不同适温海洋富油微藻在富碳培养条件下的油脂积累特性研究

Effect on lipid accumulation of marine oil-rich microalgae under different temperature and CO_2 enrichment cultivation

本实验分别针对3株低温藻株：微拟球藻Nannochloropsis sp.ZL-12、四爿藻Tetraselmis chui ZL-33和小球藻Chlorellasp.ZL-45,3株中温藻株：球等鞭金藻Isochrysis galbana CCMM5001、等鞭金藻Isochrysis sp.CCMM5002和微拟球藻Nannochloropsis sp.CCMM7001,3株高温藻株：微拟球藻Nannochloropsis sp.JN1、绿色巴夫藻Pavlova viridis JN2和海洋小球藻Chlorellasp.JN3,研究了在通入0.03%（空气）、5%、10%3个CO2浓度梯度条件下的生长特性,同时考察了其总酯及中性脂的累积情况。结果显示,富碳培养有利于不同温度条件下9株藻株的生长,除微拟球藻Nannochloropsis sp.CCMM7001最适生长的CO2浓度为5%外,其余8株藻株最适生长的CO2浓度均为10%。在低温和高温条件下,6株海洋富油微藻在通入10%CO2时具有最大生物量产率,在中温条件下球等鞭金藻和等鞭金藻在通入10%CO2时获得最大生物量产率,而微拟球藻在通入5%时获得最大生物量产率,随着CO2浓度的增加,9株藻株的总脂含量和中性脂含量有明显提高。低温和中温藻株的总脂含量高于高温藻株的总脂含量,从中性脂的累积规律来看,9株藻株均在平台期的累积达到最大值,GC-MS分析结果表明,9株微藻适合制备生物柴油的C14～C18系脂肪酸相对含量在不同CO2条件下基本保持不变,维持在90%左右。实验结果显示,所研究的藻株作为富油高固碳优良藻株,具备用于海洋生物质能耦合CO2减排开发的潜力。

Nine marine microalgae were cultured under different CO2 concentrations of ambient air （0.03%）, 5% and 10% ,respectively. Nine marine microalgae include 3 strains of cold resisting marine microalgae （Nannochlo- ropsis sp. ZL- 12, Tetraselrnis chui ZL-33, Chlorella sp. ZL-45）, 3 strains of mesophilic marine microalgae （Isoch- rysis galbana CCMMS001, Isochrysis sp. CCMMS002 and Nannochloropsis sp. CCMM7001） and 3 strains of heat resisting marine microalgae （Nannochloropsis sp. JN1 ,Pavlova viridis JN2 and Chlorella sp. JNd）. The growth characterization, accumulation of total and neutral lipid of these microalgae were investigated. The results showed that CO2 enrichment cultivation could increase the growth of all nine microalgae, but the optimum CO2 concentra- tions were different. The optimum CO2 concentration of Nannochloropsis sp. CCMMT001 was 5%, The optimum CO2 concentration of 8 strains of marine microalgae was 10 %. 3 strains of cold resisting marine microalgae and 3 strains of heat resisting marine mieroalgae reached the maximum biomass yield when culturing with 10 % CO2. 2 strains of mesophilic marine microalgae （Isochrysis galbana CCMM5001 and Isochrysis sp. CCMM5002） run up to the maximum biomass yield when culturing with 10% CO2. However,the maximum biomass yield of Nannochlo- ropsis sp. CCMMT001 was （122. 25±1.17） mg/（L · d） when culturing with 5% CO2. With the increased CO2 concentration,the total lipid and neutral lipid of three microalgae improved significantly. The total lipid content of 3 strains of cold resisting marine microalgae and 3 strains of mesophilic marine microalgae was higher than 3 heat resisting marine microalgae. The maximum neutral lipid content of 9 strains of microalgae could be accumulated in stationary phase. The fatty acid analysis of 9 strains of microalgae showed the relative content of C14-C18 fatty acid which suitable for biodiesel preparation maintained at 90% when culturing with different CO2 coneentration. The results indicate our marine oleaginous microalgae with high carbon dioxide fixation ability are the potential ex cellent strains for marine bioenergy development coupled with CO2 emission reduction.