Catalyzes the activation of fatty acids by CoA to produce an acyl-CoA, the first step in fatty acid metabolism (PubMed:12709059). Capable of activating medium-chain fatty acids with a preference for C6-12 fatty acids (PubMed:12709059). a medium chain fatty acid + ATP + CoA = a medium-chain fatty acyl-CoA + AMP + diphosphate ATP + CoA + hexanoate = AMP + diphosphate + hexanoyl-CoA ATP + CoA + octanoate = AMP + diphosphate + octanoyl-CoA ATP + CoA + decanoate = AMP + decanoyl-CoA + diphosphate ATP + CoA + dodecanoate = AMP + diphosphate + dodecanoyl-CoA Detected in adult olfactory epithelium. Detected in all cell layers of the dorso-medial part of the embryonic olfactory placode and olfactory epithelium. First detected in olfactory placode on embryonic day 11.5. Detected in olfactory placode on embryonic day 12, 14, 16 and 18. Belongs to the ATP-dependent AMP-binding enzyme family.