Microbiology is the study of microorganisms which must be viewed with the aid of a microscope or electron microscope. The importance of microbiology includes: used in biomedical research, creation of medicines, environmental applications and new research tools. Disease causing organisms include: protists, bacteria, viruses and other microorganisms. Bacteria are important for fixing N2 in a usable form for plants. Bacteria and some fungi are important in decomposition and recycling of raw materials. Industry applications of microbiology: waste management, food industry, mining, medicine, research and biotechnology. 1660’s Robert Hooke observed microorganisms for the first time with a microscope and coined the term “cell”. 1632-1723 Anton van Leeuwenhoek credited with having observed the first bacteria. 1828-1898 Ferdinand Cohn developed the first classification scheme based on bacteria shape. Cohn detailed and described the life cycle of Bacillus.
Cohn’s Classification System:
Sphaerobacteria are spherically shaped.
Microbacteria are rod shaped
Desmobacteria are filamentous
Spirobacteria are spiral shaped
1822-1895 Louis Pasteur Defined pasteurization to prevent spoilage of food by bacteria, develop vaccines and disproved the scientific dogma of “Spontaneous Generation”. He defined “Germ Theory” and demonstrated that germs were responsible for disease. 1843-1910 Robert Koch identified anthrax and developed agar growth medium. Koch’s postulates was a systematic method to establish the microbial cause of disease. Ignaz Semmelweis was the first to recognize the need for good hygiene during medical procedures.
The first to identify nosocomial infections. 1827-1912 Joseph Lister developed antiseptic methods for use in surgery and medicine. 1854-1915 Paul Ehrlich developed chemotherapy to cure infectious diseases and discovers antibiotics to treat sleeping sickness and syphilis. 1881-1951 Alexander Fleming discovered penicillin and lysozyme. 1864-1920 Dmitri Ivansvski discovered the first virus which is known as the tobacco mosaic virus (TMV). 1952 Hershey & Chase Experiments identified that DNA was the genetic material of bacteriophages. Hershey Case Experiment: using phage radioactively labeled with P32 (DNA) or S35 (protein) they infected bacteria cells. They found the P32 inside the bacteria not S35.
Recommendations for Success in Microbiology
Successful completions of general biology 2 semesters
Knowledge of basic chemistry and biochemistry
Basic understanding of classification
Review layout of text book used in the course.
Read and master learning objectives laid out in the text book. Master definitions presented in the course.