A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria

Roberto Ferro, Maja Rennig, Cristina Hernández Rollán, Daniel O. Daley, Morten H H Nørholm*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

444 Downloads (Pure)


The market for recombinant proteins is on the rise, and Gram-positive strains are widely exploited for this purpose. Bacillus subtilis is a profitable host for protein production thanks to its ability to secrete large amounts of proteins, and Lactococcus lactis is an attractive production organism with a long history in food fermentation. We have developed a synbio approach for increasing gene expression in two Gram-positive bacteria. First of all, the gene of interest was coupled to an antibiotic resistance gene to create a growth-based selection system. We then randomised the translation initiation region (TIR) preceding the gene of interest and selected clones that produced high protein titres, as judged by their ability to survive on high concentrations of antibiotic. Using this approach, we were able to significantly increase production of two industrially relevant proteins; sialidase in B. subtilis and tyrosine ammonia lyase in L. lactis. Gram-positive bacteria are widely used to produce industrial enzymes. High titres are necessary to make the production economically feasible. The synbio approach presented here is a simple and inexpensive way to increase protein titres, which can be carried out in any laboratory within a few days. It could also be implemented as a tool for applications beyond TIR libraries, such as screening of synthetic, homologous or domain-shuffled genes.
Original languageEnglish
Article number37
JournalMicrobial Cell Factories
Issue number1
Number of pages11
Publication statusPublished - 2018


Dive into the research topics of 'A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria'. Together they form a unique fingerprint.

Cite this