PPT-Controlling Microbial Growth in the Environment

9 Figure 91 A plot of microbial death rate Constant percentage of the extant population is killed each minute Basic Principles of Microbial Control Action of Antimicrobial Agents Alteration of cell walls and membranes. 1. 41. Copyright © McGraw-Hill Global Education Holdings, LLC. Permission required for reproduction or display.. Microbial Growth and . Food . Spoilage. Results . from growth of microbes in food. alters food visibly and in other ways, rendering it unsuitable for . A. Microbial Reproduction. 1. binary (transverse) fission. A) parent cell enlarges and duplicates all its genetic material. B) DNA copies move to opposite ends of parent and attach to a section of the cell membrane as it begins to pinch together at the center. In the Environment. Table 9.1 Terminology of Microbial Control. Figure 9.1 A plot of microbial death rate.. Basic Principles of Microbial Control. Action of Antimicrobial Agents. Alteration of cell walls and membranes. Microbiology. Microbial Growth. Microbial requirements for growth:. 1. . Physical. A. . Temperature. Optimal growth temperature. Permissible range. human pathogens optimal = . 37°C. Microbial Growth. Vocabulary. Bactericidal. : . Bacteria-killing. Bacteriostasis. : Bacterial growth . inhibiting. Disinfection. :. . Destruction of . vegetative pathogens. Antisepsis. :. . Destruction of vegetative pathogens . The ability of microorganisms to grow or multiply in a food is determined by the food environment ( intrinsic environment of food) as well as the environment in which the food is stored (extrinsic environment ).. (a) Intrinsic factors: . These. . are inherent in the food. They include:. pH,. . water activity,. . oxidation reduction potential,. . nutrient content,. . antimicrobial contents,. . biological structure. Musafer. PhD. Microbial growth defined as an increase in cellular constituents resulting an increase in a microorganism size, population number or both.. 1-Lag phase. When M.O are inoculated into fresh culture medium, will not reproduce immediately, therefore this period is called the lag phase. . Growth: . A. n . increase in cell number, not in cell size. .. Bacteria . grow and divide by binary fission, a rapid and relatively simple process. .. Phases . of Growth Bacterial Growth Curve : . When . 1. Microbial survival strategies. 2. Microbial growth. 3. Effects of the environment. 4. Microbial cultures. 5. Growth measurements. 6. Antimicrobial agents. 7. Antibiotics. 1. . Microbial. . survival. 1. Temperature. 2. . PH. 3. . Water activity. 4. . Oxygen and redox. Temperature. Minimum Temperature. . The temperature below which no growth occurs.. At temperature below the minimum the properties of cell membranes change so that they can no longer transport materials into the cell. biotechnology.important. branch of Microbiology where economically valuable products are produced from cheaper raw materials by using large culture of . m.o.. Up stream and Downstream process.. Screening-Definition.. Microbiology. Outline. Microbial growth . in . natural environments. . Measurement . of . microbial population size. Principles of . microbial control. . Physical, chemical and biological control. Microbiological quality of pharmaceutical products is influenced by:. Environment . Materials . . Good Manufacturing Practices (GMP). It is developed to minimize contamination by a study:. Ecology of microorganisms.