Role of bacteria of the genus Leuconostoc in the dairy industry.

摘要

Lactic acid bacteria of the genus Leuconostoc play an important role in the dairy industry because of their ability to produce aroma compounds and carbon dioxide through lactose heterofermentation and citrate utilization. Leuconostocs ferment hexoses by the pentose phosphate pathway, producing D-lactate, ethanol and CO2. The carbon dioxide produced is responsible for eye formation in certain types of cheese. Citrate utilization by these bacteria leads to the production of diacetyl (and other substances such as acetoin and ethanol), which is considered a main flavour compound of a range of fermented dairy products such as cultured butter, cultured sour cream, buttermilk and some acid and rennet cheeses. Many strains of Leuconostoc synthesize extracellular polysaccharides (EPS). Exopolysaccharide producing Leuconostocs can enhance the functional properties of fermented milk products. In addition, many Leuconostocs produce bacteriocins that may or may not be active against other lactic acid bacteria, but all include Listeria spp. in their activity spectra. The use of Leuconostocs as starter bacteria in controlled fermentations make the bacteriocins produced by these bacteria of interest as possible food preservatives for dairy products, especially raw milk products. Bacteriophage contamination is an important problem that is common in food fermentations, especially in the dairy industry. Among the bacteriophages that infect lactic acid bacteria, those specific for other LAB have been investigated most extensively, but little information is available on bacteriophages of species of the genus Leuconostoc..