PPT-Microbial Growth

CLS 212 Medical Microbiology Factors Affecting Microbial Growth There are some factors that affect and control the growth of microorganisms around us in hospitals in the laboratory and in industrial settings . 1 Microbial Growth:4Refers to an increase in cell , not in cell size.4Bacteria grow and divide by binary a rapid and relatively simple process. Requirements for GrowthPhysical Requirements1. : Microb in vitro. CLS 212: Medical Microbiology. . Microbicidal. or . Microbistatic. ?. . Microbicidal. . Microbicidal. . is . the process . or . an agent . that . kills. the microorganism. . 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. Microbial growth is the increase in number of cells, not cell size. Microbial Growth. The Requirements for Growth: . Physical Requirements. Temperature. Minimum growth temperature. Optimum growth temperature. 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.. 9. Figure 9.1 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. Microbiology. Outline. Microbial growth . in . natural environments. . Measurement . of . microbial population size. Principles of . microbial control. . Physical, chemical and biological control. . Kinetics. Growth Curve. Log CFU/ml. Optical Density. Lag. First Order Kinetics. Food microbiology is concerned with all phases. Of microbial growth (. lag,log. , stationary, death phase).Growth curves are normally plotted as the number of cells on a log scale or log10 cell number versus time..