The Microbial WorldThe Microbial World

Kathy HuschleNorthland Community and Technical College

Historical PerspectiveHistorical PerspectiveRobert Hooke: 1635 – 1703Robert Hooke: 1635 – 1703– discovered “little boxes” on a thin slice of corkdiscovered “little boxes” on a thin slice of cork– came to be known as cells, the world’s smallest came to be known as cells, the world’s smallest

structural unitstructural unit– beginning of the cell theory:beginning of the cell theory:

“ “all living things are all living things are

composed of cells”composed of cells”Robert Hooke drawing of fungi

VanLeeuwenhoekVanLeeuwenhoek

van Leeuwenhoek: 1632-1723van Leeuwenhoek: 1632-1723– first man to view live first man to view live

microorganisms using a microorganisms using a single lens microscopesingle lens microscope

Hooke’s Microscope

AnimalculesAnimalcules

Van Leeuwenhoek”s “animalcules”Van Leeuwenhoek”s “animalcules”– this is what he called them, this is what he called them,

based on how they movedbased on how they moved

drawings are representations drawings are representations

of bacteria and protozoaof bacteria and protozoa

Van Leeuwenhoek drawings of animalcules: found in rainwater soaked in peppercorns and material scraped from teeth

Louis PasteurLouis Pasteur

spontaneous generationspontaneous generation– ability of microorganisms to arise spontaneously from ability of microorganisms to arise spontaneously from

non-living matternon-living matter– belief until 2belief until 2ndnd half of 19 half of 19thth century century– proven inaccurate by Louis Pasteur in 1861proven inaccurate by Louis Pasteur in 1861

Louis Pasteur

Louis Pasteur on spontaneous Louis Pasteur on spontaneous generationgeneration

demonstrated the presence of microorganisms in air and demonstrated the presence of microorganisms in air and their ability to contaminate sterile solutionstheir ability to contaminate sterile solutions

Spontaneous GenerationSpontaneous Generation

proved that “spontaneous” is a result of the presence of proved that “spontaneous” is a result of the presence of microorganisms in the air or the fluids themselvesmicroorganisms in the air or the fluids themselves

Aseptic TechniqueAseptic Technique

basis of basis of aseptic techniqueaseptic technique– techniques used to techniques used to

prevent contamination by prevent contamination by unwanted unwanted microorganismsmicroorganisms

– standard laboratory standard laboratory practicepractice

Golden Age of MicrobiologyGolden Age of Microbiology1857 - 19141857 - 1914

rapid advances in the science of microbiologyrapid advances in the science of microbiology– fermentation and pasteurizationfermentation and pasteurization– germ theory of diseasegerm theory of disease

Fermentation Process In Lab

Fermentation & PasteurizationFermentation & Pasteurization

fermentationfermentation– discovery that yeast (microorganisms) ferments sugar discovery that yeast (microorganisms) ferments sugar

to alcohol in the absence of airto alcohol in the absence of air– souring and spoiling caused by bacteria in the souring and spoiling caused by bacteria in the

presence of airpresence of air

sugar to beer: goodsugar to beer: good

beer to vinegar: badbeer to vinegar: bad

Beer Fermentation Tank

Fermentation & PasteurizationFermentation & Pasteurization

pasteurizationpasteurization– use of heat to kill use of heat to kill

bacteria to diminish bacteria to diminish spoilage spoilage

fermentation and fermentation and pasteurization solidified pasteurization solidified the connection between the connection between microorganisms and microorganisms and diseasedisease

Milk Pasteurization Equipment

Germ Theory of DiseaseGerm Theory of Disease

proof that bacteria caused diseaseproof that bacteria caused disease– Robert Koch 1843-1910 developed the germ theory Robert Koch 1843-1910 developed the germ theory

of disease while studying the cattle disease anthraxof disease while studying the cattle disease anthrax– established that established that Bacillus anthracisBacillus anthracis was the was the

causative agent “germ” of anthrax in 1876causative agent “germ” of anthrax in 1876

Robert Koch

VaccinationVaccination Edward Jenner developed the first vaccine in 1798 for Edward Jenner developed the first vaccine in 1798 for smallpoxsmallpox

in 1880 Pasteur discovered the use of a virulent bacteria in 1880 Pasteur discovered the use of a virulent bacteria for a vaccine against fowl cholera and coined the term for a vaccine against fowl cholera and coined the term vaccinevaccine

Edward Jenner

Birth of Modern ChemotherapyBirth of Modern Chemotherapy

chemotherapy: chemical treatment of a disease, chemotherapy: chemical treatment of a disease, including antibiotics and chemicals used to treat cancerincluding antibiotics and chemicals used to treat cancer

Paul EhrlichPaul Ehrlich– used arsenic to treat syphilisused arsenic to treat syphilis

Alexander FlemingAlexander Fleming– penicillin was accidentally discoveredpenicillin was accidentally discovered

Chemotherapeutic AgentsChemotherapeutic Agents

synthetic drugssynthetic drugs– chemically prepared in the labchemically prepared in the lab

antibioticsantibiotics– substances produced naturally by bacteria and substances produced naturally by bacteria and

fungusfungus

both synthetic drugs and antibiotics inhibit the growth both synthetic drugs and antibiotics inhibit the growth or kill other microorganismsor kill other microorganisms

Paul ErlichPaul Erlichfirst use of a chemotherapeutic agent in 1910first use of a chemotherapeutic agent in 1910– used an arsenic containing compound to treat syphilisused an arsenic containing compound to treat syphilis– repeated his experiments with minor changes 605 times repeated his experiments with minor changes 605 times

before he found a concentration that workedbefore he found a concentration that worked

Paul Erlich

Alexander FlemingAlexander Fleming

accidentally discovered that accidentally discovered that mold (mold (PenicilliumPenicillium) inhibited ) inhibited the growth of bacterial the growth of bacterial cultures in his lab in 1928cultures in his lab in 1928

Alexander Fleming

PenicillinPenicillin

usefulness of penicillin was not apparent until the 1940’susefulness of penicillin was not apparent until the 1940’s– clinically tested and as a result of the test, it was mass clinically tested and as a result of the test, it was mass

producedproduced– World War II spurred on the production of penicillin as it was World War II spurred on the production of penicillin as it was

initially used for the war effortinitially used for the war effort

Click on the icon below, then click on “Play the Discovery of the Penicillin

Game”. Follow the instructions to help discover Penicillin.

Modern MicrobiologyModern Microbiology

new and different directions that the study of new and different directions that the study of microbiology is going towardsmicrobiology is going towards– drug resistancedrug resistance– new branches of microbiologynew branches of microbiology– develop new vaccinesdevelop new vaccines– recombinant DNA technologyrecombinant DNA technology

Drug ResistanceDrug Resistance

result of genetic changes result of genetic changes in microbesin microbes

production of microbial production of microbial enzymes that inactivate enzymes that inactivate antibioticsantibiotics

Drug ResistanceDrug Resistance

surface changes in microbes surface changes in microbes – disallowing antibiotics from attaching to itdisallowing antibiotics from attaching to it– preventing antibiotics from entering the microbepreventing antibiotics from entering the microbe

New Branches of MicrobiologyNew Branches of Microbiology

study of microbiology broadened and became more study of microbiology broadened and became more specializedspecialized– bacteriologybacteriology

study of bacteriastudy of bacteria– mycologymycology

study of fungistudy of fungi

Clavaria: a fungi

New Branches of MicrobiologyNew Branches of Microbiology

parasitologyparasitology– study of protozoa and parasitic wormsstudy of protozoa and parasitic worms

immunologyimmunology– study of immunitystudy of immunity

virologyvirology– study of virusesstudy of viruses

New VaccinesNew Vaccines

as new diseases emerge, microbiologists strive to find as new diseases emerge, microbiologists strive to find curescures– new vaccines appear to be the best hope as new vaccines appear to be the best hope as

microorganisms continue to develop drug resistancemicroorganisms continue to develop drug resistance

Recombinant DNA TechnologyRecombinant DNA Technology

also referred to as genetic engineeringalso referred to as genetic engineering– microorganisms are used for the study of genetic microorganisms are used for the study of genetic

engineering for several reasonsengineering for several reasons

short life cycleshort life cycle

less complex structure than plant or animal, but less complex structure than plant or animal, but still have DNAstill have DNA

Recombinant DNA TechnologyRecombinant DNA Technology

used to manufacture used to manufacture large amounts of medical large amounts of medical substancessubstances

enhances agricultural enhances agricultural productionproduction

potential for medical potential for medical breakthroughs in area of breakthroughs in area of genetic diseasesgenetic diseases

Microbes and Human WelfareMicrobes and Human Welfare

microorganismsmicroorganisms– beneficial to all life on Earthbeneficial to all life on Earth

microorganismsmicroorganisms– degrade dead plants and animals, recycling the degrade dead plants and animals, recycling the

nutrients to be used by living plants and animalsnutrients to be used by living plants and animals

Soil microbiota decomposing crop residue

Microorganisms as DecomposersMicroorganisms as Decomposers

microorganismsmicroorganisms– decompose organic matter in sewage, breaking it decompose organic matter in sewage, breaking it

down and releasing the beneficial elements, such as down and releasing the beneficial elements, such as carbon, nitrogen, oxygen and sulfur, back into the carbon, nitrogen, oxygen and sulfur, back into the environmentenvironment

Sewage Treatment Plant

Microorganisms and BioremediationMicroorganisms and Bioremediation

microorganismsmicroorganisms– are used in are used in

bioremediation, a bioremediation, a process that cleans up process that cleans up toxic wastes and toxic wastes and pollutantspollutants

Microorganisms and Food ProductionMicroorganisms and Food Production

microorganismsmicroorganisms– used in the production of foodused in the production of food

PharmaceuticalsPharmaceuticals

microorganismsmicroorganisms– used in the development used in the development

and production of and production of pharmaceuticalspharmaceuticals

Microorganisms for Medical UsesMicroorganisms for Medical Uses

microorganismsmicroorganisms– used in the process of diagnosis and treatment of used in the process of diagnosis and treatment of

human diseasehuman disease

Picking cloned yeast colonies for production

Microorganisms as the Medical EnemyMicroorganisms as the Medical Enemy

the other side of the picturethe other side of the picture– influenza: 1918-1919influenza: 1918-1919

killed more people killed more people than WW1, WW2, than WW1, WW2, Korea, and Viet Nam Korea, and Viet Nam combinedcombined

Micrograph of Influenza virus

Microorganisms as the Medical EnemyMicroorganisms as the Medical Enemy

plaque: 13plaque: 13thth century century– killed 25% of the population of Europekilled 25% of the population of Europe

Plague bacteria

Medical MicrobiologyMedical Microbiologyresurgence of new diseases is due to any or all of the resurgence of new diseases is due to any or all of the followingfollowing– resistance to antibioticsresistance to antibiotics– increase in foreign travelincrease in foreign travel– increase in foreign visitorsincrease in foreign visitors– parents becoming lax on childhood vaccinationsparents becoming lax on childhood vaccinations– increase in the # of elderly in the worldincrease in the # of elderly in the world

the immune system weakens with agethe immune system weakens with age

Medical MicrobiologyMedical Microbiology

emerging diseases due toemerging diseases due to– changing lifestyleschanging lifestyles– mutation ability of infectious agentsmutation ability of infectious agents

Medical Microbiology SuccessesMedical Microbiology Successes

smallpoxsmallpox– last known disease in the world was documented in last known disease in the world was documented in

19771977– believed at one time prior to eradication, that 80% of believed at one time prior to eradication, that 80% of

the world’s population would be affected by smallpoxthe world’s population would be affected by smallpox

Smallpox virus Clinical Manifestation of Smallpox

Microbiology SuccessesMicrobiology Successes

potato famine in Irelandpotato famine in Ireland– 1850’s1850’s– late blight funguslate blight fungus– through the process of genetic engineering, through the process of genetic engineering,

microbiologists are able to protect the potato microbiologists are able to protect the potato industry from this plight happening againindustry from this plight happening again

Infected potato plant

Blight fungi

What is a Microorganism?What is a Microorganism?often referred to as a “germ”often referred to as a “germ”– very few microbes cause diseasevery few microbes cause disease

very small life formsvery small life forms

300 300 µm 60 µm 3 µm µm 60 µm 3 µm

E. coli on the head of a pin

Perspective on sizePerspective on size

smallest object visible to the naked eye is smallest object visible to the naked eye is

0.1 mm which is = to 100 um(micrometers)0.1 mm which is = to 100 um(micrometers)

most microorganisms range in size from 5um - .1ummost microorganisms range in size from 5um - .1um

viruses, the smallest microorganism, have a size range viruses, the smallest microorganism, have a size range from .1um – 0.01 um.from .1um – 0.01 um.

Click on the icon to for more information on microbial size.Then click on the items listed on the right to gain perspective on how small microorganisms are.

Microbial SizeMicrobial Size

3 Domains 3 Domains of all living organismsof all living organisms

BacteriaBacteria

ArchaeaArchaea

EucaryaEucarya

BacteriaBacteria

single-celled single-celled prokaryoteprokaryote

– prokaryote is a simple cell with a nucleoid region, prokaryote is a simple cell with a nucleoid region,

surrounded by cytoplasm and a cellsurrounded by cytoplasm and a cell wall wall

BacteriaBacteria

comprised of specific shapescomprised of specific shapes– rod or bacillirod or bacilli– spherical or coccispherical or cocci– spiralspiral

Rod shaped bacteria Spherical shaped cocci Spiral shaped bacteria

BacteriaBacteria

bacterial cells multiply by binary fissionbacterial cells multiply by binary fission– one cell divides into two cells, identical to originalone cell divides into two cells, identical to original

E. Coli undergoing division Binary fission of protozoa

BacteriaBacteria

cell walls contain peptidoglycan, which is cell walls contain peptidoglycan, which is uniqueunique to to bacteria cellsbacteria cells

ArchaeaArchaea

Archaea means ancientArchaea means ancient

Archaea bacteria look identical Archaea bacteria look identical microscopically to members of microscopically to members of the Bacteria domainthe Bacteria domain

chemical composition of cell wall chemical composition of cell wall differs: Archaea do not have differs: Archaea do not have peptidoglycanpeptidoglycan

Bacteria in a Deep Sea vent

ArchaeaArchaea

have the ability to grow in extreme environmentshave the ability to grow in extreme environments– extreme temperatures: hot or coldextreme temperatures: hot or cold– acidic or alkaline conditionsacidic or alkaline conditions– extreme salt concentrationextreme salt concentration

Hotsprings at Yellowstone

EucaryaEucaryaall members of the living world except the prokaryotes all members of the living world except the prokaryotes are considered Eucaryaare considered Eucarya– single celled and multi-celledsingle celled and multi-celled– contain organellescontain organelles– membrane bound nucleusmembrane bound nucleus

EucaryaEucarya

includeinclude– algaealgae– fungifungi– protozoaprotozoa

Ciliated protozoan

Fungi

Algae

Prokaryotic & Eukaryotic CellsProkaryotic & Eukaryotic Cells

notice the additional structures found in the eukaryotic cell

Microbial WorldMicrobial World

bacteriabacteria

archaebacteriaarchaebacteria

algaealgae

fungifungi

protozoaprotozoa

virusvirus

viroidsviroids

prionsprions

BacteriaBacteria

E. coli

FungiFungi

AlgaeAlgae

ProtozoaProtozoa

VirusesViruses

VirusVirus

considered acellular, non-livingconsidered acellular, non-living

made up of a core containing DNA or RNA surrounded made up of a core containing DNA or RNA surrounded by a protein coatby a protein coat

can reproduce only by using the cellular mechanism of can reproduce only by using the cellular mechanism of another cellanother cell– often considered the parasites of the microbial worldoften considered the parasites of the microbial world

ViroidsViroids

viroidsviroids– single piece of nucleic acid with no protein coatsingle piece of nucleic acid with no protein coat– only capable of causing plant diseasesonly capable of causing plant diseases

Pear blister canker viroid

PrionsPrions

prionsprions– contain only proteincontain only protein– causative agent for some causative agent for some

neurodegenerative diseases in humans and neurodegenerative diseases in humans and animalsanimals

Prion