CH 1: Members of the microbial world

molecular systematics has aided in characterization

tree of life

eukaryotes

protozoa, algae, fungi, plants, and animals

prokaryotes

bacteria and archaea

eukaryotic differences

true membrane bound nucleus, organelles, large, single celled

prokaryotic differences

circular DNA, unicellular, no nucleus, small

hooke publishes micrographia

1665

leeuwenhoek discovers animacules

1674-1676

koch postulates

1884

knoll and ruska first electron microscope

1932

watson and crick DNA double helix

1953

Gallo and Montagnier PCR

1983

antony van leeuwenhoek was the first person to

observe and describe microorganisms accurately

Leeuwenhoek observed

bacteria and protozoa

spontaneous generation

living organisms can develop from nonliving or decomposing matter

francesco reddi

disproved spontanteous generation for large animals

John Needham spontaneous generation experiment

mutton broth in flasks → boiled → sealed

John Needham experiment results

broth became cloudy and contained microorganisms

Lazzaro spallanzani experiment

broth in flask → sealed → boiled

lazzaro spallanzani experiment results

no growth of microorganisms and air carries germs

Louis Pasteur experiment

nutrient solution in flasks w/ curved necks → boiled → exposed to air

John tyndall

dust carries microorganisms and heat resistent forms of bacteria

john tyndall experiment

no dust → broth remained sterile even if directly exposed to air

agostini bassi

disease of silkworms was caused by a fungus

M.J. Berkeley

great potato blight of ireland caused by a fungus

Heinrich de bary

smut and rust fungi → cerea crop diseases l

Louis Pasteur

silkworm disease caused by a protozoan

Joseph Lister 1827-1912

indirect evidence for microbial cause of disease

Joseph Lister founded

antiseptic surgical techniques in 1865 using heat sterilization

Robert Koch established

relationship between Bacillus anthracis and anthrax

koch’s postulates are used to prove

a causal relationship between microorganisms and disease

1st koch postulate

the microorganism must be present in every case of the disease but absent from healthy individuals

2nd Koch postulate

the suspected microorganism must be isolated and grown in a pure culture

3rd Koch postulate

same disease must result when the isolated microorganism is inoculated into a healthy host

4th koch postulate

same microorganism must be isolated again from the diseases host

Koch’s work led to the discovery/development of

agar, petri dish, nutrient broth, methods for isolating microorganisms

koche’s work increased

the understanding of pathogens and led onto immunological studies

Edward Jenner

vaccination procedure to protect individuals from smallpox 1798

Pasteur and Roux

incubation of cultures for long intervals → pathogens lost ability to cause disease → transfer to healthy host → protection from infection

Pasteur and coworkers vaccines

chicken, cholera, anthrax, and rabies

Emil von Behring and Shibasaburo Kitasato

produced transferrable antitoxin for diphtheria and tetanus

Emil von Behring and Shibasaburo Kitasato evidence for

immunity from soluble substances in blood

Elie Metchnikoff

discovered bacteria engulfing phagocytic cells in blood

Sergei Winogradsky and Martinus Beijerinck

pioneered use of enrichment cultures, selective media

Sergei Winogradsky and Martinus Beijerinck discovered

numerous metabolic processes such as N2 fixation and CO2 fixation

importance of microorganisms

• first living organisms on planet

• live everywhere life is possible

• more numerous than any other kind of organisms

• global ecosystem depends on activity

• influence human society

study of basic biology of microorganisms

microbial morphology, physiology, genetics, ecology

understanding microorganisms has improved

understanding of other organisms

medical microbiology

identify causative pathogen

immunology

response o host to pathogen

food and dairy microbiology

spoilage of food; transmission of disease

public health microbiology

control spread of disease

industrial microbiology

use of microorganisms to produce things

agricultural microbiology

impact of microorganisms on agriculture

future of microbiology

• infectious disease

• industrial processes

• microbial diversity

• biofilms

• genome analysis