微生物学英文课件-Controlling Microbes
微生物学英文课件
HyServe
Compact Dry SL (Salmonella)
• Salmonella form green colonies/aereas and change the medium to yellow
-> Salmonella decarboxylase alkalizes the medium and changes the medium from purple to yellow
3M Petrifilm • flexible film -> not stackable
-> elaborate closing procedure
-> 3-dimensional growth impos • different technology -> squeezer causes problems with air bubbles
HyServe
Benefits compared to the 3M Petrifilm concept
Compact Dry • solid cartridge -> unlimited stackable -> safe, closed cover -> 3-dimensional growth of molds • similar to petridish -> higher acceptance for conventional microbiology customer -> colony picking is possible
-> risk of contamination during inoculation procedure
HyServe
微生物学英文-ControllingMicrobes
– kills endospores
• Pasteurization
– kills certain microorganisms
– Bacteria
Fungi
Spores
5-10 min. 60-70oC
5-10 min.
5-10 min.
50-60oC 70-80oC
© 2004 Wadsworth – Thomson Learning
– minimal time – kill all microorganisms (sterilize)
• liquid suspension
– at given temperature
© 2004 Wadsworth – Thomson Learning
Conditions that Affect Antimicrobial Activity
© 2004 Wadsworth – Thomson Learning
Decimal Reduction Time
• Example: 1,000,000 (106) • 1 minute = 90% killed • 2 minutes = 100,000 (90%) • 3 minutes = 10,000 • 4 minutes = 1,000 • 5 minutes = 100 • 6 minutes = 1 cell
© 2004 Wadsworth – Thomson Learning
Microbial Death Rate
• Decimal reduction time
– D-value – time required to kill
90% of cells
• Heat treatments
《微生物学》双语教学
《微生物学》双语教学授课教案授课教师：李淑彬华南师范大学生命科学学院2003.2Chapter1 The introduction of microbiology第1 章绪论Microbiology（微生物学）：Microbiology is specialized area of biology that deals with living things ordinarily too small to be seen with the naked eyes.Microorganisms（微生物，microbe）：Microorganisms are defined as the organisms that are so small that ,normally,it cannot be seen without the use of a mocriscope.The word is therefore used to describe virus,bacreria,fungi,protozoom and some algae.Bacteria(细菌) ：Bacteria are some small,single celle organisms. Because they have no nucleus, the cells are described as prokaryotes.Fungi(真菌)：Fungi (mushrooms（蘑菇）, molds（霉菌）, and yeasts) have eukaryotic（真核的）cells (with a true nucleus). Most fungi are multicellular.Fungi obtain nutrients by absorbing organic material from their environment.Protozoom(原生动物)：Protozoans are unicellular eucaryotes and are classified according to their means of locomotion. Protozoans obtain nourishment by absorption or ingestion through specialized structures.Algae（藻类）：Alage are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis.Algae produce oxygen and carbohydrates that are used by other organisms.Viruses（病毒）：Viruses are noncellular entities that are parasites of cells. Viruses consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat. An envelope may surround the coat.A brief history of microbiologyThe science of microbiology did not start until the invention of the microscope in the mid 16th century and it was not until the late 17th century that Antoine van Leeuwenhoek made their first records of fungi, bacteria and protozoa.The late 19th century was the time when the first real breakthroughs on the role of microbes in the environment and medicine were made. Louis Pasteur disproved the theory of spontaneous generation（自然发生）(that living organisms spontaneously arose from inorganic material) and Robert Koch's development of pure culture techniques allowed him to show unequivocally that a bacterium was responsible for a particular disease. Since then the science has grown dramatically as microbiology impinges on all aspects of life and the environment.2.Louis Pasteur stated that microorganisms are in the air everywhere and offered proof ofbiogenesisLouis Pasteurˊdiscoveries led to the developmemt of aseptic（无菌的）techniques used in laboratory and medical procedures to prevent contamination by microorangisms that are in the air.Louis Pasteur found that yeast ferments（发酵）sugar to alchhol and that can oxidize alcohol to acetic acid.A heating process called pasteurization（巴斯德消毒）is used to kill bacteria in some alcohol beverages and milks.Joseph Lister introduced the use of a disinfectant（消毒）to clean surgical dressings in order to control infections in humans.Robert Koch proved that microorganisms transmit diseases.He used a sequence of procedures called Koch’s postulates（科赫法则）,Which areused today to prove that a particular microorganism casues a particular disease.Koch’s postulates：Koch's postulates are a number of criteria that have been used in the past to prove that a bacterium is responsible for a particular disease.1.The bacteria should be found in all cases and at all sites of the disease.2.The bacteria should be isolated from the infected person and maintained in pure culture.3.The pure cultured microbe should cause symptoms of the disease on inoculation into asusceptible individual.4.The bacteria should be reisolated from the intentionally infected host.The importance of microbiology：microbes in our body1.Everyone has microorganisms in and on the body Some microorganisms live in humans andother animals and are needed to maintain the animals health. these make up the normal flora （正常菌群）;2.Some Microorganisms cause disease.3.The disease-producing properties of a species of microbe and the host's resistance areimportant factors in determining whether a person will contract a disease.2.Microbes and Human Welfare1.Microorganisms degrade dead plants and animals and recycle chemical elements to beused by living plants and animals.2.Bacteria are used to decompose organic matter in sewage. Bioremediation processes usebacteria to clean up toxic wastes.3.Bacteria that cause diseases in insects are being used as biological controls of insect pests.Biological controls are specific for the pest and do not harm the environment.ing recombinant DNA, bacteria can produce important human proteins, such as insulin,beta-endorphin,and hepatitis B vaccine.Microorganisms can be used to help produce foods.They are also food sources (single-cell protein) themselves.3.As a basic biological science：microorganisms are the best model systems for understanding basic life processes.All cells have much in common, what is true for E. coli is also true for elephant, only more soSimple yet representativeEasiness and quickness to grow large quantityCommon characterizes of microorganism•Big surface/volume•High absorption and transformation•Rapid growth and reproduction•Easiness to variation•high adaptation to environment•DiversityReview question1.Match the following people to their contribution toward the advancement of microbiology.__ Ehrlich (a) First to observe bacteria__ Fleming (b) First to observe cells in__ Hooke plant material and name_ Koch them__ Lister (c) Disproved spontaneous__ Pasteur generation__ Van Leeuwenhoek (d) Proved that microorganisms can cause disease(e)Discovered penicillin(f)Used the first syntheticchemotheraputic agent First to employdisinfectants in surgical procedures2. Match the following microorganisms to their descriptions.__ Algae (a) Not composed of cells__ Bacteria (b) Cell wall made of chitin__ Fungi (c) Cell wall made of__ Protozoom peptidoglycan__ Viruses (d) Cell wall made of cellulose; photosynthetic(e) Complex cell structure lacking a cell wall3.Briefly state the role played by microorganisms in each of the following.(a)Biological control of pests(b)Recycling of elements(c)Normal flora(d)Sewage treatment(e)Human insulin production4 The microbes were first formally observed in the mid-1600's, but the cell theory wasn't enunciated until 1839. Write a brief essay explaining why microbiology did not become a formally recognized science until Pasteur's time.5. Compare and contrast the works of Louis Pasteur and Robert Koch, in terms of both applied and basic science.6. Microorganisms can be both beneficial and harmful to humans. Although we tend to emphasize the harmful microorganisms (infectious disease agents), many more are beneficial than harmful.●In what ways are microorganisms important in the food , agriculture,and industries?7. Louis Pasteur´s work on spontaneous generation led to the development of methods for control of the growth of microorganisms. Robert Koch developed criteria for the study of infectious microorganisms, and developed the first methods for the growth of pure cultures of microorganisms. Beijerinck and Winogradsky studied bacteria in soil and water, and developed the enrichment culture technique. In the twentieth century, basic and applied microbiology have worked hand in hand to yield a number of important practical advances and a revolution in molecular biology.●How did Pasteur´s famous experiment defeat the theory of spontaneous generation?●How can Koch´s postulates prove cause and effect in a disease?●Who was the first person to use solid culture media in microbiology?●What advantages do so lid media offer for the culture of microorganisms?●What is the enrichment culture technique and why was it a useful new method inmicrobiology?Chapter 2 prokayotic microorganism(原核微生物)第二章原核微生物prokaryotic cellsThe chief distinguishing characteristics of procaryotic cells are:1.genetic material (DNA) is not enclosed within a membrane.2.They lack other membrane bounded organelles.3.Their DNA is not associated with histone proteins (special chromosomalproteins found in eucaryotes).Their cell walls almost always contain thecomplex polysaccharide peptidoglycan（肽聚糖）.Bacteria(细菌) and archaeobacteria（古细菌）Bacteria are small, single-celled, microorganisms that belong to a group called prokaryotes . Bacteria are ubiquitous. They are a highly successful and diverse group of organisms that can obtain energy and carbon from a wide range of sources and therefore can colonize every niche on our planet from deep ocean trenches to volcanic craters. In the 1970s, using DNA sequencing information, it was found that the group we know as the bacteria could be split into two, the eubacteria and the archaeobacteria and it appears that these two groups evolved away from each other very early in the history of living things at about the same time that the first group of eukaryotic cells evolved. Members of the eubacteria include some of the more familiar bacteria such as Escherichia colt（大肠埃希氏菌）and Staphylococcus aureus（金黄色葡萄球菌）and are the prokaryotes that are best studied and understood. The archaebacteria are a very diverse group of organisms, which differ from the eubacteria（真细菌0 in a number of features having, in particular, very different cell walls and membranes. This group includes bacteria that are capable of existing in extreme environments。
华中农业大学微生物英文版课件
目录
CONTENTS
• Introduction • Types of Microorganisms • Microbial Metabolism • Microbial Life Processes • Microbial Ecology • Microbial Pathogenesis and Disease
04 Microbial Life Processes
Cell Structure and Function
Cell membrane
Composition, function, and transport processes across the membrane
Cell wall
Structure, function, and role in maintaining cell shape and protecting the cell
Fungi play important roles in composition, nutrient cycling, and symbolic relationships with plants and animals
Some fungi are editable and have culinary uses, while others can cause diseases in plants and animals
Cultivation and Respiration
Microorganisms can be cultured in different environments, such as on solid surfaces or in liquid media The choice of cultivation environment depends on the type of microbiology and the desired outcome of the experience or study
Chapter 8 Microbial genetics 微生物学 教学课件 英文版
A number of prokaryotes have been found to be naturally transformable
• certain species of G+ and G- Bacteria
• some species of Archaea
However, even within transformable genera, only certain strains or species are transformable
8.2 Genetic recombination
Genetic recombination is the process by which genetic elements contained in two separate genomes are brought together in one unit.
❖ Value in industry
• Antibiotics
• Increase yields and improve manufacturing processes ❖ Diseases
• Understanding the genetics of disease-causing microorganisms
• The colonies not appearing on the replica plate are marked with an X
• The replica plate lacked one nutrient (leucine) present in the master plate
• Therefore, the colonies marked with an X are leucine auxotrophs
6 微生物的生长及其控制(英文教案简版)
over the depression creating a precise volume
between 0.02-0.1uL.
血球计数板
• 1个大方格分为25个中方格，每个中方格分为16个小方格
• 1个大方格分为16个中方格，每个中方格分为25个小方格
• 计数室容积 = 1×1×0.1mm3
• 1mL菌液中的总菌数 =
• No growth occurs;
• Cells are very active metabolically;
• Cells changes very little; • Microbes are sensitive to adverse conditions antibiotics anti-microbial agents
• The length of this time depends on the history of the culture and growth conditions.
If this comes from a fresh culture in the same medium, the lag phase will be short; If the inoculum is old or the medium has been changed ( especially moving bacteria from a rich medium to a poor one )，the lag phase will be longer.
2、Incubation
• A temperature—controlled chamber or incubator; • Setting the optimum temperature and gas content; • Incubation produces a culture---the visible growth of the microbe in the medium.
(优选)华中农业微生物学第一章英文版ppt讲解
Our world is populated by invisible creatures too small to be seen with the unaided eye. These life forms, the microbes or microorganisms, may be seen only by magnifying their image with a microscope.
of microbiology
Concepts
• Microorganisms are responsible for many of the changes observed in organic and inorganic matter (e.g., fermentation and the carbon, nitrogen and sulfur cycles that occurred in nature.
Fungi (unicellular or multicellular)
Protozoa (unicellular)
Other (multicellular organisms)
The size and cell type of microbes
Most of the bacteria, protozoa, and fungi are single-celled microorganisms, and even the multicelled microbes do not have a great range of cell types. Viruses are not even cells, just genetic material surrounded by a protein coat and incapable of independent existence.
微生物英文课件-control
Dr. Qin LUO
He instructed surgeons under his responsibility to wear clean gloves and wash their hands before and after operations with 5% carbolic acid solutions. Instruments were also washed in the same solution and assistants sprayed the solution in the operating theatre.
industrial clean rooms
9.3 Chemical agents in microbial control
1. Halogens(鹵素) 2. Phenolics(酚醛) 3. Chlorhexidine(洗必太,雙氯苯雙胍己烷) 4. Alcohols 5. Hydrogen peroxide(過氧化氫) 6. Detergents (去污劑)& soaps 7. Heavy metals 8. Aldehydes(醛)
5. Hydrogen peroxide過氧化氫
• Weak (3%) to strong (25%) • Produce highly reactive hydroxyl-free(游離羥基)radicals(原
子團)that damage protein & DNA while also decomposing to O2 gas – toxic to anaerobes
1. Halogens(鹵素)
• C劑h)l,ocrhinloer–amCiln2,ehs氯yp胺ochlorites (次氯酸,chlorine bleach氯漂白 – Denaturation of proteins by disrupting disulfide bonds – Can be sporicidal殺孢子的
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• Heat treatments
– – – – temperature type of microorganism physiological state other substances
© 2004 Wadsworth – Thomson Learning
Decimal Reduction Time
– Lysol
• Hexachlorophene
– prescription use
© 2004 Wadsworth – Thomson Learning
Phenol: antiseptic
• 5% solution kills vegetative cells • Lysol and hexachlorophene contain phenol-related compounds – Less toxic and more effective as antimicrobial agents
– Lysol (Paracersol) – disinfectant – Hexachlorophene – antiseptic
• Chlorhexidine – replaced hexachlorophene
– Kills by disrupt the cytoplasmic membrane
•
Mode of action
– Disrupts cell membranes and their permeability – Denature proteins – Bactericidal or bacteriostatic, depending on concentration
© 2004 Wadsworth – Thomson Learning
© 2004 Wadsworth – Thomson Learning
Chemical controls
• Antimicrobial agents
– chemotherapeutic agents
• used to treat disease
– germicides and germistats
– not sterilization – evaporation – lyophilization
© 2004 Wadsworth – Thomson Learning
Specifications of an Ideal Chemical Agent
• • • • • • • • • A. Broad spectrum of activity B. Soluble in water or alcohol C. Storage ability D. Nontoxic to humans or animals E. Active at normal temperatures F. Penetrating ability G. Safe for associated materials H. Odorless or pleasant smelling I. Inexpensive and readily available
• Pasteurization
– kills certain microorganisms
– Bacteria 5-10 min. 60-70oC Fungi Spores 5-10 min. 5-10 min. 50-60oC 70-80oC
© 2004 Wadsworth – Thomson Learning
© 2004 Wadsworth – Thomson Learning
Physical Controls
• Heat
– Moist
• boiling
– kills most vegetative cells, not sterile
• autoclave
– steam under pressure: 15 lbs./in2 at 121oC for 15 min. – kills endospores
© 2004 Wadsworth – Thomson Learning
Mechanisms of Microbial Agents
• MODE OF ACTION • Interferes with cellular components
– Cell membrane – Cell wall – Ribosomes – Genetic material (DNA) – Enzymes – Cytosol
© 2004 Wadsworth – Thomson Learning
Sterilization
• Thermal death point
– lowest temperature – kill all microorganisms in broth – 10 minutes
• Thermal death time
© 2004 Wadsworth – Thomson Learning
Testing germicides
• Paper disc method
– germicide placed on paper disc – disc placed on agar seeded with microorganism – after incubation, observe zone of inhibition
© 2004 Wadsworth – Thomson Learning
Classes of germicides
• Phenols and phenolics
– denature proteins – act on lipids – disrupt cytoplasmic membrane – Examples: • Paracresol
Classes of germicides
• Alcohols
– disrupt lipids
• attack cytoplasmic membrane
– denature proteins – 50-70% solutions more effective
• Sterilization
– destroy all microbial life
• Disinfection
– reduces number of pathogens – pose no danger of disease
• Microbiocidal
– Kills all microbes
• Sterilant
• Temperature
– Higher Temp. greater number killed
• Substrate
– Affect the efficiency of agent
• Microbial characteristics
– Susceptibility to different agents
– media, vitamins, antibiotics, hormones
• Osmotic strength
– salts and sugars – damage cells by plasmolysis – preserving foods
• air filters (HEPA)
• Drying
• • • • • • • Example: 1,000,000 (106) 1 minute = 90% killed 2 minutes = 100,000 (90%) 3 minutes = 10,000 4 minutes = 1,000 5 minutes = 100 6 minutes = 1 cell
• Population density
– Larger number the more time
• Concentration
– Increase in concentration decreases in time
• Time exposure
– Increase exposure increases the number of killed
– Kills vegetative & endospores
• Decontamination
– renders contaminated surface safe to handle
• Microbiostatic
– Only inhibits the growth of microbes
• Antisepsis
• New method of Pasteurization
– Short term flash 71.6oC for15 seconds
© 2004 Wadsworth – Thomson Learning
Physical Controls
Dry
• long periods • 160oC for 2 hours • 171oC for 1 hour
Pasteurization
• Involves heating to temperatures below boiling for certain time periods (63-66oC for 30 minutes)
– Does not kill all microbes, but only those causing disease – Reduces the numbers of microbes that cause food spoilage
Chapter 9 Controlling Microorganisms
© 2004 Wadsworth – Thomson Learning
Controlling Microbial Growth