MICRB 202 Lecture Notes - Lecture 4: Protozoa, Microbiology, Microorganism
Document Summary
Objective: in nature, microorganisms exist rarely in a pure culture because most of the time they live in the environment which consists of many species of bacteria, fungi, protozoa, and viruses. In order to study bacteria, it is necessary that they be isolated into a pure culture from their mixed culture. Thus pure culture is a cultivation of a single species of bacteria. In this lab agar strokes were used and broth cultures to replace the pour plates. Part i: examination of bacteria in a mixed culture (spread & spread plates) 10-6 dilution x 5 colonies = 5,000,000 organisms. 10-6 dilution x 14 colonies = 140,000,000 organisms. 10-6 dilution x 11 colonies = 110,000,000 organisms. 10-4 40 colonies/0. 1 ml = 400 organisms per 1. 0 ml (confluent) . 400 x 104 organisms in the original suspension. Part ii: cultural characteristics (spread plates, agar strokes, & broth cultures)
