Name: biofilm growth and surface attachment
Uploaded: 2025-06-12T09:42:10.000Z
Duration: 1 min 29 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Biology

BIO.4

BIO.4.b

Biofilms

Un biofilm est un consortium microbien intégré dans une matrice polysaccharidique autoproduite attachée à une surface. La formation du biofilm se produit en quatre étapes : l’attachement, la colonisation, le développement et la dispersion. Lors de la fixation, les cellules planctoniques adhèrent à une surface. Lors de la colonisation, les cellules produisent des polysaccharides extracellulaires, formant une matrice collante qui les lie ensemble dans un biofilm. Au cours de la maturation, le biofilm se développe en structures multicouches, ce qui protège les micro-organismes des stress environnementaux. À l’occasion, certaines cellules peuvent se détacher et se disperser pour coloniser de nouvelles surfaces. Alors que la dispersion permet l’expansion du biofilm, la structure restante continue de résister aux défis externes, y compris les antibiotiques, en limitant la pénétration des médicaments et en réduisant l’activité métabolique au sein de la matrice. Cela permet aux biofilms d’échapper aux réponses immunitaires et de persister dans des maladies comme la mucoviscidose, où ils obstruent les voies respiratoires. D’autres effets nocifs comprennent la plaque dentaire, entraînant des caries dentaires, et les biofilms sur les dispositifs médicaux comme les cathéters, qui provoquent des infections. Les biofilms peuvent également offrir des avantages écologiques en décomposant la matière organique pour le cycle des nutriments et en soutenant le traitement des eaux usées par la dégradation des polluants.

biofilm

Les biofilms sont des communaut&#233;s complexes de micro-organismes enferm&#233;es dans une matrice extracellulaire polysaccharidique auto-produite et fix&#233;es aux surfaces. Ces consortiums microbiens peuvent r&#233;unir une ou plusieurs esp&#232;ces, ce qui conf&#232;re des avantages de survie accrus gr&#226;ce &#224; la formation de structures organis&#233;es et stratifi&#233;es.
La formation d&#8217;un biofilm se d&#233;roule en quatre &#233;tapes cl&#233;s : l&#8217;attachement, la colonisation, le d&#233;veloppement et la dispersion.
Lors de l&#8217;attachement, des cellules planctoniques libres adh&#232;rent &#224; une surface, souvent gr&#226;ce &#224; la communication intercellulaire, telle le quorum sensing, ou d&#233;tection du quorum. Ce m&#233;canisme permet aux bact&#233;ries de coordonner leurs comportements via la s&#233;cr&#233;tion de mol&#233;cules signal, entra&#238;nant leur agr&#233;gation. Vient ensuite la colonisation : les micro-organismes produisent des polysaccharides extracellulaires formant une matrice visqueuse. Celle-ci lie les cellules entre elles, &#233;tablissant ainsi le biofilm.
Au stade de maturation, le biofilm devient une structure complexe et multicouche, travers&#233;e de canaux aqueux assurant le transport des nutriments et des d&#233;chets. Ces adaptations structurales prot&#232;gent la communaut&#233; contre les stress environnementaux, y compris la p&#233;n&#233;tration des antibiotiques et les r&#233;ponses immunitaires. Parfois, des cellules se d&#233;tachent lors de la dispersion, ce qui favorise la colonisation de nouvelles surfaces et l&#8217;expansion du biofilm.
Les biofilms jouent des r&#244;les &#224; la fois &#233;cologiques et pathog&#232;nes. Ils contribuent au cycle des nutriments en d&#233;gradant la mati&#232;re organique et sont essentiels au traitement des eaux us&#233;es par la d&#233;gradation des polluants. Cependant, leur pathog&#233;nicit&#233; repr&#233;sente un risque sanitaire majeur : ils obstruent les voies respiratoires chez les patients atteints de mucoviscidose (souvent par Pseudomonas aeruginosa) et forment la plaque dentaire (principalement par Streptococcus mutans) &#224; l&#8217;origine des caries. Sur les dispositifs m&#233;dicaux, tels que les cath&#233;ters, les biofilms engendrent des infections persistantes en raison de leur r&#233;sistance aux antibiotiques.
Pr&#233;venir la formation de biofilms reste difficile. Les strat&#233;gies incluent l&#8217;utilisation de la lactoferrine, qui inhibe l&#8217;agr&#233;gation bact&#233;rienne en ch&#233;latant le fer, ainsi que la conception de surfaces antimicrobiennes pour r&#233;duire l&#8217;adh&#233;sion. Les recherches se poursuivent sur les m&#233;canismes mol&#233;culaires du quorum sensing et son r&#244;le dans la r&#233;sistance des biofilms afin de d&#233;velopper des interventions plus efficaces. Comprendre la dynamique des biofilms s&#8217;av&#232;re indispensable pour g&#233;rer leurs r&#233;percussions industrielles et m&#233;dicales.

Biofilm

Les biofilms sont des communaut&#233;s complexes de micro-organismes enferm&#233;es dans une matrice extracellulaire polysaccharidique auto-produite et ...

Education

Enseignement

JoVE Core

Microbiology

Microbiologie

Unit

Unité

Microbial Growth      

Croissance microbienne

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

biofilm growth and surface attachment

Biofilms are communities of microorganisms that attach to a surface and build a self-made sticky matrix around themselves. This matrix is made of extracellular polysaccharides, which are sugar-based substances secreted by the cells. Biofilms may contain one species or several species, and their organized layers help the microbes survive better together.

Biofilm formation happens in four main stages: attachment, colonization, development, and dispersal. In the first stage, free-swimming planktonic cells stick to a surface. Cell-to-cell communication called quorum sensing often helps this process by using signaling molecules to coordinate bacterial behavior and promote cell aggregation.

During colonization, the microorganisms release extracellular polysaccharides that create the matrix holding the cells in place. The biofilm then matures into a multilayered structure with water channels. These channels move nutrients in and waste out, while the overall structure helps protect the community from environmental stress, including antibiotics and immune responses.

Biofilms also have a dispersal stage. At this point, some cells leave the biofilm and move to new surfaces, which allows the community to spread. This ability, along with its protective matrix, makes the biofilm a resilient form of microbial growth.

Biofilms can be helpful in nature and in industry. They help break down organic matter and support nutrient cycling. They are also important in wastewater treatment because they can help degrade pollutants. At the same time, biofilms can cause problems in the body. They can block airways in cystic fibrosis patients, often because of Pseudomonas aeruginosa, and dental plaque is a biofilm mainly formed by Streptococcus mutans that leads to tooth decay.

Biofilms are also a major concern on medical devices such as catheters, where they can cause long-lasting infections that are hard to treat with antibiotics. Preventing them is difficult. Strategies include lactoferrin, which blocks bacterial aggregation by binding iron, and antimicrobial surfaces that reduce attachment. Scientists continue to study quorum sensing and biofilm resistance to find better ways to stop them.

Biofilm Growth and Surface Attachment

binary fission

Bacterial Cell Division by Binary Fission

Binary fission is the main way prokaryotes, such as bacteria, reproduce asexually. It produces two daughter cells that are genetically identical. When conditions are favorable, this process helps bacterial populations grow quickly. The process starts when the bacterial chromosome is copied. The circular DNA unwinds at a specific origin of replication called oriC. DNA polymerases then build matching strands in both directions until replication reaches the terminus. This creates two identical...

generation time

Bacterial Doubling Time

Bacterial generation time is the time needed for a bacterial population to double during exponential growth. It is a useful measure of microbial growth under optimal conditions. The rate can vary a lot from one species to another, and it can be affected by temperature, pH, and nutrient availability. Some bacteria grow quickly, while others grow much more slowly. Escherichia coli can have a generation time of about 20 minutes. Mycobacterium tuberculosis has a much longer doubling time, often 12...

bacterial growth curve

Stages of Bacterial Population Growth

Bacterial population growth in a closed system follows a set pattern called the bacterial growth curve. It describes how a bacterial population changes when temperature and nutrient levels are controlled. The curve has four phases: lag, log, stationary, and death. The lag phase is the first stage. During this time, bacteria adjust to their new environment. They make enzymes and other needed molecules for cell division, but the number of cells changes very little. This step prepares the...

microbial growth measurement: direct methods

microbial-growth-measurement-direct-methods

Counting Microbes with Direct Methods

Counting microbes with direct methods gives a fast way to measure how many cells are in a culture. In microbiology, these methods provide quantitative data for research and diagnostics. The main approaches are microscopic counts, plate counts, and serial dilution. Microscopic counting uses a Petroff-Hausser chamber, which is a special microscope slide with a grid and a known depth. A liquid culture is viewed under the microscope, and the cells in the grid are counted to estimate cell density...

microbial growth measurement: indirect methods

microbial-growth-measurement-indirect-methods

Measuring Microbial Growth Without Counting

Measuring microbial growth with indirect methods helps scientists estimate population size without counting every cell. These methods track signs of growth such as turbidity, metabolic activity, and biomass. They are useful because they are efficient and can give reproducible results. Turbidity is one common approach. During exponential growth, microbial cells scatter light in proportion to their biomass. A spectrophotometer measures this as optical density, or OD, also called absorbance.

microbial growth media

Selecting Microbial Growth Media

Microbial growth media give microorganisms the nutrients and conditions they need to grow in the lab. These media let scientists study microbial physiology, behavior, and interactions. Choosing the right medium is important for research, diagnosis, food safety, and environmental studies. Growth media can be solid, liquid, or semisolid. Solid media, often made with agar, support visible colony growth so microbes can be isolated and counted. Liquid media support even growth throughout the tube...

need for obtaining pure cultures

Isolating and Preserving Pure Cultures

Pure cultures are single microorganism species grown apart from mixed samples. They help scientists study microbes with the same genetic and physical traits under controlled conditions. This makes pure cultures important in microbiology research and in many real-world uses. To obtain a pure culture, a single microbial type must first be separated from a mixed population. Common methods include serial dilution, streak plating, pour plating, and spread plating. The chosen sample is then placed...

techniques for isolation of pure cultures

techniques-for-isolation-of-pure-cultures

Microbial Colony Isolation Methods

Microbial colony isolation methods are used to grow, separate, and count microorganisms in the laboratory. These techniques depend on placing microbes into a suitable growth medium under aseptic conditions, which help prevent contamination. The inoculum, or sample added to the medium, may be transferred directly or prepared as a diluted bacterial suspension. The streak-plate method is a common way to obtain pure microbial colonies. In this method, a sample is spread across the agar surface in...

factors influencing microbial growth: ph

Microbial pH Preferences and Growth Adaptation

Microbial growth depends on pH, the measure of how acidic or alkaline an environment is. Different microorganisms grow best in different pH ranges. Their ability to keep a stable internal pH helps protect enzymes and other macromolecules. External pH changes can challenge that balance. Neutrophiles grow best near neutral pH, usually between 5.5 and 8.0. Escherichia coli is a common example. These microbes often live in neutral or slightly acidic places. They can use potassium-proton exchange...

factors influencing microbial growth: temperature

factors-influencing-microbial-growth-temperature

Microbial Growth at Different Temperatures

Temperature shapes microbial growth by changing enzyme activity, membrane fluidity, and other cell processes. Each microorganism has a minimum, optimum, and maximum temperature range. Below the minimum, membranes lose fluidity and transport stops. Above the maximum, proteins denature and membranes break down. At the optimum temperature, enzyme reactions run fastest and growth is highest. Microorganisms are grouped by the temperatures they prefer. Psychrophiles grow in cold environments from...

factors influencing microbial growth: osmolarity

factors-influencing-microbial-growth-osmolarity

Microbes and Water Availability in Salty Environments

Microbes and water availability in salty environments are closely linked to osmolarity, which is the measure of solute concentration in a solution. Osmolarity helps determine how much water is available for living things. Water moves across semipermeable membranes by osmosis. It flows from a more dilute area to a more concentrated one. When the outside environment has a high solute level, microbial cells lose water. This can cause dehydration and slow or stop growth. The amount of water...

oxygen requirements and growth patterns

Microbial Oxygen Needs and Tolerance

Microbial oxygen needs and tolerance shape how bacteria grow and survive. Oxygen can support energy production in some microorganisms, but it can also become harmful in certain environments. These differences help explain why microbes live in very specific places. Microorganisms are grouped by how they use oxygen. Obligate aerobes, such as Mycobacterium tuberculosis, need oxygen because it serves as the terminal electron acceptor in aerobic respiration. Obligate anaerobes, such as Clostridium...

biofilms

Biofilms are communities of microorganisms that attach to a surface and build a self-made sticky matrix around themselves. This matrix is made of extracellular polysaccharides, which are sugar-based substances secreted by the cells. Biofilms may contain one species or several species, and their organized layers help the microbes survive better together. Biofilm formation happens in four main stages: attachment, colonization, development, and dispersal. In the first stage, free-swimming...

key terms and concepts

Explore how biofilms form, mature, and spread, plus why they matter in wastewater treatment, dental plaque, infections, and antibiotic resistance.

Biofilm Growth and Surface Attachment | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

Introduction to Virus

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Size and Structure of Viral Genomes

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Viral Replication: Lytic Cycle

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Viral Replication: Lysogenic Cycle

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DNA Bacteriophages

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Viruses of Archaea

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the-antiviral-system-of-bacteria-and-archaea-crispr

The Antiviral System of Bacteria and Archaea: CRISPR

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CRISPR/Cas9 Genome Editing

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Subviral Agents

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The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  viruses depend on a host for metabolic processes;

BIO.4.a

Binary Fission

Binary fission is the primary mode of asexual reproduction in prokaryotes, such as bacteria. It results in the production of two genetically identical ...

Generation Time

Bacterial generation time, the period required for a bacterial population to double during its exponential growth phase, serves as a critical measure of ...

Bacterial Growth Curve

The bacterial growth curve is a fundamental concept in microbiology that describes the dynamics of bacterial population growth in a closed system with ...

Microbial Growth Measurement: Direct Methods

Direct methods for measuring microbial populations in a culture are essential tools in microbiology, providing quantitative data for various applications. ...

Microbial Growth Measurement: Indirect Methods

Estimating microbial growth is essential for understanding population dynamics and environmental adaptations. Indirect methods provide valuable insights ...

Microbial Growth Media

Microbial growth media are essential tools in microbiology, providing the nutrients and conditions necessary to cultivate and study microorganisms. These ...

Need for Obtaining Pure Cultures

Pure cultures, defined as the growth of a single microorganism species isolated from mixed populations, are fundamental tools in microbiological research ...

Techniques for Isolation of Pure Cultures

Microorganisms are routinely cultured in the laboratory using various techniques to isolate, grow, and quantify them for further study. These methods rely ...

Factors Influencing Microbial Growth: pH

Microorganisms are classified as acidophiles, neutrophiles, or alkaliphiles based on their pH growth preferences, reflecting their adaptations to specific ...

Factors Influencing Microbial Growth: Temperature

Microorganisms display remarkable adaptations, enabling them to thrive in diverse ecological niches across a wide range of temperatures. Temperature ...

Factors Influencing Microbial Growth: Osmolarity

Osmolarity is the measure of solute concentration in a solution. It plays a critical role in determining water availability for organisms. Water moves ...

Oxygen Requirements and Growth Patterns

Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while ...

Biofilms are complex communities of microorganisms encased in a self-produced extracellular polysaccharide matrix attached to surfaces. These microbial ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include the modes of reproduction/replication can be compared

Prokaryotic vs. Eukaryotic Cells

Prokaryotic and eukaryotic cells represent two fundamental types of cellular organization, differing significantly in structure, complexity, and function. ...

Microbial Morphologies 

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Bacterial Cell Wall 

The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and ...

Archaeal Cell Wall

Archaeal cell walls are structurally and compositionally distinct from their bacterial counterparts, lacking the characteristic peptidoglycan layer found ...

Peptidoglycan Synthesis

Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. ...

Plasma Membrane in Bacteria and Archaea

The plasma membrane is an essential cellular structure responsible for maintaining cellular integrity and regulating the selective transport of molecules. ...

Outer Layers of the Cell Envelope

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Flagella and Motility in Bacteria

Flagella are specialized, thread-like structures that extend from a bacteria's cell envelope. They play a crucial role in motility and chemotaxis. Their ...

Fimbriae, Pili, and Axial Filaments

Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of ...

Cell Inclusions

Prokaryotic cells possess a variety of inclusions that play crucial roles in nutrient storage, metabolic processes, and environmental adaptation. These ...

Endospores and Sporulation

Endospores are specialized, dormant cells primarily formed by Gram-positive bacteria, including Bacillus and Clostridium, enabling survival under extreme ...

Nucleoid

The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. ...

Surface Appendages of Archaea

Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  the structures and functions can be compared

BIO.4.c

Types of Microorganisms

Microorganisms are a diverse group of microscopic entities broadly categorized into cellular and acellular types based on their structural organization. ...

environmental-applications-of-microorganisms

Environmental Applications of Microorganisms

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community-dna-extraction-from-bacterial-colonies

Community DNA Extraction from Bacterial Colonies

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Demonstrating Author: Luisa Ikner
Traditional methods of analysis ...

detecting-environmental-microorganisms-with-polymerase-chain-reaction

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RNA Analysis of Environmental Samples Using RT-PCR

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Reverse ...

quantifying-environmental-microorganisms-and-viruses-using-qpcr

Quantifying Environmental Microorganisms and Viruses Using qPCR

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Demonstrating Author: Bradley Schmitz
Quantitative polymerase ...

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Water Quality Analysis via Indicator Organisms

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Water quality analysis monitors ...

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Isolation of Fecal Bacteria from Water Samples by Filtration

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
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The quality of water destined ...

detection-of-bacteriophages-in-environmental-samples

Detection of Bacteriophages in Environmental Samples

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Viruses are a unique group of ...

culturing-and-enumerating-bacteria-from-soil-samples

Culturing and Enumerating Bacteria from Soil Samples

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Surface ...

bacterial-growth-curve-analysis-and-its-environmental-applications

Bacterial Growth Curve Analysis and its Environmental Applications

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
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Bacteria are among the most ...

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BIO.4.d

History of Microbiology

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Infection

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Defense Mechanism Against Infection

Natural flora, body system defenses, and inflammation are natural barriers of the body against infectious agents regardless of previous exposure. Normal ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  the germ theory of infectious disease is supported by evidence.

BIO.4.e

Biofilm Growth and Surface Attachment

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