Bacteria can be classified on the basis of their nutrition requirement and on the basis of different condition of oxygen in which they live. Two main types of bacteria are aerobic bacteria and anaerobic bacteria.
Anaerobic bacteria grows in the absence of oxygen. The facultative anaerobe bacteria can undergoes the process of respiration in presence as well as in absence of oxygen. Thioglycollate chemicals helps to known the aero tolerance of the organism. The turbidity on the whole tube indicates that the bacteria is facultative anaerobe.
