不同无机盐对柱胞鱼腥藻固氮作用的影响

Effects of Different Inorganic Salts on N 2-Fixation in a Blue-green Alga Anabaena Cylindrica

低渗水平浓度（０．０５ｍｏｌ／Ｌ）的ＮａＣｌ，ＣａＣｌ２和ＭｇＣｌ２对柱胞鱼腥藻（Ａｎａｂａｅｎａｃｙｌｉｎｄｒｉｃａ）固氮活性有刺激作用，ＮａＣｌ的刺激作用最为显著。ＫＣｌ，Ｋ２ＳＯ４，ＫＨ２ＰＯ４，ＮａＨ２ＰＯ４对固氮有明显抑制作用，以ＫＨ２ＰＯ４抑制作用最大。多盐组合对固氮作用表现为中间值或抑制作用叠加。不同无机盐对固氮作用和对异形胞分化的影响表现出不一致性，说明无机盐对二者的影响遵循不同的机制。

NaCl,CaCl 2 and MgCl 2, in the low-osmotic concentration(0.05 mol/L), showed activating effect on the N 2-fixing activity of Anabaena cylindria. The NaCl, by enhancing N 2-fixing activity from 100% to 131% of the control, showed the most significantly positive effect, CaCl 2 was the next . KCl,K 2SO 4 and KH 2PO 4 caused the decline of N 2-fixing activity, and the inhibitory effect of KH 2PO 4 was the highest, followed by K 2SO 4. Different salt combinations showed different effects on N 2-fixation. Salt combinations had the intermediate values of the individual salts or showed additively inhibitory effects on N 2-fixation. The effect of different salts on N 2-fixation was independent of that on the heterocyst differentiation.