光照强度、温度、pH、盐度对小球藻(Chlorella)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、盐度对小球藻(Chlorella sp.XQ-200419)和海洋小球藻(Chlorella marina NJ-016)光合作用的影响。小球藻(Chlorella sp.XQ-200419)的适宜光照强度范围为100～1600μmo·lm-2·s-1,光饱和点在500μmo·lm-2·s-1附近;适宜温度范围为25～42.5℃,最适温度为37.5℃;适宜pH值范围为6.5～9.0,最适pH值为7.0;对盐度的适应范围较广,在0～0.6mol/L范围内,随着盐度的升高,净光合放氧速率有下降趋势。海洋小球藻(Chlorella marina NJ-016)的适宜光照强度范围为400～1600μmol·m-2·s-1,光饱和点在1400μmo·lm-2.s-1附近;适宜温度范围为25～42.5℃,最适温度为37.5℃;适宜pH值范围为5.0～9.0,最适pH值为8.0;对盐度有很好的适应性,在0～0.6mol/L范围内,随着盐度升高,净光合放氧速率明显上升。小球藻和海洋小球藻的净光合放氧速率随光照强度、温度、pH值和盐度变化的规律,表明了两种小球藻的基本生理生态学特性:能适应较强的光照强度、较高的温度、中性偏碱的环境和较高的盐度。研究结果有助于小球藻培养条件的优化。两种小球藻对光照强度、温度、pH值和盐度变化的反应也有所不同:与小球藻(Chlorella sp.XQ-200419)相比,海洋小球藻(Chlorella marina NJ-016)对光照强度有更好的适应性,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明显的促进作用。这表明海洋小球藻(Chlorella marina NJ-016)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 Light Intensities,Temperatures, pH and Salinities on Photosynthesis of Chlorella

The effects of light intensities,temperatures,pH and salinities on photosynthesis of Chlorella sp.XQ 200419 and Chlorella marina NJ 016 were studied by measuring net photosynthetic O2 evolution.For Chlorella sp.XQ 200419,the suitable light intensities ranged from 100 to 1600 μmol•m-2•s-1,and the saturation light intensity is about 500 μmol•m-2•s-1.The suitable temperatures ranged from 25℃ to 42.5℃,with the optimal temperature of 37.5℃.The suitable pH values ranged from 6.5 to 9.0,and the optimum is pH 70.The net photosynthetic O2 evolution decreased a little while the salinity increased from 0 mol/L to 0.6 mol/L.For Chlorella marina NJ 016,the suitable light intensities ranged from 400 to 1600 μmol•m-2•s-1,and the saturation light intensity is about 1400 μmol•m-2•s-1.The suitable temperatures ranged from 25℃ to 42.5℃,with the optimal temperature of 37.5℃.The suitable pH values ranged from 5.0 to 9.0,and the optimum is pH 8.0.The net photosynthetic O2 evolution increased obviously while the salinity increased from 0 mol/L to 0.6 mol/L.The results indicated the basic physiological and ecological characteristics of the two Chlorella species:adapting to relatively strong light intensity,higher temperature,neutral to alkalescent conditions and higher salinity.However,there are some differences between these two species in their response to the change of environmental conditions.Compared with Chlorella sp.XQ 200419, Chlorella marina NJ 016 has higher saturation light intensity,and is able to adapt to much broader pH values.Besides,its photosynthesis is promoted by appropriate increase of salinity.It reveals that Chlorella marina NJ 016 might have more potential for fast growth in cultivation. The results are helpful for optimization of culture conditions for Chlorella,and also valuable for selection of Chlorella strains suitable for mass culture.