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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.
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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)
Chen Feng, Shanghai Jiao Tong University
The machine and
coding functions of
the cell
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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.
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
A Modern Bright-Field Microscope
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
Downfall of Spontaneous generation (2)
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.
Chen Feng, Shanghai Jiao Tong University
Downfall of Spontaneous generation (3)
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
Chen Feng, Shanghai Jiao Tong University
Downfall of Spontaneous generation (3)
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
if the flask remains upright, no microbial growth will occur
Chen Feng, Shanghai Jiao Tong University
if microbes trapped in the neck reach the sterile liquid, growth will
occur
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
Koch’s Work with anthrax (2)
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?
Chen Feng, Shanghai Jiao Tong University
Koch’s Work with anthrax (3)
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
Chen Feng, Shanghai Jiao Tong University
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
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.
Chen Feng, Shanghai Jiao Tong University
Postulate
#2
the suspected
organism
should be
grown in pure
culture.
Chen Feng, Shanghai Jiao Tong University
Postulate #3
the cells from a
pure culture of
the suspected
organism should
cause disease in
a healthy animal.
Chen Feng, Shanghai Jiao Tong University
Postulate #4
the organism
should be
reisolated and
shown to be
the same as
the original.
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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.
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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
Chen Feng, Shanghai Jiao Tong University
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!