Klein S, Jaynes J M, Kent S S, Vernon L P
Department of Chemistry and Botany, Brigham Young University, Provo, Utah.
Plant Physiol. 1981 Aug;68(2):407-10. doi: 10.1104/pp.68.2.407.
The cyanelle from the photosynthetic biflagellate protist Cyanophora paradoxa has been studied in terms of its photosynthetic properties. Structurally, the cyanelle resembles unicellular cyanobacteria. The cyanelle is readily released from the host cell by means of the French press. The isolated cyanelle shows typical photosystem I and photosystem II activities as well as phenazine methosulfate-mediated photophosphorylation. The kinetic parameters K(m) and V(max) were determined for CO(2) fixation in the cyanelle and cells of C. paradoxa and compared to a cyanobacterium. The determined values were not much different, although the cyanobacterium had a significantly greater rate of CO(2) fixation, and the cyanelle was least active in this regard. Photosystem I chlorophyll-protein complex is readily isolated from the thylakoid membrane. In all these respects, the photosynthetic apparatus of the cyanelle resembles that of cyanobacteria. No nitrogen fixation activity was observed. Attempts to regenerate the isolated cyanelle were not successful, but in some cases, an unidentified cyanobacterium grew up in standing cultures of C. paradoxa cyanelles. Buoyant density data indicate that the strain of C. paradoxa we have investigated differs from that employed by others, since our strain shows a value of 1.716 grams per cubic centimeter and others report values of 1.695 and 1.691.
人们已对光合双鞭毛原生生物蓝氏拟甲色球藻（Cyanophora paradoxa）中的蓝小体进行了光合特性方面的研究。在结构上，蓝小体类似于单细胞蓝细菌。通过法国压榨机可轻松地将蓝小体从宿主细胞中释放出来。分离出的蓝小体显示出典型的光系统I和光系统II活性，以及吩嗪硫酸甲酯介导的光合磷酸化作用。测定了蓝氏拟甲色球藻蓝小体和细胞中二氧化碳固定的动力学参数K(m)和V(max)，并与一种蓝细菌进行了比较。尽管蓝细菌的二氧化碳固定速率明显更高，且蓝小体在这方面活性最低，但测定值并无太大差异。光系统I叶绿素 - 蛋白复合物很容易从类囊体膜中分离出来。在所有这些方面，蓝小体的光合装置类似于蓝细菌。未观察到固氮活性。再生分离出的蓝小体的尝试未成功，但在某些情况下，一种未鉴定的蓝细菌在蓝氏拟甲色球藻蓝小体的静置培养物中生长。浮力密度数据表明，我们所研究的蓝氏拟甲色球藻菌株与其他研究中使用的菌株不同，因为我们的菌株显示的值为每立方厘米1.716克，而其他研究报告的值为1.695和1.691。
