Is there a way to increase the expression level of eGFP protein integrated into the E. coli genome so that the green fluorescence is visible to the naked eye? I have already integrated the ORF of eGFP into the E. coli glms-pstS region, but the expression level is very low. Under UV light, there is no obvious green fluorescence, and it can only be barely detected through Western blot, with faint and unclear bands. I am using the Ptac promoter (with LacI in front of it) induced by IPTG. Could promoter optimization improve the expression? If changing the promoter is an option, which promoters can still be used with IPTG induction? Could you recommend a few?

Alternatively, could altering the sequence of the ribosome binding site (RBS) to enhance ribosomal binding improve eGFP expression in the E. coli genome? I appreciate any guidance.