Tian W, Hong K, Chen G Q, Wu Q, Zhang R Q, Huang W
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China.
Antonie Van Leeuwenhoek. 2000 Jan;77(1):31-6. doi: 10.1023/a:1002099023046.
Pseudomonas mendocina strain 0806 was isolated from oil-contaminated soil and found to produce polyesters consisting of medium chain length 3-hydroxyalkanoates (mclPHAs). The monomers of mclPHAs contained even numbers of carbon atoms, such as 3-hydroxyhexanoate (HHx or C6), 3-hydroxyoctanoate (HO or C8), and/or 3-hydroxydecanoate (HD or C10) as major components when grown on many carbon sources unrelated to their monomeric structures, such as glucose, citric acid, and carbon sources related to their monomeric structures, such as myristic acid, octanoate, or oleic acid. On the other hand, PHA containing both even and odd numbers of hydroxyalkanoates (HA) monomers was synthesized when the strain was grown on tridecanoic acid. The molar ratio of carbon to nitrogen (C/N) had a significant effect on PHA composition: the strain produced PHAs containing 97-99% of HD monomer when grown in a glucose ammonium sulfate medium of C/N<20, and 20% HO, and 80% of the HD monomer when growth was conducted in media containing C/N>40. It was demonstrated that the HO/HD ratio in the polymers remained constant in media with a constant C/N ratio, regardless of the glucose concentration. Up to 3.6 g/L cell dry weight containing 45% of PHAs was produced when the strain was grown for 48 h in a medium containing 20 g/L glucose with a C/N ratio of 40.
从受油污染的土壤中分离出门多萨假单胞菌菌株0806，发现其能产生由中链长度3-羟基链烷酸酯（mclPHA）组成的聚酯。当在许多与其单体结构无关的碳源（如葡萄糖、柠檬酸）以及与其单体结构相关的碳源（如肉豆蔻酸、辛酸或油酸）上生长时，mclPHA的单体包含偶数个碳原子，如3-羟基己酸酯（HHx或C6）、3-羟基辛酸酯（HO或C8）和/或3-羟基癸酸酯（HD或C10）作为主要成分。另一方面，当该菌株在十三烷酸上生长时，会合成同时含有偶数和奇数个羟基链烷酸酯（HA）单体的PHA。碳氮摩尔比（C/N）对PHA组成有显著影响：当在C/N<20的葡萄糖硫酸铵培养基中生长时，该菌株产生的PHA含有97-99%的HD单体；当在C/N>40的培养基中生长时，产生的PHA含有20%的HO和80%的HD单体。结果表明，无论葡萄糖浓度如何，在C/N比恒定的培养基中，聚合物中的HO/HD比保持恒定。当该菌株在含有20 g/L葡萄糖、C/N比为40的培养基中生长48小时时，可产生高达3.6 g/L细胞干重且含有45%PHA的产物。
