Bacterial outer membrane (OM), an asymmetric lipid bilayer functioning as a self-protective barrier with reduced permeability for Gram-negative bacteria, yet wasting nutrients and energy to synthesize, has not been studied for its effect on bioproduction. Here we construct several OM-defected halophile Halomonas bluephagenesis strains to investigate the effects of OM on bioproduction. We achieve enhanced chassis properties of H. bluephagenesis based on positive cellular properties among several OM-defected strains. The OM-defected H. bluephagenesis WZY09 demonstrates better adaptation to lower salinity, increasing 28%, 30% and 12% on dry cell mass (DCM), poly(3-hydroxybutyrate) (PHB) accumulation and glucose to PHB conversion rate, respectively, including enlarged cell sizes and 21-folds reduced endotoxin. Interestingly, a poly(3-hydroxybutyrate-co-21mol%4-hydroxybutyrate) (P(3HB-co-21mol%4HB)) is produced by H. bluephagenesis WZY09 derivate WZY249, increasing 60% and 260% on polyhydroxyalkanoate (PHA) production and 4HB content, respectively. Furthermore, increased electroporation efficiency, more sensitive isopropyl β-D-1-thio-galactopyranoside (IPTG) induction, better oxygen uptake, enhanced antibiotics sensitivity and ectoine secretion due to better membrane permeability are observed if OM defected, demonstrating significant OM defection impacts for further metabolic engineering, synthetic biology studies and industrial applications.

细菌外膜 (OM) 是一种不对称脂质双层，可作为自我保护屏障，降低革兰氏阴性细菌的渗透性，但浪费营养和能量来合成，尚未对其对生物生产的影响进行研究。在这里，我们构建了几种 OM 缺陷的嗜盐菌 Halomonas bluephagenesis菌株，以研究 OM 对生物生产的影响。我们基于几种 OM 缺陷菌株中的阳性细胞特性实现了H. bluephagenesis的增强底盘特性。OM 缺陷的H. bluephagenesisWZY09 表现出对较低盐度的更好适应，分别增加了 28%、30% 和 12% 的干细胞质量 (DCM)、聚（3-羟基丁酸）（PHB）积累和葡萄糖到 PHB 的转化率，包括扩大的细胞大小和 21 -folds 减少内毒素。有趣的是，聚（3-羟基丁酸酯共-21mol％4-羟基丁酸酯）（P（3HB-共-21mol％4HB））通过产生H. bluephagenesis WZY09衍生物WZY249，聚羟基脂肪酸酯上增加60％和260％（PHA）产量和 4HB 含量。此外，提高电穿孔效率，更灵敏的异丙基β如果 OM 缺陷，则观察到 -D-1-硫代吡喃半乳糖苷 (IPTG) 诱导、更好的氧气吸收、增强的抗生素敏感性和由于更好的膜通透性导致的四氢嘧啶分泌，这表明对进一步代谢工程、合成生物学研究和工业应用的重大 OM 缺陷影响.