Modulation of CO2 utilization by Cupriavidus necator H16 for high value chemical production

点击翻译按钮获取中文摘要

CO2 assimilation in R. eutropha, is mediated by Calvin-Benson-Bassham (CBB) cycle encoded by two almost identical cbb operons, one located on the pHG1 megaplasmid and the other on chromosome 2 (Pohlmann et al., 2006). The effective expression of these operons, and in particular the genes encoding the major rate-limiting enzyme, ribulose 1,5-bisphosphate carboxylase/ oxygenase (RubisCO), are crucial. Both operons and are tightly regulated by the cbbR transcriptional activator located at the 5' end of the chromosomal copy of the cbb operon (Kusian and Bowien, 1995). This LysR-type regulatory protein con-trols the expression of the cbb operons by binding to their identical promoter sequences (Dangel and Tabita, 2015). LysR independent, and preferably constitutive transcription of the cbb operon might prove advantageous for enhancing the efficiency of CO2 fixation efficiency of the CBB cycle. To further improve the endogenous CO2 assimilation pathway we bring about the controllable expression of synthetic DNA modules encoding functional carboxysomes for the co-localisation of CAs and RuBisCO molecules with improved CO2-capture capabilities.