I agree with the observation of Dr Pathak. Azotobacter is a heaviest breathing organisms and require a large amount of organic C for its growth. Beside this, they need P, Mg, Na and Fe as well as slight alkaline environment. So, accordingly you may manipulate your media for economic and better growth.
Pea peal powder has already been used for natural pigment production using pigment producing fungi. Our purpose is to reduce the cost of liquid bioinoculants.