| Abstract [eng] |
Inducible gene expression systems, composed of transcription factor (TF) and cognate inducible promoter have come into the focus as a platform for the development of genetically encoded TF-based biosensors. The interaction of TFs with specific inducers activates the expression of the reporter protein in a dose-dependent manner, resulting in quantitatively measurable output. TF-based biosensors have been employed as synthetic biology devices and enable the development of microbial cell factories using high-throughput screening strategies. Native TFs and promoter pairs are widespread and are adapted to the organism’s purposes, for this reason, TF-based biosensors are often limited in sensitivity and are incompatible with non-native hosts. Although several TF-based biosensors were applied in different α-, β-, and γ-proteobacteria, however, detection of inducers with biosensors in non-native host cells remains a challenge and their use in purple phototrophic bacteria is limited so far. Previously, we developed and characterized TF-based biosensors for organic and phenolic acids. Several inducible gene expression systems induced by phenolic acids, including o-hydroxybenzoic acid, m-hydroxybenzoic acid, vanillic acid, and protocatechuic acid, have been predicted to be applicable in well-studied microorganisms E. coli, C. necator, and P. putida. Additionally, we utilize a protocatechuic acid-biosensor in E. coli to identify enzymes with enhanced activity for the conversion of p-hydroxybenzoate to protocatechuate. These systems are currently being developed for the purple photoautotrophic bacterium R. capsulatus. |
