Genetic algorithms (GA) based on the principle of mimicing Darwinian evolution and survival of the fittest in a natural environment was used to optimize the medium for astaxanthin production by the mutant strain W6-8 ...Genetic algorithms (GA) based on the principle of mimicing Darwinian evolution and survival of the fittest in a natural environment was used to optimize the medium for astaxanthin production by the mutant strain W6-8 of Xantho-phyllomyces dendrorhous. The 50 concentration levels of 6 medium components were optimized within 50 experiments (full experimental plan: 50^6 experiments). The results showed that GA could be applied in the medium optimization and better results were obtained. By employing optimized medium components (glucose 39.8 g l^-1, yeast extract 4.08 g l^-1,(NH4)2SO4 7.36 g l^-1, MgSO4 2 g l^-1, K2HPO4 2.04 g l^-1 and KH2PO4 3.48 g l^-1), the highest astaxanthin production was 9.855 mg l^-1, approximately 31% higher than that under the initial conditions, and was approximately 15.46% higher than that by orthogonal array but only slightly higher than that by response surface methodology. In the sequent scale-up experiments, the astaxanthin yield was obtained approximately 14.753 mg l^-1, employing the optimal medium. The results indicated that GA, as an euiicient method for medium optimization, was superior to other optimal means such as orthogonal array.展开更多
文摘Genetic algorithms (GA) based on the principle of mimicing Darwinian evolution and survival of the fittest in a natural environment was used to optimize the medium for astaxanthin production by the mutant strain W6-8 of Xantho-phyllomyces dendrorhous. The 50 concentration levels of 6 medium components were optimized within 50 experiments (full experimental plan: 50^6 experiments). The results showed that GA could be applied in the medium optimization and better results were obtained. By employing optimized medium components (glucose 39.8 g l^-1, yeast extract 4.08 g l^-1,(NH4)2SO4 7.36 g l^-1, MgSO4 2 g l^-1, K2HPO4 2.04 g l^-1 and KH2PO4 3.48 g l^-1), the highest astaxanthin production was 9.855 mg l^-1, approximately 31% higher than that under the initial conditions, and was approximately 15.46% higher than that by orthogonal array but only slightly higher than that by response surface methodology. In the sequent scale-up experiments, the astaxanthin yield was obtained approximately 14.753 mg l^-1, employing the optimal medium. The results indicated that GA, as an euiicient method for medium optimization, was superior to other optimal means such as orthogonal array.
