11th Class Biology Photosynthesis in Higher Plants Chemosynthesis

Some forms of bacteria obtain energy by chemosynthesis. This process of carbohydrate formation in which organisms use chemical reactions to obtain energy from inorganic compounds is called chemosynthesis. Such chemoautotrophic bacteria do not require light and synthesize all organic cell requirements from \[C{{O}_{2}}\] and \[{{H}_{2}}O\] and salts at the expense of oxidation of inorganic substances like (\[{{H}_{2}},N{{O}_{3}}^{},S{{O}_{4}}\]or carbonate). Some examples of chemosynthesis are :

(1) Nitrifying bacteria : e.g., Nitrosomonas, Nitrosococcus, Nitrobacter etc.

(2) Sulphur bacteria : e.g., Beggiatoa, Thiothrix and Thiobacillus.

(3) Iron bacteria : e.g., Ferrobacillus, Leptothrix and Cladothrix.

(4) Hydrogen bacteria : e.g., Bacillus pentotrophus

(5) Carbon bacteria : e.g., Carboxydomonas, Bacillus oligocarbophilus.