Acyltransferase activity of amidase from Bacillus sp. APB-6 was enhanced (24 U) by multiple feedings of N-methylacetamide (70 mM) into the production medium. Hyperinduced whole resting cells of Bacillus sp. APB-6 corresponding to 4 g/L (dry cell weight), when treated with 10 mM DTT (dithiothreitol) resulted in 93% molar conversion of acetamide (300 mM) to acetohydroxamic acid in presence of hydroxylamine-HCl (800 mM) after 30 min at 45 degrees C in a 1 L reaction mixture. After lyophilization, a 62 g powder containing 34% (wt wt(-1)) acetohydroxamic acid was recovered. This is the first report where DTT has been used to enhance acyltransfer reaction and such high molar conversion (%) of amide to hydroxamates was recorded at 1 L scale. (C) 2011 Elsevier Ltd. All rights reserved.