Abstract | Lipase and esterase production by Ophiostoma piceae and Fusarium oxysporum were enhanced and extended by developing a fed-batch process in stirred tank reactors. Fed-batch strategy improved lipolytic enzyme production from Ophiostoma piceae in both 2 and 20 dm3 stirred tank reactors. However, fed-batch fermentation of Fusarium oxysporum in the 2 dm3 reactor was more effective than both batch and fed-batch fermentations in the 20 dm3 reactor. When a medium composed of only carbon and nitrogen source was intermittently fed to the cultures, the maximum specific lipase activity was improved by more than 80% and 35% in Ophiostoma piceae and Fusarium oxysporum cultures respectively. The maximum specific esterase activity was improved by 20% and 15% in Ophiostoma piceae and Fusarium oxysporum cultures respectively. The duration of production for both fungi extended from 144 to 216 h compared with a batch culture under the same condition. |
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