Effect of spent coffee grounds extract on astaxanthin production by Xanthophyllomyces dendrorhous

The world generates a large amount of used coffee grounds every day. These spent coffee grounds could potentially be used to cultivate microorganisms for fine chemical productions. Here, the effect of spent coffee grounds extract (SCGE) on astaxanthin-producing yeast, Xanthophyllomyces dendrorhous was explored. The SCGE addition to the culture medium notably increased growth of cell and decreased intracellular astaxanthin (ASX) content. The caffeine contained in SCGE was found to activate ASX biosynthesis, not to effect on cell growth. In X. dendrorhous, the addition of SCGE resulted in significant cell growth, and the addition of caffeine contained therein suppressed the decrease in ASX biosynthesis, resulting in an overall increase in ASX production.