School of Life Sciences, Tsinghua University, Beijing 100084, China.
Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
Bioresour Technol. 2017 Nov;244(Pt 1):534-541. doi: 10.1016/j.biortech.2017.07.149. Epub 2017 Jul 27.
Poly(3-hydroxybutyrate-co-4-hydroxybutyrate), short as P(3HB-co-4HB), was successfully produced by engineered Halomonas bluephagenesis TD01 grown in glucose and γ-butyrolactone under open non-sterile conditions. Gene orfZ encoding 4HB-CoA transferase of Clostridium kluyveri was integrated into the genome to achieve P(3HB-co-4HB) accumulation comparable to that of strains encoding orfZ on plasmids. Fed-batch cultivations conducted in 1-L and 7-L fermentors, respectively, resulted in over 70g/L cell dry weight (CDW) containing 63% P(3HB-co-12mol% 4HB) after 48h under non-sterile conditions. The processes were further scaled up in a 1000-L pilot fermentor to reach 83g/L CDW containing 61% P(3HB-co-16mol% 4HB) in 48h, with a productivity of 1.04g/L/h, again, under non-sterile conditions. The elastic P(3HB-co-16mol% 4HB) shows an elongation at break of 1022±43%. Results demonstrate that the engineered Halomonas bluephagenesis TD01 is a suitable industrial strain for large scale production under open non-sterile conditions.
聚（3-羟基丁酸-co-4-羟基丁酸），简称 P（3HB-co-4HB），由工程化的盐单胞菌蓝藻 TD01 在葡萄糖和γ-丁内酯下于开放非无菌条件下成功生产。来源于克氏柠檬酸杆菌的基因 orfZ 编码 4HB-CoA 转移酶被整合到基因组中，以实现与质粒上编码 orfZ 的菌株相当的 P（3HB-co-4HB）积累。在 1-L 和 7-L 发酵罐中进行分批补料培养，分别在 48 小时内于非无菌条件下获得超过 70g/L 的细胞干重（CDW），其中含有 63%的 P（3HB-co-12mol%4HB）。该过程在 1000-L 中试发酵罐中进一步放大，在 48 小时内达到 83g/L 的 CDW，其中含有 61%的 P（3HB-co-16mol%4HB），在非无菌条件下的生产率为 1.04g/L/h。弹性 P（3HB-co-16mol%4HB）的断裂伸长率为 1022±43%。结果表明，工程化的盐单胞菌蓝藻 TD01 是在开放非无菌条件下进行大规模生产的合适工业菌株。
