Lycopene production using Blakeslea trispora in the presence of 2-methyl imidazole: yield, selectivity, and safety aspects.

The potential role of 2-methyl imidazole in improving lycopene production by Blakeslea trispora with regards to yield, selectivity, and safety aspects was investigated in batch culture. Optimization of the bioprocess conditions in terms of (a) (+) and (-) strain ratio in the inoculum, (b) initial crude soybean oil (CSO) addition level, and (c) the amount of 2-methyl imidazole was based on response surface methodology to achieve maximum lycopene production. The dependence of growth kinetics, lycopene yield, and selectivity of the bioprocess on the above factors was clear. 2-Methyl imidazole at 50 mg/L was found equally active in terms of lycopene cyclase inhibition with that at 200 or 100 mg/L; in all cases, lycopene accounted for 94% of the total carotenoids. The highest yield was observed at a 50 mg/L level of addition (24 mg/g of biomass dry weight,) in a substrate supplemented with CSO (48 g/L of culture medium) and inoculated with 1(+)/7(-) strain ratio.