CO2对亚心形扁藻生长及光合放氢的影响

Enhanced Hydrogen Photoproduction by Marine Green Microalga Platymonas subcordiformis Grown under CO_2-Supplemented Air Bubble Bioreactor

利用鼓泡式光生物反应器,比较通入空气及不同φ(CO2)(1%、3%、5%、10%、15%)对亚心形扁藻生长及光合放氢的影响.实验结果表明:CO2含量对扁藻生长及光合放氢均有影响,其中φ(CO2)为3%时培养及光合放氢的效果最好,培养的藻细胞10 d细胞密度倍增3.8倍,比生长速率为0.134 d-1;培养到第7 d,细胞密度调整为6×106个/mL,暗诱导12 h后,在15μmol/L解偶联剂羰基氰化物间氯苯腙(CCCP)作用下连续光照24 h,培养的藻细胞产氢量提高70%,最大比产氢速率为3.24 mmol/(g.h).代谢分析表明,φ(CO2)为3%时培养的藻细胞淀粉含量最高,是对照组的2.1倍,CO2作为惟一碳源时淀粉含量与产氢量密切相关.利用CO2培养提高扁藻细胞产氢量的工艺有利于温室效应气体的减排.

The kinetics of cell growth and photohydrogen evolution of P. subcordiformis grown under CO2-supplemented air bubble bioreactor is investigated. The highest cell growth was achieved as φ（CO2） got to 3 %, and was supplemented to the air, with a specific growth rate of 0. 134 d^-1. The hydrogen photoproduction was enhanced by 70% for ceils grown under 3% of φ（CO2）, with a specific hydrogen production rate of 3.24 mmol/（g · h）^-1. The metabolic analysis of algal cells indicated a significant increase in starch accumulation with the increasing CO2 concentrations. The highest starch content was achieved under 3% of φ（CO2）supplemented alga cells, 2. 1 times the control culture in air. The improved hydrogen production may correlate with the increased starch accumulation where CO2 serves as the sole carbon source. These results suggest that hydrogen photoproduction by marine green alga can be beneficial from CO2-supplemented cultivation, which exerts a positive impact on the greenhouse gas mitigation.