ABSTRACT
Objective@#To assess the risk of public health emergencies in Zhejiang Province, March 2021. @*Methods@#An expert counsel was conducted to assess the risk of coronavirus disease 2019 ( COVID-19 ) , enteritis due to norovirus, chicken pox and influenza by professionals in Zhejiang CDC, based on the information from infectious disease and public health emergency surveillance in Zhejiang Province, domestic health administrative departments, World Health Organization, and European CDC. @*Results@#In March 2021, the risk of imported COVID-19 epidemic will be high in Zhejiang Province, and the possibility of local spread could not be ruled out. The possibility of a large-scale outbreak of enteritis due to norovirus and a small-scale outbreak of chickenpox in schools and kindergartens could not be ruled out after the new term begins. An increased risk of influenza epidemic is predicted in collective units such as schools and kindergartens, yet the risk of a large-scale one will be low.@*Conclusion@#High attention should be paid to COVID-19 and enteritis due to norovirus, and general attention should be paid to chicken pox and influenza outbreak.
ABSTRACT
Background: D-Hydroxyphenylglycine is considered to be an important chiral molecular building-block of antibiotic reagents such as pesticides, and β-lactam antibiotics. The process of its production is catalyzed by D-hydantoinase and D-carbamoylase in a two-step enzyme reaction. How to enhance the catalytic potential of the two enzymes is valuable for industrial application. In this investigation, an Escherichia coli strain genetically engineered with D-hydantoinase was immobilized by calcium alginate with certain adjuncts to evaluate the optimal condition for the biosynthesis of D-carbamoyl-p-hydroxyphenylglycine (D-CpHPG), the compound further be converted to D-hydroxyphenylglycine (D-HPG) by carbamoylase. Results: The optimal medium to produce D-CpHPG by whole-cell immobilization was a modified Luria-Bertani (LB) added with 3.0% (W/V) alginate, 1.5% (W/V) diatomite, 0.05% (W/V) CaCl2 and 1.00 mM MnCl2.The optimized diameter of immobilized beads for the whole-cell biosynthesis here was 2.60 mm. The maximized production rates of D-CpHPG were up to 76%, and the immobilized beads could be reused for 12 batches. Conclusions: This investigation not only provides an effective procedure for biological production of D-CpHPG, but gives an insight into the whole-cell immobilization technology.