Intracellular Nicotinamide Adenine Dinucleotide Content of Brewer's Yeast During Different Stages of Fermentation. R. B. Saha, Anheuser-Busch, Inc., Technical Center, One Busch Place, St. Louis, MO 63118. J. Am. Soc. Brew. Chem. 46:0072, 1988.

A method for extraction and estimation of nicotinamide adenine dinucleotide (NAD) and reduced NAD (NADH) in yeast during different stages of fermentation was developed. Yeast cells were washed in normal saline, incubated at 85° C for 5 min, and centrifuged to obtain cell-free extracts. A lactic dehydrogenase enzyme system was used to measure the intracellular NADH and NAD activity in yeast before, during, and after fermentation. Brink yeast was found to contain 10 times more NADH and three times more NAD than the yeast recovered after secondary fermentation (end-fermentation yeast). The pattern of NADH and NAD concentration was established during the first 120 hr of primary fermentation. These studies indicate that there is a relationship between yeast's fermentative state and its intracellular NADH and NAD content. Measurement of these parameters can serve as an important tool in the understanding of yeast physiology during normal and stress conditions.

Keywords: Fermentative state, Intracellular NADH, NAD, Yeast