Overexpression of D-psicose 3-epimerase from Clostridium cellulolyticum H10 in Bacillus subtilis and its Prospect for D-psicose Production

• Published in: Advance Journal of Food Science and Technology Vol. 5; no. 3; pp. 264 - 269
• Main Authors: Li, Xiaobo, Zhu, Yueming, Zeng, Yan, Zhang, Tongcun, Sun, Yuanxia
• Format: Journal Article
• Language: English
• Published: Maxwell Science Publishing 15.03.2013
• Subjects: Clostridium cellulolyticum; 3-epimerase; D-psicose food-grade; D-psicose; Bacillus subtilis
• ISSN: 2042-4876; 2042-4868; 2042-4876
• DOI: 10.19026/ajfst.5.3255

The aim of this study was to overexpress the D-psicose 3-epimerase from Clostridium cellulolyticum H10 in food-grade microbe. This gene was cloned and expressed in Bacillus subtilis. The results showed that the recombinant protein was soluble, bioactive, and expressed at high levels. The optimum pH and temperature of the enzyme were 8.0 and 50°C, respectively. The activity of the enzyme was not dependent on metal ions; however, some metal ions, such as Co^(2+), can make the enzyme more thermostable. The Michaelis-Menten constant (K_m) of the enzyme for D-psicose was much lower than that for D-tagatose, suggesting that the optimum substrate of the enzyme is D-psicose. D-Psicose 3-epimerase expressed in the food-grade B. subtilis may be used for the industrial production of D-psicose.