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Abstract(s)
Neste trabalho de investigação pretendeu-se aumentar a produção de desmetiltetraciclina (DMT), tornando-a o produto dominante da fermentação, utilizando uma estirpe de Streptomyces aureofaciens, originalmente produtora de desmetilclorotetraciclina (DMCT) e DMT.
Deste modo, procedeu-se ao desenvolvimento e otimização de um meio constituído por diferentes fontes de carbono e azoto que permitiria esta produção de um modo viável, uma vez que a constituição do meio em conjunto com a capacidade metabólica do microrganismo influencia a síntese do produto.
Para isso, foram realizadas várias experiências a nível laboratorial onde foram efetuadas diversas alterações de matérias-primas como o uso de sulfato de amónio, tiossulfato de sódio, corn steep liquor, tiocianato de benzilo, entre outras, de forma a diminuir a concentração de iões cloreto em solução e, consequentemente, conduzir ao aumento do produto pretendido, a DMT. Posteriormente, analisou-se quais os efeitos destas variações na produção de desmetiltetraciclina. Estes ensaios foram avaliados tendo em consideração o pH, packed mycelium volume e o rendimento de produção determinado por HPLC.
Os resultados obtidos foram bastante favoráveis, tendo-se destacado o uso de sulfato de amónio que foi essencial para o aumento de DMT, atingindo uma média de produção 7 vezes superior à DMCT.
The aim of this research is to increase production of demethyltetracycline (DMT) making it the dominant fermentation product by using a strain of Streptomyces aureofaciens that originally produces both demethylchlortetracycline (DMCT) and DMT. Thus, we proceeded to the development and optimization of a culture medium consisting of different sources of carbon and nitrogen that would allow viable production, since the constitution of the medium together with the metabolic capacity of the organism influences the synthesis of the desired product. For this, several laboratory experiments were conducted where various changes of existing raw materials such as the use of ammonium sulfate, sodium thiosulfate, corn steep liquor, benzyl thiocyanate, among others, in order to reduce the concentration of chloride ions in solution and consequently lead to an increase of the desired product, DMT. Subsequently, we analyzed their effects on the production of demethyltetracycline. These assays were evaluated taking into consideration the pH, packed mycelium volume and the production yield determined by HPLC. The results were quite favorable, having stood out the use of ammonium sulfate which was essential for the increase of DMT production averaging seven times higher than DMCT.
The aim of this research is to increase production of demethyltetracycline (DMT) making it the dominant fermentation product by using a strain of Streptomyces aureofaciens that originally produces both demethylchlortetracycline (DMCT) and DMT. Thus, we proceeded to the development and optimization of a culture medium consisting of different sources of carbon and nitrogen that would allow viable production, since the constitution of the medium together with the metabolic capacity of the organism influences the synthesis of the desired product. For this, several laboratory experiments were conducted where various changes of existing raw materials such as the use of ammonium sulfate, sodium thiosulfate, corn steep liquor, benzyl thiocyanate, among others, in order to reduce the concentration of chloride ions in solution and consequently lead to an increase of the desired product, DMT. Subsequently, we analyzed their effects on the production of demethyltetracycline. These assays were evaluated taking into consideration the pH, packed mycelium volume and the production yield determined by HPLC. The results were quite favorable, having stood out the use of ammonium sulfate which was essential for the increase of DMT production averaging seven times higher than DMCT.
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Keywords
Desmetilclorotetraciclina Desmetiltetraciclina Fermentação Streptomyces Aureofaciens Sulfato de Amónio.