Novel precursor substrates for polythioesters (PTE) and limits of PTE biosynthesis in Ralstonia eutropha
Novel precursor substrates for polythioesters (PTE) and limits of PTE biosynthesis in Ralstonia eutropha
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DOI：
10.1016/s0378-1097(03)00185-x
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发表时间：
2003-04-25
影响因子：
2.1
通讯作者：
Steinbüchel, A
中科院分区：
文献类型：
--
作者：
Lütke-Eversloh, T;Steinbüchel, A
当在3-巯基丙酸（3 MP）或3，3 '-硫代二丙酸（TDP）存在下培养聚羟基链烷酸酯（PHA）积累细菌真养罗尔斯通氏菌（Ralstonia eutropha）时，最近检测到一类称为聚硫酯（PTE）的新型生物聚合物。在本研究中，3，3 '-二硫代二丙酸（DTDP）和3-巯基戊酸（3 MV）被鉴定为两种额外的前体碳源，用于在R.真养型。参考不同的前体底物，比较了3-羟基丁酸酯（31413）和3 MP的共聚物的生物合成，其贡献了细胞干物质的19-25%。使用DTDP作为碳源，它可能被切割成两个分子的3 MP，产生了约2.3倍高的摩尔3 MP含量比TDP，这可能是只切割成一个分子的3 MP的。此外，还对R.在3 MV的存在下，真养菌导致主要由3 HB与少量的3 MV和3-羟基戊酸组成的共聚物的生物合成，每种贡献小于5mol%的组分。相反，4-巯基丁酸不能掺入PHA中，尽管-如本研究中所记录的-五种不同的策略，各种前体底物，R。真养型和大肠杆菌的重组菌株。因此，本研究不仅扩大了适合PTE生物合成的底物范围，而且扩大了R.真养型细菌，它也证明了在这种细菌中PTE生物合成的限制。(C)2003年，欧洲微生物学会联合会。由Elsevier Science B. V.出版，版权所有。
A novel class of biopolymers referred to as polythioesters (PTE) was recently detected when the polyhydroxyalkanoate (PHA) accumulating bacterium Ralstonia eutropha was cultivated in the presence of 3-mercaptopropionic acid (3MP) or 3,3'-thiodipropionic acid (TDP). In this study, 3,3'-dithiodipropionic acid (DTDP) and 3-mercaptovaleric acid (3MV) were identified as two additional precursor carbon sources for in vivo biosynthesis of PTE in R. eutropha. Biosynthesis of copolymers of 3-hydroxybutyrate (31413) and 3MP, which contributed 19-25% of cell dry matter, was compared referring to the different precursor substrates. Using DTDP as carbon source, which is probably cleaved into two molecules 3MP, yielded an about 2.3-fold higher molar 3MP content of the copolyester than TDP, which is probably cleaved into only one molecule 3MP. Furthermore, cultivation of R. eutropha in the presence of 3MV resulted in biosynthesis of copolymers consisting predominantly of 3HB with low amounts of 3MV and 3-hydroxyvalerate, each contributing less than 5 mol% of the constituents. In contrast, 4-mercaptobutyric acid could be not incorporated into PHAs, although - as documented in this study - five different strategies, various precursor substrates, R. eutropha and also a recombinant strain of Escherichia coli were employed. Therefore, this study not only extended the range of substrates suitable for PTE biosynthesis and also the range of PTE constituents in R. eutropha, it also demonstrates limits for PTE biosynthesis in this bacterium. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.