Influence of the luxR Regulatory Gene Dosage and Expression Level on the Sensitivity of the Whole-Cell Biosensor to Acyl-Homoserine Lactone

Biosensors

Vladimir Chistyakov¹  Ekaterina Scheglova²  Ilya Manukhov²  Sergey Bazhenov²  Uliana Novoyatlova²  Vadim Fomin²  Svetlana Khrulnova²  Olga Melkina³ 

[1] Academy of Biology and Biotechnology, Southern Federal University, 344022 Rostov-on-Don, Russia;Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia;State Research Institute of Genetics and Selection of Industrial Microorganisms of the National Research Center “Kurchatov Institute”, 117545 Moscow, Russia;

关键词: whole-cell biosensor;    LuxR;    autoinducer;    quorum sensing;   

DOI  :  10.3390/bios11060166

来源: DOAJ

【 摘 要 】

Aliivibrio fischeri LuxR and Aliivibrio logei LuxR1 and LuxR2 regulatory proteins are quorum sensing transcriptional (QS) activators, inducing promoters of luxICDABEG genes in the presence of an autoinducer (3-oxo-hexanoyl-l-homoserine lactone). In the Aliivibrio cells, luxR genes are regulated by HNS, CRP, LitR, etc. Here we investigated the role of the luxR expression level in LuxI/R QS system functionality and improved the whole-cell biosensor for autoinducer detection. Escherichia coli-based bacterial lux-biosensors were used, in which Photorhabdus luminescensluxCDABE genes were controlled by LuxR-dependent promoters and luxR, luxR1, or luxR2 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 luxRA. fischeri (sensitivity to 3-oxo-hexanoyl-l-homoserine lactone reached 30–100 pM).

【 授权许可】

Unknown