A novel plasmid vector designed for chromosomal gene integration and expression: Use for developing a genetically stable Escherichia coli melanin production strain

► Plasmid pLoxGentrc was constructed to facilitate chromosomal gene integration. ► Derivate plasmid pLoxGentrcmelA carries the melA gene from Rhizobium etli. ► pLoxGentrcmelA enabled chromosomal integration of the melA gene in Escherichia coli. ► E. coli strain with integrated melA gene displayed melanin production capacity. ► High genetic stability was observed in E. coli strain with integrated melA gene.