An improved bioprocess for synthesis of acetohydroxamic acid using DTT (dithiothreitol) treated resting cells of Bacillus sp. APB-6

Acyltransferase activity of amidase from Bacillus sp. APB-6 was enhanced (24U) by multiple feedings of N-methylacetamide (70mM) into the production medium. Hyperinduced whole resting cells of Bacillus sp. APB-6 corresponding to 4g/L (dry cell weight), when treated with 10mM DTT (dithiothreitol) resulted in 93% molar conversion of acetamide (300mM) to acetohydroxamic acid in presence of hydroxylamine-HCl (800mM) after 30min at 45°C in a 1L reaction mixture. After lyophilization, a 62g powder containing 34% (wtwt^-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 1L scale.