Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia.
Academy of Biology and Biotechnology, Southern Federal University, 344022 Rostov-on-Don, Russia.
Biosensors (Basel). 2021 May 23;11(6):166. doi: 10.3390/bios11060166.
LuxR and LuxR1 and LuxR2 regulatory proteins are quorum sensing transcriptional (QS) activators, inducing promoters of genes in the presence of an autoinducer (3-oxo-hexanoyl-l-homoserine lactone). In the cells, genes are regulated by HNS, CRP, LitR, etc. Here we investigated the role of the expression level in LuxI/R QS system functionality and improved the whole-cell biosensor for autoinducer detection. -based bacterial -biosensors were used, in which genes were controlled by LuxR-dependent promoters and , , or regulatory genes. We varied either the dosage of the regulatory gene in the cells using additional plasmids, or the level of the regulatory gene expression using the lactose operon promoter. It was shown that an increase in expression level, as well as dosage of the regulatory gene in biosensor cells, leads to an increase in sensitivity (the threshold concentration of AI is reduced by one order of magnitude) and to a two to threefold reduction in response time. The best parameters were obtained for a biosensor with an increased dosage of (sensitivity to 3-oxo-hexanoyl-l-homoserine lactone reached 30-100 pM).
LuxR 和 LuxR1 和 LuxR2 调节蛋白是群体感应转录（QS）激活剂，在自诱导剂（3-氧代己酰基-L-高丝氨酸内酯）存在的情况下诱导基因的启动子。在细胞中，基因受 HNS、CRP、LitR 等调节。在这里，我们研究了表达水平在 LuxI/R QS 系统功能中的作用，并改进了用于自动诱导检测的全细胞生物传感器。使用基于 LuxI 的细菌生物传感器，其中基因由 LuxR 依赖性启动子和、或调节基因控制。我们通过使用附加质粒来改变细胞中调节基因的剂量，或者使用乳糖操纵子启动子来改变调节基因表达的水平。结果表明，表达水平的增加以及生物传感器细胞中调节基因的剂量增加会导致灵敏度增加（AI 的阈值浓度降低一个数量级），并且响应时间缩短两到三倍。对于具有增加的 （对 3-氧代己酰基-L-高丝氨酸内酯的灵敏度达到 30-100 pM）的生物传感器获得了最佳参数。
