佐夫色绿藻高产虾青素的诱导条件及发酵工艺优化

Optimization of the Induction Conditions and Fermentation Processes for High-yield Production of Astaxanthin by Chromochloris zofingiensis

本研究了不同诱导条件及光发酵罐培养工艺对混养佐夫色绿藻的影响,通过参数优化提高了藻细胞生物量和虾青素积累量。本研究首先系统地比较了在摇瓶系统中不同混合碳源和过氧化氢浓度对佐夫色绿藻的生长和虾青素积累的影响,并在光发酵罐中研究了恒定高光强、低光强-高光强以及低光强-高光强-补加过氧化氢三种不同发酵工艺对佐夫色绿藻积累虾青素的影响。结果表明:采用20 g/L葡萄糖和2.50 g/L醋酸钠作为混合碳源取代单一碳源,可以获得最高6.50 g/L生物量,并且添加107.50 mg/L过氧化氢可以将虾青素含量提高到3.23 mg/g,产量最高为72.47 mg/L,是空白组虾青素产量的1.80倍,有效促进了佐夫色绿藻细胞生长和虾青素积累。在5 L光发酵罐中,以20 g/L葡萄糖和2.50 g/L醋酸钠作为混合碳源培养佐夫色绿藻,通过低光强-高光强-补加过氧化氢的组合方式,可获得较优的虾青素含量(3.82 mg/g)和产量(41.41 mg/L),相较于恒定高光强培养,分别提高了36.92%和92.96%。本研究通过诱导条件和发酵工艺优化有效提高了混养佐夫色绿藻生物量和虾青素产量,为利用光发酵罐培养色绿藻生产虾青素提供基础。

In this study,the effects of different induction conditions and tank photo-fermentation processes on mixotrophic Chromochloris zofingiensis were investigated,and the algal cell biomass and astaxanthin accumulation were increased through parameter optimization.Different induction conditions including the effects of different mixed carbon sources and hydrogen peroxide concentrations in the shake-flask system on the growth and astaxanthin accumulation of Chromochloris zofingiensis were first systematically compared.In the photo-fermentation tanks,the effects of three different fermentation process conditions,i.e.,constant high light intensity,lowlight intensity-high light intensity,and lowlight intensity-high light intensity combined with hydrogen peroxide addition,on the accumulation of astaxanthin in Chromochloris zofingiensis were examined.The results demonstrated that the highest biomass(6.50 g/L)was obtained in C.zofingiensis cultivation using the mixed carbon source(a mixture of glucose(20 g/L)and sodium acetate(2.50 g/L))instead of the sole carbon source.The supplementation of hydrogen peroxide at 107.50 mg/L further increased the astaxanthin content to 3.23 mg/g with the highest astaxanthin yield as 72.47 mg/L(which was 1.80 times that of the control),resulting in effective promotion of cellular growth of algal biomass and accumulation of astaxanthin.In a 5-L photo-fermenter,20 g/L glucose and 2.50 g/L sodium acetate were used as a mixed carbon source to cultivate C.zofingiensis via the combination of low light intensity-high light intensity-hydrogen peroxide supplementation,leading to a relatively high astaxanthin content(3.82 mg/g)and yield(41.41 mg/L),which were 36.92%and 92.96%,respectively,higher than those obtained under theconstant high light intensity conditions.This work improved effectively the biomass and astaxanthin production of Chromochloris zofingiensis through the optimization of induction conditions and fermentation processes,which provides a basis for astaxanthin production by C.zofingiensis in photo-fermenters.