tailieunhanh - Ebook Microbiological applications: Laboratory manual in general microbiology: Part 2

(BQ) Part 2 book "Microbiological applications: Laboratory manual in general microbiology" presents the following contents: Microbiology of water, microbiology of milk and food products, medical microbiology and immunology. Invite you to consult. | Benson Microbiological Applications Lab Manual Eighth Edition XI. Microbiology of Water Introduction The McGraw-Hill Companies 2001 Part 11 Microbiology of Water The microorganisms of natural waters are extremely diverse. The numbers and types of bacteria present will depend on the amounts of organic matter present the presence of toxic substances the water s saline content and environmental factors such as pH temperature and aeration. The largest numbers of heterotrophic forms will exist on the bottoms and banks of rivers and lakes where organic matter predominates. Open water in the center of large bodies of water free of floating debris will have small numbers of bacteria. Many species of autotrophic types are present however that require only the dissolved inorganic salts and minerals that are present. The threat to human welfare by contamination of water supplies with sewage is a prime concern of everyone. The enteric diseases such as cholera typhoid fever and bacillary dysentery often result in epidemics when water supplies are not properly protected or treated. Thus our prime concern in this unit is the sanitary phase of water microbiology. The American Public Health Association in its Standard Methods for the Examination of Water and Wastewater has outlined acceptable procedures for testing water for sewage contamination. The exercises of this unit are based on the procedures in that book. 221 Benson Microbiological Applications Lab Manual Eighth Edition XI. Microbiology of Water 63. Bacteriological Examination of Water Qualitative Tests The McGraw-Hill Companies 2001 63 Bacteriological Examination of Water Qualitative Tests Water that contains large numbers of bacteria may be perfectly safe to drink. The important consideration from a microbiological standpoint is the kinds of microorganisms that are present. Water from streams and lakes that contain multitudes of autotrophs and saprophytic heterotrophs is potable as long as pathogens for humans are .