Zenvirth D, Volokita M, Kaplan A
Department of Botany, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Plant Physiol. 1985 Jan;77(1):237-9. doi: 10.1104/pp.77.1.237.
The intracellular pH and membrane potential were determined in the acidophilic algae Cyanidoschyzon merolae as a function of extracellular pH. The alga appear to be capable of maintaining the intracellular pH at the range of 6.35 to 7.1 over the extracellular pH range of 1.5 to 7.5. The membrane potential increase from -12 millivolts (negative inside) to -71 millivolts and thus DeltamuH(+) decreased from -300 to -47 millivolts over the same range of extracellular pH. It is suggested that the DeltamuH(+) may set the upper and lower limits of pH for growth. Photosynthetic performance was also determined as a function of pH. The cells appeared to utilize CO(2) from the medium as the apparent K(m(co(2))) was 2 to 3 micromolar CO(2) over the pH range of 1.5 to 7.5 C. merolae appear to possess a ;CO(2) concentrating' mechanism.
测定了嗜酸性藻类梅洛拉蓝细菌（Cyanidoschyzon merolae）的细胞内pH值和膜电位随细胞外pH值的变化情况。在细胞外pH值为1.5至7.5的范围内，该藻类似乎能够将细胞内pH值维持在6.35至7.1的范围内。在相同的细胞外pH值范围内，膜电位从-12毫伏（内侧为负）增加到-71毫伏，因此ΔμH(+)从-300毫伏降低到-47毫伏。有人认为，ΔμH(+)可能设定了生长的pH值上限和下限。还测定了光合性能随pH值的变化情况。细胞似乎利用培养基中的CO₂，因为在pH值为1.5至7.5的范围内，表观K(m(co(2)))为2至3微摩尔CO₂。梅洛拉蓝细菌似乎具有一种“CO₂浓缩”机制。
