MBAA Home

Measurement of Brewing Yeast Viability and Vitality:A Review of Methods

PEER REVIEWED SUBMISSION

MBAA TQ vol. 37, Number 4, 2000, Pages 409-430 VIEW ARTICLE

By Heather Heggart, A. Margaritis, R. J. Stewart, H. Pikington, J. Sobczak, and I. Russell Dept. of Chemical and Biochemical Engineering, University of Western Ontario, London, Ontario, Canada, N6A 5B9 2. Technology Development Dept., Labatt Brewing Co., Ltd., London Ontario, Canada, N6A 4M3 * Corresponding author: A. Margaritis, e-mail: amarg@julian.uwo.ca

Abstract
This review, written with the practical brewer in mind, examines numerous analytical techniques that have been applied to the mea-surement of brewing yeast viability and vitality. Outlined are yeast viability measurement methods based on cell replication (standard plate count and slide count technique), brightfield and fluorescent staining, measurement of intracellular ATP and NADH, and other methods such as electrokinetic potential and capacitance. Vitality assessment techniques that measure metabolic activity (staining, microcalorimetry, vicinal diketone reduction, yeast protease activity, magnesium ion release, specific oxygen uptake rate, acidification power and intracellular pH), cellular components (ATP, adenylate energy charge, NADH, glycogen and trehalose, sterols and unsaturat-ed fatty acids) and fermentative capacity (glycolytic flux rates, CO 2 measurement and short fermentation tests) are discussed in detail. In summary, it appears that using a combination of various methods may be the best course of action to obtain an accurate picture of the fer-mentation capabilities of brewing yeast.
Keywords: yeast, viability, vital staining, fermentaion  

Sintesis
Este documento, escrito tomando en cuenta al cervecero pr�ctico, examina numerosas t�cnicas anal�ticas que han sido aplicadas para la medida de la vitalidad y viabilidad de la levadura para la elaboraci�n de la cerveza. Se describen m�todos para la medida de la viabilidad de la levadura basados en la replicaci�n celular (la t�cnica del conteo de plato est�ndar y l�mina est�ndar), la tinci�n fluorescente y de campo luminoso, la medida del ATP y NADH intracelular y otros m�todos tales como la capacitancia y el potencial electrokinetico. Las t�cnicas de valoraci�n de vitalidad que miden la actividad metab�lica (la tinci�n, microcalorimetr�a, reducci�n diketona vici-nal, la actividad de la proteasa de levadura, la liberaci�n del i�n mag-nesio, el grado del uso espec�fico de ox�geno, el poder de acidificaci�n y el pH intracelular), los componentes celulares (ATP, la carga de energ�a de adenilato, el NADH, el glic�geno y la tre-halosa, los esteroles y los �cidos grasos no saturados) y la capacidad fermentativa (el grado de flujo glicol�tico, la medida de CO2 y las pruebas de fermentaci�n corta) se discuten en detalle. En resumen, parece ser que el usar una combinaci�n de m�todos varios es el mejor curso de acci�n para obtener una vista correcta de las capacidades de fermentaci�n de la levadura para la elaboraci�n de cerveza.

HOME | CONTACT | JOIN/RENEW | ADVERTISE | STORE

© Copyright Master Brewers Association of Americas