Microbial Ecology of Phototrophic Biofilms

Microbial Ecology of Phototrophic Biofilms PDF Author: Guus Roeselers
Publisher: Guus Roeselers
ISBN: 9090221646
Category :
Languages : en
Pages : 120

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Book Description
Biofilms are layered structures of microbial cells and an extracellular matrix of polymeric substances, associated with surfaces and interfaces. Biofilms trap nutrients for growth of the enclosed microbial community and help prevent detachment of cells from surfaces in flowing systems. Phototrophic biofilms can best be defined as surface attached microbial communities mainly driven by light as the energy source with a photosynthesizing component clearly present. Eukaryotic algae and cyanobacteria generate energy and reduce carbon dioxide, providing organic substrates and oxygen. The photosynthetic activity fuels processes and conversions in the total biofilm community, including the heterotrophic fraction. This thesis starts with a brief introduction in the ecology of phototrophic biofilms and discusses their actual and potential applications in wastewater treatment, bioremediation, fish-feed production, biohydrogen production, and soil improvement and their role in biofouling. The next chapter describes the diversity of phototrophic bacteria in hot spring microbial mats found on the east coast of Greenland. In this study we utilized a polyphasic approach using a combination of isolation techniques, microscopic observation of morphological features, and cultivation-independent molecular methods. We observed a relationship between the cyanobacterial community composition and the in situ temperatures of different microbial mat parts. Chapter 4 focuses on the successional changes in community composition of freshwater phototrophic biofilms growing under different light intensities. Our results suggest that surface colonization by heterotrophic pioneers facilitates the development of phototrophic biofilms. In Chapter 5 we compared the community composition of phototrophic biofilms cultivated in three microcosm systems operated under identical conditions but placed in different laboratories. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of both 16S and 18S rRNA gene fragments showed that the communities developed differently in terms of species richness and community composition. Chapter 6 demonstrates that nifD gene sequences, coding for a nitrogenase subunit, can be used to detect and identify diazotrophic cyanobacteria in natural communities. PCR products generated using primers homologous to conserved regions in the cyanobacterial nifD genes were subjected to DGGE and clone library analysis in order to determine the genetic diversity of diazotrophic cyanobacteria in environmental samples. In the last chapter we describe the development of PCR primers targeting conserved regions within the cyanobacterial hupS gene family. This gene is involved in the hydrogen metabolism of diazotrophic microorganisms. We analyzed hupS diversity and transcription in cultivated phototrophic biofilms by the direct retrieval and analysis of mRNA that was reverse transcribed, amplified with hupS specific primers, and cloned. Overall, the community composition and species richness of phototrophic biofilms was shown to be highly variable. Cultivation-independent molecular methods proved very useful to study diversity and function in phototrophic biofilms.

Microbial Ecology of Phototrophic Biofilms

Microbial Ecology of Phototrophic Biofilms PDF Author: Guus Roeselers
Publisher: Guus Roeselers
ISBN: 9090221646
Category :
Languages : en
Pages : 120

Get Book Here

Book Description
Biofilms are layered structures of microbial cells and an extracellular matrix of polymeric substances, associated with surfaces and interfaces. Biofilms trap nutrients for growth of the enclosed microbial community and help prevent detachment of cells from surfaces in flowing systems. Phototrophic biofilms can best be defined as surface attached microbial communities mainly driven by light as the energy source with a photosynthesizing component clearly present. Eukaryotic algae and cyanobacteria generate energy and reduce carbon dioxide, providing organic substrates and oxygen. The photosynthetic activity fuels processes and conversions in the total biofilm community, including the heterotrophic fraction. This thesis starts with a brief introduction in the ecology of phototrophic biofilms and discusses their actual and potential applications in wastewater treatment, bioremediation, fish-feed production, biohydrogen production, and soil improvement and their role in biofouling. The next chapter describes the diversity of phototrophic bacteria in hot spring microbial mats found on the east coast of Greenland. In this study we utilized a polyphasic approach using a combination of isolation techniques, microscopic observation of morphological features, and cultivation-independent molecular methods. We observed a relationship between the cyanobacterial community composition and the in situ temperatures of different microbial mat parts. Chapter 4 focuses on the successional changes in community composition of freshwater phototrophic biofilms growing under different light intensities. Our results suggest that surface colonization by heterotrophic pioneers facilitates the development of phototrophic biofilms. In Chapter 5 we compared the community composition of phototrophic biofilms cultivated in three microcosm systems operated under identical conditions but placed in different laboratories. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of both 16S and 18S rRNA gene fragments showed that the communities developed differently in terms of species richness and community composition. Chapter 6 demonstrates that nifD gene sequences, coding for a nitrogenase subunit, can be used to detect and identify diazotrophic cyanobacteria in natural communities. PCR products generated using primers homologous to conserved regions in the cyanobacterial nifD genes were subjected to DGGE and clone library analysis in order to determine the genetic diversity of diazotrophic cyanobacteria in environmental samples. In the last chapter we describe the development of PCR primers targeting conserved regions within the cyanobacterial hupS gene family. This gene is involved in the hydrogen metabolism of diazotrophic microorganisms. We analyzed hupS diversity and transcription in cultivated phototrophic biofilms by the direct retrieval and analysis of mRNA that was reverse transcribed, amplified with hupS specific primers, and cloned. Overall, the community composition and species richness of phototrophic biofilms was shown to be highly variable. Cultivation-independent molecular methods proved very useful to study diversity and function in phototrophic biofilms.

Microbial Biofilms

Microbial Biofilms PDF Author: Hilary M. Lappin-Scott
Publisher: Cambridge University Press
ISBN: 9780521542128
Category : Medical
Languages : en
Pages : 332

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Book Description
Biochemistry and ecology of biofilms from industrial, medical and other viewpoints.

Microbial Ecology of Biofilms

Microbial Ecology of Biofilms PDF Author: Bruce E. Rittmann
Publisher: IWA Publishing (International Water Assoc)
ISBN:
Category : Nature
Languages : en
Pages : 316

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Book Description
Biofilms are ubiquitous, yet until recently scientists and engineers involved in biofilm research or application had a severely limited insight into the structure and functioning of biofilms on a microbial level. However the past decade has seen an explosion of new techniques to elucidate the structure and functions of biofilms, e.g. molecular probes, microsensors, scanning electron microscopy, and a new generation of mathematical models. The 35 contributions selected for these proceedings after peer review reflect these developments with papers grouped into the following themes: nutrient removal systems; anaerobic systems; biofilm physical structure and aerobic water treatment; multidimensional modelling; detoxification of hazardous chemicals; and transport processes in and to the biofilm. The proceedings provide a unique panorama of the latest scientific tools, the emerging new concepts and the widespread applications that are making microbial ecology of biofilms such an exciting field. These genuinely state-of-the-art papers lay foundations for great progress in the next century.

Fossil and Recent Biofilms

Fossil and Recent Biofilms PDF Author: W.E. Krumbein
Publisher: Springer Science & Business Media
ISBN: 9401701938
Category : Science
Languages : en
Pages : 485

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Book Description
MICROBIAL BIOFILMS: PROTECTIVE NICHES IN ANCIENT AND MODERN GEOMICROBIOLOGY J. W. Costerton and Paul Stoodley Center for Biofilm Engineering Montana State University As this book is published based on discussions of a conference that was held in 2001, it may be useful to provide an update on the most recent revelations about biofilms, so that this excellent exposition of the contribution of microbial biofilms to geological processes may be placed in a modem context. The importance of the contribution of microbial biofilms to global processes is only now being appreciated as it is revealed that all terrestrial surfaces are teeming with microbial life in the form of biofilm communities. These communities live on soil particles, in rock fissures, marine and river sediments and at the very extremes of terrestrial habitats from inside Antarctic ice to the walls of deep sea hydrothermal vents. The contribution of these biofilm communities generally went unrecognized because it was the water that was where microbiologists looked for life, not the surfaces, although, evidence of the early association of microbes with surfaces was in fact present in the fossil record (Rasmussen, 2000; Reysenbach, and Cady, 2001). It is also revealing that biofilm formation is found in prokaryotes from the most deeply rooted branches of the phylogenetic tree in both the Archaea and Bacteria kingdoms, the Korarchaeota and Aquificales respectively (Jahnke et al. 2001; Reysenbach et al. 2000).

Microbial Growth in Biofilms

Microbial Growth in Biofilms PDF Author: Ronald J. Doyle
Publisher: Gulf Professional Publishing
ISBN: 9780121822385
Category : Bacterial growth
Languages : en
Pages : 516

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Book Description
This volume and its companion, Volume 337, supplement Volume 310. These volumes provide a contemporary sourcebook for virtually any kind of experimental approach involving biofilms. They cover bioengineering, molecular, genetic, microscopic, chemical, and physical methods.

Biofilms

Biofilms PDF Author: L V Evans
Publisher: CRC Press
ISBN: 0203304721
Category : Science
Languages : en
Pages : 507

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Book Description
Biofilms affect the lives of all of us, growing as they do for example on our teeth (as plaque), on catheters and medical implants in our bodies, on our boats and ships, in food processing environments, and in drinking and industrial water treatment systems. They are highly complex biological communities whose detailed structure and functioning is only gradually being unravelled, with the development of increasingly sophisticated technology for their study. Biofilms almost always have a negative impact on human affairs (flocs in sewage treatment plants are a major exception) and a lot of research is being carried out to gain a better understanding of them, so that we will be in a better position to control them. This volume, with contributions by international experts from widely diverse areas of this field, presents a state-of-the-art picture of where we are at present in terms of our knowledge of biofilms, the techniques being used to study them, and possible strategies for controlling their growth more successfully. It should provide a valuable reference source for information on biofilms and their control for many years to come.

Community Structure and Co-operation in Biofilms

Community Structure and Co-operation in Biofilms PDF Author: Society for General Microbiology. Symposium
Publisher: Cambridge University Press
ISBN: 9780521793025
Category : Medical
Languages : en
Pages : 366

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Book Description
The study of biofilm considers the close association of micro-organisms with each other at interfaces and is relevant to a variety of disciplines, including medicine, dentistry, bioremediation, biofouling, water technology, engineering and food science. Although the habitats studied differ widely, some common elements exist such as method of attachment, coadhesion and regulation of biofilm phenotype and architecture. This book aims to distil the common principles of biofilm physiology and growth for all interested disciplines.

Biofilms

Biofilms PDF Author: Jean F. Brisou
Publisher: CRC Press
ISBN: 1351368842
Category : Science
Languages : en
Pages : 212

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Book Description
This text presents a new technique for detecting microorganisms, specifically bacteria found in all levels of the biosphere. It also discusses methods for enzymatic release of these microbes as well as their interactions in all ecosystems. Drawings and micrographs help to illustrate this concept. Part one is devoted to the mechanisms of adherence. The second part discusses microbial ecology and the bacterial population of tissues as well as both land and aquatic microbiocenoses in general. Part three specifically covers technique. What is known about the mechanisms of adherence justifies the choice of techniques suggested. Applications in areas such as nature, medicine, environmental hygiene and the food industry are discussed. The explanation of useful techniques, the author's research results, and practical application methods make this volume an essential reference tool for researchers, technicians and practitioners.

Microbial Mats

Microbial Mats PDF Author: Joseph Seckbach
Publisher: Springer Science & Business Media
ISBN: 9048137993
Category : Science
Languages : en
Pages : 595

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Book Description
This book provides information about microbial mats, from early fossils to modern mats located in marine and terrestrial environments. Microbial mats – layered biofilms containing different types of cells – are most complex systems in which representatives of various groups of organisms are found together. Among them are cyanobacteria and eukaryotic phototrophs, aerobic heterotrophic and chemoautotrophic bacteria, protozoa, anoxygenic photosynthetic bacteria, and other types of microorganisms. These mats are perfect models for biogeochemical processes, such as the cycles of chemical elements, in which a variety of microorganisms cooperate and interact in complex ways. They are often found under extreme conditions and their study contributes to our understanding of extremophilic life. Moreover, microbial mats are models for Precambrian stromatolites; the study of modern microbial mats may provide information on the processes that may have occurred on Earth when prokaryotic life began to spread.

Biofilms in Medicine, Industry and Environmental Biotechnology

Biofilms in Medicine, Industry and Environmental Biotechnology PDF Author: Piet Lens
Publisher: IWA Publishing
ISBN: 1843390191
Category : Science
Languages : en
Pages : 629

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Book Description
Biofilms are of great practical importance for beneficial technologies such as water and wastewater treatment and bioremediation of groundwater and soil. In other settings biofilms cause severe problems, for example in 65% of bacterial infections currently treated by clinicians (particularly those associated with prosthetics and implants), accelerated corrosion in industrial systems, oil souring and biofouling. Until recently, the structure and function of biofilms could only be inferred from gross measures of biomass and metabolic activity. This limitation meant that investigators involved in biofilm research and application had only a crude understanding of the microbial ecology, physical structure and chemical characteristics of biofilms. Consequently, opportunities for the exploitation and control of biofilms were very limited. The past decade has witnessed the development of several new techniques to elucidate the structure and function of biofilms. Examples include: the use of molecular probes that identify different microbes in complex communities as well as their metabolic functions; the use of microsensors that show concentration gradients of key nutrients and chemicals; the use of confocal laser scanning microscopy to describe the physical structure of biofilms and the development of a new generation of mathematical models that allow for the prediction of biofilm structure and function. However, much progress remains to be made in efforts to understand, control and exploit biofilms. This timely book will introduce its readers to the structure and function of biofilms at a fundamental level as determined during the past decade of research, including: Extracellular polymers as the biofilm matrix; Biofilm phenotype (differential gene expression, interspecies signalling); Biofilm ecology; Biofilm monitoring; Resistance of biofilms to antimicrobial agents and Biofilm abatement. Biofilms in Medicine, Industry and Environmental Technology offers a holistic and multi-disciplinary description of the topic, including biofilm formation and composition, but also biofilm monitoring, disinfection and control. All these aspects are presented from three points of views: medical, industrial and environmental biotechnological in a compact, easy to read format.