What is the most important gene expected to over express in E.Coli cells grown in minimal media compared to cells grown in fully enriched medium?

The gene expected to over express in E.Coli cells grown in minimal media is rpos-gene (RNA-Polymerase Sigma-S) which encodes for a regulatory transcription factor-Sigma S, a 37.8 KD protein. The gene is shown to be over expressed in cells subjected to environmental stress particularly nutrient deprivation and UV-irradiation. Other stress factors like acid, temperature, osmotic and oxidative shocks have also shown to be significantly contributing to the expression of the gene. Rpos mutant cells have over 200 genes rendered inactive through a complex regulatory mechanism which is not fully characterized.