Influences of Light-dark Cycle on Production of Extracellar Polysaccharide in Three Marine Planktonic Diatom Species
- 生命科学－已发表论文 
[中文文摘]3种海洋浮游硅藻,网纹三角藻(Triceratiumreticulum),骨条藻(Skeletonemasp.)和三角褐指藻(Phaeodacty lumtriconutum)培养在3种不同的光暗周期下,研究了光暗周期对硅藻胞外多糖生产的影响.结果表明,光暗周期对硅藻胞外多糖生产的影响具有种间特异性,且与细胞生长周期有关.网纹三角藻和三角褐指藻在长光照条件下(L/D:16/8h),胞外多糖含量较高,前者最大值出现在生长期前期,而后者则在生长期后期;骨条藻在短光照条件下(L/D:8/16h)胞外多糖含量较高,最大值出现在生长期后期.3种硅藻中,网纹三角藻的胞外多糖的产量最高,达103～104pg/cell,中肋骨条藻和三角褐指藻则较低.光暗周期可能影响了细胞内光吸收总量、细胞分裂模式及细胞内有机物质的合成,从而影响到胞外多糖的生产分泌.[英文文摘]Three marine planktonic diatom species, Triceratium reticulum, Skeletonema sp. and Phaeodactylum triconutum were cultured in modified f/2 medium, and the influence of light-dark cycle on the production of extracellular polysaccharide was investigated. The results showed that the influences of light-dark cycle on production of extracellular polysaccharide were species specific, and dependent on the growth phase. The extracellular polysaccharide content of T. reticulum and P. triconutum was higher under long light cycle (L/D , 16/ 8h) , however the highest content was found at the exponential phase in T. reticul umn and at the late growth phase in P. triconut um . The content of extracellular polysaccharide in S keletonema sp. was higher under longer dark cycle (L/ D , 8/ 16h) and peaked at the late growth phase. Among the three species , the produc2 tion of ext racellular polysaccharide (pg·cell - 1) was the highest in T. reticul umn , up to 103～104 pg·cell - 1 , while the production of P. t riconut um and S keletonema sp. was very low. Light2dark cycle might affect the total amount of light absorption , cell division pattern and synthesis of organic materials , which inversely influenced the ext racellular polysaccharide production of algal cells.