PDF-Chapter 6: Microbial Growth

1 Microbial Growth4Refers to an increase in cell not in cell size4Bacteria grow and divide by binary a rapid and relatively simple process Requirements for GrowthPhysical Requirements1 Microb. 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. . corticosterone. Two microbe strains were more commonly found in nests gathered at the rural site.. . Background. Discussion. Results. Methods. Acknowledgements. Correlations between nest commensal species, nestling health and hormones in the Eastern bluebird, . A. Metabolism. 1. Anabolism. A) synthesis reactions (building up). 2. Catabolism. A) lysis reactions (breaking down). B. Enzymes. 1. proteins that facilitate chemical reactions. Microbial Metabolism. Batch culture and Kinetics of Microbial growth in batch culture. After inoculation the growth rate of the cells gradually increases.. The cells grow at a constant, maximum, rate and this period is known as the . A. Structure of DNA. 1. discovered by James Watson and Francis Crick in 1953. 2. stores genetic information for the production of proteins. 3. composed of nucleotides. A) a nucleotide is composed of a nitrogenous base, sugar, and phosphate. 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. (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. 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. . 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..