Metabolite Production - Microorganisms produce an exceedingly large number of metabolites during their growth using usually cheap substrates; some of the metabolites are as follows:
(i) acetone butanol,
(ii) alcohol,
(iii) antibiotics,
(iv) enzymes,
(v) organic acids, e.g., lactic acid (production 40,000 tons/yr),citric acid (300,000 tons/yr),
(vi) amino acids, e.g., glutamic acid (300,000 tons/yr), lysine (40,000 tons/yr), etc., and
(vii) vitamins, etc.