This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Lab Exercise 12: Effects of oxygen on growth OBJECTIVES 1. To differentiate between oxygen requirements using anaerobic culture media. INTRODUCTION Microbes can be classified into 5 groups based on their requirement for air that contains 20% oxygen: 1. Obligate aerobes: Require oxygen for growth via respiratory metabolism in which oxygen is the terminal electron acceptor. 2. Obligate anaerobes: Can not survive in the presence of oxygen due to lack of enzymes superoxide and catalase or peroxidase, which detoxify damaging oxygen by- products such as peroxides and superoxides. Use fermentation or anaerobic respiration. 3. Facultative anaerobes: Can grow in oxygen or without. Use oxidative respiration and fermentation/ anaerobic respiration. 4. Microaerophiles: Require small amounts of oxygen (5-10%) for respiration but can not survive in atmospheric oxygen due to limited ability to carry out respiration or presence of oxygen-sensitive enzymes. 5. Aerotolerant anaerobes: Can survive in oxygen due to presence of superoxide dismutase but do not use oxygen as a terminal electron acceptor. Use fermentation or anaerobic respiration. The oxygen requirements of a given organism can be easily determined in the microbiology laboratory by the use of both solid and liquid media. microbiology laboratory by the use of both solid and liquid media....
View Full Document
This note was uploaded on 12/23/2009 for the course BIO 205 taught by Professor Murphy during the Fall '09 term at Miramar College.
- Fall '09