PPT-The major factors which effect on microbial growth in foods include

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. 1. 19. Copyright © McGraw-Hill Global Education Holdings, LLC. Permission required for reproduction or display.. Introduction to . Microbial . Taxonomy. Taxonomy. science of biological classification. Dr. . Kamal. E. M. . Elkahlout. Food Microbiology 2 . Microbial Nutrition and Factors Affecting Growth. Intrinsic and Extrinsic Factors . Factors affecting the growth and survival of micro-organisms in foods. 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. Alex LK Ng, Ian YH Wong. Department of Ophthalmology, . The University . of Hong Kong. All authors have no proprietary interests in the materials discussed in this presentation. Background. Microbial keratitis. 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 . THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE. HOW DID LIFE ORIGINATE?. SPONTANEOUS GENERATION. LIFE ARISING FROM NON-LIVING MATTER. LONG BELIEVED AS THE ACCEPTED EXPLANATION OF ORIGINATION OF LIFE. EXPERIMENTS EVENTUALLY SHOWED IT TO BE IMPOSSIBLE. 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. 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. . Definitions. Indigenous . flora. microorganisms . native or belonging naturally to a region.. Colonization. establishment . of a site of reproduction of microbes on a person without necessarily resulting in tissue invasion or . Microbiology. Microbial Growth. Microbial requirements for growth:. 1. . Physical. A. . Temperature. Optimal growth temperature. Permissible range. human pathogens optimal = . 37°C. Microbial Growth. 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. Cause of spoilage:. Spoilage may be due to one or more of the following:. 1. Growth and activity of microorganisms. 2. Insects. 3. Action of the enzymes of the plant or animal food.. 4. Purely chemical reactions i.e., those not . . 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..