scholarly journals Superresolution Imaging of Intact Microbial Communities Reveals Molecular Architecture of Biofilm Development and Bacterial Organization

2011 ◽  
Vol 100 (3) ◽  
pp. 617a ◽  
Author(s):  
Veysel Berk ◽  
Nicholas Fong ◽  
Graham Dempsey ◽  
Omer Develioglu ◽  
Xiaowei Zhuang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Molecular Architecture ◽  
Superresolution Imaging ◽  
Biofilm Development

scholarly journals Microbial biofilm in human health - an updated theoretical and practical insight

2017 ◽  
Vol 25 (1) ◽  
pp. 9-26
Author(s):  
Monica Licker ◽  
Roxana Moldovan ◽  
Elena Hogea ◽  
Delia Muntean ◽  
Florin Horhat ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Medical Devices ◽  
Microbial Biofilm ◽  
Organic Structure ◽  
New Methods ◽  
Microbial Biofilms ◽  
Biofilm Development ◽  
Antimicrobial Treatments ◽  
And Control

Abstract The term biofilm designates an aggregate of microorganisms belonging to one or more species which adhere to various surfaces but also to each another. These microbial communities are included and interconnected within an organic structure known as slime, composed of protein substances, polysaccharides, and DNA. The Center for Disease prevention and control considers infections with bacteria in biofilms among the 7 most important challenges which must be overcome in order to improve the safety of health services. The risk of microbial biofilm development exists for a long list of medical devices and equipment, as well as in certain diseases such as cystic fibrosis. An aggravating aspect is represented by the almost 1,000 times higher antimicrobial resistance of bacteria growing and multiplying within biofilms. Thus, in case of biofilm-infected medical devices, the resistance to antimicrobial treatments requires the removal of the device which essentially means the failure of the exploratory or therapeutic intervention in question. The role of microbial biofilms in medical pathology is a subject that raises interest for both researchers and clinicians in order to establish new methods for prevention and treatment of biofilms. This paper is intended as an overview in the management of microbial biofilms, presenting future insights, with technological progress in microscopy, molecular genetics, and genome analysis. Therefore the present paper will focus on describing the mechanisms involved in biofilm development, biofilm related infections, methods of detection and quantification of microbial communities and therapeutical approaches.

scholarly journals Role for Glycine Betaine Transport in Vibrio cholerae Osmoadaptation and Biofilm Formation within Microbial Communities

2005 ◽  
Vol 71 (7) ◽  
pp. 3840-3847 ◽  
Author(s):  
Dagmar Kapfhammer ◽  
Ece Karatan ◽  
Kathryn J. Pflughoeft ◽  
Paula I. Watnick
Keyword(s):  
Microbial Communities ◽  
Vibrio Cholerae ◽  
Glycine Betaine ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Compatible Solutes ◽  
Compatible Solute ◽  
Human Pathogen ◽  
Biofilm Development ◽  
Solute Transporters

ABSTRACT Vibrio cholerae is a halophilic facultative human pathogen found in marine and estuarine environments. Accumulation of compatible solutes is important for growth of V. cholerae at NaCl concentrations greater than 250 mM. We have identified and characterized two compatible solute transporters, OpuD and PutP, that are involved in uptake of glycine betaine and proline by V. cholerae. V. cholerae does not, however, possess the bet genes, suggesting that it is unable to synthesize glycine betaine. In contrast, many Vibrio species are able to synthesize glycine betaine from choline. It has been shown that many bacteria not only synthesize but also secrete glycine betaine. We hypothesized that sharing of compatible solutes might be a mechanism for cooperativity in microbial communities. In fact, we have demonstrated that, in high-osmolarity medium, V. cholerae growth and biofilm development are enhanced by supplementation with either glycine betaine or spent media from other bacterial species. Thus, we propose that compatible solutes provided by other microorganisms may contribute to survival of V. cholerae in the marine environment through facilitation of osmoadaptation and biofilm development.

scholarly journals Evaluation of biofilm development on various pipelines in the domestic hot water system

2017 ◽  
Vol 18 (2) ◽  
pp. 638-647 ◽  
Author(s):  
Huijin Zhang ◽  
Yanling Yang ◽  
Xing Li ◽  
Yongwang Liu ◽  
Li Zhao
Keyword(s):  
Microbial Communities ◽  
Biological Diversity ◽  
Growth Characteristics ◽  
Hot Water ◽  
Plate Count ◽  
Biofilm Growth ◽  
Domestic Hot Water ◽  
Biological Safety ◽  
Biofilm Development ◽  
Dominant Bacteria

Abstract Biological safety of hot water is important, and it is affected by pipeline material to a certain degree. Polypropylene random (PPR), polyvinyl chloride (PVC) and stainless steel (SS) are the common materials for pipelines in domestic hot water systems (DHWS), and biofilm growth characteristics, and biofilm microbial communities and biological diversity on the walls of pipelines are affected by the pipeline materials to a certain extent. In this paper, the effects of different materials on the growth characteristics and diversity of microbial communities were studied. The results showed that after about 60 days, the bacteria of the biofilm on the wall of pipelines completed a microbial growth cycle. Compared with PPR and SS, a greater amount of the total number of bacteria, Escherichia coli and heterotrophic plate count (HPC) attached to the PVC pipeline. Although the types of bacteria on the pipelines were similar, the proportions of species were different. Proteobacteria were the dominant bacteria at the phylum level on all the walls of the PPR, PVC and SS pipelines, and the dominant bacteria at the genus level changed before and after the exfoliation of biofilm. Some potential pathogens, such as Pseudomonas and Legionella, were detected in biofilm, so effective biofilm disinfection should be considered to ensure biological safety in DHWS.

scholarly journals Development of Biofilms for Antimicrobial Resistance

2020 ◽  
Author(s):  
Asma Bashir ◽  
Neha Farid ◽  
Kashif Ali ◽  
Kiran Fatima
Keyword(s):  
Antimicrobial Resistance ◽  
Quorum Sensing ◽  
Microbial Communities ◽  
Biofilm Formation ◽  
Genetic Transfer ◽  
Microbial Cells ◽  
Resistant Genes ◽  
Area Unit ◽  
Biofilm Development

Biofilms are a unit referred to as assemblage of microbial cells growing as surface-attached microbial communities within the natural surroundings. Their genetic and physiological aspects are widely studied. Biofilm development involves the assembly of extracellular compound substances that forms the most bailiwick network. Quorum sensing is one more crucial development specifically connected with biofilm formation in several microorganism species. In ecological purpose, the biofilm offers protection against unfavorable conditions and provides a platform for the genetic transfer. A biofilm-forming bacterium area unit is medically necessary, as they are resistant to several antibiotics and might spread resistant genes. This chapter provides the summary of microorganism biofilm formation and its significance in ecology.

scholarly journals Spatiometabolic Stratification of Shewanella oneidensis Biofilms

2006 ◽  
Vol 72 (11) ◽  
pp. 7324-7330 ◽  
Author(s):  
Tracy K. Teal ◽  
Douglas P. Lies ◽  
Barbara J. Wold ◽  
Dianne K. Newman
Keyword(s):  
Protein Synthesis ◽  
Microbial Communities ◽  
Alternative Hypothesis ◽  
Shewanella Oneidensis ◽  
Living Cells ◽  
Anaerobic Conditions ◽  
Fluorescent Reporters ◽  
Growth Activity ◽  
Biofilm Development

ABSTRACT Biofilms, or surface-attached microbial communities, are both ubiquitous and resilient in the environment. Although much is known about how biofilms form, develop, and detach, very little is understood about how these events are related to metabolism and its dynamics. It is commonly thought that large subpopulations of cells within biofilms are not actively producing proteins or generating energy and are therefore dead. An alternative hypothesis is that within the growth-inactive domains of biofilms, significant populations of living cells persist and retain the capacity to dynamically regulate their metabolism. To test this, we employed unstable fluorescent reporters to measure growth activity and protein synthesis in vivo over the course of biofilm development and created a quantitative routine to compare domains of activity in independently grown biofilms. Here we report that Shewanella oneidensis biofilm structures reproducibly stratify with respect to growth activity and metabolism as a function of size. Within domains of growth-inactive cells, genes typically upregulated under anaerobic conditions are expressed well after growth has ceased. These findings reveal that, far from being dead, the majority of cells in mature S. oneidensis biofilms have actively turned-on metabolic programs appropriate to their local microenvironment and developmental stage.

scholarly journals Profiling Signal Transduction in Global Marine Biofilms

2022 ◽  
Vol 12 ◽  
Author(s):  
Ruojun Wang ◽  
Weipeng Zhang ◽  
Wei Ding ◽  
Zhicong Liang ◽  
Lexin Long ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Microbial Communities ◽  
Red Sea ◽  
Interspecies Interactions ◽  
Marine Biofilms ◽  
Local Ecosystem ◽  
Biofilm Development ◽  
Almost All ◽  
Signal Transduction Genes ◽  
Signal Transduction Systems

Microbes use signal transduction systems in the processes of swarming motility, antibiotic resistance, virulence, conjugal plasmid transfer, and biofilm formation. However, the signal transduction systems in natural marine biofilms have hardly been profiled. Here we analyzed signal transduction genes in 101 marine biofilm and 91 seawater microbial metagenomes. The abundance of almost all signal transduction-related genes in biofilm microbial communities was significantly higher than that in seawater microbial communities, regardless of substrate types, locations, and durations for biofilm development. In addition, the dominant source microbes of signal transduction genes in marine biofilms were different from those in seawater samples. Co-occurrence network analysis on signal communication between microbes in marine biofilms and seawater microbial communities revealed potential inter-phyla interactions between microorganisms from marine biofilms and seawater. Moreover, phylogenetic tree construction and protein identity comparison displayed that proteins related to signal transductions from Red Sea biofilms were highly similar to those from Red Sea seawater microbial communities, revealing a possible biological basis of interspecies interactions between surface-associated and free-living microbial communities in a local marine environment. Our study revealed the special profile and enrichment of signal transduction systems in marine biofilms and suggested that marine biofilms participate in intercellular interactions of the local ecosystem where they were seeded.

scholarly journals Rhamnolipid Surfactant Production Affects Biofilm Architecture in Pseudomonas aeruginosa PAO1

2003 ◽  
Vol 185 (3) ◽  
pp. 1027-1036 ◽  
Author(s):  
Mary E. Davey ◽  
Nicky C. Caiazza ◽  
George A. O'Toole
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Microbial Communities ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Opportunistic Pathogen ◽  
Bacterial Cells ◽  
Intercellular Interaction ◽  
Environmental Signals ◽  
Biofilm Architecture ◽  
Biofilm Development

ABSTRACT In response to certain environmental signals, bacteria will differentiate from an independent free-living mode of growth and take up an interdependent surface-attached existence. These surface-attached microbial communities are known as biofilms. In flowing systems where nutrients are available, biofilms can develop into elaborate three-dimensional structures. The development of biofilm architecture, particularly the spatial arrangement of colonies within the matrix and the open areas surrounding the colonies, is thought to be fundamental to the function of these complex communities. Here we report a new role for rhamnolipid surfactants produced by the opportunistic pathogen Pseudomonas aeruginosa in the maintenance of biofilm architecture. Biofilms produced by mutants deficient in rhamnolipid synthesis do not maintain the noncolonized channels surrounding macrocolonies. We provide evidence that surfactants may be able to maintain open channels by affecting cell-cell interactions and the attachment of bacterial cells to surfaces. The induced synthesis of rhamnolipids during the later stages of biofilm development (when cell density is high) implies an active mechanism whereby the bacteria exploit intercellular interaction and communication to actively maintain these channels. We propose that the maintenance of biofilm architecture represents a previously unrecognized step in the development of these microbial communities.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

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