In protocols for minimal media for growing bacteria I often see that a vitamin mix or a mix of various trace metals is added. But at least for E. coli I know that those are not strictly necessary, they also grow in minimal medium without any of this.
Does it make sense to add vitamins or trace elements when growing common E. coli for protein expression like BL21 (DE3) in minimal medium? Is there some literature data on how this can affect the growth of the bacteria?