Significance of the primary sodium pump in marine bacteria.

研究了溶藻弧菌138-2及其Na^+泵缺陷突变体Nap 1在不同条件下的生长特性和生存力丧失情况。随着有机质含量的降低，138-2与Nap1之间的差异越来越明显，说明在低营养条件下，原生Na^+泵具有更大的生态意义，这在大多数海洋环境中是普遍存在的。在高pH条件下，Nap 1的生长更加依赖Na^+浓度，因为在高pH条件下，溶藻弧菌使用Na^+循环，因此Nap 1在碱性条件下面临更多的能量问题。在没有任何有机化合物的培养基中存活的情况也清楚地显示出同样的情况。综上所述，原生Na^+泵在溶藻弧菌中具有重要的能量作用。此外，还探讨了钠驱动极性鞭毛的生态意义，特别是其对细菌附着的作用。澄清了溶藻弧菌在玻璃表面的附着与钠浓度或游动速度有关。这一发现与DLVO理论的一般概念相反，DLVO理论认为细菌的运动性不足以克服表面电排斥。进一步的研究建立了由于鞭毛旋转引起的细菌附着的新概念。

The growth characteristics and loss of viability of a marine bacterium, Vibrio alginolyticus 138-2 and its primary Na^+ pump defective mutant, Nap 1 were observed under several different experimental conditions.The difference between 138-2 and Nap1 became more prominent with decreasing organic content, implying that the primary Na^+ pump has more ecoogical significance under low nutrient condition, which is prevailing in most of marine environments.The growth of Nap 1 became more Na^+ concentration dependent at higher pH.Because V.alginolyticus uses Na^+ cycle at higher pH,Nap 1 has to face more energetic problem at alkaline condition.The same situation was also clearly shown in the case of survival at medium without any organic compounds.It is concluded that the primary Na^+ pump has a significant energetic role in Vibrio alginolyticus.In addition, the ecological significance of sodium driven polar flagellum was also investigated with special reference to its role on the bacterial attachment.It was clarified that attachment of V.alginolyticus to glass surface is dependent on sodium concentration or swimming speed.This finding is contrary to the general concept by DLVO theory, which state that bacterial motility is not enough to overcome the surface electrical repulsion.Further investigation has been undertaken to establish a new concept of bacterial attachment due to flagellar rotation.