Study on the culture of Escherichia coli with different hydrolysis depth of globin

Abstract

Objective: To explore the effect of culture medium made of peptide fragments of different sizes of globin hydrolyzed by protease on the culture of Escherichia coli. Method: with fresh pig blood as raw material, hydrolyze pig blood protein under fixed conditions, and screen out the enzyme with the highest degree of hydrolysis. Then conduct orthogonal test on the enzyme to determine the best hydrolysis conditions; the beads were obtained under the best hydrolysis conditions. The Escherichia coli was cultured on different peptone culture bases that were prepared by hydrolysate going through different pore size ultrafiltration membrane samples. The culture of Escherichia coli at different hydrolysis depths is determined by detecting the total amount with Escherichia coli detection method. Results: Trypsin has the best hydrolysis effect. The best hydrolysis conditions are as follows: enzyme dosage of 0.2%, hydrolysis time of 12h, temperature of 50°C, initial pH of 7.5 and mass fraction of substrate protein of 8%. Through growth curves of Escherichia coli, it is known that the smaller the pore size of the ultrafiltration membrane, the smaller the molecular weight of the peptide fragment, and the greater the density of the Escherichia coli bacterial solution. Conclusion: Through analyzing the production curves of Escherichia coli in different culture medium, it is concluded that the smaller the molecular weight of the protein peptides, the higher the density of Escherichia coli solution in the LB liquid medium prepared by it, and the better the Escherichia coli culture effect.