二乙醇胺强化胶球藻Coccomyxa subellipsoidea C-169固定CO_(2)和积累油脂

Diethanolamine strengthening CO_(2) fixation and lipid accumulation in Coccomyxa subellipsoidea C-169

以优良藻株胶球藻Coccomyxa subellipsoidea C-169为受试对象,探究不同二乙醇胺(DEA)浓度对胶球藻固定CO_(2)及积累油脂的影响。结果表明,适宜浓度DEA可显著提高胶球藻固定CO_(2)和积累油脂效率。在40mg/L DEA条件下,胶球藻生物量、CO_(2)固定效率、油脂含量、油脂产率均达到最大值为0.97g/L、225.98mg/(L·d)、64.33%、59.9mg/(L·d),分别较无DEA对照提高了1.64倍、1.64倍、1.15倍和1.27倍。外源DEA作用提高了体系气液传质系数,增强CO_(2)传质效率,使得胶球藻可用无机碳源比例增加,同时上调固碳路径Rubisco和CA加强胶球藻固定CO_(2),上调脂肪酸路径ACCase以及下调ACCase竞争路径PEPC为油脂合成积累提供前体和能量,从而协同强化了胶球藻固定CO_(2)和积累油脂。本文研究结果为工业化胶球藻CO_(2)生物减排及可再生能源开发提供依据。

The effects of different diethanolamine concentrations on growth,CO_(2) biofixation,and lipid accumulation of eminent microalga Coccomyxa subellipsoidea C-169 was explored.The results showed that the appropriate concentration of DEA could significantly improve CO_(2) biofixation and lipid accumulation efficiency.The highest levels of biomass,CO_(2) biofixation rate,lipid content and lipid productivity were achieved to 0.97g/L,225.98mg/(L·d),64.33%,and 59.9mg/(L·d)under 40mg/L DEA,respectively,which were separately 1.64-,1.64-,1.15-and 1.27-fold more than that without DEA group.Exogenous DEA improved gas-liquid mass transfer coefficient and CO_(2) mass transfer efficiency,and consequently enhanced the proportion of available inorganic carbon sources for C.subellipsoidea.Synchronously,exogenous DEA up-regulated 1,5-bisphosphate carboxylase Rubisco and carbonic anhydrase CA in carbon fixation pathway,and consequently improved CO_(2) bio-fixation of C.subellipsoidea.DEA also up-regulated acetyl-coa carboxylase ACCase in lipid pathway and down regulated pyruvate carboxylase PEPC in ACCase competition pathway to strengthen lipid accumulation in C.subellipsoidea.These results provided a basis for industrial CO_(2) emission reduction and renewable energy development of C.subellipsoidea.