What nutrients are best suited for growing E.Coli
Optimal is a funny thing; it depends upon what you want. The purpose of the bacteria, is probably the most important aspect when considering the nutrients. There are many recipes capable of growing E. coli. What does optimal or best mean to you and why? Is selectivity or differentiation a factor? How important is cost? Are you aiming for industrial level production or just testing. Do you have a bioreactor? Or are you looking for something low tech... maybe from food-mart?

For what it's worth, you might find minimal salts media and solid state fermentation interesting.

Different strains like different nutrients, of course. So, phenotypical tests are sometimes helpful when figuring what an undescribed strain likes (and doesn't like).

That being said... I can offer a little insight here. 

"+" for growth/utilization;  "-" for weak or no growth/utilization:

                 E. coli    E. coli inactive**  E. coli 0157:H7

Pectin                 -            -                   -   
Dextrin                ++           ++                  -
Sucrose                -            -                   +++
Glycerol               +++          +++                 +++
Stachyose              -            -                   - 
D-Fructose             ++           ++                  ++
D-Maltose              +            ++                  ++
D-Raffinose            +            -                   +++
α-D-Glucose            +            +                   +
α-D-Lactose            +            -                   ++
D-Trehalose            ++           +++                 +++
D-Galactose            ++           +++                 +++
L-Fucose               +++          +++                 +++
L-Rhamnose             +++          -                   ++
D-Sorbitol             +++          +                   -
D-Mannitol             +            ++                  ++
Methyl Pyruvate        +++          +++                 +++ 
Tween 40               -            -                   -




Gelatin                -            -                   -
L-Alanine              +++          +++                 +++
L-Arginine             +            -                   -
L-Histidine            -            -                   -
D-Serine               +++          +++                 -
L-Serine               +++          +++                 +++
D-Aspartic Acid        -            -                   -
L-Aspartic Acid        +++          +++                 +++




D-Glucoronic Acid      +++          +++                 +++




Citric Acid            -            -                   -
L-Malic Acid           +++          +++                 +++
Acetic Acid            +++          +++                 +++
Acetoacetic Acid       +            +                   -
L-Lactic Acid          +            -                   -
Mucic Acid             ++           -                   +++
D-Malic Acid           +            +++                 +++
Propionic Acid         ++           ++                  +++
Formic Acid            +            -                   +




D-Salicin              -            -                   -
Lithium Cloride        +++          ++                  ++
Na Butyrate            +++          +++                 +++
pH 5                   +++          +++                 +++
8% NaCl                ++           +                   -
D-Serine (high)        ++           +                   -
Potassium Tellurate    +            +                   +++
Na Bromate            +/-           -                   ++




E. coli inactive** is lactose-negative, non-motile- often misidentified as Shigella