To study the relationship between intracellular anabolismand astaxanthin production, the influence
of intracellular protein and fatty acids on astaxanthin production by four mutant Phaffia rhodozyma
their variations was investigated in this research.
First, the content of astaxanthin in cells showed a reverse fluctuation in contrast to that of protein
during the whole fermentation process. Moreover, compared with the three other strains, the
astaxanthin-overproducing mutant strain of the yeast P. rhodozyma
, called JMU-MVP14, had the highest
specific productivity of astaxanthin as 6.8 mg/g, whereas its intracellular protein and fatty acid contents were
the lowest. In addition, as a kind of sugar metabolic product, ethanol was only produced by P. rhodozyma
JMU-VDL668 and JMU-7B12 during fermentation.
The results indicated that the accumulation of ethanol, intracellular protein, and fatty acids had
competition effects on astaxanthin synthesis. This condition may explain why the P. rhodozyma
JMU-VDL668 and JMU-7B12 achieved relatively lower astaxanthin production (1.7 and 1.2 mg/L) than the
other two strains JMU-MVP14 and JMU-17W(20.4 and 3.9 mg/L).