Systems Biology, School for Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
Molecules. 2024 Jul 11;29(14):3288. doi: 10.3390/molecules29143288.
Surfactants are amphiphilic molecules that are capable of mixing water and oil. Biosurfactants are eco-friendly, low-toxicity, and stable to a variety of environmental factors. Optimizing conditions for microorganisms to produce biosurfactants can lead to improved production suitable for scaling up. In this study, we compared heterologous expression levels of the luminescence system operon controlled by regulatable promoters araC-P and its strong version araC-P in K12, PAO1, and KT2440. Real-time monitoring of luminescence levels in the three strains indicated that controlled by araC-P promoter with 0.2% arabinose supplementation in produced the highest level of luminescence. By using the araC-P promoter-controlled expression in , we were able to produce mono-rhamnolipid at a level of 1.5 g L when 0.02% arabinose was supplemented. With the same system to express , lyso-ornithine lipid was produced at a level of 10 mg L when 0.2% arabinose was supplemented. To our knowledge, this is the first report about optimizing conditions for lyso-ornithine lipid production at a level up to 10 mg L. Taken together, our results demonstrate that regulatable araC-P promoter in KT2440 is a useful system for heterologous production of biosurfactants.
表面活性剂是一种两亲性分子，能够混合水和油。生物表面活性剂具有环保、低毒性和对各种环境因素稳定的特点。优化微生物生产生物表面活性剂的条件可以提高适合放大生产的产量。在这项研究中，我们比较了可调控启动子 araC-P 和其强版本 araC-P 控制的发光系统操纵子在 K12、PAO1 和 KT2440 中的异源表达水平。实时监测三种菌株的发光水平表明，在添加 0.2%阿拉伯糖的情况下，由 araC-P 启动子控制的 在 KT2440 中产生的发光水平最高。通过在 中使用 araC-P 启动子控制的 表达，我们能够在添加 0.02%阿拉伯糖时生产出 1.5 g/L 的单鼠李糖脂。使用相同的系统表达 ，在添加 0.2%阿拉伯糖时可以生产出 10 mg/L 的溶菌鸟氨酸脂。据我们所知，这是第一个关于优化溶菌鸟氨酸脂生产水平至 10 mg/L 的报告。总之，我们的结果表明，KT2440 中的可调控 araC-P 启动子是生物表面活性剂异源生产的有用系统。
