温度、光照、盐度与pH对淡水蓝藻拟柱胞藻生长的影响

Study on the effects of temperature, light intensity, salinity and pH on growth characteristics of freshwater cyanobacteria Cylindrospermopsis raciborskii

拟柱胞藻(Cylindrospermopsis raciborskii)是近年来发现能够引起水华的一种优势淡水蓝藻,可产生蓝藻毒素,由其引发的水质危害已逐渐引起人们的重视。为探讨环境因素与拟柱胞藻生长状态的关系,设计采用温度(25,30,35℃)、光照(2000,3000,4000 lx)、盐度(0,4,8)与p H值(7.2,8.2,9.2)四种环境因子三水平正交试验,分析在不同环境因子条件下拟柱胞藻的比平均生长速率,最高藻丝密度,叶绿素a(Chl-a)及类胡萝卜素(Carotenoid)含量。研究结果表明,在9种环境因子组合中,除温度25℃、光照4000 lx、p H 9.2及盐度8,拟柱胞藻不能生长外,其余条件均能生长。藻丝生长速率、藻丝密度及光合色素的影响程度上,盐度影响最大,其次是p H和温度,光照影响最小。拟柱胞藻藻丝最佳生长的环境条件为温度30℃,p H 8.2,光照4000 lx及盐度0。

The Cylindrospermopsis raciborskii, a kind of freshwater cyanobacteria, is identified a new dominant alga causing freshwater bloom in China in recent years. It can also produce toxins, which has gradually attracted people＇s attention. To figure out the relationship of growth of C. raciborskii and its environmental conditions, the temperature（25 ℃, 30 ℃ and 35 ℃）, illumination intensity（2000 lx, 3000 lx and 4000 lx）, salinity（0, 4, 8） and pH value（7.2, 8.2, 9.2） were taken as indexes. A four-factor and three-level orthogonal experiments were designed to analyze the specific growth rate, the high alga cell density, chlorophyll a and carotenoids of Cylindrospermopsis raciborskii. The results showed that the C. raciborskii could grow in the culture conditions except for the 25 ℃, 4000 lx, pH 9.2 and salinity 8. The salinity had significant influences on growth rate, cell density and photosynthetic pigments of C. raciborskii, followed by pH value and temperature, and illumination intensity had minimum influence. The best growth conditions of the C. raciborskiiare were at 30 ℃, pH 8.2, 2000 lx and salinity 0.