Microbiology Chapter 1

National Microbiome Initiative (2016)

A U.S. government project that supports research on microbiomes of humans as well as those of our surrounding environment

Because less than 1% of microorganisms ca currently be grown in the laboratory, most of what we know about the other 99% comes from what?

DNA sequencing

Paul Erlich

Developed the first chemotherapeutic agent, for treating syphilis.

Robert Koch

Devised postulates for establishing causative relationship between a microbe and a disease

Who worked on viruses?

Dmitri Iwanosky and Martinus Beijernick (said pathogens must pass through a filter)

Identify all of the statements that describe positive applications of microbiology.

Food production Biodegradation Commercial products

Which of the following scientists first challenged spontaneous generation?

Francesco Redi

Who is considered the father of modern microbiology?

Louis Pasteur

What started the golden age of microbiology?

Pasteur's work: spontaneous generation was disproved

Joseph Lister

Published the first work on antiseptic surgery.

Microorganisms in the environment

Recycling of nutrients -Oxygen production through photosynthesis -Nitrogen fixation -Decomposers of material (cellulose, plant material in the digestive tract)

Which of these scientists were involved in investigating the idea of spontaneous generation?

Redi and Pasteur

Microbiome

The community of microorganisms, as well as their genetic information, in a given environment. 2 meanings: -the total genetic content of a microbial community -the microbial community itself (must be examined by studying genetic material) (cant grow 99% in lab)

Nomenclature

The system by which organisms are named

T/F: studies indicate early exposure to certain common microorganisms may actually protect humans from asthma and various allergies

True

Scientific theory

an explanation supported by a large amount of evidence (when an extensive amount of experimental evidence supports a hypothesis, the explanation may become a theory)

Microorganism examples

bacteria, fungi, algae, protozoa

Why are viruses not considered microorganisms?

because they are acellular, not composed of cells

What is manufactured by microbial fermentation?

beer, cheese, yogurt

Bacteria produces ethanol, hydrogen gas, and certain oils, which all have the potential to be used as...

biofuels

Microbiology history

born in 1674 by Antony Van Leeuwenhoek and Robert Hooke

Plants are dependent on microorganisms for

changing atmospheric nitrogen to a usable form.

Microbe

general term encompassing microorganisms and acellular infectious agents such as viruses

Microbes as research materials

good because they have the same metabolic and genetic properties as all higher life forms

Smallpox

has not occurred anywhere in the word since 1977 -Smallpox has been eliminated as a naturally occurring infection in human beings, AND has been eliminated by effective vaccination.

Plague

killed 1/3 of the population of Europe in the 14th century

Fermentation

large scale products of microbial products including antibiotics (fermintation- vaccine)

Pasteur's swan-necked flask experiments resolved the criticism that without "vital force" microorganisms cannot grow, by

leaving the flasks open to the air so that "vital force" was present.

Although it is said that the twentieth century was the Age of Physics, it is predicted that the twenty-first century will be the age of

microbial biodiversity

Microorganisms are useful in the study of higher life forms for what reasons?

microorganisms... -have the same fundamental genetic properties -have the same basic metabolic mechanisms -multiply quickly -are cheaper to study

In research bacteria often serves as __________, meaning that they are studied as a means to better understand processes fundamental to higher life forms

model organisms -they have the same fundamental metabolic and genetic properties as higher organisms.

Influenza (1918-19)

more people died because of the flu than all the wars combined

Bioremediation

process that uses microorganisms to degrade harmful chemicals (decomposition of harmful pollutants by microbes) (i.e. oil spill) -using bacteria to clean up pollutants

Lazzaro Spallanzani's experiment in the 1700s showed that flasks of broths that had been boiled for long periods of time and sealed...

remained sterile (pic- observation vs conclusion)

Bacteria are good research models because they

share many biochemical and physiological properties with more complex organisms

John Needham experiment

showed flasks containing various broths (by soaking a nutrient source (hay) in water) gave rise to microorganisms even when the flasks were boiled and sealed with a cork (bc boiling should have killed MO)

Why was Spallanzani's experiment still under controversy?

some argues that heating the flasks destroyed a "vital force" in the air necessary for spontaneous generation

What did Pasteur demonstrate?

that sterile broths in specially constructed swan neck flasks remained sterile even when left open to air. Microorganism in the air settles in the flask neck but never reached the broth -finally ended this series and created biogenesis

What happened when Pasteur dropped the cotton plug into a sterilized broth?

the broth became cloudy from the growth of microorganisms

Choose which of the following results Pasteur might have obtained if the broth in his swan-necked flask experiment had contained endospores.

the broth would seem sterile after boiling but would soon develop bacterial growth

Normal microbiota (normal flora)

the group of microorganisms that colonize the body surfaces but do not usually cause disease -organisms that populate the human body and protect it from disease

Microbiology

the study of the microbial world

A theory is correct only...

under a fixed set of conditions in a definable boundary -outside the boundary there are always new things to be discovered

Human microbiome project (2007)

undertaking that uses genomics to study the normal microbiota of the human body -used DNA sequencing technologies to characterize the microbial communities that inhibit the human body -can be considered a superorganism

Cervical cancer caused by the human papillomavirus (HPV) can be prevented by a(n)

vaccine

Microorganisms benefits

we could not survive without them -Nitrogen fixation (N2 > NH3) -Oxygen production -degrataion of materials (cellulose, sewage waste)

Superorganism

our own cell interacts with the body's normal microbiota to form a single cooperative movement

Biogenesis

production of living things from other living things/ matter (PIC) as opposed to spontaneous generation

Microorganisms are involved in all of the following

production of medicinal products. food production. pollution cleanup. converting nitrogen to a form useful to plants.

Germ theory of disease

the principle that microorganisms cause certain diseases -most pathogenic bacteria identified -work on viruses begin -understand that microscopic agents could cause disease led to control efforts -huge improvements in past century in human health

If Pasteur had done his experiments investigating spontaneous generation in a horse stable,

the results would probably have supported the idea of spontaneous generation

Biotechnology

the use of microbiological and biochemical techniques to solve practical problems and produce valuable products -genetically modifying bacteria to produce compounds useful to humans

John Needham (1749)

-Catholic priest -showed flasks containing various broths (by soaking a nutrient source (hay) in water) gave rise to microorganisms even when the flasks were boiled and sealed with a cork (bc boiling should have killed MO)

T/F: some scientists could not reproduce the results of Pasteur's swan necked flask experiment

True (used hay instead of sugar so kept growing after boiling

Microorganisms

organisms too small to be seen with the naked eye, discovered by Antony when he thought they were "animalcules" -foundation for all life on Earth -have existed for 3.5 billion years -plants, animals, and modern microorganisms all evolved from ancestoral bacteria -our lives depend on their activities (imunology)

Identify all the statements that describe the benefits of microbes from a human perspective.

-Nitrogen gas is not accessible for use by most organisms without the help of some microbes -Today's environmental oxygen levels may be a direct result of photosynthetic microbes -Microbes degrade/recycle metabolic wastes from other living organisms.

Tyndall concluded that some microorganisms exist in two forms:

-a cell easily killed by boiling, and -one that is heat resistant

Robert Hooke

-also credited with discovery -reproduced Antony's findings 10 years later -described "microscopical mushroom" aka "common bread mold" in 1665

How has the germ theory had huge improvements in past century in human health?

-antibiotics used to treat infectious diseases -vaccines to prevent diseases

Ignaz Semmelweis

-before Lewis Pasteur and Jacob Lister -Hungarian, Budapest (PIC) -known for introducing hand disinfection to avoid contamination -standards in obstetrical clinics, from 1847

Swan neck flask

-boiled infusion remained sterile despite opening for air -ended arguments that unheated air or broths contained "vital force" necessary for spontaneous generation -(can be redone, doesn't spoil)

Lazzaro Spallanzani (1776)

-contradicted Needham (bc cork) -boiled longer -sealed by melting necks together -broths remained sterile -crack= cloudy

What are produced metabolically by microorganisms?

-ethanol as a biofuel -cellulose used in stereo headsets -antibiotics

Applications of microbiology

-food production (contamination/recall) -biodegradation (waste) and biomedication -fermentation -biotechnology and genetic engineering -microorganisms as model organisms (isolate enzymes) -medical microbiology (infectious diseases)

Scientific method steps

-make an observation -formulate a question -hypothesis: a testable explanation -design an experiment, do it -collect and analyze data -draw conclusions -communicate methods, results, and conclusions -scientific theory? -share your findings

Match the steps of Pasteur's swan-necked flask experiments with the scientific method process

-observation:Sterile broth develops microbial growth when exposed to air -question: Where do the microorganisms come from? -hypothesis: Microorganisms enter from the air. -experiment: Construct swan-necked flasks allowing air but no microbes to enter. -recording data- Broth remains sterile unless flask is tilted, then gowth occurs. -conclusion: Spontaneous generation is false. Life comes from pre-existing life.

Normal microbiota benefits

-prevent diseases by competing with pathogens -promote the development of immune system response -aid in digestion and produce vitamins -(antibodies affect healthy bacteria too) -pathogens damage body tissues (disease symptoms)

Normal microbiota play a number of essential roles, including

-preventing disease by competing with disease-causing microbes -helping degrade foods that would otherwise be undigestible. -promoting immune system development.

John Tyndall

-redid Pasteur's experiment and confirmed that his findings were correct -explained conflicting data -found that broths have different boiling times for sterilization -found that hay had heat resistant microorganisms which was then transferred to a broth

Animalcules

-roundish/oval -2 legs on the head, 2 fins -slow, not numerous -diverse colors -swift movement

Past disease triumphs

-smallpox: no case since 1977 -plague: from rodents and respiration, antibiotics -polio: paralysis, vaccine

Emerging diseases

-swine flu (H1N1, H3N2) -influenza B -Wuhan covid, and Ebola virus -SARS, MERS -multi drug resistant tuberculosis -lyme disease -Hepatitis C (liver cancer) -AIDS -Hantavirus pulmonary syndrome (killed NA) -mad cow disease -TSE -West Nile encephalitis -cyclospora illness from basil in Mexico (HIV 1 cam from chimps, E. Coli)

Microbes are useful research tools because

-they are cheap and easy to grow in the laboratory. -they use the same metabolic pathways as eukaryotic cells. -they can be grown in large numbers very easily. -they are cheap and easy to grow in the laboratory AND they use the same metabolic pathways as eukaryotic cells

Disproving spontaneous generation

-took another 200 years -reason: conflicting results between labs

Numbers of microorganisms

-trillions of bacterial cells in the body -some say carry 10 times more microbical cells than human cells -more likely ratio is 3:1 or 1:1

How did John Tyndall's work help to explain why some scientists had difficulty reproducing Pasteur's work proving that life comes from pre-existing life?

He demonstrated that some broths require greater boiling times because they contain heat-resistant bacterial forms

Walter and Fanny Hesse

Introduced agar-agar as a solidifying gel in culture media

What 2 men are considered the founders of microorganisms?

Leeuwenhoek and Hooke

Scientists recently cloned Louis Pasteur and put him back to work in a modern lab. He promptly developed a topical gel (used externally) that breaks down proteins. Since he hasn't been around for some time, he's unsure what the best application for his invention might be. Help him out. What pathogenic agent would this gel be most effective and safe at eliminating?

Viruses on the surface of the skin

Ferdinand Cohn

a German botanist who discovered endospores that same year (1876)

Ulcers, previously thought to be caused by stress, are in fact often caused by

a bacterial infection

The outbreak of measles within the last few years is due to

a decline in vaccination of children in the previous years

When considering the human body and its microbial inhabitants, we could best be described as...

a plant composed of various ecosystems, with an important part of these ecosystems being a population of interacting microbes

Scientific method

a process of formulating a testable explanation for a question, doing controlled experiments to test that explanation and then publishing the methods, results, and conclusions

Hypothesis

a testable explanation of an observation

Old friends hypothesis

early exposure to certain common microorganisms lessens the likelyhood that the individual will develop allergies, asthma, etc. (distinguishes between friendly and harmful

John Tyndall's experiment in the 1800's showed that live microorganisms remained in some broths even after they had been boiled for 5 hours. This observation can be explained by the presence of a heat resistant form of bacteria called...

endospore

Christian Gram

Developed staining method for differentiating between groups of bacteria.

Control

component of a science experiment that helps rule out alternative explanations of the results (only feature that varied?)

John Needham's experiment in the 1700s showed that broths that had been boiled and then sealed with a cork...

could still give rise to micoorganisms

Emerging

describe infectious diseases that are newly identified or becoming more common -due to organisms jumping from a natural animal host to using humans as a host -this infection hasn't been observed in the human population prior to recent (within the last 50 years) outbreaks -hasn't been around that long, and it has made a jump across continents into a new susceptible population.

An outbreak of foot and mouth disease in England was controlled by

destroying millions of pig, sheep, and cattle

Spontaneous generation

discredited belief that organisms can arise from non living matter

Francesco Redi (1668)

disproved spontaneous generation by finding that worms on rotting meat came from eggs laid by flies, not decaying meat (covered meat with gauze, no flies) -not reproducable

Microorganisms dangers

have killed more people that wars have (weapons in bioterrorism attacks)

Compared to the range of types of plants and animals, microbes as a group are ___________ diverse

more

Antony Van Leeuwenhoek

-Dutch fabric merchant -studied lake water -made simple magnifying glass -(others used curved lens) -observed "animalcules" microbes -didn't share findings

Louis Pasteur (1822-1895)

-French chemist -1861 demonstrated air is filled with microorganisms -filtered the air through a cotton plug -this trapped microorganisms -observed and found that many microorganisms looked identical to those found in broths -developed swan neck -Developed a microbial control technique for preserving food and liquid.

The golden age of microbiology (1876-1918?)

-It is a time when the knowledge of bacteria and work with them expanded. -It was during this time that people realized that diseases could be caused by invisible agents. -It was a time when several major advances were made in microbiology.

Endospores

an extraordinarily resistant dormant cell produced by some types of bacteria -explains the differences in Pasteur's results -found in soil (P only used sugar/yeast) -highlights importance of reproducing all conditions -The structures present in the hay infusions used in experiments on spontaneous generation that made them difficult to sterilize are