Fig. 3

Several different conditions to trigger the accumulation of astaxanthin. The induction of astaxanthin synthesis and fermentation either requires the occurrence of a REDOX imbalance can be categorized as follows: (1) Impairment of electron flow through the mitochondrial respiratory chain, such as hypoxia or genetic mutations through the mitochondrial electron transport chain (mETC). (2) Impairment of oxidative ADP-phosphorylation, potentially caused by nitrogen deficiency, phosphate deficiency, etc. (3) Conditions that lead to excessive NADH levels, including active re-assimilation of ethanol and high sugar concentration