Use of nisin in brewing

It has been postulated that the primary site of action of nisin is the cell membrane (Ogden et ah, 1988). The permeability of the cell membrane may be altered, which would facilitate the movement of intracellular metabolites, ions and ADP and/or ATP, into the extracellular medium. Leakage of ADP would prevent the regeneration of ATP, which is required to energise metabolic processes. The majority of the cells of sensitive strains were inactivated (killed) within 1 min of contact with nisin. There was, however, no evidence of cell lysis (Ogden and Waites, 1986). Furthermore, nisin is more effective against actively growing cells than those in stationary phase (Ruhr and Sahl, 1985). 

At present, in Australia and the UK, there are no restrictions on the amount of nisin that can be added to beer, although the upper limit 

2 Fermentation. Fermentation processes in general play an important role in determining the precise flavour of the final product. During fermentation, spoilage microorganisms may proliferate, leading to the formation of volatiles, such as acetaldehyde, diacetyl, various sulphur 

4 Plant sanitation. Nisin may be used as an alternative cleanser in breweries that do not employ a caustic or alkali-based detergent cleaning system, as the activity of nisin is reduced under such conditions (Ogden et al., 1988). 

S Reduced pasteurisation. At present, pasteurisation is the preferred means for destroying spoilage bacteria, in particular, lactobacilli. Tunnel pasteurisation is employed for cans and glass and flash pasteurisation for beers destined for kegs or polyethylene terephthalate (PET) bottles. It is essential that both excessive and insufficient filtration is 

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