Amino Acids The Study Of Humanoid Collagen Metabolism Flux Expansion

Recombinant Escherichia coli (E.coli) BL21was used to produce human-like collagen (HLC) II in oader to improve human-like collagen production, the culture medium was optimized. The key constituents of amino acids were optimized using Response Surface Methodology (RSM). The optimization results were mentioned as follows:In order to enhance the production of HLC, amino acids were added into the initial fermentation broth, and RSM was used to screen the suitable varieties of amino acids and optimize their dosages. Single-factor experiment showed that arginine, proline, threonine, cysteine and methionine could increase the production of HLC by23.32%to66.95%. With the method of RSM, the final optimal concentration of arginine, cysteine and methionine were5.95g·L-1,8.73g·L-1and0.35g·L-1, respectively. Under the optimal cultivation condition the maximal production of HLC reached0.59g·L-1which was150.43%higher than that of the control group at0.23g·L-1, while the acetate accumulation was12.51%less than that of the control.This paper introduced the application of Micro Control Unit (MCU) and Back Propagation (BP) neural networks in fermentation process. It showed that the fluctuation of DO was smaller when the new controller system was used. The controller could make a accurate regulation, glucose was pumped in the bioreator when DO was larger than the set point, and there is a close relationship between feeding and cell respiration.The effects of feeding strategies of L-methionine on Yp/x (product yield coefficient, HLC/DCW, g·g-1), OD, DCW and by-products were examined. The optimal operating conditions were:0.6g/L L-methionine addition at beginning with1.2g/L addition after induce. The result showed that Yp/x (product yield coefficient, HLC/DCW, g·g-1) and cell OD600could reach0.18g·g-1and136, and they were raised by14.62%and8.37%, respectively, while the concentration of by-products was reduced largely.