Inactivates phosphinothricin (PPT) by transfer of an acetyl group from acetyl CoA. Can also acetylate demethylphosphinothricin but not PTT or glutamate. This enzyme is an effector of phosphinothricin tripeptide (PTT or bialaphos) resistance. acetyl-CoA + phosphinothricin = CoA + H(+) + N-acetylphosphinothricin Introduced by genetic manipulation and expressed in glufosinate-tolerant maize by Dekalb Genetics. Belongs to the acetyltransferase family. PAT/BAR subfamily.