Fed-batch cultures of Nocardia sp. were carried out in a 5-1 fermentor for production of cis-epoxysuccinate hydrolase (EH). Since EH production was significantly repressed by glucose, the cultivation process was divided into a growth phase on glucose and a production phase induced by cis-epoxysuccinate (ES). The cells of Nocardia sp. were unable to utilize exogenous tartrate, so the intracellular tartrate produced from ES was the only carbon source in the production phase, and supply of enough ES was crucial, When ES was supplied at a constant rate of 0.3 g/(1 h), the specific EH activity of the culture was only 75.1 U/g wet cell weight (WCW) due to limitation of ES. When the ES concentration in the culture was maintained at about 5 g/l by adding more ES based on material balance, the specific EH activity reached 182 U/g WCW. The EH activity measured with intact cells was influenced by the ES concentration in the culture clue to the effect on cell permeability, the activity in this study was measured with ultrasound-disrupted cells. (C) 2008 Elsevier Ltd. All rights reserved.