Fructophilic lactic acid bacteria (FLAB) - a new group of heterofermentative microorganisms from the plant environment

Recently, a unique kind of lactic acid bacteria (LAB) i.e. fructophilic lactic acid bacteria (FLAB), has been described. This specific group prefers D-fructose over D-glucose as a carbon source to growth. They can be found in fructose rich environments such as flowers, fruits and food products made of fermented fruits, for example tempoyak. In recent years, it has been revealed that insects which feed on food high in fructose are an abundant source of fructophilic bacteria. Bacterial communities inhabiting intestinal tracts of honeybees, bumblebees, Camponotus ants and tropical fruit flies were examined. At present FLAB includes six species: Fructobacillus fructosus, Fructobacillus durionis, Fructobacillus ficulneus, Fructobacillus pseudoficulneus, Fructobacillus tropaeoli and Lactobacillus kunkeei classified by Endo as obligatorily fructophilic, and only one species, namely Lactobacillus forum, as facultatively fructophilic. Latest publications describe new species of potential fructophilic characteristics, which suggests that there is still much to discover in that group.