RESUMO
Background: Increased economic competitiveness in the biopharmaceutical industry requires continuous improvement of bioprocesses. In this regard compositions of fermentation media have an important role in bioprocesses. Objectives: The modification of the culture medium has proven effective in enhancing the yield and productivity of fermentation processes. The objective was to investigate the influence of castor oil as the main carbon source for Saccharopolyspora erythraea, on the yield of antibiotic fermentative production. Material and Methods: The titer of erythromycin was evaluated in Saccharopolyspora erythraea cultures, containing various concentrations of castor oil, in comparison to the control culture containing rapeseed oil. Results: The results showed an enhancement in erythromycin production when 50 g.L-1and 40 g.L-1of castor oil were added to the fermentation culture instead of rapeseed oil, respectively. The highest amount of production was obtained on the eleventh day of fermentation time in all media. Conclusion: Erythromycin production in the control medium was relatively less than that of the treatments, indicating that S. erythraea consumed castor oil as a rich alternative carbon source. The results show that castor oil was more suitable as a carbon source for erythromycin production than a medium containing rapeseed oil.
RESUMO
BACKGROUND: Magnetite nanoparticles have widespread biomedical applications. In the aerobic bioprocesses, oxygen is a limiting factor for the microbial metabolic rate; hence a high availability of oxygen in the medium is crucial for high fermentation productivity. This study aimed to examine the effect of using magnetite nanoparticles on oxygen transfer rate in erythromycin fermentation culture. METHODS: Magnetite nanoparticles were synthetized through co-precipitation method. After observing the enhanced oxygen transfer rate in deionized water enriched with magnetite nanoparticles, these nanoparticles were used in the media of by Saccharopolyspora erythraea growth to explore their impact on erythromycin fermentation titer. Treatments comprised different concentrations of magnetite nanoparticles, (0, 0.005, 0.02 v/v). RESULTS: In the medium containing 0.02 v/v magnetite nanoparticles, KLa was determined to be 1.89 time higher than that in magnetite nanoparticle-free broth. An improved 2.25 time higher erythromycin titer was obtained in presence of 0.02 v/v nanoparticles. CONCLUSIONS: Our results, demonstrate the potential of magnetite nanoparticles for enhancing the productivity of aerobic pharmaceutical bioprocesses.
