Oren Aharon, Pri-El Nuphar, Shapiro Orr, Siboni Nachshon
Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
Saline Syst. 2006 Apr 14;2:4. doi: 10.1186/1746-1448-2-4.
Possession of gas vesicles is generally considered to be advantageous to halophilic archaea: the vesicles are assumed to enable the cells to float, and thus reach high oxygen concentrations at the surface of the brine.
We studied the possible ecological advantage of gas vesicles in a dense community of flat square extremely halophilic archaea in the saltern crystallizer ponds of Eilat, Israel. We found that in this environment, the cells' content of gas vesicles was insufficient to provide positive buoyancy. Instead, sinking/floating velocities were too low to permit vertical redistribution.
The hypothesis that the gas vesicles enable the square archaea to float to the surface of the brines in which they live was not supported by experimental evidence. Presence of the vesicles, which are mainly located close to the cell periphery, may provide an advantage as they may aid the cells to position themselves parallel to the surface, thereby increasing the efficiency of light harvesting by the retinal pigments in the membrane.
一般认为拥有气体囊泡对嗜盐古菌有利：这些囊泡被假定能使细胞漂浮，从而在盐水表面达到高氧浓度。
我们研究了以色列埃拉特盐田结晶池中扁平方形极端嗜盐古菌密集群落中气体囊泡可能具有的生态优势。我们发现，在这种环境下，细胞内气体囊泡的含量不足以提供正浮力。相反，下沉/漂浮速度过低，无法实现垂直再分布。
气体囊泡能使方形古菌漂浮到其生存的盐水表面这一假设未得到实验证据的支持。主要位于细胞周边的囊泡的存在可能具有优势因为它们可能有助于细胞平行于表面定位，从而提高膜中视黄醛色素捕获光的效率。
