胶球藻C-169户外诱导培养积累脂肪酸和色素的研究

本研究分别采用Basal、BBM以及无氮磷添加的培养基，在户外开放跑道池中培养胶球藻C-169，系统比较了比生长速率、生物量浓度、脂肪酸和色素含量的差异。研究表明，胶球藻C-169在户外开放跑道池中，水温13~20 ℃下，生长良好。在第二阶段氮磷限制Basal、BBM培养基中的8 d，细胞处于生长的对数期，Basal培养基中平均比生长速率是BBM培养基的1.92倍，生物量干重浓度最高为0.22 g/L。第一阶段细胞在BBM、Basal两种培养基中亚麻酸含量可分别高达总脂肪酸含量的36.6%、53.9%；第二阶段在氮磷限制的BBM培养基中，亚麻酸占总脂肪酸的比例下降了32.4%，油酸的比例增大了38.5%；氮磷限制BBM培养基中细胞内总脂肪酸含量由起始的3.99%增大到18.18%。上述两种藻液以1:1混合培养5 d，平均比生长速率下降到0.0094 d-1，总脂肪酸含量增大到20.2%。藻细胞中色素含量随着脂肪酸含量的增加而降低，呈明显的负相关。
Coccomyxa subellipsoidea C-169 was cultivated outdoors in raceway open ponds using Basal medium, Bold’s Basal medium (BBM), and medium without adding nitrogen (N), and phosphorus (P). Comparisons were made across the three culture conditions in terms of cell-specific growth rate, biomass concentration, as well as content of fatty acids and pigments. The results showed good growth of Coccomyxa subellipsoidea C-169 at temperatures ranging from 13 ℃ to 20 ℃ in outdoor open ponds. During stage II, cells were in logarithmic phase after eight days of cultivation in Basal medium and BBM with limited N and P, where cell-specific growth rate in Basal medium was 1.92 times that in BBM and maximal biomass was 0.22 g/L. Linolenic acid content in the cells cultured in Basal medium and BBM accounted for 36.6% and 53.9% of total fatty acids, respectively, during stage I. However, during stage II, the proportion of linolenic acid content of total fatty acids in the cells cultured in Basal medium, with N and P limitations decreased by 32.4%, while that of oleic acid increased by 38.5%. In BBM containing low N and P concentrations, the content of total fatty acids increased from 3.99% to 18.18%. In stage III, cells were cultivated for five days in a 1:1 mixture of Basal medium and BBM. During stage III, average growth rate of cells decreased to 0.0094 d-1, total fatty acid content in biomass increased to 20.2% dry weight, and pigment content decreased with increasing fatty acid content, showing a significant negative correlation.