Institut für Biologie II (Mikrobiologie), Universität Freiburg, Schänzlestraße 1, D-79104, Freiburg, Germany.
Photosynth Res. 1994 Jul;41(1):145-50. doi: 10.1007/BF02184154.
The dependence of chlorosome development on bacteriochlorophyll (BChl)c synthesis was studied with the phototrophic green bacteriumChloroflexus aurantiacus. By selecting defined culture conditions, three possibilities could be identified. Upon addition of 5-aminolevulinic acid, cells of resting cultures increased their specific BChlc contents as well as the volumes of already existing chlorosomes. The number of chlorosomes, however, remained constant. Serine-limited chemostat cultures grown under steady state conditions exhibited constant rates of synthesis of both BChlc as well as of chlorosomes. The volume of the latter remained constant, as well. Upon addition of ALA to chemostat cultures, chlorosomes were synthesized at the same rate as before but their volumes increased as a consequence of increased BChlc incorporation. In chlorosomes isolated from resting cultures supplied with ALA the amounts of all of the polypeptides increased only slightly, if at all. Moreover, the ratio of all of the chlorosomal polypeptides remained largely constant. These results show that chlorosomes may incorporate newly synthesized BChlc without concomitant formation of chlorosomal polypeptides. This means that there was no obvious coordination of polypeptide and BChlc synthesis. On this basis, it appears unlikely that one of the chlorosomal polypeptides functions as an apoprotein of a presumed BChlc holochrome complex.
研究了嗜硫菌（Chloroflexus aurantiacus）中类菌叶绿素（BChl）c 合成对菌光体发育的依赖性。通过选择特定的培养条件，可以确定三种可能性。在添加 5-氨基乙酰丙酸后，静止培养物的细胞增加了它们的特定 BChlc 含量以及已经存在的菌光体的体积。然而，菌光体的数量保持不变。在稳态条件下生长的丝氨酸限制恒化器培养物表现出 BChlc 和菌光体的合成速率恒定。后者的体积也保持不变。在向恒化器培养物中添加 ALA 后，菌光体以与之前相同的速率合成，但由于 BChlc 掺入的增加，其体积增加。在从添加 ALA 的静止培养物中分离的菌光体中，所有多肽的含量仅略有增加（如果有的话）。此外，所有菌光体多肽的比例基本保持不变。这些结果表明，菌光体可以在没有伴随形成菌光体多肽的情况下掺入新合成的 BChlc。这意味着多肽和 BChlc 合成之间没有明显的协调。在此基础上，似乎不太可能有一种菌光体多肽作为假定的 BChlc 全色复合物的脱辅基蛋白发挥作用。
