition changes likely depended on mangrove stand characteristics. Article History: Received 19 September 2014; Revised 5 December 2014; Accepted 23 December 2014 Article Note: (miscellaneous) Editor: C.E.W. Steinberg
    Keywords: Seafood Industry – International Economic Relations ; Aquaculture Industry – International Economic Relations
    ISSN: 0048-9697
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Journal of Experimental Marine Biology and Ecology, 30 December 2012, Vol.438, pp.52-60
    Description: In soft-bottom tidal flats, sediment stability is one of the crucial parameters modulating the abundance and composition of benthic assemblages. It is dependent on a wide range of variables, both abiotic and biotic. Investigating how these variables and their interactions influence sediment stability is therefore essential to understand how benthic assemblages are distributed in their environment. In this context, we designed a microcosm study to examine how microorganisms and macrofauna interact to alter sediment stability. We cultured a natural microbial community, enriched with diatoms, both alone and together with the common ragworm , and monitored their effects on photosynthetic biomasses, bacterial abundances, exopolymer secretions and sediment stability. We also assessed the consumption of biofilm by worms using fatty acid biomarkers. Our results demonstrate that even if fed on diatoms, they stimulated biofilm development, in terms of photosynthetic biomass and exopolymer production. Also, sediment cohesiveness was enhanced when both diatoms and were cultured together; this result was unexpected since macrofauna, through consumption of microorganisms and modification of sediment properties, is often considered to have a destabilising effect on sediment. Predicting the effect of macrofauna on microphytobenthic biofilms and their associated influence of sediment stability is therefore not straightforward. Similar experiments including different types of organisms or more complex assemblages might help to further characterise the effect of biota on sediment stability. ► We tested the effect of microphytobenthos and on sediment adhesion. ► Worms stimulated biofilm development: higher chl and EPS content. ► Fatty acid biomarkers showed that worms fed on diatoms. ► Sediment adhesion was maximal when both microphytobenthos and worms were present.
    Keywords: Diatoms ; Extracellular Polymeric Substances (EPS) ; Fatty Acids ; H. Diversicolor ; Microphytobenthos ; Sediment Stability ; Biology ; Oceanography ; Ecology
    ISSN: 0022-0981
    E-ISSN: 1879-1697
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: PLoS ONE, 02 November 2010, Vol.5(11), pp.1-12
    Description: It is recognized that microorganisms inhabiting natural sediments significantly mediate the erosive response of the bed (‘‘ecosystem engineers'') through the secretion of naturally adhesive organic material (EPS: extracellular polymeric substances). However, little is known about the individual...
    Keywords: Life Sciences ; Ecology, Environment ; Life Sciences ; Microbiology and Parasitology ; Sciences (General)
    ISSN: 1932-6203
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Marine Ecology Progress Series, 2016, Vol.544, pp.225-241
    Description: The feeding ecology of leptocephali has remained poorly understood because they apparently feed on particulate organic matter (POM), which varies in composition, and it is unclear which components of the POM they assimilate. The δ13C and δ15N stable isotope (SI) and fatty acid (FA) compositions...
    Keywords: Life Sciences ; Oceanic Currents ; Fatty Acids ; Stable Isotopes ; Biomarkers ; Trophic Ecology ; Leptocephali ; Biology ; Ecology
    ISSN: 0171-8630
    E-ISSN: 1616-1599
    Source: Hyper Article en Ligne (CCSd)
    Source: Hyper Article en Ligne Open Access (CCSd)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: PLoS ONE, 05 December 2013, Vol.8(12), p.e82329
    Description: There is a relative absence of studies dealing with mats of purple sulphur bacteria in the intertidal zone. These bacteria display an array of metabolic pathways that allow them to disperse and develop under a wide variety of conditions, making these mats important in terms of ecosystem...
    Keywords: Sciences of the Universe ; Earth Sciences ; Oceanography ; Sciences (General) ; Oceanography
    ISSN: 1932-6203
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages