May bacterias are found in water most of them are of no sanitary significance. Few in numbers are pathogenic. These include bacteria causing typhoid fever, Para typhoid, Dysentery,
Gastro enteric diseases, etc…
Water bacteria may be classified in 4 ways.
1) According to Oxygen Demand
a. Aerobic bacteria = those which require light and free oxygen for their living and development.
b. Anaerobic bacteria = those which do not require light and free oxygen for their living and development.
c. Facultative bacteria = those which can exist in presence or absence or light and free oxygen. They grow more in absence of oxygen.
2) According to Shape
a. Cocci bacteria = Cells are round or spherical.
b. Bacilli = Cells are rod shaped.
c. Spirilla = Spiral shaped cells.
3) According to their diseases producing characteristics
a. Pathogenic bacteria = those which are harmful to human life. They causes diseases like typhoid, Dysentery, cholera, etc…
b. Non-pathogenic bacteria = those do not cause diseases to human.
4) According to the Temperature Flourish
a. Psycryophilic bacteria = which can persist at low temperature only Range 10 - 200C.
b. Mesophillic = which can thieve within the temperature range of 200C to 400C.
c. Thermophillic = It is most effective in the temperature range of 40-650C.
Copyright Â© 2018-2021 BrainKart.com; All Rights Reserved. (BS) Developed by Therithal info, Chennai.