Last modified on 7 May 2014, at 13:14

Microbiology

Part I The Basics

  1. Introduction to Microbiology

Microbiology is the branch of biology which deals with the study of micro organisms. In this modern world the importance of microbiology is increasing

    1. What is Microbiology?
      1. What are microbes?
      2. What makes microbes different from other organisms?
    2. Why Study Microbiology?
      1. Fields of microbiology
        1. Medical microbiology
        2. Environmental microbiology
        3. Food microbiology
        4. Microbiology as a basic science
      2. Uses of microbiology
        1. Biotechnology
        2. Bio-remediation
        3. Natural products (Bio-Pharmaceutics)
        4. Synthetic biology
      3. Medical microbiology
        1. Pathology and the microbial basis of disease
        2. Microbial nature of the human body
        3. Virology

The branch of science which deals with the study of viruses

      1. Summery
    1. History of Microbiology
      1. Ancient History, what we knew before we knew what we didn't know
        1. Ancient microbial foods
        2. Ancient preservation techniques
        3. The understanding of disease in a pre-microbial world
      2. Conflict and Transition, the discovery of microbes and the debate surrounding spontaneous generation
        1. Leeuwenhoek, microscopes, and animalcules
        2. Hooke and Kircher, two alternate early microscopists
        3. The theory of spontaneous generation and its detractors
        4. Louis Pasture and the end of spontaneous generation
      3. Pasture and Koch, the fathers of modern microbiology
        1. Vaccination and pasteurization
        2. The germ theory of disease
        3. Koch's postulates
      4. Summery
  1. A Tour of the Microbial World
    1. The Three Domains of Life
      1. A historical perspective
      2. Prokaryotes vs. eukaryotes
    2. Bacteria
      1. What are bacteria?
      2. Common bacterial characteristics
      3. Classifying bacteria by cell wall
        1. Gram Positive
        2. Gram Negative
        3. Acid Fast
        4. Mycoplasma
        5. Aside: use of the gram stain in microbiology and health today
      4. Classifying bacteria by morphology
        1. Cocci
        2. Bacilli
        3. Spirillum
        4. Less common shapes
      5. Classifying bacteria by metabolism
        1. Energy source
        2. Fermentation
        3. Gas production/fixation
      6. Classifying bacteria by genetics
    3. Archea
    4. Eukarya
  1. Structure and Function of Prokaryotic Cells
  2. The Chemistry of Life and Metabolism of Microbial Cells
  3. Nutrition and Growth
  4. Genetics and Gene Expression
  5. Viruses

Bacteria can be classified by general morphology. Characteristic cell shape and size help to name and differentiate microorganisms. There are five types of bacterial cells: Cocci, Bacilli, Coccobacilli, Fusiform, and Spirilla. Cocci bacterium are spherical or oval shape. The cocci can occur in pairs (diplococci), chains (streptococci), and irregular clusters (staphylococci). The entire bacterial cell is very small, about the size of an eukaryotic mitochondria. The second type, bacilli, are rod shaped. Coccibacilli are very short rods that can easily be mistaken for cocci. Fusiform are rod-shaped bacteria that have tapered ends (like an American football). Spirilla are spiral shaped. If the spirilla is spiral shaped and the cell is more flexible it is called a spirochete.

Part II Microbial Diversity

  • Taxonomy and Phylogeny
  • Bacteria
  • Archea
  • Fungi
  • Protozoa
  • Unicellular Algae
  • Viruses
  • Actinomycetes

Part III Medical Microbiology

Medical Microbiology is an important concept, generally dealing with microbes that cause diseases. It helps to find the effect of microbes in producing diseases and the remedial of the diseases. One of the major field of Medical Microbiology is the study of antibiotics producing organisms.

The following fields are related to Medical Microbiology: Immunology Bacteriology Virology Pharmacology

Part IV Environmental Microbiology

Part V Food and Industrial Microbiology

Industrial Microbiology

Introduction-

Use of microbes in industrial or large scale productions is known as industrial microbiology. Mostly the bacteria and fungi are used in industrial applications. Bacteria have the property of rapid reproduction, as they divide rapidly leading to an exponential increase in population. By using bacteria we can transform substrates into more useful or valuable products.

Modern Industrial Microbiology has evolved in demand to develop cheap and faster substitute of chemical reactions. In earlier years of industrial development the transformation reactions are carried out by several steps of lengthy and delicate chemical reactions. They are very hard to control, depend on various other factors, sometimes require harsh conditions like high temperature, high pressure, use of alkali and acids and use of costly transition metals as catalyst. Often, performing a single transformation requires many steps of chemical reaction. By using industrial microbiology we can transform substrates without such harsh conditions more easily than ever.

Microbes are also used to produce antibiotics, vitamins, amino acids, organic acids, alcohols, and also as food called single cell proteins (SCP).

In industrial microbiology we use the native properties of microbes to grow in various environmental conditions (can use various materials as their carbon/energy source). The yeast sacchromyces spp. for example, can grow in both in presence or absence of oxygen. When it grows in presence of oxygen it breaks glucose into CO2 and water and yields energy for growth. while growing in anaerobic conditions it produces ethyl alcohol and CO2 and just survives with little growth. This property was identified earlier in the development of humankind and thus humans started production of various alcoholic beverages.

List of Products
  • Ethanol
  • Acetic acid
  • Lactic acid
  • Vitamins
  • Amino acids
  • Enzymes
  • Some insecticides
  • Lipids
  • Coloring compounds
  • Polysaccharides(gum)

Most important use of microbes is as enzyme producers. In the beginnings of microbiology it was discovered that something within the yeast is responsible for the conversion of sugar into alcohol. This biological compound was known as an enzyme ( en= within, zyme= yeast)

Nowadays the following industrially important enzymes are produced by microbes:

  • Amylases (to degrade starch)
  • Proteases (to degrade proteins)
  • Lipases (to degrade lipids)
  • Pectinases (clarification of wine and fruit juices)
  • Cellulases (to convert cellulose into glucose)
  • Proteases and lipases are used as additives in modern detergents.

Microbes naturally produce enzymes in order to utilize the food sources present around them. For example, various fungi and bacteria growing on fruit-based substrates produce pectinases and cellulases to degrade the materials present on the cell wall of fruit cells.