Match the following list of bacteria and their commercially important products:
Bacterium Product
(i) Aspergillus niger (a) Lactic acid
(ii) Acetobacter aceti (b) Butyric acid
(iii) Clostridium butylicum (c) Acetic acid
(iv) Lactobacillus (d) Citric acid
i-d, ii-c, iii-b, iv-a
Many microbes produce commercially important chemicals as a byproduct on fermentation of organic compounds that can be readily extracted in large scale. For example the fungus Aspergillus niger makes citric acid, the bacteria Acetobacter aceti makes acetic acid, the bacteria Clostridium butylicum makes butyric acid, and the bacteria Lactobacillus make lactic acid.