几种主要环境因子对布朗葡萄藻(Botryococcus braunii)光合作用的影响

利用测定净光合放氧速率的方法研究了光照强度、温度、pH值、盐度对布朗葡萄藻Botryococcus braunii UTEX 572和B.braunii UTEX 2441两个品系的光合作用的影响。B.braunii UTEX 572的适宜光照强度范围400～1600μmol·m^-2·s^-1,光饱和点在800μmol·m^-2·s^-1附近;适宜温度范围25～35℃,最适温度30℃;适宜pH范围5.0～8.0,最适pH7.0;适宜盐度范围0～0.2mol/L,最适盐度0.1mol/L。B.braunii UTEX 2441的适宜光照强度范围400～1600μmol·m^-2·s^-1,光饱和点在400μmol·m^-2·s^-1附近;适宜温度范围25～35℃,最适温度30℃;适宜pH范围5.0～8.0,最适pH7.0;对盐度的适应范围较小,盐度升高,光合放氧速率明显下降。两个布朗葡萄藻净光合放氧速率随光照强度、温度、pH值和盐度变化的规律,表明布朗葡萄藻的基本生理生态学特征:适应于较强的光照强度、较高的温度、中性偏酸的环境和较低的盐度。对布朗葡萄藻基本生理生态学特征的了解,为培养条件的优化提供了依据。2个布朗葡萄藻品系对光强、温度、pH值和盐度变化的反应有所不同:与B.braunii UTEX 2441相比,B.braunii UTEX 572具有更高的光饱和点,适应更高的温度,对pH值变化有更宽的适应范围,适当提高盐度对其光合作用有促进作用,表明B.braunii UTEX 572在快速生长繁殖方面具有更大的潜力,这一研究结果为筛选适合于大量培养的优良藻种提供了依据。

The Effects of Several Environmental Factors on the Photosynthesis of Botryococcus braunii

The effects of temperature,light intensity,pH value and salinity on photosynthesis of Botryococcus braunii UTEX 572 and B.braunii UTEX 2441 were studied by measuring net photosynthetic O₂ evolution.For B.braunii UTEX 572,the suitable light intensity range was 400-1600 μmol·m^-2·s^-1,with the saturation light intensity 800 μmol·m^-2·s^-1;the suitable temperature range was 25-35℃,with the optimal temperature about 30℃;the suitable pH range was 5.0-8.0,with the optimal pH about 7.0,the suitable salinity range was 0-0.2 mol·L^-1,with the optimal salinity about 0.1 mol·L^-1.For B.braunii UTEX 2441,the suitable light intensity range was 400-1600 μmol·m^-2·s^-1,with the saturation light intensity 400 μmol·m^-2·s^-1;the suitable temperature range was 25-35℃,with the optimal temperature about 30℃;the suitable pH range was 5.0-8.0,with the optimal pH about 7.0;the net photosynthetic O₂ evolution decreased dramatically while the salinity increased.The photosynthetic characteristics of two B.braunii strains indicated the basic physiological and ecological characteristics:adaption to relative strong light intensity,relative high temperature,neutral to acid environment and lower salinity.The results are helpful for optimizing the culture condition.Some differences exist between two B.braunii strains in their response to the change of light intensity,temperature,pH value and salinity,compared with B.braunii UTEX 2441,B.braunii UTEX 572 has higher saturation light intensity,adaptive to higher temperature and much broader pH,its growth is promoted by mild increase of salinity,which indicates that B.braunii UTEX 572 has greater potential for fast growth in cultivation,the result provided evidence for selecting good strain that suitable for mass culture of B.braunii.