Lactobacillus Delbrueckii Subsp. bulgaricus - Use in Industry

Use in Industry

Lactobacillus delbrueckii subsp. bulgaricus is commonly used alongside Streptococcus salivarius subsp. thermophilus as a starter for making yogurt. The two species work in synergy, with L.d. bulgaricus producing amino acids from milk proteins, which are then used by S.s. thermophilus. Both species produce lactic acid, which gives yogurt its tart flavor and acts as a preservative. The resulting decrease in pH also partially coagulates the milk proteins, such as casein, resulting in yogurt's thickness. While fermenting milk, L.d. bulgaricus produces acetaldehyde, one of the main yogurt aroma components. Some strains of L.d. bulgaricus also produce bacteriocins, which kill undesired bacteria in vitro.

It is often helpful to sufferers of lactose intolerance, whose digestive systems lack the enzymes to break down lactose to simpler sugars.

Some of the biggest importers of the bacterium are Japan, the USA, and the EU.

It has also been considered a contaminant of beer due its homofermentatative production of lactic acid, an off-flavor in many styles of beer. In other styles of beer, however, lactic acid bacteria can contribute to the overall appearance, aroma, taste, and/or mouthfeel, and generally produce and otherwise pleasing sourness.