Screening Of Lincomycin High-yield Strains And Application Of The Quality Risk Management In Its Production

Lincomycin,a highly effective antibiotic against Gram-positive bacteria produced by Streptomyces lincolnensis,which has the advantages of strong antibacterial activity,slow drug resistance and low toxicity.It is one of the main antibiotics for clinical use,and has great commercial and social value.In order to ensure the safety and effectiveness of drugs,enterprises are constantly exploring to improve the quality of lincomycin while increasing its output.In this paper,the protoplasts of Streptomyces lincolnensis were mutated by ultraviolet and pulsed light to screen high-yield strains.Through the investigation of culture medium and culture conditions,the best fermentation process of lincomycin was obtained,and the screened strains were cultured by the optimized fermentation process.Compared with the original strains,the yield of lincomycin was significantly increased.The quality risk management tool（FMEA）was used to identify the risk points in the lincomycin production process,and the corresponding measures were put forward to reduce the risks in order to obtain high-quality and high-yield metabolites.The main resarch contents and results are as follows:1.Mutation and screening of lincomycin high-yield strains.Protoplasts were prepared from the original strain（Streptomyces lincolnensis,NO.SL-98-2#）,and three mutant strains with high yield were obtained by the combined method of ultraviolet irradiation and pulsed strong light.After five generations of stability test,the data were shown that the lincomycin-producing strain（NO.SL-98-2#-2）had a good genetic stability,and the content of lincomycin,a metabolite of the fifth generation strain,was increased by 24.32%compared with the original strain（NO.SL-98-2#）.2.Research on fermentation technology of lincomycin.The effects of phosphate,nitrate and soluble starch on lincomycin metabolism were studied by 24-well plate culture.L₂₅（5⁶）orthogonal design method was used to optimize the screened medium,and the best medium（NO.24）was obtained.By using the optimized medium for fermentation,the yield of lincomycin was 40.63%higher than that before optimization.Based on the optimized medium,the effects of p H value,strain age,inoculum size,fermentation temperature,dissolved oxygen and fermentation period on lincomycin fermentation were further investigated,and the best fermentation conditions were obtained.The mutant strain of Streptomyces lincolnensis（No.SL-98-2#-2）was cultured in the optimized medium and fermentation conditions.The content of lincomycin was 5804μg/m L,which was 24.23%higher than that before the optimization of fermentation process.3.Selection of the quality risk tools.By comparing the common tools of quality risk management,the risk assessment management tool（FMEA method）suitable for lincomycin production process is determined.The risk management of drug production was analyzed by bibliometrics,and the risk of lincomycin production was evaluated by FMEA.4.Application of FMEA in risk assessment of lincomycin production.In order to ensure the scientificity of the evaluation,β-weight coefficient is introduced into the FMEA evaluation.The evaluation ofβ-weight depends on the position,educational background,length of service and familiarity with the process of the staff.The factors involved in lincomycin production,such as people flow,preparation before production and clearance after production,production materials,process parameters and process control,cleaning and sterilization,collinear risk analysis,were analyzed,and risk control measures were formulated to reduce lincomycin production risk.