Rational promoter engineering for robust transgene expression in Chlamydomonas reinhardtii

Chlamydomonas reinhardtii is an established model for microalgal synthetic biology as well as genetic engineering and has already been used to successfully produce various bioproducts. Nevertheless, limited nuclear transgene expression due the lack of strong expression elements and sparse comparative evaluation of these prevent further development of C. reinhardtii towards a biotechnological host for industrial-relevant applications.

Researchers at the Center for Biotechnology (CeBiTec) from Bielefeld University (Germany) have now designed a new, synthetic algal promoter for efficient transgene expression (published in ACS Synthetic Biology1). By systematically evaluating existing expression elements, combined with rational promoter engineering strategies, Einhaus et al. established novel, synthetic expression elements and improved the standardized application of synthetic biology tools. The new AßSAP(i)-promoter is optimized for cytosolic expression and increases the expression by 4- fold compared to commonly used pAR. The promoter sequence is now available at the CRC as plasmid pCM0-TB129, matches the C. reinhardtii MoClo syntax and can be applied in A1-B2 position.