Two recently-opened downtown Miami eateries have closed their doors. DGB, (Damn Good Burger) along with seafood restaurant Mare Nostrum (The Romans’ term for the Mediterranean Sea) have shuttered. DGB opened in May 2011, while Mare Nostrum has been open for just a few months. “It is with much sadness that we must announce: effective immediately, DGB will no longer be operating,” the burger joint’s Web site said. Mare Nostrum included a 42-person kitchen and was helmed by Spanish chef Pedro Gallardo. [Eater]