Study On Hydrolysis Of Penicillin Residue By Thermophilic Bacteria And Protein Extraction

Anaerobic digestion technology is one of the effective ways to recycle antibiotic bacterial residue.Antibiotic bacterial residue is rich in protein and has a low C/N ratio,so the accumulation of ammonia nitrogen is easy to occur in the process of anaerobic digestion,which will seriously inhibit the gas production in anaerobic digestion.Using thermophilic enzyme technology to release the protein from the residue can not only extract the protein from the residue for resource utilization,improve the anaerobic digestion performance of the residue.This subject takes penicillin residue as the research object,and studies the precipitation and separation of the penicillin residue hydrolyzed by thermophilic bacteria,the metal ion-enhanced thermophilic bacteria hydrolyze penicillin residue,and the precipitation and separation of proteins in the penicillin residue.The results are as follows:1)The optimal treatment conditions for hydrolysis of penicillin residue by thermophilic bacteria are hydrolysis temperature of 60℃,inoculation volume of 15%（V/V）,and hydrolysis p H of 7.0.Under this treatment condition,after 12 hours of reaction,the concentration of SCOD,ammonia nitrogen,soluble protein and soluble carbohydrate reached 18480 mg·L^-1,749.79 mg·L^-1,16279.34 mg·L^-1,and 1632.32 mg·L^-1,respectively.Compared with the original bacterial residue supernatant,it increased by 33.27%,27.6%,36.25%,and 21.1%,respectively.2)By analyzing the lysis effects of five metal ions on the hydrolysis of penicillin residues by thermophilic bacteria,K⁺has the strongest promotion effect on the hydrolysis of thermophilic bacteria residues.The concentration of[K⁺]was 200μmol·L^-1,the reaction was 12 h,the concentration of SCOD,ammonia nitrogen and protein were 18980mg·L^-1,862.54 mg·L^-1 and 19166.01 mg·L^-1,respectively,compared with the group without K⁺Increased 11.42%,7.47%and 12.5%.The main reason is that K⁺increases the activity of protease and amylase.3)By comparing the effects of five precipitation methods on protein precipitation in penicillin residues,it is determined that the trichloroacetic acid precipitation method is the best process.The best precipitation conditions are:trichloroacetic acid mass fraction 20%,hydrolysate p H 3.0,precipitation time 10 h.The centrifugal speed is 10000 r·min^-1,and the protein precipitation rate is 89.5%.