Monitoramento da fermentação da d-glicose pela Saccharomyces cerevisiae por microcalometria de fluxo

AUTOR(ES)
DATA DE PUBLICAÇÃO

1992

RESUMO

In this work a flow microcalorimeter was used to study in situ and in real time the fermentative process of d-glucose by Saccharomyces cerevisiae (FTPT 754). This work mark out the begining of a research area (biological microcalorimetry) in the I. Q. where a metabolic process was studied by pumping a defined medium plus microorganisms through a microcalorimeter. The inocula was prepared by FTPT with viable count of 10 cells/ml and was stored in liquid nitrogen. The medium was standarized - defined medium and the process was studied in N2 atmosphere at 300 K and pH=5,0. The effect of glucose concentration, pH of the medium (from 2,1 till 7,0) and addition of heavy metals salts as copper, iron, cadmium, zinc and mercury was also studied in this work. The variation on the glucose concentration affected exponentially the exaustion time. A minimum vaIue of tex was observed in pH range 4,0 - 6,0. Consequently a higher slope for curves log Q x t was obtained. The inhibitory concentration of each studied heavy metal added to the medium was determined. For zinc, iron and copper the concentration was 10M and 10M, 10M for mercury and cadmium respectively. An unexpected effect for the addition of cadmium was observed compared to the other cations. The addition of cadmium has potentialized the heat output productioneven in Iower concentrations than the inhibitory one.

ASSUNTO(S)

colorimetria termoquimica

ACESSO AO ARTIGO

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