三角褐指藻跑道池规模化培养及岩藻黄素积累条件的优化

Scaling-up Cultivation of Phaeodactylum tricornutum in Open Raceway Pond and Optimization of the Culture Conditions for Fucoxanthin Accumulation

岩藻黄素是一种广泛存在于海洋藻类的类胡萝卜素,具有清除自由基、抗癌和抗肥胖等生理活性,尤其在抗肿瘤和减肥方面功效突出。三角褐指藻中的岩藻黄素含量丰富,而环境因子及营养因素对微藻生长及岩藻黄素含量有着显著影响。本文以OD值、细胞密度、干重和岩藻黄素含量等为评价指标,研究了不同盐度(20、25、30)、pH值(7.5、8.0、8.5)、氮源种类(尿素、碳酸氢铵)等因素对三角褐指藻户外生长、岩藻黄素积累的影响。研究表明:盐度为20条件下,三角褐指藻获得最大细胞密度6.01×10~6/m L,不同盐度对岩藻黄素含量的增长无明显效果;pH值8.0条件下,三角褐指藻细胞密度及岩藻黄素含量均达到最大值(5.8×10~6/m L和17.79 mg/g);与碳铵相比尿素作为氮源更有利于三角褐指藻的生长,最终细胞密度为4.1×10~6/m L,但以碳铵为氮源条件下,更利于岩藻黄素的积累,岩藻黄素含量达到9.96 mg/g。因此,户外跑道池中的最适培养条件为盐度20、pH值8.0、碳铵为氮源。

As a kind of carotenoid which existed in various marine microalgae, fucoxanthin had many biological activities including scavenging free radicals, anti-cancer, anti-obesity and other physiological activities, especially in anti-tumor and slimming effect. Phaeodactylum triconutum（P. tricornutum） had the capability to accumulate plenty of fucoxanthin, while the environment and nutritional factors have a significant effect on the growth of microalgae and the content of fucoxanthin. In this study, effects of different salinity（20, 25, 30）, pH values（7.5, 8.0, 8.5） and nitrogen source types（urea, ammonium bicarbonate） on the OD value, cell concentration, dry cell weight, fucoxanthin content of P. tricornutum were investigated in outdoor mass culture. The results showed that maximum cell concentration was 6.01×10^6/m L, which was obtained in the culture medium with salinity of 20. There was no significant effect of different salinity on the increase of fucoxanthin content of P. tricornutum. Optimal p H value of the culture medium for P. tricornutum was 8.0. Maximum cell concentration and fucoxanthin content were 5.8×10^6/m L and 17.79 mg/g, respectively. Compared with ammonium bicarbonate, urea as a nitrogen source was more suitable for the growth of P. tricornutum and the final cell concentration reached 4.1×10^6/m L. However, in terms of fucoxanthin accumulation, ammonium bicarbonate as nitrogen source was more advantageous since the maximum fucoxanthin content reached 9.96 mg/g. Therefore, the optimum culture conditions in open raceway pond for P. tricornutum were summed up to be salinity of 20, pH 8.0 and ammonium bicarbonate as the nitrogen source.