Hi, I am a Brazilian with a Italian citizenship and waiting for my Italian passport to arrive, can I apply for the job?

If you're an EEA citizen (which as an italian you would be) you can freely work anywhere in the EU.

You would however need proof (most people use their passport), if it'll take a while for you to get your passport another option in the UK is to get a Home Office registration certificate (you'll have to prove to their satisfaction that you are italian, via birth record, etc.).