优化碳源提升法夫酵母虾青素产量和占类胡萝卜素比例

Optimized carbon source increased the titer of astaxanthin and the astaxanthin-to-carotenoid ratio in Phaffia rhodozyma

为进一步提升法夫酵母虾青素产量和虾青素占类胡萝卜素比例,考察了大宗碳源及其组合对法夫酵母细胞生长和虾青素生产的影响,并在70 L发酵罐上进行配比确定,在10 m 3发酵罐上进行中试放大。结果表明:有利于细胞增殖的碳源为糖蜜、葡萄糖、麦芽糊精和麦芽糖浆,有利于类胡萝卜素合成的为麦芽糊精、麦芽糖浆、淀粉水解液和蔗糖,有利于虾青素合成的为麦芽糊精、淀粉水解液和麦芽糖浆;不同碳源组合中,糖蜜或葡萄糖与麦芽糊精组合时虾青素产量最高,分别达到(58.7±1.2)、(55.1±0.8)μg/mL;在70 L发酵罐中,葡萄糖和麦芽糊精质量比为1∶1时较佳,虾青素产量和干菌体虾青素含量分别为(341.0±7.2)μg/mL和4.08 mg/g(细胞干重);在10 m 3发酵罐中进行工艺放大,虾青素产量和虾青素占类胡萝卜素比例分别为(360.3±0.8)μg/mL和42.2%,干菌体虾青素含量为3.88 mg/(g细胞干重),稍低于小试。该研究确定了法夫酵母虾青素生产的碳源种类和混合补加比例,为虾青素商业化生产提供了重要参考。

To increase the titer of astaxanthin and the astaxanthin-to-carotenoid ratio in Phaffia rhodozyma fermentation,the types of bulk carbon sources and their combinations were investigated.The ratio of glucose to maltodextrin was determined in a 70 L fermenter,and the optimized process was scaled up in a 10 m 3 fermenter.The results showed that molasses,glucose,maltodextrin and maltose syrup were favorable for the growth of P.rhodozyma,maltodextrin,maltose syrup,starch hydrolysate and sucrose were beneficial to the synthesis of carotenoids,while maltodextrin,starch hydrolysate and maltose syrup facilitated the production of astaxanthin.Maltodextrin combined with molasses or glucose resulted in the highest astaxanthin titers of(58.7±1.2)and(55.1±0.8)μg/mL,respectively.The optimal ratio of glucose to maltodextrin of 1∶1 in a 70 L fermenter yielded an astaxanthin titer of(341.0±7.2)μg/mL,which is 4.08 mg/g dry cell weight.When scaled up in a 10 m 3 fermenter,the titer and the astaxanthin-to-carotenoid ratio were(360.3±0.8)μg/mL and 42.2%,respectively,while the astaxanthin content toward dry cell weight was 3.88 mg/g,which was slightly lower than that of lab scale fermentation.In summary,the types of carbon sources and their compositions were optimized for astaxanthin production,the results provided important reference for commercial production of astaxanthin.