VPE 511: Environment and Environmental Hygiene (2+1)

BACTERIOLOGY OF WATER

• The presence of bacteria in water depend largely on the character of the water and on the source from which it is drawn.
• Classification of Bacteria
• The bacteria found in water may be broadly classified into two main groups
• Firstly, Saprophytic bacteria which are indigenous to water are adapted to live and multiply at temperature lower than body heat
  eg: at 20-22⁰c and derive their nutrient from decaying organic matter. These free living forms are of little importance from the hygienic standpoint except that their presence in a water in very large number denotes an abundance of organic matter.
• The Second broad group which may be called the adventitious water microorganisms are introduced from outside sources and are incapable of surviving in water for an indefinite period. Amongst these are included bacteria precipitated from the air by rain or snow, soil bacteria washed in after heavy rainfall and excretal bacteria from human or animal sources.
• Coliform Bacilli
• Soil Bacteria
• Iron Bacteria