The specific production of lycopene can be promoted by adding compounds which inhibit the action of enzyme
lycopene-cyclase that is responsible for cyclization of the ends of the chain to the subsequent production of β-carotene.
When concentrations (50–500 ppm) of imidazole were evaluated, the highest concentration of lycopene (6.82mg/l) was
obtained by adding imidazole 250 ppm at 24 h of fermentation (Fig. 3). At the concentrations (375 and 500 ppm),the microorganisms could not assimilate imidazole,in some cases due to inhibition of microbial growth.