排序方式: 共有2条查询结果,搜索用时 62 毫秒
1
1.
A threonine overproducing mutant of Alcaligenes sp. SH-69 was isolated and its ability to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3HB-co-3HV), was investigated. The 3HV fraction in poly(3HB-co-3HV) produced from glucose as the sole carbon source exceeded 22 mol%, which is approximately six times higher than that achieved by the wild type under the same culture conditions. Furthermore, the addition of a relatively low concentration (10 mM) of propionic acid, valeric acid or levulinic acid to the glucose medium greatly increased the molar fraction of 3HV in the copolyester, to 38–77 mol%. The results suggest that metabolic engineering of the biosynthetic pathways supplying polyhydroxyalkanoate monomers, such as the threonine biosynthetic pathway, can lead to new poly(3HB-co-3HV)-producing strains. 相似文献
2.
Hye Ok Kang Chung Wook Chung Hyung Woo Kim Young Baek Kim Young Ha Rhee 《Antonie van Leeuwenhoek》2001,80(2):185-191
A newly isolated strain, designated as Pseudomonas sp. DSY-82, synthesized medium-chain-length polyhydroxyalkanoate (MCL-PHA) copolyesters when grown on alkanoates from hexanoate to undecanoate as the sole carbon source. When used alone, butyrate and valerate supported the growth of the isolate but not PHA production. However, unusual polyesters containing 3-hydroxyvalerate, as well as various MCL 3-hydroxyalkanoate monomeric units, were synthesized when valerate was cofed with either nonanoate or 10-undecenoate, suggesting the formation of monomer units from both substrates. Concentrations of 3-hydroxyvalerate, 3-hydroxyoctanoate, and 3-hydroxydecanoate in the PHAs produced were significantly elevated by the addition of valerate, indicating that the incorporation of these monomer units to PHA occurred primarily through cometabolism. The total amount of these monomer units in the PHAs reached up to 30%. The PHAs produced in this study were most likely random copolyesters as determined by differential scanning calorimetric analysis. This is the first case of microbial synthesis of copolyesters consisting of 3-hydroxyvalerate and MCL 3-hydroxyalkanoate monomer units through cometabolism. 相似文献
1