Write the most important characteristic that Aspergillus niger, Clostridium butylium, and Lactobacillus share.

Explanation

Their common characteristic is that they produce organic acids as part of their metabolism and are therefore, used for commercial and industrial production of the same.
(i) Aspergillus niger (a fungus) for citric acid.
(ii) Clostridium butylicum (a bacterium) for butyric acid.
(iii) Lactobacillus (a bacterium) for lactic acid.