PDF(Pubmed)
Abstract：
Polyhydroxyalkanoates (PHA) have received attention owing to their biodegradability and biocompatibility, with studies exploring PHA-producing bacterial strains. As vegetable oil provides carbon and monomer precursors for poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HHx)), oil-utilizing strains may facilitate PHA production. Herein, Cupriavidus necator BM3-1, which produces 11.1 g/L of PHB with 5% vegetable oil, was selected among various novel Cupriavidus necator strains. This strain exhibited higher preference for vegetable oils over sugars, with soybean oil and tryptone determined to be optimal sources for PHA production. BM3-1 produced 33.9 g/L of exopolysaccharides (EPS), which was three-fold higher than the amount produced by H16 (10.1 g/L). EPS exhibited 59.7% of emulsification activity (EI24), higher than that of SDS and of EPS from H16 with soybean oil. To evaluate P(3HB-co-3HHx) production from soybean oil, BM3-1 was engineered with P(3HB-co-3HHx) biosynthetic genes (phaCRa, phaARe, and phaJPa). BM3-1/pPhaCJ produced 3.5 mol% of 3HHx and 37.1 g/L PHA. BM3-1/pCB81 (phaCAJ) produced 32.8 g/L PHA, including 5.9 mol% 3HHx. Physical and thermal analyses revealed that P(3HB-co-5.9 mol% 3HHx) was better than PHB. Collectively, we identified a novel strain with high vegetable oil utilization capacity for the production of EPS, with the option to engineer the strain for P(3HB-co-3HHx).
摘要：
聚羟基链烷酸酯(PHA)因其可生物降解性和生物相容性而受到关注,研究探索产生PHA的细菌菌株。由于植物油为聚（3-羟基丁酸酯-co-3-羟基己酸酯）（P（3HB-co-3HHx））提供碳和单体前体，利用油的菌株可以促进PHA的生产。在这里，CupriavidusnecatorBM3-1，产生11.1g/L的PHB，含有5％的植物油，在各种新的Cupriavidusnecator菌株中选择。该菌株对植物油的偏好高于糖，大豆油和胰蛋白胨被确定为PHA生产的最佳来源。BM3-1产生33.9g/L的胞外多糖（EPS），比H16的产量（10.1g/L）高三倍。EPS表现出59.7%的乳化活性(EI24)，高于SDS和大豆油H16的EPS。为了评估大豆油中P(3HB-co-3HHx)的产量，BM3-1用P(3HB-co-3HHx)生物合成基因(phaCRa，PhaARe,和phaJPa）。BM3-1/pPhaCJ产生3.5mol%的3HHx和37.1g/LPHA。BM3-1/pCB81（phaCAJ）产生32.8g/LPHA，包括5.9mol%3HHx。物理和热分析显示P(3HB-co-5.9mol%3HHx)优于PHB。总的来说，我们确定了一种具有高植物油利用率的新型菌株，用于生产EPS，可以选择设计P（3HB-co-3HHx）的菌株。
