Cultured media revolutionary in Portuguese tarts business (10)

I believe the answer is:

substrates

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'cultured media' is the definition.
The definition and answer can be both locations as well as being plural nouns.
Perhaps there's a link between them I don't understand?

'revolutionary in portuguese tarts business' is the wordplay.
'revolutionary' is a reversal indicator (letters revolve around).
'in' says the answer is hidden in the clue.
'setartsbus' can be found hidden inside 'portuguese tarts business'.
'setartsbus' backwards is 'SUBSTRATES'.

Can you help me to learn more?

I've seen this clue in The Independent.

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