MIC101: Development of Microbiology as a Scientific Field

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Questions and Answers

What is the main purpose of pasteurization?

To reduce the number of viable pathogen (correct)

To improve the nutritional value of food

To enhance the flavor of beverages

To extend the shelf life of food

What temperature and time duration did Louis Pasteur find to be effective in pasteurization?

62.8°C for half an hour (correct)

70°C for 15 minutes

80°C for 2 hours

60°C for 1 hour

What was the prevailing belief about disease before the Germ Theory of Disease?

Disease was caused by bad air

Disease was caused by invisible microorganisms

Disease was a punishment for one's sins (correct)

Disease was caused by poor nutrition

Who applied the Germ Theory of Disease to medical procedures?

Joseph Lister Signup and view all the answers

What was the significance of the discovery of yeast's role in fermentation?

It showed the link between microorganisms and physical and chemical changes in organic materials Signup and view all the answers

What is the term for the process of heating a food to a specific temperature for a definite length of time to reduce spoilage and kill bacteria?

Pasteurization Signup and view all the answers

What is the primary goal of the Germ Theory of Disease?

To understand the cause of diseases Signup and view all the answers

What is the significance of Louis Pasteur's work in relation to the Germ Theory of Disease?

He proved that microorganisms cause disease Signup and view all the answers

What was the main contribution of Ignaz Semmelweis in the 1840s?

He demonstrated that physicians transmitted infections to patients without disinfecting their hands Signup and view all the answers

What was Lister's innovation in surgery?

He began treating surgical wounds with a phenol solution Signup and view all the answers

What was the significance of Robert Koch's work on anthrax?

He established the link between microbes and infectious diseases Signup and view all the answers

What are the four postulates of Koch?

The pathogen must be isolated from the diseased host and grown in pure culture Signup and view all the answers

What is the first statement of Koch's postulates?

The same pathogen must be present in every case of the disease Signup and view all the answers

What is the significance of Lister's work in the context of the germ theory of disease?

It provided evidence that microorganisms cause surgical wound infections Signup and view all the answers

What is the limitation of Koch's postulates?

They are not applicable to viral diseases Signup and view all the answers

Who wrote the textbook 'Microbiology: An Introduction'?

Gerard J. Tortora Signup and view all the answers

What was the primary problem faced by French merchants who shipped beer and wine over long distances?

Souring and spoilage of their products Signup and view all the answers

What was the outcome of yeast fermentation in the absence of air?

Conversion of sugars to alcohol Signup and view all the answers

What was the main cause of souring and spoilage of beer and wine?

Bacteria converting alcohol to organic acids Signup and view all the answers

What was Louis Pasteur's solution to the spoilage problem?

Heating the beer and wine just enough to kill most bacteria Signup and view all the answers

What is the period known as the 'First Golden Age' of microbiology?

1857-1914 Signup and view all the answers

What is the outcome of bacterial fermentation in the presence of oxygen?

Conversion of sugars to carbon dioxide Signup and view all the answers

What is the term used to describe the conversion of carbohydrates to alcohols and carbon dioxide or organic acids?

Fermentation Signup and view all the answers

What is the byproduct of bacterial fermentation that causes souring and spoilage of beer and wine?

Acetic Acid Signup and view all the answers

What is the process of introducing organisms into a defined location such as on a culture media plate?

Inoculation Signup and view all the answers

What is the term used to describe the increase in the number of cells in a culture medium?

Bacterial growth Signup and view all the answers

What is the term used to describe the detection of the taxonomy, genetic makeup, metabolic pattern, and virulence factor of an organism?

Identification Signup and view all the answers

What is the term used to describe the non-intended or accidental introduction of infectious material like bacteria, yeast, mould, fungi, virus, prions, or their toxins and by-products?

Microbiological contamination Signup and view all the answers

What is the primary source of agar?

Marine red algae Signup and view all the answers

What is the term used to describe a culture that has cells from only one species?

Pure culture Signup and view all the answers

What is the function of agar in culture media?

Acts as a solidifying agent Signup and view all the answers

What is the term used to describe a culture that has more than one species present in it?

Mixed culture Signup and view all the answers

What is the chemical composition of agar?

Complex polysaccharide Signup and view all the answers

Why is agar not metabolized by microbes?

It has no nutritional value Signup and view all the answers

What is the temperature range at which agar liquefies and solidifies?

Liquefies at 100°C, solidifies at 40°C Signup and view all the answers

What is a bacterial colony?

A visible cluster of cells derived from a single ancestor Signup and view all the answers

What is the term for a group of organisms having the same genetic content, morphology, metabolic pattern, and able to reproduce?

Species Signup and view all the answers

Who played an important role in the development of the use of agar as a solid medium?

Robert Koch Signup and view all the answers

Study Notes

Development of Microbiology as a Scientific Field

1857-1914: First Golden Age of Microbiology
- Fermentation and Pasteurization
- The Germ Theory of Disease
- Vaccination
1940-1990: Second Golden Age
- The First Synthetic Drugs
- Discovery of antibiotics
- Emergence of distinct fields of microbiology
1990 to Present: Third Golden Age
- Genomics, rDNA technology, Proteomics

Fermentation and Pasteurization

Fermentation: conversion of carbohydrates to alcohols and carbon dioxide or organic acids
Louis Pasteur's work on fermentation:
- Yeasts convert sugars to alcohol in absence of air
- Unwanted bacteria convert alcohol into organic acids/vinegar
Pasteurization:
- Heating a food/liquid to a specific temperature for a definite length of time
- Cooling it immediately to slow microbial growth and reduce the number of viable pathogens
- Developed by Louis Pasteur to prevent spoilage of beverages

The Germ Theory of Disease

Early concept: disease was believed to be punishment for one's sins, bad character, or poverty
Realization that microorganisms might cause disease:
- Yeasts play a crucial role in fermentation
- Microorganisms might have similar relationships with plants and animals
Joseph Lister's application of the germ theory to medical procedures:
- Using phenol to disinfect surgical wounds and reduce infections

Connecting the Dots between Disease and Microbes

Robert Koch's work on anthrax:
- Demonstrated that certain bacteria are always present in the blood of animals with the disease
- Established the link between microbes and infectious diseases
Koch's Postulates:
1. The same pathogen must be present in every case of the disease
2. The pathogen must be isolated from the diseased host and grown in pure culture
3. The pathogen from the pure culture must cause the disease when it's inoculated into a healthy, susceptible laboratory animal
4. The pathogen must be isolated from the inoculated animal and must be shown to be the original organism

Limitations of Koch's Postulates

Statement 1: The same pathogen must be present in every case of the disease
Agar: a complex polysaccharide used as a solidifying agent for culture media
Robert Koch's role in the development of agar as a solid medium

Useful Definitions

Inoculation: introduction of organisms into a defined location, such as on a culture media plate
Bacterial Growth: increase in the number of cells
Identification: detecting the taxonomy, genetic makeup, metabolic pattern, and virulence factor of an organism
Contamination: non-intended or accidental introduction of infectious material
Pure Culture: a culture with cells from only one species
Mixed Culture: a culture with more than one species present

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Description

This quiz covers the development of microbiology as a scientific field from 1857 to present, including the Golden Ages of microbiology and key discoveries.