Molecular mass of poly[(R)-3-hydroxybutyric acid] produced in a recombinant Escherichia coli
Molecular mass of poly[(R)-3-hydroxybutyric acid] produced in a recombinant Escherichia coli
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DOI：
10.1007/s002530050902
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发表时间：
1997-02-01
影响因子：
5
通讯作者：
Doi, Y
中科院分区：
文献类型：
--
作者：
Kusaka, S;Abe, H;Doi, Y
利用富营养性产碱菌生物合成PHB-CAB基因的重组大肠杆菌，在10-30g/L葡萄糖的Luria-Bertani培养基中，在不同pH值、37℃下合成了聚[(R)-3-羟基丁酸](PHB)，并研究了PHB的相对分子质量随时间的变化。当葡萄糖存在于细胞内时，PHB聚合物在细胞内积累。在PHB的积累过程中，PHB的数均相对分子质量随着时间的推移而下降，并且PHB的值明显依赖于大肠杆菌的培养条件，范围在0.5MDA到20MDA之间。在特定条件下(pH 6.0)，大肠杆菌产生的PHB具有极高的相对分子质量(20mda)。有人认为，在PHB的积累过程中，大肠杆菌细胞中产生了一种链转移剂。
Poly[(R)-3-hydroxybutyric acid] (PHB) was produced at 37 degrees C by a recombinant Escherichia coli harboring the Alcaligenes eutrophus biosynthesis phb-CAB genes in Luria-Bertani media containing glucose at 10-30 g/l at different pH values and the time-dependent changes in the molecular mass of PHB were studied. PHB polymers accumulated within cells while glucose was present in the medium. The number-average molecular mass of PHB decreased with time during the course of PHB accumulation, and the values for PHB were markedly dependent on the cultivation conditions of the E. coli, ranging from 0.5 MDa to 20 MDa. Under specific conditions (pH 6.0), E. coli produced PHB with an extremely high molecular mass (20 MDa). It has been suggested that a chain-transfer agent is generated in E. coli cells during the accumulation of PHB.