Microbiological production of industrial chemicals

The synthetic capabilities of microorganisms are not confined to food, drink and pharmaceuticals. Microorganisms are known also to produce industrial chemicals that can either serve as or be employed to make solvents, lubricants, plastics, surface coatings, explosives, etc. often an organic substance with industrial applications can be made either biologically or by chemical synthesis, the decision to make it one way or the other being essentially an economic one. A major consideration proves to be the cost of the raw materials. In microbiological fermentation the chief raw material has been found to be the growth substrate, it usually being starch. In chemical synthesis the principal raw material has been found to be petroleum or a derivative of it. The efficiency of the process must be taken into account. Another factor to be taken into account is the cost of recovering the product from the fermentation medium. One must also weight the potential value of by-products, and the cost of disposing wastes.

Microorganisms are known to produce some 200 substances of commercial value, only a few of them being currently made by biological methods in industry, they include ethanol, n-butanol, acetone, acetic acid, amino acids and enzymes. Scientists consider microorganisms to have a larger role in many industries. With the new genetic methods the microbiologists and chemists are able to replace an existing pathway with a new one. To put it another way, they can construct organisms that have new characteristics and capabilities. Thus microbiological fermentation in conjunction with the new techniques could contribute significantly to the production of three broad classes of industrial chemicals: aliphatic organic compounds, amino acids and enzymes.

Enzymes can catalyze both the making and the braking of chemical bonds. Each enzyme is stated to act only on a particular substrate molecule. Commercially produced enzymes are playing an increasing role in medical diagnosis.