Use of metabolic stimulators and inhibitors for enhanced production of β-carotene and lycopene by Blakeslea trispora NRRL 2895 and 2896

• Published in: Bioresource technology 2008-05, Vol.99 (8), p.3166-3173
• Main Authors: Choudhari, Sheetal M., Ananthanarayan, Laxmi, Singhal, Rekha S.
• Format: Article
• Language: English
• Subjects: Amino Acids - pharmacology; beta Carotene - biosynthesis; Biological and medical sciences; Biomass; Blakeslea trispora; Carotenoids - biosynthesis; Culture Media; Fermentation; Fundamental and applied biological sciences. Psychology; Kinetics; Lycopene; Mucor - cytology; Mucor - drug effects; Mucor - metabolism; Span 20; Zygomycetes; β-Carotene
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2007.05.051

This work investigates the potential of metabolic stimulators, firstly to enhance the production of β-carotene, and later use of inhibitors of lycopene cyclase so as to accumulate lycopene in the fermentation medium. Various non-ionic surfactants, natural oils, stimulators such as amino-acids, tricarboxylic acid cycle (TCA) intermediates, vitamin A and antibiotics were investigated for improved production of β-carotene using the zygomycete fungus Blakeslea trispora. Span 20 at 0.2% increased the β-carotene production from 139 mg/l to 318 mg/l. Examination of the mycelial morphology of the B. trispora with span 20 showed a shorter mycelial length, which allowed a well-dispersed growth of B. trispora. Supplementation of the medium with 1000 ppm vitamin A acetate gave highest concentration of β-carotene (830 ± 6 mg/l). Several chemical inhibitors such as imidazole, pyridine, triethylamine, piperidine, and nicotinic acid were then evaluated to block the biosynthesis at lycopene. Piperidine at 500 ppm gave a 7.76-fold improvement, and produced high titers of lycopene (775 ± 5 mg/l) in a medium supplemented with vitamin A acetate.