《植物生理学报》 2013, 49(9): 909-916

外源碳源和盐度对微拟球藻QA2生长和油脂积累的影响

王通¹, 刘帅帅¹, 刘家尧¹, 刘建国², 衣艳君^1,*

¹青岛农业大学生命科学学院, 山东省高校植物生物技术重点实验室, 山东青岛266109; ²中国科学院海洋研究所, 山东青岛266071

通信作者：衣艳君；E-mail: qdyiyanjun@163.com；Tel: 0532-86080640

摘　要：

微藻因生长速度快、含油量高、可作为生物柴油的优质原料而备受关注。本实验以一株海洋微拟球藻QA2为材料, 研究了外源碳源的种类和浓度对其生长和油脂积累的影响。结果表明, 以NaHCO₃、CH₃COONa和Na₂CO₃为外源碳源均能促进QA2藻株的生长, 但以培养液中添加15 mmol·L^-1 CH₃COONa对QA2藻株的生长和油脂积累的促进作用最为明显, 总脂和脂肪酸的日产率分别是对照的2.73倍和5.67倍。同时利用叶绿素荧光技术研究了盐度对QA2光合作用的影响, 表明QA2对盐度有较宽的适应范围, 盐度在1.5%~6.0%范围内, 不会对油脂产率造成明显的影响, 但盐度增加能抑制QA2藻株PSII的电子传递, 引起反应中心色素和捕光色素的降解, 影响QA2的光合作用和生长, 可见QA2培养的最适盐度应为3.0%。这为开放式规模培养微藻及其相关研究提供依据和参考。

关键词：微拟球藻; 碳源; 盐度; 生长; 油脂积累

收稿：2013-05-10   修定：2013-07-04

资助：国家重点基础研究发展计划课题(2011CB200904)、山东省自然科学基金(ZR2011CM010)和青岛农业大学人才基金(630743)。

Effects of Exogenous Carbon Sources and Salinity on the Growth and Oil Ac-cumulation of Nannochloropsis sp. QA2

WANG Tong¹, LIU Shuai-Shuai¹, LIU Jia-Yao¹, LIU Jian-Guo², YI Yan-Jun^1,*

¹University Key Laboratory of Plant Biotechnology in Shandong Province, College of Life Sciences, Qingdao Agricultural University, Qingdao, Shandong 266109, China; ²Institude of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong 266071, China

Corresponding author: YI Yan-Jun; E-mail: qdyiyanjun@163.com; Tel: 0532-86080640

Abstract:

Abstract: Microalgae lipids are regarded as the feedstock for sustainable biodiesel production because microal-gae had much higher growth rate and photosynthetic efficiency than conventional terrestrial plants. In this study, a marine microalgae strain (Nannochloropsis sp. QA2) was used to study the type and concentration of exogenous carbon source to its growth and oil accumulation in an autotrophic culture condition. The results showed that the strain QA2 could use Na2CO3, NaHCO3 or CH3COONa as a carbon source to promote the mi-croalgae growth. Further study revealed that the daily yield of total lipid and fatty acid were 2.73-fold and 5.67-fold increase respectively when the CH3COONa at 15 mmol·L^-1 was added. The effect of salinity on the photo-synthesis of the strain QA2 was analyzed by chlorophyll fluorescence, and the results showed that the optimal salinity of the strain QA2 was 3.0%, although the QA2 had a wide range of salinity adaptation (1.5% to 6.0%), and no significant effect of the salinity on the oil production of QA2 was observed. With the increase of salinity the electron transfer of PSII was inhibited, which caused the degradation of the reaction center pigments and light harvesting pigments. This study also provided a theoretical basis for an outdoor open scale cultivation of microalgae.

Key words: Nannochloropsis sp.; carbon sources; salinity; growth; oil accumulation