Involved in the protection against polyamine toxicity by regulating their concentration. Could also be involved in the negative control of sporulation as well as production of degradative enzymes such as alpha-amylase, levansucrase and alkaline phosphatase. Catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to an acceptor substrate and release both CoA and the acetylated product. It can use a variety of substrates including spermidine, L-tryptophan, L-leucine, L-lysine, dopamine and tyramine. acetyl-CoA + an alkane-alpha,omega-diamine = an N-acetylalkane-alpha,omega-diamine + CoA + H(+) kcat is 42 min(-1) for acetyltransferase activity with acetylspermidine as substrate (at pH 8.3). kcat is 31 min(-1) for acetyltransferase activity with AcCoA as substrate (at pH 8.3). Monomer or homodimer. Belongs to the acetyltransferase family.