Gram-positive spoilage bacteria in brewing

Quality Control Center, Asahi Breweries, Ltd., Ibaraki, Japan 

Beer-spoilage LAB were found by Pasteur in 1871 through microscopic examinations of spoiled beer (Pasteur, 1876). Initially beer-spoilage LAB were grouped in rods and cocci. Rod-shaped LAB strains were originally designated Saccharobacillus pastorianus by van Laer (1892). This species was named in honor of Pasteur and later redesignated Lactobacillus pastorianus. van Laer also reported that L pastorianus did 

Apart from spoilage incidents of beer products, certain thermophilic lactobacilU, including Lactobacillus delbrueckii, have been noted as contaminants of sweet wort. They are killed by the boiling process, but if the wort is kept sweet for an extended period, even stored hot (less than 60 °C), thermophilic lactobacilli spoil sweet wort by producing lactic acid (Priest, 2(X)6). 

3 Association of beer-spoilage LAB with their habitat 

Species Beer- spoilage ability Primary/ secondary contamination s Exopolysaccharide formation Diacetyl production Culturability on MRS agar  

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