温度和pH变化对旋链角毛藻生长及释放二甲基硫化物的影响

以旋链角毛藻(Chaetoceros curvisetus)为研究对象,通过实验室培养,研究了温度和pH变化对其生长周期内生物量及培养液中二甲基硫(DMS)和二甲巯基丙酸内盐(DMSP)含量的影响。设置的4组实验条件分别为pH=7.8,20℃、pH=7.8,25℃、pH=8.1,20℃和pH=8.1,25℃。实验结果表明,pH=8.1,20℃时,旋链角毛藻生长情况最佳,而pH=7.8,25℃时,旋链角毛藻生长情况最差。温度升高时藻密度、比生长率、DMS和DMSP浓度均有明显的降低,pH减小时四者略有降低。四组实验中旋链角毛藻单细胞释放DMS浓度的峰值(4.54×10-5,2.71×10-5,4.67×10-5,3.46×10-5μmol·cell-1)均出现于藻类生长的衰亡期。说明旋链角毛藻衰亡期细胞破裂会导致大量DMSP进入培养液中,进而降解生成DMS。

Effects of Temperature and pH on the Growth of Chaetoceros Curvisetus and Its Release of Dimethyl Sulfide

Chaetoceros curvisetus was taken to study the algal biomass changes and the releases of dimethylsulfide(DMS)and dimethylsulfoniopropionate(DMSP)through the orthogonal culture experiments under different temperature and pH conditions.Four sets of experimental conditions were set as pH=7.8,20℃;pH=7.8,25℃;pH=8.1,20℃;pH=8.1,25℃.The experimental results showed that when the pH=8.1,20℃,the growth of Chaetocero scurvisetus was best,while the worst case was observed at pH=7.8 and 25℃.When the temperature increased,the algal density,specific growth rates,DMS and DMSP concentrations decreased significantly.When the pH decreased,the four observed variables decreased slightly.The peaks of DMS concentrations in the four groups of experiments(4.54×10-5,2.71×10-5,4.67×10-5,3.46×10-5μmol·cell-1)all appeared in the decline period of algal growth.It was verified that a large amount of DMSP was released into the culture solution and degraded into DMS due to cell rupture during the decline period of chaetoceros curvisetus.