Ethanolic Fermentation Enzymes, their Products and Transcription of Alcohol Dehydrogenase from Bell Pepper Fruit Held under Various Low Oxygen Atmospheres.

Abstract

The concentrations of ethanol and acetaldehyde in bell pepper fruit were very low during storage at 1%, 3%, 5%, and 10% O2, and air at 20°C. At 0% O2, ethanol and acetaldehyde to a lesser extent, rapidly accumulated in its tissue. The activity of alcohol dehydrogenase (ADH) was about 10 times that of pyruvate decarboxylase (PDC) during storage. The ADH activity greatly increased in the fruit exposed to 1% and 3% O2, but in those exposed to 0%, 5%, and 10% O2 it was slightly higher than that of the control. The PDC activity greatly increased in the fruit exposed to 1%, 3%, and 5% O2, while those of fruits exposed to 0% and 10% O2 were slightly higher than that of the control. ADH transcripts in the fruit exposed to 5% and 10% O2 or air were not detectable, whereas those in the fruit exposed to 1% O2 were significantly higher than those in 0% and 3% O2 on day 1 at 20°C. The discrepancy of the enzyme activities and their product levels are discussed.