Name: microorganism groups and their roles
Uploaded: 2025-06-12T09:27:08.000Z
Duration: 1 min 29 s
Channel: JoVE

K12 Standards

Tennessee Academic Standards

Earth and Space Sciences

Earth's Systems

D. Weather and Climate

Types of Microorganisms

Les micro-organismes sont classés en types cellulaires et acellulaires. Les formes cellulaires comprennent les bactéries, les archées, les champignons, les protozoaires et les algues, tandis que les formes acellulaires sont constituées de virus. Les bactéries sont des procaryotes unicellulaires aux formes et adaptations métaboliques diverses, qui prospèrent dans des environnements allant du sol à l’intestin humain. Exemples : E. coli et Streptococcus. Les archées, également procaryotes, prospèrent dans des environnements extrêmes, comme les sources chaudes, et dans des environnements modérés, comme les sols, les océans et les microbiomes humains. Les champignons sont des eucaryotes de formes unicellulaires et multicellulaires. Ils décomposent la matière organique, recyclent les nutriments et soutiennent la croissance des plantes via des associations mycorhiziennes. Les protozoaires, tels que Amoeba et Plasmodium, sont des eucaryotes unicellulaires. Certains vivent librement, tandis que d’autres sont parasites et peuvent provoquer des maladies. Les algues sont des eucaryotes photosynthétiques qui produisent de l’oxygène et soutiennent les réseaux trophiques aquatiques. Les virus sont des entités acellulaires constituées de matériel génétique à l’intérieur d’une enveloppe protéique. Les virus dépendent des cellules hôtes pour se répliquer, provoquant des infections et des maladies.

types de micro-organismes

Les micro-organismes constituent un groupe diversifi&#233; d&#8217;entit&#233;s microscopiques, class&#233;es de mani&#232;re g&#233;n&#233;rale en types cellulaires et acellulaires selon leur organisation structurale. Les micro-organismes cellulaires comprennent les bact&#233;ries, les arch&#233;es, les champignons, les protozoaires et les algues, tandis que les micro-organismes acellulaires sont repr&#233;sent&#233;s par les virus.
Micro-organismes cellulaires
Les bact&#233;ries
Les bact&#233;ries, minuscules organismes procaryotes, pr&#233;sentent des formes fascinantes telles que des b&#226;tonnets, des sph&#232;res et des spirales. Elles s&#8217;adaptent &#224; divers habitats, notamment le sol, l&#8217;eau et des environnements associ&#233;s &#224; l&#8217;&#234;tre humain, comme le microbiote intestinal. Certaines bact&#233;ries, telles que Escherichia coli et Streptococcus, jouent un r&#244;le majeur dans la sant&#233; humaine et les &#233;cosyst&#232;mes. D&#8217;autres, comme le Rhizobium et l&#8217;Azotobacter, participent &#224; des processus essentiels tels que la fixation de l&#8217;azote, enrichissant ainsi la fertilit&#233; des sols.
Les arch&#233;es
Les arch&#233;es, comme les bact&#233;ries, sont des organismes procaryotes. Elles sont r&#233;put&#233;es pour prosp&#233;rer dans des milieux extr&#234;mes, tels que les sources hydrothermales et les eaux hautement salines, tout en colonisant &#233;galement des habitats plus mod&#233;r&#233;s comme les sols et les oc&#233;ans. Les m&#233;thanog&#232;nes, un groupe sp&#233;cialis&#233; d&#8217;arch&#233;es, suivent des voies biochimiques uniques, notamment la production de m&#233;thane, qui est un ph&#233;nom&#232;ne d&#8217;une importance &#233;cologique et industrielle cruciale.
Les champignons
Les champignons sont des organismes eucaryotes qui existent sous des formes unicellulaires, comme les levures, et pluricellulaires, telles que les moisissures ou les champignons macroscopiques. Ils jouent un r&#244;le essentiel de d&#233;composeurs dans les &#233;cosyst&#232;mes, recyclant la mati&#232;re organique et formant des associations symbiotiques mycorhiziennes qui am&#233;liorent l&#8217;absorption des nutriments par les plantes. Les champignons ont &#233;galement d&#8217;immenses applications industrielles, notamment dans la production d&#8217;antibiotiques et d&#8217;aliments ferment&#233;s.
Les protozoaires
Les protozoaires sont des eucaryotes unicellulaires aux modes de vie vari&#233;s. Ils peuplent divers environnements, y compris le sol et les syst&#232;mes aquatiques, o&#249; ils assurent des fonctions &#233;cologiques telles que la pr&#233;dation des bact&#233;ries et servent de proies &#224; des organismes de rang trophique sup&#233;rieur. Les protozoaires libres, tels que l&#8217;Amoeba, contribuent au recyclage des nutriments, tandis que les protozoaires parasites, comme le Plasmodium, sont des pathog&#232;nes qui provoquent des maladies telles que le paludisme.
Les algues
Les algues, autre groupe d&#8217;eucaryotes, sont des organismes photosynth&#233;tiques essentiels aux &#233;cosyst&#232;mes aquatiques. Des exemples notables incluent les diatom&#233;es et Chlorella. Elles produisent de l&#8217;oxyg&#232;ne et constituent la base des r&#233;seaux trophiques aquatiques, soutenant les niveaux trophiques sup&#233;rieurs. Les algues jouent &#233;galement un r&#244;le crucial dans le maintien de l&#8217;&#233;quilibre des gaz atmosph&#233;riques en lib&#233;rant de l&#8217;oxyg&#232;ne.
Micro-organismes acellulaires
Les virus	
Les virus, consid&#233;r&#233;s comme des entit&#233;s acellulaires, se situent &#224; la fronti&#232;re du vivant et du non-vivant. Compos&#233;s de mat&#233;riel g&#233;n&#233;tique enferm&#233; dans une capside prot&#233;ique, les virus d&#233;pendent enti&#232;rement des cellules h&#244;tes pour leur r&#233;plication. Leurs interactions avec les h&#244;tes varient du b&#233;nin au pathog&#232;ne, comme le montrent les virus responsables de la grippe, du VIH et d&#8217;autres infections. Malgr&#233; leur simplicit&#233;, les virus pr&#233;sentent d&#8217;importantes applications en biotechnologie, notamment dans le d&#233;veloppement de vaccins et la th&#233;rapie g&#233;nique.

Types de micro-organismes

Les micro-organismes constituent un groupe diversifi&#233; d&#8217;entit&#233;s microscopiques, class&#233;es de mani&#232;re g&#233;n&#233;rale en types ...

Education

Enseignement

JoVE Core

Microbiology

Microbiologie

Unit

Unité

Introduction to Microbiology

Introduction à la microbiologie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

microorganism groups and their roles

Microorganisms are tiny life forms and particles that can be grouped by structure. Cellular microorganisms include bacteria, archaea, fungi, protozoa, and algae. Viruses are acellular, which means they are not made of cells.

Bacteria are prokaryotic organisms, so they do not have a nucleus. They can be rod-shaped, spherical, or spiral-shaped. Bacteria live in soil, water, and human-associated places like the gut. Some, such as Escherichia coli and Streptococcus, are important in health and ecosystems. Others, like Rhizobium and Azotobacter, help fix nitrogen and improve soil fertility.

Archaea are also prokaryotes. Many are known for living in extreme places such as hydrothermal vents and highly saline waters. They also live in more common habitats, including soils and oceans. Methanogens are a special group of archaea that produce methane, which matters in ecology and industry.

Fungi are eukaryotic organisms, which means their cells have a nucleus. They can be unicellular, like yeast, or multicellular, like molds and mushrooms. Fungi act as decomposers by recycling organic matter. They also form mycorrhizal partnerships that help plants absorb nutrients. People also use fungi to make antibiotics and fermented foods.

Protozoa are single-celled eukaryotes with varied lifestyles. They live in soil and aquatic environments. Some protozoa eat bacteria, and others serve as food for larger organisms. Free-living protozoa, such as Amoeba, help with nutrient cycling. Parasitic protozoa, such as Plasmodium, can cause malaria.

Algae are eukaryotic organisms that use photosynthesis. Examples include diatoms and Chlorella. They are important in aquatic ecosystems because they produce oxygen and form the base of many food webs. This makes them key to the balance of gases in the atmosphere.

Viruses are acellular and contain genetic material inside a protein coat. They cannot replicate on their own and must use host cells to make more viruses. Some viruses are harmful and cause illnesses such as flu and HIV infection. Even so, viruses are useful in biotechnology, including vaccine development and gene therapy.

Microorganism Groups and Their Roles

history of microbiology

Microbiology's Key Discoveries Over Time

Microbiology is the study of microorganisms, and its history is shaped by major discoveries about life at the microscopic level. Since the 17th century, new tools and experiments have changed how scientists understand microbes and their effects on medicine, agriculture, and industry. The early foundations of microbiology began with better microscopes and careful observation. In 1665, Robert Hooke examined thin slices of cork with a crude microscope and described the small boxlike spaces he saw.

two-dimensional microscopy in microbiology

two-dimensional-microscopy-in-microbiology

Microscopy Methods for Viewing Microbes

Two-dimensional microscopy helps scientists view microbes and cells in a single focal plane. It is widely used in biological and medical research because it shows cellular and subcellular structures with different levels of contrast and detail. Each method has its own strengths, so the best choice depends on the specimen and the question being studied. Bright-field microscopy is the most common form of light microscopy. It uses transmitted light that passes through the specimen, and stains are...

three-dimensional microscopy in microbiology

three-dimensional-microscopy-in-microbiology

Live and Deep Cell Imaging Methods

Three-dimensional imaging methods help scientists see cell structures with more detail. In microbiology, Differential Interference Contrast Microscopy, or DIC, and Confocal Scanning Laser Microscopy, or CSLM, are two important tools. They each solve different imaging problems and give useful views of cells and tissues. DIC microscopy improves contrast in transparent, unstained samples. It works by turning phase differences, which come from changes in refractive index inside cell structures,...

simple staining technique

Staining Microbes for Shape and Arrangement

Simple staining helps reveal the size, shape, and arrangement of microorganisms under the microscope. It uses one dye to color the whole cell. That creates strong contrast between the cells and the background. A careful preparation step comes first. A small drop of microbial culture is spread on a clean glass slide to make a thin smear. The smear is air-dried and then heat-fixed, which means it is briefly passed over a flame. Heat fixation keeps the cells attached to the slide. It also helps...

differential staining technique

Gram and Acid-Fast Staining Methods

Gram and acid-fast staining methods help scientists tell bacteria apart by looking at their cell walls. These differential stains are important in microbiology because they support identification, diagnosis, and research. They use structural and chemical differences in bacterial cell walls to separate microorganisms into clear groups. Gram staining classifies bacteria as gram-positive or gram-negative. A heat-fixed bacterial smear is first stained with crystal violet, and iodine is added to...

special staining techniques

Bacterial Stains for Capsules, Spores, Flagella

Special bacterial stains help reveal capsule, endospore, and flagella structures that standard microscopy cannot show clearly. These stains improve how microbiologists identify bacteria and understand features linked to disease and classification. They are also useful in diagnosis and research because they expose key parts of bacterial cells. Capsule staining is a negative staining method that makes the capsule visible. A bacterial capsule is an outer layer that can act as a virulence factor,...

key techniques in microbiology

Aseptic Methods for Microbial Cultures

Aseptic methods help keep microbial cultures clean, safe, and accurate in the laboratory. These practices reduce contamination and protect both researchers and the microbes being studied. They are important in clinical, industrial, and research settings where sterility matters. Laboratory sterility starts with cleaning tools and surfaces. Scientists sterilize equipment with heat or chemicals and disinfect work areas before handling cultures. They also work near an open flame or inside a...

types of microorganisms

Microorganisms are tiny life forms and particles that can be grouped by structure. Cellular microorganisms include bacteria, archaea, fungi, protozoa, and algae. Viruses are acellular, which means they are not made of cells. Bacteria are prokaryotic organisms, so they do not have a nucleus. They can be rod-shaped, spherical, or spiral-shaped. Bacteria live in soil, water, and human-associated places like the gut. Some, such as Escherichia coli and Streptococcus, are important in health and...

environmental applications of microorganisms

environmental-applications-of-microorganisms

Microbes in Ecosystems and Pollution Control

Microorganisms help keep ecosystems balanced by recycling carbon, nitrogen, and phosphorus. They also support sewage treatment, bioremediation, and biofuel production. These roles make microbes important in both natural and human-made systems. In the carbon cycle, microorganisms break down dead organic matter. During aerobic respiration, they release carbon dioxide. Photosynthetic organisms then use that carbon dioxide to make organic compounds, which helps close the carbon loop. Microbes are...

microorganisms in agriculture and food industry

microorganisms-in-agriculture-and-food-industry

How Microbes Improve Farming and Food

Microbes improve farming and food production by helping plants grow, protecting crops, and making foods such as bread, yogurt, and pickles. These tiny organisms support soil fertility, pest control, fermentation, and food preservation. They are a key part of sustainable agriculture and food safety. In agriculture, nitrogen-fixing bacteria turn nitrogen from the air into ammonia, which plants can use to build amino acids and proteins. Rhizobium lives with plant roots, while Azotobacter is...

microorganisms in medicine and therapeutics

microorganisms-in-medicine-and-therapeutics

Microbes in Vaccines and Gene Therapy

Microbes in vaccines and gene therapy help modern medicine prevent disease and treat genetic disorders. Scientists use the biological properties of microorganisms to support public health, improve immune protection, and make therapeutic products. These uses also include gut health and antibiotic production. Live attenuated vaccines use weakened pathogens, such as the measles, mumps, and rubella (MMR) vaccine. They act like a natural infection and can trigger cellular, humoral, and mucosal...

key terms and concepts

Explore bacteria, archaea, fungi, protozoa, algae, and viruses. Learn how these microorganisms live, support ecosystems, and affect health and biotechnology.

Microorganism Groups and Their Roles | 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

Louisiana Student Standards for Science

High School

Life Sciences

from-molecules-to-organisms-structures-and-processes

From Molecules To Organisms: Structures And Processes

HS-LS1-8

Virginia  Standards of Learning

HIgh School

Biology

BIO.4

BIO.4.d

new-york-state-science-learning-standards

New York State Science Learning Standards

Middle School

Weather and Climate

MS-ESS2-5

MS-ESS2-6

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

Earth and Space Science

6-ESS2-5

6-ESS2-6

Earth and Human Activity

7-ESS3-5

Convection

Convection is the transfer of heat through fluids (liquids or gases) caused by the movement of molecules. It occurs when warmer, less dense parts of a

Density and Volume

Density and volume are important properties that help us understand the nature of matter. Volume measures the amount of space an object occupies, whil

Solar Energy on Earth

The Sun is the main source of energy for life on Earth. This energy travels through space in the form of electromagnetic radiation. It moves in waves 

Gather evidence to justify that oceanic convection currents are caused by the sun's transfer of heat energy and differences in salt concentration leading to global water movement.
EXPLANATION: Understanding of ocean convection currents requires that students are familiar with: unequal heating of the earth's surface (built from 5.ess1.5), the density-related rise of heated fluids, and the density-related descent of cooler fluids. From third grade, students will have developed understandings of mass and volume; however, the topic of density will need to be explored to fully support 6.ESS2.1 and 6.ESS2.2. Demonstrations of the temperature-based behavior can be performed by heating one side of a water-filled baking dish and cooling the opposite side. If the water is initially allowed to settle, drops of food coloring will trace out the convection patterns which develop. Pipets can be used to insert the food coloring into the lower currents. Models for the effect of salt on creating a sinking mass of water can be accomplished by partially filling a large container with water then covering the surface of the water with plastic wrap and pouring an additional volume of salt-containing, colored water onto the wrap. With the gentle removal of the plastic wrap, the mixing will be visible. Reversing the order that the waters are added will provide alternate effects, and finally using two samples with coloring but no salt can provide a control. (Calculations of density are beyond the scope of this standard.)

c-the-roles-of-water-in-earth-s-surface-processes

C. The Roles of Water in Earth's Surface Processes

Circulation in the Atmosphere

Atmospheric circulation is the large-scale movement of air that helps distribute heat and moisture around the Earth. This circulation is driven by sol

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

Solar Energy and Latitude

The amount of solar energy that reaches different parts of the Earth’s surface depends on latitude. Areas near the equator receive more direct sunligh

Heat Transfer in the Atmosphere

The Sun heats Earth’s surface, and that energy is then transferred throughout the atmosphere in different ways. Heat moves through the atmosphere by t

Diagram convection patterns that flow due to uneven heating of the earth.
EXPLANATION: The process of convection is explored both in the ocean (6.ESS2.1) and in the atmosphere (6.ESS2.2). Models for oceanic convection based on temperature differences are appropriate for use to explain atmospheric convection processes. Atmospheric movements lead to the transport of water from stores and to certain areas of Earth's surface. A model for heating of the Earth shows more direct heating of the earth's equator relative to the poles creating two large convection cycles which move upward at the equator and descend at the poles. When the rotation of the earth is factored in, the two convection cycles are broken into a total of six cycles. This effect (Coriolis effect) can be modeled by a pair of students using a marker and a large sphere. If the sphere is stationary, a student can use a marker to draw a straight line from the equator to the poles. If the ball is rotated while drawing this same straight line, the resulting line drawn on the sphere will curve. Rate of rotation determines the severity of the curvature, Earth's angular velocity results in three cells, with deserts focused at latitudes near 30 degrees and 60 degrees north and south, and predictable surface winds. (Memorization of global wind patterns and layers of the atmosphere are beyond the scope of this standard.)

Weather vs Climate

The weather is the short-term state of the atmosphere in a specific place. It includes conditions like temperature, wind, clouds, and precipitation th

effect-of-altitude-and-mountains-on-climate

Effect of Altitude and Mountains on Climate

Altitude, or elevation, is the height of a place above sea level. As altitude increases, temperature generally decreases. This means that even in trop

effect-of-continental-position-on-climate

Effect of Continental Position on Climate

A location’s position on a continent can affect its climate. Coastal areas near oceans tend to have milder climates, with smaller temperature changes 

Carbon Cycle and Climate

The carbon cycle is the way carbon moves through Earth’s systems, air, water, soil, rocks, and living things. Carbon is stored in places like the ocea

Construct an explanation for how atmospheric flow, geographic features, and ocean currents affect the climate of a region through heat transfer.
EXPLANATION: Weather describes the immediate atmospheric conditions in a particular location, whereas climate describes long term patterns in a region's weather. It is possible for the climate in a region to vary from the climate seen at similar latitudes due to the presence of geographic features such as mountains or lakes. Coastal air rising over mountains will be depleted of its moisture and create deserts on the back side of the mountain. Likewise, large bodies of water can influence the temperature and humidity of a region due to the ability of water to store large amounts of thermal energy.

Groundwater

Groundwater is the water located beneath Earth's surface in soil pore spaces and in the fractures of rock formations. It plays a crucial role in the h

Groundwater Aquifers

Aquifers are underground layers of water-bearing permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt) from which ground

Soil Erosion

Soil is one of Earth’s most valuable natural resources, but it can be lost through erosion—the process of soil being worn away by wind, water, and hum

Avoiding Soil Loss

Soil is essential for plant growth, water filtration, and supporting ecosystems, but it can be lost due to erosion, deforestation, and poor farming pr

Erosion by Streams - I

Water erosion happens when moving water carries away soil, sand, and rocks. Runoff from rain or melting snow flows over land, picking up loose particl

Erosion by Streams - II

Streams that begin in the mountains help shape the land as they flow. When the water moves quickly down steep slopes, it carries rocks and sediments w

Erosion by Groundwater

Groundwater is water that moves slowly through spaces in soil and rock beneath Earth’s surface. Over time, groundwater can cause erosion by dissolving

Water Conservation

Water conservation means using water wisely so we don’t waste it or run out. Freshwater is limited, and agriculture uses the most, often inefficiently

Apply scientific principles to design a method to analyze and interpret the impact of humans and other organisms on the hydrologic cycle.
EXPLANATION: Biogeological discussions in 4.ESS2.3 were general, whereas 6.ESS2.4 focuses specifically on the hydrologic cycle. Some organisms such as plants have very defined and ongoing involvement through transpiration. Other impacts have occurred over time including changes to water tables, and the effects of rates of weathering and erosion to land surfaces on watersheds and wetlands.

E. Biogeology

Collecting Weather Data

Weather data is information that scientists gather to understand and predict atmospheric conditions. This includes measurements like temperature, air 

Predicting Weather

Predicting the weather means using data about the atmosphere to forecast what conditions will be like in the near future. Meteorologists gather inform

Weather Maps

Weather maps are visual tools that show current and forecasted atmospheric conditions across different areas. They can display temperature, air pressu

Radar Systems: Applications

Radar systems are tools that use waves—usually radio or microwaves—to detect the location, speed, and shape of objects. RADAR stands for Radio Detecti

Air Pressure

Air pressure is the force exerted by air molecules as they move and collide with surfaces. It plays a crucial role in weather patterns, breathing, and

Analyze and interpret data from weather conditions, weather maps, satellites, and radar to predict probable local weather patterns and conditions.
EXPLANATION: The ability to recognize global patterns in climate distributions, describe deviations such as deserts created by the rain shadow effect is dependent, or to make predictions for future weather is dependent on collecting and interpreting weather related data. Examples of data from weather conditions include wind speed, wind direction, air temperature, humidity, and air pressure. In 3.ESS2.3, students were introduced to the use of tools to read temperature, precipitation, wind speed, and wind direction. By making a barometer, students are able to gain a better understanding of the intangible idea of air pressure. A vacuum demonstration is a good method to experience the phenomenon of air pressure. At this grade level, understanding should move beyond making readings and include a focus on using data to make predictions. (Emphasis should be how high and low pressures are related to current weather conditions. Differentiation of cloud types was addressed in 3.ESS2.2.)

Air Masses

An air mass is a large body of air that has the same temperature and moisture level throughout. Air masses form over land or water and take on the cha

Fronts

A front is the boundary between two different air masses. When warm and cold air masses meet, they don’t mix well because of differences in temperatur

Thunderstorms

A thunderstorm is a powerful weather event that forms when warm, moist air rises quickly into cooler air. This rapid rise causes clouds to grow tall a

Cyclones

Cyclones, also known as hurricanes or typhoons, depending on their location, are powerful rotating storm systems characterized by low-pressure centers

Explain how relationships between the movement and interactions of air masses, high and low pressure systems, and frontal boundaries result in weather conditions and severe storms.
EXPLANATION: The underlying principle is that high-pressure areas will push into or fill low-pressure areas. Low-pressure areas are columns of the atmosphere with a lower-pressure than surrounding air. As the surrounding higher pressure air pushes in to fill this area, the air in this low pressure column is displaced upward where condensation and precipitation occur as the elevation of this air increases. This air mass spins due again to Earth's rotation (Coriolis Effect). The opposite phenomenon occurs for high pressure areas, with a resulting spin in the opposite direction. The convergence of opposing pressure fronts creates severe weather phenomena due to the inverse nature of the air masses. This standard includes both occluded and stationary fronts, but not the memorization of specific air masses (e.g., continental polar or maritime tropical).

Microorganism Groups and Their Roles

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