The effect of pH and temperature on haemolysin production by Listeria species |
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| Authors: | Shakeel A. Khan S. M. Khalid Roquya Siddiqui |
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| Affiliation: | Department of Food Science and Technology, Cornell University, Geneva, NY 14456, USA |
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| Abstract: | Acetoin reductase (EC 1.1.1.4) from Kluyveromyces marxianus var. marxianus NRRL Y-1196 was found to possess the highest specific activity (3.64 units/mg protein) of the four cultures studied. The enzyme was NADH-dependent and catalysed the conversion of acetoin to 2,3-butanediol. It was stable at 40°C for 30 min, but lost 50% cf its activity after 15 min at 50°C. The optimum pH for the enzymatic reduction of acetoin was 7.0. The K m values of the crude enzyme for acetoin and NADH were determined to be 0.57 mmol/l and 0.045 mmol/l, respectively. |
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