为提高混养条件下单细胞红藻-嗜硫原始红藻（G. sulphuraria）的藻胆蛋白生产，本研究以细胞密度、藻胆蛋白含量为评价指标，系统优化了培养温度、培养基碳氮比、初始细胞密度、光照强度等环境因素。结果表明，适当降低培养温度和碳氮比有利于促进藻胆蛋白的积累，提高光强和初始细胞密度也可促进细胞生长和藻胆蛋白合成。研究证实，G. sulphuraria混养培养体系的最适条件为：30 ℃、碳氮比6.0、初始细胞密度为1×108 cells/mL、光照强度为110 μmol/(m2·s)。在优化后的培养体系中培养8 d，最大细胞密度可达5.48×108 cells/mL；同时最大生物量产量可达到11.65 g/L，是优化前的1.46倍；藻胆蛋白含量占生物量干重的13.63%，对应产量为1588.36 mg/L，产量比优化前提高了187.91%。因此，混养培养条件系统优化是强化嗜硫原始红藻生物量和藻胆蛋白生产的有效手段。

In order to improve the phycobiliprotein production in unicellular red algae Galdieria sulphuraria under mixotrophic conditions, systematic optimization of environmental factors including the culture temperature, C/N ratio, initial cell density and light intensity were performed by using cell density and PBP content as the evaluation indices. The results showed that moderate reduction of culture temperature and C/N ratio of medium was beneficial for improving the accumulation of phycobiliprotein. Increasing the light intensity and initial cell density could promote the cell growth and phycobiliprotein synthesis. The study indicated that the optimal conditions for cell mixotrophic culture were determined as 30 ℃, C/N ratio of 6, initial cell density of 1×108 cells/mL, light intensity of 110 μmol/(m2·s). In the optimized culture system, the maximum cell density (5.48×108 cells/mL) could be achieved after mixotrophic cultivation for 8 days, leading to the highest biomass yield of 11.65 g/L which was 1.46 times that before optimization. The content of phycobiliprotein was 13.63% of dry cell weight, with the corresponding yield of 1588.36 mg/L which was 187.91% higher than that before optimization. Therefore, the systematical optimization of mixotrophic culture conditions was the effective strategy to enhance the biomass and phycobiliprotein production in G. sulphuraria.

中国石化催化剂有限公司科技项目（36100002-19-FW2099-0035）