氮饥饿/过氧化氢协同胁迫促进法夫酵母合成虾青素

虾青素是一种强抗氧化剂,在细胞抵御外界环境胁迫方面起到重要作用。研究了氮饥饿/过氧化氢协同胁迫对法夫酵母合成虾青素的影响,结果表明:低含氮量有利于虾青素的合成,随着碳氮比的降低,虾青素的合成受到抑制,最佳的碳氮比为3∶0.6,每克干细胞虾青素的含量最高达0.32mg/g;在此基础上添加5mmol/L过氧化氢协同胁迫法夫酵母可进一步提高虾青素的产量,在发酵24h(对数生长期)加入3mmol/L的H2O2,36h补加2mmol/L,虾青素产量达到0.59mg/g,比空白对照提高63.9%。

Enhancing astaxanthin synthesis of Phaffia rhodozyma by nitrogen starvation and peroxide collaborative stresses

Astaxanthin as antioxidant plays an important role in the responses of microorganisms to the environmental stimulation and stress.The collaborative effects of nitrogen starvation and peroxide stresses on astaxanthin production of Phaffia rhodozyma were investigated.The results showed that low concentration of nitrogen source accelerated astaxanthin biosynthesis,production of astaxanthin was inhibited rapidly with the reduction carbon and nitrogen source ratio,the highest astaxanthin productivity was 0.32mg/g at the carbon and nitrogen source ratio of 3∶0.6.Peroxide collaborative stress could farther enhance astaxanthin yield significantly with feeding of 3mmol/L and 2mmol/L peroxide at 24h(exponential phrase)and 36h respectively,a maximal astaxanthin yield of 0.59mg/g cell was achieved,which was 63.9% higher than the control.