Optimization Of Rifamycin SV Fermentation Medium And Preliminary Analysis Of Metabolism

Rifamycin SV is produced mainly by Amycolatoposis mediterranei and widely used in tuberculosis, leprosy and aids-related M.tuberculosis infection treatment. This paper focused on Optimization of rifamycin SV fermentation and control filling material culture and discussion of effect of regulatory factors on rifamycin SV biosynthesis according to ways and traits of rifamycin SV biosynthesis. At lst ,the rezult was verified in10 Lfaermenter level. The results were as follows:1) Organic nitrogen source in fermentation medium was optimized by the response surface method. Optimal proportion of fishmeal, soya-bean powder and peptone was respectively 0.50 g/100mL,0.69 g/100mLand 0.74 g/100mL。The yield of rifamycin SV was up to 5072 U/ mL under the optimum condition,which was 11.0% higher than the control.2) Effects of soybean oil and alanine additions on rifamycin SV biosynthesis in 250 mL flask were studied.Result showed that when 3 mL/L soybean oil and 0.8 g/L alanine was added into the medium at 72 h, rifamycin SV production was increased by 5.3% and 6.9% over the control, respectively. Response surface methodology was used to study the interaction between soybean oil and alanine. Result showed that their optimal amount was 2.57 mL/L and 0.89 g/L, respectively. Under the optimal conditions, rifamycin SV production reached 5179 U/mL that was 12.3% higher than the control. The results of organic acids analysis demonstrated that utilization rate of a-ketoglutarate and citriate was 0.86 mg/(L·h) and 0.77 mg/(L·h), respectively, which was 115.7% and 23.3% higher than that of control in the fermentation process from 72 h to120 h. Meanwhile, succinate concentration reached 1.01 g/L, which was 16.1% higher than the control, which indicated that the conversion efficiency of a-ketoglutarate and citrate to succinate in the TCA cycle was improved efficiently with the additions of oil and alanine. Thus the supplies of succinyl-CoA and methylmalony-CoA were enhanced, which consequently facilitated rifamycin SV biosynthesis.3) The stimulative effect of soybean oil and alanine on rifamycin SV biosynthesis was further verified through studying of changes of dissolved oxygen value, pH, reducing sugar and accumulation of rifamycin SV fermentation unit rifamycin SV fermentation process in fermentater. Results showed that after adding soybean oil and alanine,oxygen consumption rate was fast,pH was high and reducing sugar was high, compared with the control.After fermentation, fermentation unit of the test cans was 5236 U/mL, which was 11.1% higher than the control (4612 U/m).