Simple method for the isolation of astaxanthin from the basidiomycetous yeast Phaffia rhodozyma.
A method is described for the quantitative and, possibly, large-scale extraction of astaxanthin from the yeast Phaffia rhodozyma. The method utilizes extracellular enzymes produced by the bacterium Bacillus circulans WL-12, which partially digests the yeast cell wall and renders the carotenoid pigments extractable by acetone or ethanol. Complete recovery of astaxanthin from heat-killed P. rhodozyma cells was obtained after growing B. circulans WL-12 on these yeast cells for 26 h and then extracting the yeast-bacterium mixture with acetone. A bacteria-free lytic system, which gave quantitative extraction of astaxanthin from P. rhodozyma, was obtained by concentrating the culture broth from the growth of B. circulans WL-12 on P. rhodozyma cells. Hydrolytic enzyme activities detected in this concentrate included beta-(1 leads to 3)-glucanase, beta-(1 leads to 6)-glucanase, alpha-(1 leads to 3)-glucanase, xylanase, and chitinase. The lytic system was found to work most efficiently at pH 6.5 and with low concentrations of yeast.
D001407:Bacillus / Q000201:enzymology; D002338:Carotenoids / Q000031:analogs & derivatives* / Q000302:isolation & purification; D002473:Cell Wall / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000378:metabolism; D008722:Methods; D015003:Yeasts / Q000032:analysis* / Q000378:metabolism
D002338:Carotenoids; D006867:Hydrolases