Fedorov D N, Zamakhaeva S A, Ezhov V A, Doronina N V, Trotsenko Iu A
Prikl Biokhim Mikrobiol. 2014 May-Jun;50(3):289-94.
The effect of the increased copy number of polyhydroxybutyrate (PHB) biosynthesis genes in pink-pigmented methylobacterium Methylobacterium extorquens G10 on properties of the biopolymer was studied. The activity of poly-3-hydroxybutyril-synthase (PHB-synthase) was shown to increase and the molecular weight of synthesized PHB decreases twofold (150 --> 79 kDa) after insertion of extra copies of phaC and phaCAB genes into cells of the producer strain, whereas the physicochemical properties of the plastic changed insignificantly. White mutant M. extorquens G10-W with disrupted synthesis of the carotenoid pigment (defect by the crtI gene, which codes for phytoene desaturase) was established to have the same rate of growth and level of PHB accumulation as the initial strain G10. The G10-W strain is a promising producer of PHB, with decreased expenses for purification and PHB biosynthesis.
研究了粉色色素甲基obacterium Methylobacterium extorquens G10中聚羟基丁酸酯（PHB）生物合成基因拷贝数增加对生物聚合物性质的影响。将phaC和phaCAB基因的额外拷贝插入生产菌株细胞后，聚-3-羟基丁酰合成酶（PHB合成酶）的活性增加，合成的PHB分子量降低两倍（150 --> 79 kDa），而塑料的物理化学性质变化不明显。已确定白色突变体M. extorquens G10-W（类胡萝卜素色素合成中断，由编码八氢番茄红素去饱和酶的crtI基因缺陷导致）与初始菌株G10具有相同的生长速率和PHB积累水平。G10-W菌株是一种有前景的PHB生产菌株，可降低纯化和PHB生物合成的成本。
