NaHCO_3对发状念珠蓝细菌光合作用及生长的影响

研究不同浓度的NaHCO3对液体悬浮培养发状念珠蓝细菌（Nostoc flagelliforme）生长,光合作用以及营养盐吸收的影响。在BG-11培养基中培养15d,结果表明,添加NaHCO3浓度为15mmol/L时,对发状念珠蓝细菌细胞生长有明显的促进作用,细胞生物量达到1.03g/L,胞外多糖含量为43.23mg/L,与空白对照（不加NaHCO3）相比分别提高了28%、52%,吸收NO3-和PO34-为0.91g/L、6.30mg/L。对数生长期时,真正的光合速率（净光合速率与呼吸速率之和）为103.84μmo（lO2）（/mg（Chl）.h）,与空白对照相比,提高39%。随着添加NaHCO3浓度升高,反而抑制了发状念珠蓝细菌细胞的光合作用以及生长。由此可知,培养基中加入适量NaHCO3能够促进发状念珠蓝细菌细胞生长。

Effect of NaHCO3 on growth and photosynthesis of Nostoc flagelliforme cells

The effect of different concentration of NaHCO3 on growth and photosynthesis of Nostoc flagelliforme cells in liquid suspension culture were studied.When the concentration of NaHCO3 was 15mmol/L,the cell biomass and the exopolysaccharides were 1.03g/L and 43.23mg/L after 15d of cultivation in the BG-11 medium,which increased by 28% and 52% compared to those of the control,respectively.The absorption of NO-3 and PO3-4 were 0.91g/L and 6.30mg/L,respectively.The net photosynthetic rate of N.flagelliforme cell reached 103.84μmol(O2)/(mg(Chl)·h) in the logarithm period,which increased by 39% compared that of the control.However,the growth and photosynthetic rate were inhibited with the further increase of NaHCO3 concentration.These results indicated that adding proper amount of NaHCO3 in the culture medium could promote the growth of N.flagelliforme cells efficiently.