Acid Bacteria and Probiotics

LAB are a heterogeneous group of bacteria, which include Lactobacillus, Lactococcus, Enterococcus, Streptococcus, Leuconostoc, and Oenococcus genera as the better known members. Their common characteristic is their ability to produce lactic acid as the major end-product of fermentation. They have been used for centuries for their technological and functional properties in food fomentations. Most LAB species have a Generally Recognized as Safe status (delivered by the FDA, in the US) and a Qualified Presumption of Safety status (in Europe). 

The definition of probiotics has evolved. Probiotics were firstly defined as A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance (Fuller 1989). The new definition by the World Health Organization (FAO/WHO 2001), five microorganisms which, when administered in adequate amounts, confa- a health benefit on the hosL opens new fields of application of probiotics beyond feed supplementation. The use of LAB as vaginal- and mammary- probiotics is indeed now being investigated. 

Beside LAB, many probiotic microorganisms are investigated and or used in animal feed (Table 9.1). Commercial preparations do not always use vahd taxonomic designations although a clear indication is mandatory on the label of the product. Among the non-LAB species. Bacillus and Saccharomyces are the most used probiotics in livestock and poultry. 

LAB Lactobacillus Lact. acidophilus, Lact. amylovorus, Lact. brevis, Lact. casei subsp. casei Lact. 

Lactococcus casei), Lact. crispatus, Lact. farmicinis, Lact. fermentum, Lact. murinus, Lact. plantarum subsp. plantarum Lact. plantarum), Lact. reuteri, Lact. rhamnosus, Lact. salivarius, Lact. Amylovorus/Lact. sobrius L. lactis subsp. cremoris Streptococcus cremoris), L. lactis subsp. lactis 

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