Guan Jian, Shen Songdong, Wu Hao, Liu Xin, Shen Weijie, He Yuan, Duan R
Department of Cell Biology, School of Biology and Basic Medical, Soochow University, No. 199 Renai Road, Suzhou, China.
Taicang Micro Algae Biotechnology Co., Ltd, Biological, Medicine Industrial Park, Taicang, China.
World J Microbiol Biotechnol. 2017 Feb;33(2):33. doi: 10.1007/s11274-016-2199-9. Epub 2017 Jan 10.
The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14 °C, 43.75 μmol photons m s and performed breed conservation at 2.5 °C, 8.75 μmol photons m s. We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis, while GMPC3 was identified as Arthrospira maxima. Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16 °C and 43.75 μmol photons m s, the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057 ± 80 mg l, 68.7 ± 2.5 mg l day, 1839 ± 44 mg l, 60.6 ± 1.8 mg l day, and 2113 ± 64 mg l, 77.7 ± 2.5 mg l day respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10 °C, achieving 3258 mg dry biomass from a starting 68 mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28 °C, achieving 1140 mg l dry biomass from a starting 240 mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl-D-erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.
丝状蓝藻节旋藻已实现商业化生产，是一种功能性高价值健康食品。我们通过甲磺酸乙酯诱变和低温筛选，鉴定出5株耐低温和低光照强度的节旋藻菌株（GMPA1、GMPA7、GMPB1、GMPC1和GMPC3）。这5株节旋藻菌株在14°C、43.75 μmol光子·m⁻²·s⁻¹以下生长迅速，并能在2.5°C、8.75 μmol光子·m⁻²·s⁻¹下进行保种。我们采用形态学鉴定和分子遗传分析，确定GMPA1、GMPA7、GMPB1和GMPC1为钝顶节旋藻，而GMPC3被鉴定为极大节旋藻。使用干生物量定期测定不同培养温度下的生长情况。在16°C和43.75 μmol光子·m⁻²·s⁻¹条件下，GMPA1、GMPB1和GMPC1的最大干生物量产量和平均干生物量生产率分别为2057±80 mg·l⁻¹、68.7±2.5 mg·l⁻¹·d⁻¹，1839±44 mg·l⁻¹、60.6±1.8 mg·l⁻¹·d⁻¹，以及2113±64 mg·l⁻¹、77.7±2.5 mg·l⁻¹·d⁻¹。选择GMPB1进行额外的耐低温研究和生长温度偏好研究。冬季，GMPB1在平均温度<10°C时生长良好，从起始的68 mg达到3258 mg干生物量。夏季，GMPB1在平均温度超过28°C时生长迅速，从起始的240 mg达到1140 mg·l⁻¹干生物量。对GMPB1的植物营养素分析表明其含有高水平的C-藻蓝蛋白和类胡萝卜素。节旋藻的代谢与萜类化合物有关，甲基-D-赤藓糖醇4-磷酸途径是蓝藻中唯一的萜类生物合成途径。克隆了来自GMPB1的1-脱氧-D-木酮糖5-磷酸还原异构酶（DXR）基因，系统发育分析表明GMPB1与黑绿颤藻PCC711关系最为密切。耐低温的节旋藻菌株可以拓宽适合种植的区域，延长季节性种植时间，并降低生产成本。
