Microbiology: A Microbiology: A

Systems Approach, 2Systems Approach, 2ndnd

ed.ed.Chapter 1: The Main Themes of Chapter 1: The Main Themes of

MicrobiologyMicrobiology

1.1 The Scope of Microbiology1.1 The Scope of Microbiology

�� MicrobiologyMicrobiology: The study of living things : The study of living things

too small to be seen without magnificationtoo small to be seen without magnification

�� MicroorganismsMicroorganismsor or microbesmicrobes-- these these

microscopic organismsmicroscopic organisms

�� Commonly called “germs, viruses, agents#” Commonly called “germs, viruses, agents#”

but not all cause disease and many more are but not all cause disease and many more are

useful or essential for human lifeuseful or essential for human life

Major Groups of Major Groups of

MicroorganismsMicroorganisms��BacteriaBacteria, , algaealgae, , protozoaprotozoa, , helmintheshelminthes, ,

and and fungifungi

��VirusesViruses-- noncellular, parasitic, proteinnoncellular, parasitic, protein--

coated genetic elements that can infect all coated genetic elements that can infect all

living things, including other living things, including other

microorganismsmicroorganisms

Branches of MicrobiologyBranches of Microbiology

�� Agricultural microbiologyAgricultural microbiology

�� BiotechnologyBiotechnology

�� Food, dairy, and aquatic microbiologyFood, dairy, and aquatic microbiology

�� Genetic engineering and recombinant Genetic engineering and recombinant DNA technologyDNA technology

�� Public health microbiology and Public health microbiology and epidemiologyepidemiology

�� ImmunologyImmunology

�� Many, many moreMany, many more

Emerging Areas of MicrobiologyEmerging Areas of Microbiology

�� GeomicrobiologyGeomicrobiology

�� Marine microbiologyMarine microbiology

�� AstromicrobiologyAstromicrobiology

1.2 The Impact of Microbes on Earth: 1.2 The Impact of Microbes on Earth:

Small Organisms with a Giant EffectSmall Organisms with a Giant Effect

�� Microorganisms have a profound influence Microorganisms have a profound influence

on all aspects of the earth and its on all aspects of the earth and its

residentsresidents

�� BacterialBacterial--like organisms in the fossil like organisms in the fossil

record as far back as 3.5 billion years ago record as far back as 3.5 billion years ago

((prokaryotesprokaryotes-- organisms without a true organisms without a true

nucleus)nucleus)

�� 2 billion years later, 2 billion years later, eukaryoteseukaryotes

(organisms with a true nucleus) emerged(organisms with a true nucleus) emerged

Figure 1.1

Ubiquity of MicroorganismsUbiquity of Microorganisms

�� Found nearly everywhereFound nearly everywhere

�� Occur in large numbersOccur in large numbers

�� Live in places many other organisms Live in places many other organisms

cannotcannot

Figure 1.2

Microbial Involvement in Energy Microbial Involvement in Energy

and Nutrient Flowand Nutrient Flow

�� Bacteria conducted Bacteria conducted photosynthesisphotosynthesis

before plants appearedbefore plants appeared

�� Anoxygenic photosynthesisAnoxygenic photosynthesis

�� Oxygenic photosynthesisOxygenic photosynthesis

�� Biological Biological decompositiondecomposition and nutrient and nutrient

recyclingrecycling

1.3 Human Use of 1.3 Human Use of

MicroorganismsMicroorganisms

�� Humans have been Humans have been

using microorganisms using microorganisms

for thousands of yearsfor thousands of years

�� Baker’s and brewer’s Baker’s and brewer’s

yeastyeast

�� CheesesCheeses

�� Moldy bread on woundsMoldy bread on wounds

Figure 1.3

Biotechnology and Biotechnology and

BioremediationBioremediation�� BiotechnologyBiotechnology-- when humans manipulate when humans manipulate

microorganisms to make products in an industrial microorganisms to make products in an industrial settingsetting�� Genetic engineeringGenetic engineering-- create new products and create new products and

genetically modified organisms (GMOs)genetically modified organisms (GMOs)

�� Recombinant DNA technologyRecombinant DNA technology-- allows microbes to be allows microbes to be engineered to synthesize desirable proteins (i.e. drugs, engineered to synthesize desirable proteins (i.e. drugs, hormones, and enzymes)hormones, and enzymes)

�� BioremediationBioremediation-- introducing microbes in to the introducing microbes in to the environment to restore stability or clean up toxic environment to restore stability or clean up toxic pollutantspollutants�� Oil spillsOil spills

�� Chemical spillsChemical spills

�� Water and sewage treatmentWater and sewage treatment

1.4 Infectious Diseases and the 1.4 Infectious Diseases and the

Human ConditionHuman Condition

��PathogensPathogens-- diseasedisease--causing organismscausing organisms

Figure 1.4

Worldwide Infectious DiseasesWorldwide Infectious Diseases

�� Increasing number of emerging diseases Increasing number of emerging diseases

(SARS, AIDS, hepatitis C, viral (SARS, AIDS, hepatitis C, viral

encephalitis)encephalitis)

�� Other diseases previously not linked to Other diseases previously not linked to

microorganisms now are (gastric ulcers, microorganisms now are (gastric ulcers,

certain cancers, schizophrenia, multiple certain cancers, schizophrenia, multiple

sclerosis, obsessive compulsive disorder, sclerosis, obsessive compulsive disorder,

coronary artery disease)coronary artery disease)

�� Increasing number of drug resistant strainsIncreasing number of drug resistant strains

1.5 The General Characteristics of 1.5 The General Characteristics of

MicroorganismsMicroorganisms

�� Cellular OrganizationCellular Organization

�� Prokaryotic vs. eukaryotic cellsProkaryotic vs. eukaryotic cells

•• Prokaryotic cells are about 10 times smaller than Prokaryotic cells are about 10 times smaller than

eukaryotic cellseukaryotic cells

•• Prokaryotic cells lack many cell structures such as Prokaryotic cells lack many cell structures such as

organellesorganelles

•• All prokaryotes are microorganisms, but only some All prokaryotes are microorganisms, but only some eukaryotes areeukaryotes are

Figure 1.5

VirusesViruses

�� Not independently living Not independently living cellular organismscellular organisms

�� Much simpler than cellsMuch simpler than cells--basically a small amount of basically a small amount of DNA or RNA wrapped in DNA or RNA wrapped in protein and sometimes by a protein and sometimes by a lipid membranelipid membrane

�� Individuals are called a Individuals are called a virus virus particleparticle or or virionvirion

�� Depend on the infected cell’s Depend on the infected cell’s machinery to multiply and machinery to multiply and dispersedisperse

J8

Slide 17

J8 Insert Figure 1.5b HereJennifer, 1/21/2008

Microbial DimensionsMicrobial Dimensions

Figure 1.7

Lifestyles of MicroorganismsLifestyles of Microorganisms�� Most live a free existence (in soil or water, for Most live a free existence (in soil or water, for

example)example)

�� Some are Some are parasitesparasites

Figure 1.6

1.6 The Historical Foundations of 1.6 The Historical Foundations of

MicrobiologyMicrobiology

�� Key to the study of microorganisms was Key to the study of microorganisms was the development of the the development of the microscopemicroscope

�� Earliest record of microbes was from the Earliest record of microbes was from the work of work of Robert HookeRobert Hooke in the 1660sin the 1660s

�� The most careful observations of microbes The most careful observations of microbes was possible after was possible after Antonie van Antonie van LeeuwenhoekLeeuwenhoek created the singlecreated the single--lens lens microscopemicroscope�� Known as the father of bacteriology and Known as the father of bacteriology and

protozoologyprotozoology

Figure 1.9

Establishment of the Establishment of the Scientific Scientific

MethodMethod�� Early scientists tended to explain natural Early scientists tended to explain natural

phenomena by a mixture of belief, superstition, phenomena by a mixture of belief, superstition, and argumentand argument

�� During the 1600s, true scientific thinking During the 1600s, true scientific thinking developeddeveloped

�� From that, the development of the scientific From that, the development of the scientific methodmethod�� Formulate a Formulate a hypothesishypothesis

�� Most use the Most use the deductive approachdeductive approach to apply the to apply the scientific methodscientific method

�� Experimentation, analysis, and testing leads to Experimentation, analysis, and testing leads to conclusionsconclusions

�� Either support or refute the hypothesisEither support or refute the hypothesis

�� Hypotheses can eventually become theoriesHypotheses can eventually become theories

�� Theories can eventually become laws or principlesTheories can eventually become laws or principles

Figure 1.10

The Development of Medical The Development of Medical

MicrobiologyMicrobiology

�� The Discovery of Spores and SterilizationThe Discovery of Spores and Sterilization�� Louis PasteurLouis Pasteur-- worked with infusions in the midworked with infusions in the mid--

1800s1800s

�� John TyndallJohn Tyndall-- showed evidence that some showed evidence that some microbes have very high heat resistance and are microbes have very high heat resistance and are difficult to destroydifficult to destroy

�� Ferdinand CohnFerdinand Cohn-- spores and sterilizationspores and sterilization

�� The Development of Aseptic TechniquesThe Development of Aseptic Techniques

�� Physicians and scientist began to suspect that Physicians and scientist began to suspect that microorganisms could cause diseasemicroorganisms could cause disease

�� Joseph ListerJoseph Lister-- introduced introduced aseptic techniqueaseptic technique

�� The Discovery of The Discovery of

Pathogens and the Pathogens and the

Germ Theory of Germ Theory of

DiseaseDisease

�� Louis PasteurLouis Pasteur

•• PasteurizationPasteurization

•• The Germ Theory of The Germ Theory of

DiseaseDisease

�� Robert KochRobert Koch

•• Koch’s postulatesKoch’s postulates--

verified the germ theoryverified the germ theory

Figure 1.11

1.7 Taxonomy: Naming, 1.7 Taxonomy: Naming,

Classifying, and Identifying Classifying, and Identifying

MicroorganismsMicroorganisms�� MicrobialMicrobial nomenclaturenomenclature-- naming naming

microorganismsmicroorganisms

�� TaxonomyTaxonomy-- classifying living thingsclassifying living things

�� Originated over 250 years ago with the work Originated over 250 years ago with the work of Carl von Linnéof Carl von Linné

�� IdentificationIdentification-- discovering and recording discovering and recording the traits of organisms so they can be the traits of organisms so they can be named and classifiednamed and classified

�� Levels of ClassificationLevels of Classification

Figure 1.12

Assigning Specific NamesAssigning Specific Names

�� A standardized nomenclature allows A standardized nomenclature allows

scientists from all over the world to exchange scientists from all over the world to exchange

informationinformation

�� The The binomial system of nomenclaturebinomial system of nomenclature

�� The generic (genus) name followed by the The generic (genus) name followed by the

species namespecies name

�� Generic part is capitalized, species is lowercaseGeneric part is capitalized, species is lowercase

�� Both are italicized or underlined if italics aren’t Both are italicized or underlined if italics aren’t

availableavailable

�� Staphylococcus aureusStaphylococcus aureus

The Origin and Evolution of The Origin and Evolution of

MicroorganismsMicroorganisms�� PhylogenyPhylogeny-- the degree of relatedness between the degree of relatedness between

groups of living thingsgroups of living things

�� Based on the process of Based on the process of evolutionevolution-- hereditary hereditary information in living things changes gradually information in living things changes gradually through time; these changes result in structural through time; these changes result in structural and functional changes through many generationsand functional changes through many generations�� Two preconceptions:Two preconceptions:

•• All new species originate from preexisting speciesAll new species originate from preexisting species

•• Closely related organisms have similar features because Closely related organisms have similar features because they evolved from a common ancestorthey evolved from a common ancestor

�� Phylogeny usually represented by a treePhylogeny usually represented by a tree-- showing showing the divergent nature of evolutionthe divergent nature of evolution

Figure 1.13

Figure 1.14