The Collaborative International Dictionary of English v.0.48:

acidophilic \acidophilic\ acidophilous \acidophilous\adj.
   1. 1 growing well in an acid medium; said of some bacteria

   Syn: aciduric
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

acidophilous
    adj 1: especially of some bacteria; growing well in an acid
           medium [syn: acidophilic, acidophilous, aciduric]