Introductory Microbiology

1. Introductory Microbiology bpaul@ualberta.ca Bryan Paul University of Alberta, Canada

2. Objectives • Know the history of emergence in microbiology • Know the people who contributes to the emergence of the subject. • Know why microbiology is important and appreciate the beauty of it. bpaul@ualberta.ca

3. History Antonie van Leeuwenhoek (1632-1723) • A Dutch amateur microscope builder • First observation of ‘animalcules’ • Source of observation are from biofilm of an old man teeth and ditch at the back of his house. bpaul@ualberta.ca Figure showing his microscope and his observation Images: history.org and KunalBheecarry

4. Spontaneous generation Theory • 384-55BC • Lucretius • He said that disease is cause by invisible living creatures • Aristotles • Comes out with the spontaneous generation theory • The theory is used to logically deduce the emergence of organisms from specific sources. • The theory lasted for 2000 years until it was relinquish by modern biologist. bpaul@ualberta.ca

5. 1626 – 1799 • Francesco Redi • Notice that cheesecloth over meat did not induce the emergence of maggots • Disapprove spontaneous generation theory • John Needham • Observed broth that had been boiled and seal in a jar still became turbid. • Agree with spontaneous generation theory. • LazzaroSpallanzani • Observed that sealed flask of broth that were then boiled did not become turbid • Infer that it may be air that cause growth of microbes • Disapprove spontaneous generation theory. bpaul@ualberta.ca

6. Louis Pasteur (1882-1895) • First scientist to connect the relationship between cause (microorganism, bacteria, etc) and effect (disease, growth, etc). • Other than that, he is also the first scientist that; • discover fermentation process • determining the nature of disease • Pasteurisation process • And ultimately disapproving the spontaneous theory. bpaul@ualberta.ca

7. Pasteur experiment to disapprove spontaneous generation theory Images: Studyblue bpaul@ualberta.ca

8. Robert Koch (1843-1910) • Devise methods and principles that led to isolation of pure bacterial cultures. Good for laboratory experiments! • He rigorously validate the caused of disease from microorganism. • His postulates are still utilised and are cornerstone for the study in bacteriology. • Discover the cause of TB (tuberculosis) in which at his time caused 1 in 7 death of human populations. bpaul@ualberta.ca

9. Koch’s postulates • The microorganism or other pathogens must be present in all cases of disease. • The microorganism or pathogens can be isolated from the diseased host and grown in pure culture plate. • The microorganism or pathogens from the pure culture must cause the disease when inoculated into a healthy, susceptible animals. • The microorganism or pathogens re-isolated from the new host must show the same pathogenicity as the original isolation when culture and inoculated into other healthy and susceptible animals. bpaul@ualberta.ca

10. Major limitations of Koch’s postulates. • The microorganism need to be cultured and grown in pure culture. • At most time, wild type pathogens requires complex nutrients which cannot be supplied within a culture plate. This limitation can cause pathogens of interest to die. • Slow growing pathogens have slim chances in growing on a culture plate against other fast growing ones. • Organism that do not grow in selected media will fail. • Did not consider microevolution in which at that time, the term was not discovered yet. • Selected media might not be compactable with pathogen in which causes the pathogen to die. bpaul@ualberta.ca

11. Pure culture isolation • Was first develop by Fannie & Walter Hesse (agar media) and Richard Petri (petri plate). • Originally, gelatin was first used instead or agar but was later discarded as gelatin is easily degradable. • Uses aseptic technique to prevent interference of other microorganism. bpaul@ualberta.ca • Technique in pure culture isolation. By third streak, only microorganism of interest will be seen on the culture surface. • Images: shmoop.com

12. Milestone in Microbiology bpaul@ualberta.ca

13. Microbial world • There are a lot of diversity out there in the world. • Basically, the population of microorganism are a lot more than any human population could ever compete with. • Know that microbial world grown in pure culture do not necessarily represent the wild population. • Microbes exist and operate in diverse community. bpaul@ualberta.ca

14. World created by microbes. • Microbes are first living being that create the world where other organism can live in. • Microbes are foundation of life as well as biology. • Started out with prokaryotes and slowly emerging to what it is today. • Example: • Chloroplast is product of degenerate cyanobacteria! bpaul@ualberta.ca http://www.youtube.com/watch?v=8SgnnV8nV9g

15. Importance of microbes. • Microbes play crucial roles in the world we life today. They are important in; • Food industry (ie: Preservation, Fermentation) • Agricultures (ie: Mychorrhizae) • Environments (ie: Nitrobacteria fixation) • Medicine and Pharmaceutical (ie: Penicillin) • Internal flora of our body (ie: E. coli) • Biotechnology (ie: Fuel generated form bacteria) bpaul@ualberta.ca