pH值对沼液培养的普通小球藻生长及油含量积累的影响

以50％的沼液为普通小球藻的全营养培养基，考察培养基的起始pH值对小球藻生长及油脂含量的影响，普通小球藻对不同初始pH的沼液中氮、磷的去除情况。设定了2组实验，一组只调节初始接种培养液的pH，分别为6.0、6.5、7.0、7.5、8.0、8.5；另一组将培养液pH分别固定在6.0、6.5、7.0、7.5、8.0、8.5，pH用稀HCl和NaOH进行调节。研究发现在pH 6.5和pH 7.0的偏酸环境有利于小球藻生长，而pH在7.0~8.5的偏碱性条件下有利于小球藻油脂的积累，因此综合小球藻生长和油脂积累2个因素，得到最适合小球藻生长和油脂积累的pH为7.0。培养结束后沼液中氮磷的去除率分别达到了95％和97％，沼液中的总氮由原来的134.91 mg/L降至4.86 mg/L，总磷由10.19 mg/L降到0.32 mg/L。

Effect of pH on growth and lipid content of Chlorella vulgaris cultured in biogas slurry

Using 50% biogas slurry as basic medium, we investigated the effect of pH on the growth and lipid accumulation of Chlorella vulgaris. Setting two-group experiments, one was only control the initial medium pH, the initial pH was set at 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5, respectively. One was control the medium pH constant, set constant pH at 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5, respectively. Using HCl and NaOH regulated the pH. Results showed that algae Chlorella vulgaris grows better at pH 6.5 and 7.0, accumulate the lipid at pH 7.0?8.5, so the optimal pH for the growth and the lipid accumulation of Chlorella vulgaris was 7.0. The average removal rate of nitrate from biogas slurry was 95%, phosphate was 97%.