Generation of lycopene-overproducing strains of the fungus Mucor circinelloides reveals important aspects of lycopene formation and accumulation
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To generate lycopene-overproducing strains of the fungus Mucor circinelloides with interest for industrial production and to gain insight into the catalytic mechanism of lycopene cyclase and regulatory process during lycopene overaccumulation.
Three lycopene-overproducing mutants were generated by classic mutagenesis techniques from a β-carotene-overproducing strain. They carried distinct mutations in the carRP gene encoding lycopene cyclase that produced loss of enzymatic activity to different extents. In one mutant (MU616), the lycopene cyclase was completely destroyed, and a 43.8% (1.1 mg/g dry mass) increase in lycopene production was observed in comparison to that by the previously existing lycopene overproducer. In addition, feedback regulation of the end product was suggested in lycopene-overproducing strains.
A lycopene-overaccumulating strain of the fungus M. circinelloides was generated that could be an alternative for the industrial production of lycopene. Vital catalytic residues for lycopene cyclase activity and the potential mechanism of lycopene formation and accumulation were identified.
KeywordsCarRP Feedback regulation Lycopene Lycopene cyclas Mucor circinelloides
We thank J. A. Madrid for technical assistance. This work was funded by the Fundación Séneca (Comunidad Autónoma de la Región de Murcia, Spain), Project No. 08802/PI/08, The Program for New Century Excellent Talents (NCET-13-0831), The Program for Changjiang Scholars and Innovative Research Team in University (IRT1249). This study is supported by program of Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province.
Supplementary Table 1—Primer sequences.