Effect of Media Sterilization Time on Penicillin G Production and Precursor Utilization in Batch Fermentation

Kishore Kumar Gopalakrishna

Abstract

Benzyl Penicillin (Penicillin G) is a secondary metabolite (Antibiotic) derived from Penicillium chrysogenum. Batch fermentation is widely used in the production of Penicillin G in laboratory scale and as well as in Industrial scale. The fermentation media for the production is sterilised at 121o C for 30 minutes as a usual practise in both scales of production. In our present study the production media used to produce Penicillin G was sterilized at various time intervals and the change in penicillin production along with the level of precursors utilized by the P. chrysogenum were analysed. The change in sterilization time varied the proportion of fermentation media converted from complex to simple. Studies were carried out in both shake flask level and also in laboratory scale fermenter (3 litres) with media containing PAA (Phenyl acetic acid) as precursor. The fermentation media used in this study contained K2SO4, KH2PO4, (NH4)2SO4, corn steep liquor (N2 source), Lactose (Carbon source) and CaCO3. The steam batch sterilisation at 121oC was attempted with different time intervals between 25 to 50 minutes with 5 minutes increment. It was observed that change in the sterilization time increased the Penicillin-G production by 30 % upto 30 minute and only 6% upto 45 minute and then it started to drop. HPLC method was used to carry out quantitative analysis of the product Penicillin G and the precursor Phenyl acetic acid. The results further concluded that though the rise in the sterilization temperature increased the Penicillin G production rate, it was cost effective as more energy required to rise the sterilization temperature which in turn increased the cost of production of Penicillin G.  

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