Farnesol and tyrosol: novel inducers for microbial production of carotenoids and prodigiosin.

This study was performed to elucidate the effects of two fungal quorum sensing molecules (tyrosol and farnesol) on carotenoid synthesis in the yeast Rhodotorula glutinis and prodigioin synthesis in the bacterium Serratia marcencens. Farnesol or tyrosol was directly added to the flask cultures at the beginning (immediately after inoculation with the preculture) of day 1 or the beginning (49th h) of day 3. The results demonstrated that tyrosol supplementation increased the synthesis of carotenoids but farnesol supplementation increased the synthesis of prodigiosin. It was found that adding farnesol or tyrosol into the culture on day 3 compared to day 1 caused more increments in pigment synthesis. The maximum increase (fivefold) in the synthesis of prodigiosin was achieved with 200 μL/L farnesol supplementation, whereas the maximum increase (2.13 fold) in the synthesis of carotenoids was achieved with 4 mg/L tyrosol supplementation. This is the first report about the effects of fungal quorum sensing molecules (farnesol and tyrosol) on the synthesis of carotenoids and prodigiosin in microorganisms. Due to non-human toxicity and low price and of farnesol and tyrosol, these molecules can be used as novel inducers for large-scale production of microbial pigments.