Here as the name suggestes “50 shades” representing the diversity and variety that can be used in microbial world. Be different species , different strains of microbes , different products , different methodology and different medias , All aspects have multiple varieties .
Different media list :
Instead of different media , industries also focus on using cheaper and efficient media like agricultural waste , Let's look into some of these media –
• Animal residues – fat residues
• Crops -Cassava , potatoes .
• Dairy industry - curd , whey waste
• Distillery industry -  effluents etc
Number of other cheap substrates can be used and one will be surprised that these medias are nothing new but wastes that one regularly see

There are number of cases where the product development was successful at laboratory level but scale up wasn't possible due to financial issues and lack of funding.
There's no use of developing a product and marketing if the production cost is high and no revenue for industries.
So eventually getting a cheaper substrates with proper C , N , growth factors becomes a critical parameter.