Analysis of Biological System An understanding of biological system can be simplified by analyzing the system at several different levels: Cell level: Molecular level: Population level: Production level:

Course Outline Overview of Microbiology Biochemistry of Cells Enzyme Technology Molecular Biology and Metabolic Pathways Microbial Growth Models Bioreactor Analysis and Operation Downstream Processing (product recovery and purification) Genetic Engineering

Overview of Microbiology Microbiology (in Greek micron = small and biologia = studying life) is the study of microorganisms at the cell level. Microorganism refers to any organism too small to be viewed by the unaided eye, as bacteria, fungi and algae and protozoa. ( Random House Webster’s Unabridged Dictionary ) It is often illustrated using single-celled, or unicellular organisms

Cell: The cell is Cells are packages of living matter surrounded by membranes or walls. Within the cell are various organelles in controlling life processes for the cell intake of nutrients, production of energy, discharge of waste materials, and reproduction. Overview of Microbiology (Chapter 2, M. Shuler)

Basics of Microbiology Naming cells Primary classification of microorganism - Procaryotes: bacteria; - Eucaryotes: fungi (yeast and moled) algae - Virus Microbial cell characteristics under each cell category - cell structure and reproduction

Naming Cells A dual name (binary nomenclature) in Latin or Latinized is used, including genus & species A genus: a group of related species A species: includes organisms that are substantially alike. e.g. Escherichia coli; Bacillus subtilis; Sacchromyces cerevisiae; Penicillium chrysogenum. (in italic type) Escherichia is the genus, the first letter is capitalized coli is the species in lower case. Abbreviation:E. coli Various strain and substrains are designated by the addition of letters and numbers. e.g. E. coliK12.

Microbial diversity Cell adaptation to the environment Temperature Psychrophiles can grow. e.g. Leifsonia rubra isolated from Antarctica Mesophiles grow between important uses in food preparation such as cheese, yoghurt, beer and wine making, e.g. Saccharomyces cerevisiae. Thermophiles can grow at temperature Thermus aquaticus is a species of bacterium that can tolerate high temperatures. It thrives at 70° C, but can survive at temperatures 50°- 80° C. Regular sterilization at 121 o C.

Microbial diversity pH: –Acidophiles are microbes that tends toward acidic conditions pH e.g Acidithiobacillus ferrooxidans in acid mine drainage. –Alkaliphiles are microbes that thrive in alkaline environments with a pH of e.g. Bacillus okhensis living in carbonate soil.

Microbial diversity Moisture: Some cells can grow - where the water activity is high (e.g. algae) - on solid surface (mold)

Microbial diversity Oxygen: Some microorganism requires oxygen for growth called Other organism can be inhibited by the presence of oxygen which is called can switch the metabolic pathway to allow them to grow under either circumstance. e.g. Saccharomyces cerevisiae. Almost all animals, most fungi and several bacteria are aerobes. Most anaerobic organism are bacteria.

Microbial diversity Nutrient sources : Microorganism can be classified into two categories on the basis of their carbon sources. use organic compounds such as carbohydrates, lipids, and hydrocarbons as a carbon and energy source. use carbon dioxide as a carbon source. e.g. cyanobacteria

Microbial diversity Extremophiles: Organism from those extreme environments. Acidophile: An organism with an optimum pH level at or below pH 3. Alkaliphile: An organism with optimal growth at pH levels of 9 or above. Halophile: An organism requiring at least 0.2M of NaCl for growth. Psychrophile: An organism that can thrive at temperatures of 20 °C or lower. Thermophile: An organism that can thrive at temperatures between °C.

Microbial diversity Shape (Bacteria): coccus (cocci, pl): A cell with a spherical or elliptical shape. e.g. Streptococcus is a genus of spherical bacteria

Microbial diversity bacillus (bacilli, pl): a cylindrical cell e.g. Bacillus subtilis is a bacterium that is commonly found in soil.

Microbial diversity spirillum (spirilla, pl): a spiral-shaped cell. e.g. Rhodospirillum is a bacterium. Some cells may change shape in response to changes in their local environment.

Section Summary Organism cells are highly diverse in terms of their adaptation to the living environment: Temperature, pH, oxygen, moisture, nutrients Shapes (bacteria): Coccus, Bacillus and Spirillum