The accumulation of bacteriochlorophyll precursors by mutant and wild-type strains of Rhodopseudomonas spheroides.
The accumulation of bacteriochlorophyll precursors by mutant and wild-type strains of Rhodopseudomonas spheroides.
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球形红假单胞菌突变体和野生型菌株细菌叶绿素前体的积累。
DOI：
10.1042/bj1000175
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发表时间：
1966
期刊：
影响因子：
--
通讯作者：
J. Lascelles
中科院分区：
文献类型：
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作者：
J. Lascelles
1.抑制细菌叶绿素合成的两株球状红假单胞菌突变株均能积累色素。初步鉴定为2，4-二乙烯基邻卟啉a(5)单甲酯镁和2-脱乙基-2-羟乙基脱镁叶绿酸a镁衍生物，分别由突变体2/73和2/21产生。2.当生物悬浮液在含铁的生长介质中与低通气量孵育，并添加甘氨酸、琥珀酸、蛋氨酸和吐温80时，这些色素的胞外产量最高。3.突变株从甘氨酸和琥珀酸合成色素需要伴随蛋白质的合成，但当底物为β-氨基乙酰丙酸时，这一要求不太明显。4.在没有吐温80的情况下，总色素的相当大一部分保留在细胞内，并出现在无细胞提取物的颗粒部分中。5.含有β-氨基乙酰丙酸的母菌悬浮液可以积累胞外色素，初步鉴定为镁原卟啉单甲酯和2-脱乙烯-2-羟乙基-脱镁叶绿酸a的镁衍生物。6.在细菌叶绿素合成受到一段时间的氧气抑制后，光合作用培养的细胞产量最高。8-氮鸟嘌呤或5-氟尿嘧啶或营养突变体中腺嘌呤缺乏可促进抗焦虑素衍生物的形成；吐温80也是必需的，铁是必需的。7.细菌叶绿素的合成可能涉及脂蛋白结合的中间产物的参与，这些中间产物可能是在甘氨酸和琥珀酰辅酶A缩合的初始阶段形成的，生成了β-氨基乙酰丙酸。
1. Two mutant strains of Rhodopseudomonas spheroides, which are blocked in the synthesis of bacteriochlorophyll, accumulate pigments. These have been tentatively identified as magnesium 2,4-divinylphaeoporphyrin a(5) monomethyl ester and the magnesium derivative of 2-devinyl-2-hydroxyethyl-phaeophorbid a, formed by mutant 2/73 and 2/21 respectively. 2. Maximum extracellular production of these pigments occurs when suspensions of the organisms are incubated with low aeration in a growth medium containing iron and supplemented with glycine, succinate, methionine and Tween 80. 3. Concomitant protein synthesis is required for pigment production by the mutants from glycine and succinate but this requirement is less marked when delta-aminolaevulic acid is the substrate. 4. In the absence of Tween 80, a considerable proportion of the total pigment is retained within the cells and appears in the particulate fraction of cell-free extracts. 5. Suspensions of the parent strain containing delta-aminolaevulic acid can be made to accumulate extracellular pigments which are tentatively identified as magnesium protoporphyrin monomethyl ester and the magnesium derivative of 2-devinyl-2-hydroxyethyl-phaeophorbid a. 6. Maximum production occurs with cells incubated photosynthetically after a period of oxygen repression of bacteriochlorophyll synthesis. Formation of the phaeophorbid derivative is enhanced by 8-azaguanine or 5-fluorouracil, or by adenine deficiency in a nutritional mutant; Tween 80 is also needed and iron is essential. 7. Synthesis of bacteriochlorophyll might possibly involve the participation of lipoprotein-bound intermediates, which may be formed at the initial stage of condensation between glycine and succinyl-CoA to give delta-aminolaevulic acid.