Elsevier, Journal of Molecular Catalysis B: Enzymatic, 1-4(39), p. 179-183, 2006
DOI: 10.1016/j.molcatb.2006.01.021
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The aim of this study was to investigate the effect of redox potential (Eh) on the growth of the yeast Yarrowia lipolytica in both oxidizing (Eh = +350 mV) and reducing (Eh = −150 mV) media and its effect on the expression and activity of hydroperoxide lyase (HPL). HPL activity was assayed in media with Eh values ranging from −250 to +720 mV. In order to change the Eh value of the media, reducing agents including dithiotreitol (1 g/L) and hydrogen (4%) as well as oxidants such as potassium ferricyanide (1 g/L) and oxygen (100%), were used. The experimental findings showed that oxidizing conditions, with Eh of +350 mV, were favorable for the growth of the yeast, whereas reducing conditions, with Eh values of −150 mV, resulted in a higher expression of HPL. In addition, the results showed that the enzymatic activity of the purified HPL was enhanced in the presence of 0.5 mM dithiotreitol but decreased with 1 mM potassium ferricyanide and bubbling O2. However, HPL activity increased 1.5 times in the presence of 4% hydrogen with an Eh value of −170 mV.