We investigated the biosynthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) produced by Haloferax mediterranei NBRC14739T from glucose. When H. mediterranei grew on 5 g/L glucose in flask culture, 43.7 wt% PHBV with 12 mol% 3-hydroxyvalerate (3HV) accumulated intracellularly. Size-exclusion chromatography revealed that this polymer had a weight-average molecular weight (Mw) and polydispersity (Mw/Mn) of 4.7 × 106 g/mol and 1.7, respectively. Increasing the glucose concentration in the flask cultures slightly promoted cell growth and increased the PHBV content but had less effect on molecular weight. Scale-up cultivation in a 5-L jar yielded 4.0 g/L PHBV from 20 g/L glucose with a Mw of up to 5.0 × 106 g/mol. These results showed that H. mediterranei can produce ultrahigh-molecular-weight (UHMW) PHBV from glucose. UHMW-PHBV (7 mol% 3HV, Mw = 4.4 × 106 g/mol) was used to prepare cold-drawn films, the mechanical properties of which were characterized. The films were produced by tenfold cold drawing, followed by annealing at 100 °C, and had a tensile strength and Young’s modulus of 258.7 MPa and 0.90 GPa, respectively. We investigated the biosynthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) produced by Haloferax mediterranei from glucose. Size-exclusion chromatography revealed that PHBV produced by H. mediterranei in flask cultures had a weight-average molecular weight of 4.7 × 106 g/mol, demonstrating production of ultrahigh-molecular-weight (UHMW) PHBV. The UHMW-PHBV (7 mol% 3-hydroxyvalerate, Mw = 4.4 × 106 g/mol) obtained by jar fermenter cultivation was used to produce tenfold cold-drawn films with a tensile strength of 258.7 MPa. This suggests that UHMW-PHBV has a potential for practical, strong films.

中文翻译：

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Haloferax mediterranei生产的超高分子量聚（3-羟基丁酸酯-co-3-羟基戊酸酯）冷拉膜的力学性能

我们研究了由 Haloferax mediterranei NBRC14739T 从葡萄糖中产生的聚（3-羟基丁酸-co-3-羟基戊酸）（PHBV）的生物合成和性质。当 H. mediterranei 在烧瓶培养中以 5 g/L 葡萄糖生长时，43.7 wt% PHBV 和 12 mol% 3-羟基戊酸 (3HV) 在细胞内积累。尺寸排阻色谱显示该聚合物的重均分子量 (Mw) 和多分散性 (Mw/Mn) 分别为 4.7 × 106 g/mol 和 1.7。增加烧瓶培养物中的葡萄糖浓度会略微促进细胞生长并增加 PHBV 含量，但对分子量的影响较小。在 5-L 罐中放大培养从 20 g/L 葡萄糖中产生 4.0 g/L PHBV，Mw 高达 5.0 × 106 g/mol。这些结果表明，H. mediterranei 可以从葡萄糖中产生超高分子量 (UHMW) PHBV。UHMW-PHBV (7 mol% 3HV, Mw = 4.4 × 106 g/mol) 用于制备冷拉伸薄膜，表征其机械性能。该薄膜是通过十倍冷拉伸制成的，然后在 100°C 下退火，其拉伸强度和杨氏模量分别为 258.7 MPa 和 0.90 GPa。我们研究了由 Haloferax mediterranei 从葡萄糖中产生的聚（3-羟基丁酸-co-3-羟基戊酸）（PHBV）的生物合成和性质。体积排阻色谱显示，由地中海嗜血杆菌在烧瓶培养物中产生的 PHBV 的重均分子量为 4.7 × 106 g/mol，表明产生了超高分子量 (UHMW) PHBV。通过罐式发酵罐培养获得的 UHMW-PHBV（7 mol% 3-羟基戊酸酯，Mw = 4.4 × 106 g/mol）用于生产拉伸强度为 258 的十倍冷拉薄膜。7兆帕。这表明 UHMW-PHBV 具有制作实用、坚固薄膜的潜力。