Biofilms

Microbial Biofilms review

Excerpt from a book review of Microbial Biofilms: Current Research and Applications:

"the book comprises 11 papers addressing different applications of biofilm research ... each paper provides a useful update/review of a given area - I particularly like the interactions described in the quorum sensing paper." from Joanna Verran, Manchester Metropolitan University, UK writing in Microbiology Today (2012) read more ...

Microbial Biofilms
Edited by: Gavin Lear and Gillian D. Lewis
ISBN: 978-1-904455-96-7
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
"a useful update" Micro. Today

Genomics and Cellular Biology of Endospore Formation

Genomics and Cellular Biology of Endospore Formation

from Patrick Eichenberger writing in Bacillus: Cellular and Molecular Biology (Second edition):

Bacteria of the genera Bacillus and Clostridium can be found in two distinct states. In the vegetative state, bacteria are metabolically active and use available nutrients to grow and divide by binary fission, a process that generates two identical daughter cells. By contrast, when nutrients are scarce, a developmental program of endospore formation (sporulation) is initiated, resulting in the production of highly resistant spores. In the spore state, bacteria are metabolically dormant, and their genetic material, protected in the core of the spore, can endure a variety of challenges, including exposure to radiation, elevated temperatures and noxious chemicals. Sporulation is a complex process, which requires the generation of two distinct cell types: a forespore and a larger mother cell. The progression of the developmental program is controlled by two exquisitely regulated cell type-specific lines of gene expression that run in parallel and are connected at the post-translational level. Various genetic screens and genome-wide transcriptional analyses have identified more than 600 genes that are expressed in the course of sporulation. The function of several of these genes has been characterized in detail and subcellular localization data are available for at least 90 sporulation proteins. Thus, sporulation constitutes one of the best characterized developmental programs at the molecular and cellular levels.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

General and Regulatory Proteolysis in Bacillus subtilis

General and Regulatory Proteolysis in Bacillus subtilis

from Kürşad Turgay writing in Bacillus: Cellular and Molecular Biology (Second edition):

Proteolysis is an important part of many fundamental cellular processes. The intricate involvement of proteases and peptidases in protein quality control, general stress response, control of regulatory networks and development in Bacillus subtilis are introduced in this review. Especially the more recent developments on the role of AAA+ proteins and their adaptor proteins in regulated and general proteolysis and the role of regulated intra-membrane proteolysis and membrane proteases in signal transduction are discussed.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Bacillus review

Excerpt from a book review of Bacillus: Cellular and Molecular Biology (Second edition):

"The book contains some very high quality diagrams and figures ... It also comes with useful Internet tools ... This comprehensive book presents current scientific studies on the cellular processes of Bacillus species ... The book is well organized" from Rebecca T. Horvat (University of Kansas, USA) writing in Doodys read more ...

<i>Bacillus</i>
Edited by: Peter Graumann
ISBN: 978-1-904455-97-4
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
"high quality diagrams and figures" (Doodys)

Extracellular Enzymes in Aquatic Biofilms

Extracellular Enzymes in Aquatic Biofilms: Microbial Interactions Vs Water Quality Effects in the Use of Organic Matter

from Anna M. Romaní, Joan Artigas and Irene Ylla writing in Microbial Biofilms: Current Research and Applications:

Biofilms in aquatic ecosystems colonize various compartments (sand, rocks, leaves) and play a key role in the uptake of inorganic and organic nutrients. Due to their extracellular enzyme capabilities, biofilm microorganisms are able to use organic matter from the surrounding water and increasing activities are related to the availability of biodegradable organic carbon. The most common extracellular enzymes analysed are those involved in the decomposition of polysaccharides, peptides and organic phosphorus compounds, and changes in enzyme expression have been related to the use of different sources of organic matter available in the ecosystem (i.e., during drought-storm and/or pollution episodes). Enzymes important for microbial acquisition of nitrogen and phosphorus also respond to nutrient content and/or imbalances in the flowing water. Additionally, biofilm extracellular enzyme activities are modified by the internal recycling of organic matter and microbial interactions (competition/synergism) within the biofilm, such as algal-bacterial and fungal-bacterial interactions. Although an extensive knowledge of the biofilm structure is required for the interpretation of extracellular enzyme activities in aquatic biofilms, they give a very useful, integrative measure of the biofilm community function in relation to organic matter use and cycling.

Further reading: Microbial Biofilms: Current Research and Applications

Microbial Biofilms review

Excerpt from a book review of Microbial Biofilms: Current Research and Applications:

"Highly recommended is the chapter on interactions between plants and biofilms" from Hans-Curt Flemming (Duisburg, Germany) writing in Biospektrum (2012) 18: 109. read more ...

Microbial Biofilms
Edited by: Gavin Lear and Gillian D. Lewis
ISBN: 978-1-904455-96-7
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
"Highly recommended" (Biospektrum)

Energy from Slime Power from Microbial Fuel Cells

Energy from Slime? Power from Microbial Fuel Cells

from Koichi Nishio, Atsushi Kouzuma, Souichiro Kato and Kazuya Watanabe writing in Microbial Biofilms: Current Research and Applications:

Microbial fuel cells (MFCs) are devices that exploit microbial catabolic activities to generate electricity from a variety of starting materials, including complex organic waste and renewable biomass. The use of these energy sources provides MFCs with a great advantage over chemical fuel cells that utilize only purified reactive fuels (e.g., hydrogen). In an MFC bioreactor, microbes that respire using an anode with organics as electron donors grow preferentially, resulting in accelerated and increased current generation with time. The placement of an anode in either soil or sediment represents a simplified MFC system, known as a sediment MFC, which generates current as soil microbes utilize the anode as an electron acceptor. In addition, the irradiation of an MFC system results in the proliferation of photosynthetic microbes together with anode-respiring microbes, resulting in the syntrophic conversion of light energy into electricity. These examples demonstrate that the MFC system is based on a variety of fundamental and sustainable bioenergy processes, and we suggest that a deeper understanding of how microbes transfer electrons to anodes is essential for further developments of MFC systems.

Further reading: Microbial Biofilms: Current Research and Applications

Dynamics of DNA Double-strand Break Repair in Bacillus subtilis

Dynamics of DNA Double-strand Break Repair in Bacillus subtilis

from Begoña Carrasco, Paula P. Cardenas, Cristina Cañas, Tribuhwuan Yadav, Carolina E. César, Silvia Ayora and Juan C. Alonso writing in Bacillus: Cellular and Molecular Biology (Second edition):

All organisms have developed a variety of DNA repair mechanisms to cope with DNA lesions. Homologous recombination (HR), which uses a homologous template to restore lost information at the break site, is the ultimate step for repair of one- or two-ended double strands breaks (DSBs) and for promoting the re-establishment of replication forks. Genetic and cytological approaches were used to analyze the requirements of exponentially growing Bacillus subtilis cells to survive chemical or physical agents that generate one- or two-ended DSBs and the choreography of DSB repair. The damage-induced multi-protein complex (recombinosome), organised into focal assemblies, has been confirmed by biochemical approaches. HR is coordinated with other essential processes, such as DNA replication, transcription and chromosomal segregation. When DSB recognition or end resection is severely impaired or an intact homologous template is not available the DNA ends of two-ended DSBs are repaired via non-homologous end joining.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Corrosion and Fouling

Corrosion and Fouling

from Steve Flint and Gideon Wolfaardt writing in Microbial Biofilms: Current Research and Applications:

Biofilms can directly or indirectly be attributed to deterioration of the underlying substratum. Corrosion may result, particularly if the surface comprises metal or metal alloy. This phenomenon, referred to as microbially influenced corrosion (MIC) affects many industries from food manufacture to medicine. The economic impact of corrosion is significant due to the need for replacing corroded equipment, repairs and attempts to prevent corrosion. MIC is believed to be responsible for one third of all metallic corrosion. Although there have been many studies into the mechanisms of MIC, the process is relatively poorly understood. Most information relates to pure cultures, however biofilms are rarely composed of single species thus most models are a simplification of the real process. It is likely the MIC depends on the composition of the biofilm and the environment surrounding the biofilm. Prevention and control methods rely on mechanical cleaning of fouling and chemical removal and killing of biofilms. Future control measures are likely to focus on preventing biofilm formation.

Further reading: Microbial Biofilms: Current Research and Applications

Competence and Transformation

Competence and Transformation

from Berenike Maier writing in Bacillus: Cellular and Molecular Biology (Second edition):

Competence for transformation enables bacteria to take up exogenous DNA. The imported DNA can integrate into the chromosome by homologous recombination or anneal to form a self replicating plasmid. Development of competence in Bacillus subtilis is tightly regulated as a function of cell density during entry into the stationary growth phase. Additionally, competence occurs only in a small subpopulation of B. subtilis cells. Development of competence is switch-like and controlled by the concentration of the master regulator ComK. Quantitative analysis at the single cell level in conjunction with mathematical modeling allowed understanding of development and decline of competence at the systems level. In the current model, a complex regulatory network maintains the concentration of ComK below a threshold concentration for switching into the competent state. In the stationary growth phase, noisy expression of ComK triggers competence development as individual cells reach the threshold concentration due to random fluctuations. Competent cells express specialized proteins (late competence proteins) for binding, importing, and recombining external DNA. Cytosolic and transmembrane proteins accumulate at a single or both cell poles. Application of external DNA triggers movement of various proteins involved in recombination away from the pole, most likely undergoing search for homologous regions on the chromosome. These findings provide good evidence for a concerted action of DNA import and recombination, promoting the idea that a spatially organized and modular multiprotein machine has evolved for efficient transformation. This machine powers efficient and irreversible DNA import and can work against considerable external forces.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Chromosome Segregation

Chromosome Segregation

from Peter L. Graumann writing in Bacillus: Cellular and Molecular Biology (Second edition):

After a bit more than a decade of the use of GFP - or immuno-fluorescence microscopy to study bacterial chromosome segregation, it has become clear that this process is highly organized, temporally as well as spatially, and that a mitotic-like machinery exists that actively moves apart sister chromosomes. Several key factors in this process have been identified, and at least a rough overall picture can be drawn on how chromosomes are separated so highly rapidly and efficiently. Bacillus subtilis has a circular chromosome. Replication initiates at the origin of replication that is defined as 0 degrees, and two replication forks proceed bidirectionally to converge at the terminus region, which is defined as 180 degrees. All other regions on the chromosome are defined as the corresponding site on a circle. DNA replication occurs in the cell centre, and duplicated regions are moved away from the cell centre towards opposite cell poles. This process is driven by an active motor that involves bacterial actin-like proteins, whose mode of action is still unknown. A dedicated protein complex called SMC forms two subcellular centres that organize newly duplicated chromosome regions within each cell half, setting up the spatial organization that characterizes bacterial chromosome segregation. Several proteins, including topoisomerases, DNA translocases and recombinases, ensure that entangled sister chromosomes or chromosome dimers can be completely separated into the future daughter cells shortly before cell division occurs at the middle of the cells.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Free biofilm webinar on biofilms

Biofilm Control in Industrial Settings. A free webinar, Biofilm Control in Industrial Settings, will be presented by the Center for Biofilm Engineering at Montana State University on Tuesday 31 January 2012, 1:00-2:30 PM EST. Registration and additional information is available here
Suggested reading: Microbial Biofilms: Current Research and Applications

Cell Division

Cell Division

from Frederico Gueiros-Filho writing in Bacillus: Cellular and Molecular Biology (Second edition):

Cell division is the process of generating two viable descendants from a progenitor cell. This involves two coordinated events: the replication and segregation of the bacterial chromosome and the splitting of the progenitor cell by cytokinesis, which in bacteria is also known as septum formation. Bacterial cells have developed a remarkably sophisticated protein machine capable of precisely splitting a progenitor cell at the right place and time in every cell cycle. This machine, which is known as the divisome or septalsome, is based on a contractile protein ring, as in the case of eukaryotes. In contrast to eukaryotic cells, however, which use actin and myosin in their contractile protein ring, the bacterial contractile machine is based on the tubulin-like protein FtsZ. Here we review the mechanism of cytokinesis in Bacillus subtilis.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Catalytic Biofilms

Catalytic Biofilms: a Powerful Concept for Future Bioprocesses

from Rainer Gross, Andreas Schmid and Katja Buehler writing in Microbial Biofilms: Current Research and Applications:

Biofilms are mainly known for causing problems in medical and industrial settings due to their persistence towards treatment with bactericides, including antibiotics. However, in the area of bioremediation they are widely recognized for their ability to degrade hazardous or organic compounds to CO2 and biomass. Biofilms represent a highly interesting biological concept since they unite important characteristics such as the ability of self-immobilization and increased robustness to various physical, chemical and biological stressors, which make them exceedingly attractive for productive catalysis. The following review provides a detailed survey of biofilm applications for productive biocatalysis on lab-, pilot-, and industrial scales, regarding fermentation as well as biotransformation reactions. It discusses technological as well as biological challenges of biofilm driven catalysis, presenting developments in the field of biofilm reactor technology and the latest findings in understanding biofilm dynamics. Biocatalysis related issues like genetic stability, evolution, uncontrolled growth as well as detachment, contamination risks, monitoring of biomass, EPS, chemical and biological heterogeneity are considered.

Further reading: Microbial Biofilms: Current Research and Applications

Biofilms Applications in Bioremediation

Biofilms: Applications in Bioremediation

from Gabriele Pastorella, Giulio Gazzola, Seratna Guadarrama and Enrico Marsili writing in Microbial Biofilms: Current Research and Applications:

Bioremediation uses microorganisms to remove, detoxify, or immobilize pollutants, and does not require addition of harmful chemicals. Bioremediation is particularly suitable for large areas where contaminant concentrations are relatively low and the hydrology of the soil does not support an aggressive chemical remediation strategy. In the last few years, researchers have described the mechanisms of bioremediation for numerous priority pollutants, including chlorinated hydrocarbons, polyaromatic hydrocarbons, and heavy metals. However, most studies published to date have dealt with planktonic cultures grown under controlled laboratory conditions. Microorganisms in the environment occur mostly as biofilms, whose development is encouraged by the presence of solid surfaces and the limited amounts of organic carbon. Therefore, optimization of bioremediation processes in the field requires a thorough knowledge of biofilm structure, dynamic, and interaction with pollutants and other environmental factors. In this chapter, we describe the recent advances in bioremediation, with particular regard to the role of microbial biofilms. We discuss emerging technologies, such as bioelectroremediation and microbially produced surfactants. We also show how genetic engineering technologies may be employed to improve bioremediation effectiveness, both in laboratory and in field applications.

Further reading: Microbial Biofilms: Current Research and Applications

Biofilms in Wastewater Treatment Systems

Biofilms in Wastewater Treatment Systems

from G.A. Clark Ehlers and Susan J. Turner writing in Microbial Biofilms: Current Research and Applications:

Biofilms occur frequently inside various engineered systems for wastewater treatment. These include traditional trickling filter systems, modified lagoons, and specialized supplementary systems for nutrient removal or treatment of specialized wastes. The major advantages of biofilm systems over suspension treatment is the high microbial density that can be achieved, leading to smaller treatment system footprints, and the inherent development of aerobic, anoxic and anaerobic zones which enable simultaneous biological nutrient removal. The intrinsic resistance of biofilm communities to changing environmental conditions creates the added advantage that biofilm-based treatment systems are more resilient to influent variation in toxicity and nutrient concentrations. In contrast to biofilms of environmental or biomedical relevance comparatively little is known about development and stability in waste treatment systems. The advent of tools that enable the study of biofilms in reactor systems on a molecular level has enabled greater insight into the physiologically and biochemically relevant pathways that may facilitate optimized processes. In this chapter, the current literature on biofilms in wastewater treatment systems is reviewed and opportunities for further development in this field are identified.

Further reading: Microbial Biofilms: Current Research and Applications

Biofilms in Freshwater: Their Importance for the Maintenance and Monitoring of Freshwater Health

Biofilms in Freshwater: Their Importance for the Maintenance and Monitoring of Freshwater Health

from Gavin Lear, Andrew Dopheide, Pierre-Yves Ancion, Kelly Roberts, Vidya Washington, Jo Smith and Gillian D. Lewis writing in Microbial Biofilms: Current Research and Applications:

This chapter reviews our current understanding of the roles biofilm-associated microbial communities play in both maintaining and improving the ecological health of freshwater rivers and streams. Biofilms are where most of the bacteria present in freshwater systems are found, and have been identified as major sites for primary production, carbon and nutrient cycling. Advances in various scientific methodologies have recently been used to characterise the enormous diversity of biofilms, in terms of their structural, chemical and biological traits. The microbial life present within most natural biofilms, as well as associated exudates and lysates have been identified as a valuable, nutrient rich food source for a variety of benthic consumers. Furthermore, the diverse metabolic potential of these complex communities, in combination with various protective traits offered by the biofilm 'mode-of-life', provide biofilms with an excellent ability to degrade, or otherwise transform a vast array of freshwater pollutants. Despite this apparent resilience, we highlight the sensitivity of these poorly studied freshwater biofilm communities to various human activities, and consider their potential as a reliable and sensitive biological indicator of freshwater ecological health.

Further reading: Microbial Biofilms: Current Research and Applications

Biofilms in Disease

Biofilms in Disease

from James D. Bryers writing in Microbial Biofilms: Current Research and Applications:

Clinically related research on biofilms has expanded exponentially in the past ten years due to the pandemic of nosocomial (hospital-related) infections. Biofilms are thought to cause a significant amount of all human microbial infections, according to the Centers for Disease Control and Prevention. Nosocomial infections are the fifth leading cause of death in the U.S. with more than two million cases annually (or approximately 10% of American hospital patients). The difficulty of eradicating biofilm bacteria with classic systemic antibiotic treatments is a prime concern of medicine. Biofilm bacteria can be up to a thousand times less susceptible to antimicrobial stress than their freely suspended counterparts. This chapter discusses the pathogenesis of a number of biofilm-mediated infections, including: oral infections, biomedical device based infections, osteomyelitis, otitis media, and others. Emerging research in biofilm control and prevention is also reviewed.

Further reading: Microbial Biofilms: Current Research and Applications

An Invisible Workforce: Biofilms in the Soil

An Invisible Workforce: Biofilms in the Soil

from Mette Burmølle, Annelise Kjøller and Søren J. Sørensen writing in Microbial Biofilms: Current Research and Applications:

Biofilms in soil are composed of multiple species microbial consortia attached to soil particles and biotic surfaces including roots, fungal hyphae and decomposing organic material. The bacteria present in these biofilms gain several advantages including protection from predation, desiccation and exposure to antibacterial substances, and optimized acquisition of nutrients released in the mycosphere. Studies of soil biofilms are complicated by the composite structure of the soil environment; therefore, various simplified model systems have been applied to study succession and bacterial interactions in soil biofilms. Model system observations indicate an increased efficiency to degrade and decompose organic material and xenobiotic compounds by these multispecies bacterial communities. Consequently, soil biofilms may be valuable tools for bioremediation and biocontrol. However, soil biofilms may also provide survival sites for opportunistic pathogenic bacteria, providing enhanced protection and increasing their potential to survive and evolve in the soil environment. In this review, we provide evidence that biofilms are of major importance for the fitness of individual bacteria and the wider soil ecology, due to the accumulated selective advantage provided to bacteria by the biofilm mode-of-life.

Further reading: Microbial Biofilms: Current Research and Applications

Ins and Outs of the Bacillus subtilis Membrane Proteome

Ins and Outs of the Bacillus subtilis Membrane Proteome

from Jan Maarten van Dijl, Annette Dreisbach, Marcin J. Skwark, Mark J.J.B. Sibbald, Harold Tjalsma, Jessica C. Zweers and Girbe Buist writing in Bacillus: Cellular and Molecular Biology (Second edition):

Bacterial homeostasis is largely determined by a phospholipid bilayer that encloses the cytoplasm. The proteins residing in this cytoplasmic membrane are responsible for communication between the cytoplasm and extracytoplasmic cell compartments or the extracellular milieu of the cell. This chapter deals with the cytoplasmic membrane proteome of Bacillus subtilis. Specifically, we address current views on the roles of membrane proteins in homeostasis, their membrane targeting and retention signals, machinery for membrane insertion, localization of membrane proteins, membrane protein degradation and, finally, the identified and predicted composition of the B. subtilis membrane proteome. Known mechanisms and knowledge gaps are discussed to give a comprehensive overview of the ins and outs of the B. subtilis membrane proteome.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Microbial Biofilms book available very soon

The new book on Microbial Biofilms edited by Gavin Lear and Gillian D. Lewis will be available for dispatch within the next 2 or 3 weeks read more ...

Microbial Biofilms
Edited by: Gavin Lear and Gillian D. Lewis
ISBN: 978-1-904455-96-7
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
read more ...

Multicellularity and Social Behaviour in Bacillus subtilis

Multicellularity and Social Behaviour in Bacillus subtilis

from José Eduardo González-Pastor writing in Bacillus: Cellular and Molecular Biology (Second edition):

Most of the knowledge about Bacillus subtilis derives from studies of laboratory strains growing as planktonic cultures, in which all the individual cells are considered identical. Recently, the study of a natural and undomesticated isolate has revealed that B. subtilis cells display multicellular and social features that were lost in the laboratory strains, which were selected over generations for easy manipulation. In undomesticated strains, certain environmental conditions trigger cells of this bacterium to form multicellular communities where sporulation takes place, and to exhibit some particular social traits, like swarming motility and the fratricide of sibling cells or cannibalism during sporulation. Interestingly, some of these behaviours are based in the heterogeneity of the B. subtilis populations, which has been determined using cell biological techniques like fluorescence and light microscopy. This chapter outlines the genetic pathways governing the transition from a unicellular to a multicellular stage, swarming motility and cannibalism. The biological relevance of these alternative lifestyles is discussed.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Quorum Sensing and Social Interactions in Microbial Biofilms

Quorum Sensing and Social Interactions in Microbial Biofilms

from Robert J. Goldstone, Roman Popat, Matthew P. Fletcher, Shanika A. Crusz and Stephen P. Diggle writing in Microbial Biofilms: Current Research and Applications:

It is now well recognised that populations of bacteria from many Gram-positive and Gram-negative species cooperate and communicate to perform diverse social behaviours including swarming, toxin production and biofilm formation. Communication between bacterial cells involves the production and detection of diffusible signal molecules and has become commonly known as quorum sensing (QS). In addition, an evolutionary perspective on QS illuminates important phenomena which help in understanding the prevalence and diversity of QS phenotypes and strategies under various conditions. The research fields of QS and biofilm formation often overlap with a number of studies demonstrating that QS is an important regulatory mechanism of biofilm formation in a variety of bacterial species. However in contrast, there are conflicting reports, demonstrating that QS appears to play a minimal role in the development of biofilms. Our aim in this review is to highlight the key findings with respect to QS and the subsequent impact on biofilm formation. We also discuss QS and cooperation in the context of social evolution and how this may impact on the development and maintenance of microbial biofilms.

Further reading: Microbial Biofilms: Current Research and Applications

Replication of the Bacillus subtilis Chromosome

Replication of the Bacillus subtilis Chromosome

from Marie-Françoise Noirot-Gros, Patrice Polard and Philippe Noirot writing in Bacillus: Cellular and Molecular Biology (Second edition):

Eubacteria have evolved multicomponent protein machines, termed replisomes, which duplicate their chromosomes rapidly and accurately. Extensive studies in the model bacteria Escherichia coli and Bacillus subtilis have revealed that in addition to the replication core machinery, other proteins are necessary to form a functional replication fork. Specific subsets of proteins mediate: a) the assembly of the replisome at the chromosomal origin of replication [initiation]; b) the progression of the replication forks along the chromosome [elongation] and their maintenance by providing solutions for replication restart, which are adapted to overcome possible 'roadblocks' encountered on the DNA template; and c) the physiological arrest of replication when chromosome duplication is completed [termination]. Within the cell, DNA replication takes place within a factory positioned at the cell centre. This review summarises recent knowledge about chromosomal replication in Bacillus subtilis and related Gram-positive bacteria. It is focused on the events governing the assembly and the fate of the replication fork, describes protein networks connected with the replisome, and emphasises several novel aspects of DNA replication in this group of bacteria.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

RNA-mediated Regulation in Bacillus subtilis

RNA-mediated Regulation in Bacillus subtilis

from Wade C. Winkler writing in Bacillus: Cellular and Molecular Biology (Second edition):

Bacterial genetic regulation is generally assumed to occur at the level of transcription initiation through the use of transcription factors. Regulatory mechanisms that take place post-transcription initiation are sometimes treated as anomalies - as exceptions to the rule. However, the actual degree of usage for post-initiation regulatory strategies in bacteria still remains to be fully determined. As evidence to this fact, recent research has significantly expanded the general understanding of post-initiation regulation in Bacillus subtilis and other bacteria. Regulatory RNAs are now predicted to control expression of numerous fundamental biochemical pathways that together constitute greater than 4% of the B. subtilis genome. Therefore, post-initiation regulation is a vital layer of bacterial genetic circuitry that still remains to be fully revealed.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

The Actin-like MreB Cytoskeleton

The Actin-like MreB Cytoskeleton

from Rut Carballido-López writing in Bacillus: Cellular and Molecular Biology (Second edition):

Prokaryotic cells possess filamentous proteins, analogous to eukaryotic cytoskeletal proteins, that play a key role in the spatial organization of essential cellular processes. The bacterial homologues of actin (MreB, ParM, MamK and AlfA and Alps proteins) are involved in cell shape determination, DNA segregation, cell polarity, cell motility and other functions that require the targeting and accurate positioning of proteins and molecular complexes in the cell. In Bacillus subtilis, MreB homologues (MreB, Mbl and MreBH) assemble into dynamic helical-like structures along the sidewalls, which control morphogenesis by actively directing the growth of the cylindrical cell wall (elongation). The ultimate morphology of the cell is believed to depend on a dynamic interplay between the intracellular MreB proteins and the extracellular proteins that carry up cell wall biosynthesis and degradation, probably linked through MreCD and/or other membrane proteins such as RodZ. Recent findings rule out an essential function of the MreB isoforms of B. subtilis in chromosome segregation, but it is still possible that MreB is involved in this process. The general properties of the MreB proteins, relative to eukaryotic actin and to other prokaryotic homologues of actin, and the known functions of the MreB cytoskeleton in B. subtilis and other bacteria, will be discussed in this chapter.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

The Cell Wall of Bacillus subtilis

The Cell Wall of Bacillus subtilis

from Dirk-Jan Scheffers writing in Bacillus: Cellular and Molecular Biology (Second edition):

The cell wall of Bacillus subtilis is a rigid structure on the outside of the cell that forms the first barrier between the bacterium and the environment, and at the same time maintains cell shape and withstands the pressure generated by the cell's turgor. In this chapter, the chemical composition of peptidoglycan, teichoic and teichuronic acids, the polymers that comprise the cell wall, and the biosynthetic pathways involved in their synthesis will be discussed, as well as the architecture of the cell wall. B. subtilis has been the first bacterium for which the role of an actin-like cytoskeleton in cell shape determination and peptidoglycan synthesis was identified and for which the entire set of peptidoglycan synthesizing enzymes has been localised. The role of the cytoskeleton in shape generation and maintenance will be discussed and results from other model organisms will be compared to what is known for B. subtilis. Finally, outstanding questions in the field of cell wall synthesis will be discussed.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

The Ecological Significance of Plant-associated Biofilms

The Ecological Significance of Plant-associated Biofilms

from Venkatachalam Lakshmanan, Amutha Sampath Kumar and Harsh P. Bais writing in Microbial Biofilms: Current Research and Applications:

Microorganisms have historically been studied as planktonic or free-swimming cells, but most exist as sessile communities attached to surfaces, in multicellular assemblies known as biofilms. In the process of coping with both the pathogenic and beneficial interactions, the rhizosphere of plant roots encourages formation of sessile communities that begins with the attachment of free-floating microorganisms to a surface. Certain bacteria such as plant growth promoting rhizobacteria not only induce plant growth but also protect plants from soil-borne pathogens in a process known as biocontrol. Contrastingly, other rhizobacteria in a biofilm matrix may cause pathogenesis in plants. Although research suggests that biofilm formation on plants is associated with biological control and pathogenic response, little is known about how plants regulate this association. The scope of this chapter is restricted to biofilm-forming bacteria and their interactions with terrestrial plants, specifically emphasizing recent work. After an overview of documented interactions between bacteria and plant tissues, we examine some of the more prominent mechanisms of biofilm formation on and around plant surfaces.

Further reading: Microbial Biofilms: Current Research and Applications

The Organisation of Transcription and Translation

The Organisation of Transcription and Translation

from Peter Lewis and Xiao Yang writing in Bacillus: Cellular and Molecular Biology (Second edition):

The traditional view of transcription and translation within the cell was that of a very closely coupled process where translating ribosomes assembled on the nascent transcript as it was produced by transcribing RNA polymerase. Whilst this close physical coupling is undoubtedly important, it seems clear now that a number of other events are significant with respect to the physical organization of these two processes within the cell. Transcription is crudely segregated into two regions within the nucleoid where either stable (r- and t-) RNA, or mRNA transcription predominate. Translation by polysomes is probably enriched at cell poles, whereas the assembly of initiation complexes, and maybe some transcriptionally linked ribosomes may occur throughout the nucleoid.

Further reading: Bacillus: Cellular and Molecular Biology (Second edition)

Microbial Biofilms

Gavin Lear and Gillian D. Lewis (Lincoln University, Christchurch, New Zealand and University of Auckland, New Zealand, respectively) present a new book on Microbial Biofilms: Current Research and Applications
In this book, leading scientists provide an up-to-date review of the latest scientific research on these fascinating microbial communities and predict future trends and growth areas in biofilm-related research. Under the expert guidance of the editors Gavin Lear and Gillian Lewis, authors from around the world have contributed critical reviews on the most topical aspects of current biofilm research. Subjects covered include quorum sensing and social interactions in microbial biofilms, biofilms in disease, plant-associated biofilms, biofilms in the soil, applications in bioremediation, biofilms in wastewater treatment, corrosion and fouling, aquatic biofilms, microbial fuel cells, and catalytic biofilms. The book is essential for everyone interested in biofilms and their applications. It is also highly recommended for environmental microbiologists, soil scientists, medical microbiologists, bioremediation experts and microbiologists working in biocorrosion, biofouling, biodegradation, water microbiology, quorum sensing and many other areas read more ...
Microbial Biofilms
Edited by: Gavin Lear and Gillian D. Lewis
ISBN: 978-1-904455-96-7
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
read more ...

Microbial Biofilms

Gavin Lear and Gillian D. Lewis (Lincoln University, Christchurch, New Zealand and University of Auckland, New Zealand, respectively) present a new book on Microbial Biofilms: Current Research and Applications
In this book, leading scientists provide an up-to-date review of the latest scientific research on these fascinating microbial communities and predict future trends and growth areas in biofilm-related research. Under the expert guidance of the editors Gavin Lear and Gillian Lewis, authors from around the world have contributed critical reviews on the most topical aspects of current biofilm research. Subjects covered include quorum sensing and social interactions in microbial biofilms, biofilms in disease, plant-associated biofilms, biofilms in the soil, applications in bioremediation, biofilms in wastewater treatment, corrosion and fouling, aquatic biofilms, microbial fuel cells, and catalytic biofilms. The book is essential for everyone interested in biofilms and their applications. It is also highly recommended for environmental microbiologists, soil scientists, medical microbiologists, bioremediation experts and microbiologists working in biocorrosion, biofouling, biodegradation, water microbiology, quorum sensing and many other areas read more ...
Microbial Biofilms
Edited by: Gavin Lear and Gillian D. Lewis
ISBN: 978-1-904455-96-7
Publisher: Caister Academic Press
Publication Date: February 2012
Cover: hardback
read more ...

Symposium of the Danish Microbiological Society

November 9 - 9, 2010 Symposium of the Danish Microbiological Society
Copenhagen, Denmark Further information
Topice include Biofilms; Microbial stewards; Functional genomics; E.coli: Activity and interactions; Extremophiles and Food Microbiology. Besides the oral and poster presentations, the meeting will give scientists the possibility of getting acquainted with the newest laboratory equipment and consumables presented by the companies in a technical exhibition of suppliers and distributors in the field.
Suggested reading: Microbiology Books