Abstract: D-psicose is a unique monosaccharide sugar with prospective health benefits and physiologically safer than fructose. D-psicose is an enzymatic product of DPEase, converting fructose as substrate. The DPEase holds an important mechanism to produce D-psicose in laboratory and industrial scale. The DPEase is known to bind with certain cofactors in performing optimum enzymatic reaction. This study aimed to characterize the crude DPEase obtained from recombinant Escherichia coli in order to obtain the optimum condition for converting fructose to D-psicose in laboratory scale. Environmental parameters such as pH, temperature, and presence of metal ions were adjusted to observe any changes in DPEase activity. The results showed that optimum condition for DPEase activity were at 35oC, pH 8.0, and addition of Co2+ dan Mn2+ enhanced the enzyme activity. Meanwhile, the presence of metal ions, e.g Ni2+ , Cu2+, Zn²+ , Ca²+, Mg²+ and Mo2+ were known as inhibitors to enzyme activity.
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