Different cell disruption methods for astaxanthin recovery by Phaffia rhodozyma
Astaxanthin (3,3'-dihydroxy-b,b'-carotene-4,4'-dione) is carotenoid of high market value whose demand has increased in such fields as aquaculture, pharmaceutical supplements and natural coloring. Cell disruption is the first step for isolating intracellular materials and it depends on the cell wall permeability. In order to maximize the recovery of astaxanthin from Phaffia rhodozyma NRRL-Y17268, drying and freeze pretreatments were tested by different cell disruption methods: abrasion with celite, glass pearls in vortex agitator, ultrasonic waves, sodium carbonate (Na2CO3) and dimethyl sulfoxide (DMSO). The method with Na2CO3 was not effective; meanwhile, the agitator with glass pearls, the abrasion with celite and the ultrasonic waves were found as promising for future studies. As a result, the DMSO in freeze-dried biomass with 4 process cycles and biomass/DMSO relation of 0.025 g/ml was found to be the most efficient for analytical determination, increasing about up to 25 times the astaxanthin recovery.
Key words: Carotenoids, yeast, chemical disruption, dimethyl sulfoxide.