Lecture 1 Microorganisms & Microbiologymicro.sjtu.edu.cn/PDF-Microbiology/01-2 Lecture 1... · BROCK BIOLOGY OF MICROORGANISMS. Chen Feng, Shanghai Jiao Tong University 1.1 Microbiology

1896 1920 1987 2006

Lecture 1

Microorganisms &

Microbiology

Zhao Liping and Chen Feng

School of Life Science and Technology

Shanghai Jiao Tong University

Chapter 1 inBROCK BIOLOGY OF MICROORGANISMS

Chen Feng, Shanghai Jiao Tong University

1.1 Microbiology

As a basic biological science, microbiology provides

tools for probing the processes of life.

As an applied biological science, microbiology deals

with many important practical problems in

medicine, agriculture, and industry.


1.2 Microorganisms as Cells

1.2.1 Characteristics of living

systems

Hallmarks / characteristics

1. Metabolism代谢

2. Growth生长

3. Differentiation分化

4. Communication交流

5. Movement运动

6. Evolution进化

heredity and mutation-information

flow


1.2.2 Cells as chemical machines and as coding

devices

Cells are self-replicating entities可自我复制的主体,

they can be viewed in two ways:

As chemical machines作为化学机器的细胞

• carrying out chemical transformations of non-living

materials to living materials to provide energy and

precursors for cell reproduction

As coding devices作为编码装置的细胞

• serving as storehouses and processors of genetic

information (DNA) to give the cell instructions to make

new copies of itself


Cells are both machines and coding devices

The link between these two

cellular attributes is growth.

Machine and coding functions

work together to reproduce cells.

生长将这两项功能合二为一,

共同繁殖新细胞

Coordination and regulation are

highly needed between these

two functions.需要协调（与调

节）


The machine and

coding functions of

the cell


1.3 Microorganisms

A large and diverse group of microscopic organisms

that exist as single cells or cell clusters, it also

include non-cellular life forms such as viruses and

prions.微生物：微小的细胞或非细胞生物


Compared with plant and animal cells,

microorganisms are:

• Very small-bacteria 0.5-5μm,微小

• Highly diverse-all kinds of morphology，形态多

样

• leading an independent living独立生活


1.4 The Impact of Microorganisms on Humans 微生物对人类的影响

Disease agents病原物

• Human, animal, plants

Agriculture农业

• Nitrogen fixation-root nodule根瘤

• Animal digestion-rumen瘤胃

Food industry食品工业

• Spoilage

• Fermented food

Energy能源

• Biomass

• Biofuels

Environment环境

• Bioremediation生物修复


Pathogens-harmful microorganisms

Time: 1350 A.D. Place: the European continent.

“In less than two years' time, the Bubonic Plague wiped out

half the population of Europe. Fleas bit rats and then bit man,

but no one knew it. An estimated 25 million people died in 14

months. Some individual cities had a mortality as high as 90%.

Bodies were piled into carts and dragged away to be burned in

common graves. It was a most grotesque way to die: bleeding

and screaming and having one's organs literally liquefy. From

infection to death took perhaps one week. ”

1350年黑死病流行于欧洲，2500万人在14个月内死亡。

Bubonic Plague黑死病, 淋巴腺鼠疫


The leading causes of death in the 1900 was influenzae, pneumonia,

tuberculosis, and gastroenteritis流感、肺炎、肺结核、肠胃炎在1900

年是主要的致死原因


In the 1990’s, infectious diseases only ranked 5th as a major cause of

death. 上世纪90年代,感染性疾病重要性降低, 在致死因素中排第五位.


II. Pathways of Discovery in

Microbiology

Technological developments have been closely

related with birth and growth of microbiology.技术

发展对微生物学发展的重大意义

• Microscopy

• Culture technique

• DNA manipulation technology


1.5 Historical Roots of Microbiology:

Microscopy显微技术

Fruiting bodies observed first with microscope by

Robert Hook in 1664

Discovery of microorganisms (wee animalcules) by

Antoni van Leeuwenhoek in rain-, sea- and snow-water

(1677)

虎克与吕文虎克


A Modern Bright-Field Microscope


1.6 Pasteur, Koch and Pure Cultures

Birth of Microbiology in the mid and late

1800s

• Does spontaneous generation occur?自然

发生说

• What is the nature of contagious disease?

传染病的本质


Downfall of Spontaneous generation

French chemist Louis Pasteur (1822-1895), defeated

the theory of spontaneous generation巴斯德

Theory of spontaneous generation

• Ancient Egypt- frog from mud

• Food spoilage- microbes could be directly transformed from

non-living matters

Pasteur and the Downfall of Spontaneous Generation


Downfall of Spontaneous generation (1)

Methods

• Collection of microbes from the air

• Guncotton filters to stop particles

• Guncotton filters dissolved in alcohol and ether

• Examined particles under microscope

Results

• Microbial cells found in the air and those in spoiled food

were not distinguishable

Conclusion

• Organisms found in spoiled materials came from

microorganisms in the air

Pasteur and the Downfall of Spontaneous Generation 1st experiment

Criticism:

Can not exclude the possibility of spontaneous generation



Method

• Broth in sealed flask

• Heating

Results

• Heated broth separated from the air never spoils

Conclusion

• Spontaneous does not occur, microbial cells can only come from the air/

environment.

Pasteur and the Downfall of Spontaneous Generation 2nd

experiment

Criticism:

Fresh air is needed for spontaneous generation,

heating destroyed the power for spontaneous

generation in the air sealed in the flask.



Method

• Broth in flask with swan neck, fresh air could get inside but not

particles from the air

• Heating the broth.

Results

• Heated broth in the open flask did not spoil

Conclusion

• Spontaneous does not occur, cells can only come from cells

Pasteur and the Downfoall of Spontaneous Generation 3rd experiment



Method

• Broth in flask with swan neck, fresh air could get inside but not

particles from the air

• Heating the broth.

Results

• Heated broth in the open flask did not spoil

• Contact with particles stopped in the neck led to quick spoilage

Conclusion

• Spontaneous does not occur, cells can only come from cells

Pasteur and the Downfoall of Spontaneous Generation 3rd experiment

Criticism:

No criticism

sterilizing the contents of the flask.

FLASH

Animations/Lecture1_Pasteur's experiment.swf

if the flask remains upright, no microbial growth will occur


if microbes trapped in the neck reach the sterile liquid, growth will

occur


Koch and the Germ Theory of Disease

Robert Koch (1843-1910), physician, developed the

Germ theory of disease

• Koch’s Work with anthrax炭疽热

• Koch’s postulates柯赫法则


Koch’s Work with anthrax (1)

Method

• Microscopic observation

Results

• Bacterial cells were observed in the blood of animals

with the disease

Conclusion

• The disease might be caused by this bacterium

Criticism:

The bacterium might as well be a result of the disease



Method• Transfer of disease with blood among animals

• Observe with microscope of the artificially infected animals

Results• Blood containing the bacterium could cause disease in healthy animals and newly

infected animal’s blood contained the bacterial cells

• Highly repeatable

Conclusion• The bacteria in the blood of infected animals can cause disease in healthy

animals

Criticism:

How do you know it is the bacteria not something else resistant to microscopic observation in the blood caused the infection?



Method

• Culture of the bacterium in nutrient broth

• Transfer of disease by the isolated bacteria

• Microscopic observation

Results

• Isolated bacteria caused disease in healthy animals

• The same bacteria were isolated from dead animals

Conclusion

• The bacterial cells in the blood of infected animals are indeed the reason for

the disease

Germ theory of disease established


Koch’s postulates柯赫法则

On the basis of Germ Theory of Disease and

other experiments, Koch formulated “Koch’s

postulates” for proving that a specific type of

microorganism causes a specific disease.

FLASH

Animations/Lecture1_Koch's postulate.swf

1896 1920 1987 2006

Koch’s postulates

Postulate #1

the suspected

pathogenic

organism should

be present in all

cases of the

disease and

absent from

healthy animals.


Postulate

#2

the suspected

organism

should be

grown in pure

culture.


Postulate #3

the cells from a

pure culture of

the suspected

organism should

cause disease in

a healthy animal.


Postulate #4

the organism

should be

reisolated and

shown to be

the same as

the original.


Koch’s other contributions (1)

Development of pure culture technique纯培

养技术

• Potato slice

• Solid medium with gelatin(broth)明胶培养基

• Solid medium with agar琼脂培养基


Koch’s other contributions (2)

Demonstration of causal agent of tuberculosis肺结核

• Koch’s methods (developed by himself)

1. Microscopy

2. Differential staining鉴别染色法 of bacteria and

human tissues

3. Pure culture isolation of bacteria

4. Animal inoculation动物接种

• Received Nobel Prize for Physiology or Medicine in 1905


Differential staining of bacteria and human tissues

对人体组织和细菌的鉴别染色法

Cells of M. tuberculosis stain blue in a lung tissue sample whereas the tissue stains brown.


Cells of M. tuberculosis stain blue in a sputum sample from

a TB patient TB病人痰中的结核分枝杆菌


M. tuberculosis growing on a glass plate of

coagulated blood serum inside a glass box

在玻璃盒中用凝固血清培养基培养结核分枝杆菌


A colony of M. tuberculosis appears as long

"cordlike" forms when taken from a glass plate

结核杆菌的绳索状细菌菌落


Some landmarks in microbiology in the past. The icons or

photos above the dates are symbolic of the discoveries; each

has been covered here or will be revisited in later chapters.

1896 1920 1987 2006

Thank you for

your listening!

Documents

Lecture 1 Microorganisms & Microbiologymicro.sjtu.edu.cn/PDF-Microbiology/01-2 Lecture 1... · BROCK BIOLOGY OF MICROORGANISMS. Chen Feng, Shanghai Jiao Tong University 1.1 Microbiology