Isoorientin is a C-glycosylated derivative of luteolin and exhibits a number of biological properties. In this study, multiple strategies were adopted to improve isoorientin production from luteolin in Escherichia coli. Isoorientin production was improved substantially by adjusting induction strategies and controlling acetic acid accumulation, with maximum isoorientin production reaching 826 mg/L. Additionally, a novel UDP-glucose synthesis pathway was reconstructed in E. coli through cellobiose phosphorylase-catalyzed phosphorolysis of cellobiose for the production of glucose 1-phosphate, which serves as a precursor in UDP-glucose formation. The results from two mechanisms of UDP-glucose formation in E. coli, cellobiose phosphorolysis and sucrose phosphorolysis, were compared. Increasing the UDP-glucose supply resulted in maximal isoorientin production reaching 1371 mg/L. Finally, isoorientin (1059 mg) was obtained from 1 L of fermentation broth by simple purification steps with a yield of 81.5%. Therefore, this study provides an efficient method for isoorientin production and a novel UDP-glucose synthesis pathway.

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Nowadays the profile of integral shaped milling cutter is designed by diagram method. This method is low efficiency and bad precision. This paper deals with the application of conjugate surface theory to the profile design of integral shaped milling cutter. According to the structural characteristics of integral shaped milling cutter, the method for design of cutter profile to wood workpiece is investigated by use of conjugate surface theory. In the present study, the curve equations for integral shaped milling cutter profile are put forward, based on principles of coordinate transformation, mill cut mechanics and conjugate surface theory of differential geometry.