Topic overview

Start with the big picture

Primary metabolites are linked to essential cellular functions and are typically produced during the growth phase, with output tracking biomass. Examples include ethanol, organic acids, amino acids, vitamins, and recombinant insulin. Industrial production aims to direct resources toward the desired product, and recovery may be relatively straightforward. Secondary metabolites are not essential for growth and are commonly made later, as nutrients become limited. Antibiotics, statins, cyclosporine, and antitumor compounds illustrate their pharmaceutical importance. Their biosynthesis often involves clustered genes and can respond to signals or precursors; production may be improved through strain and pathway interventions. Their structural complexity can make purification more involved. The lesson also considers how recombinant technology blurs the distinction between these categories.