Lactic acid bacteria: Biodiversity and taxonomy pages:213-228
In 1990 the genus Tetragenococcus was created after reclassification of the halophilic lactic acid bacterium (LAB) Pediococcus halophilus as T. halophilus. Tetragenococci are typical LAB in that they are Gram-positive, catalase negative, and oxidase negative. Physiologically, tetragenococci are distinguished from other LAB mainly by their high salt tolerance and ability to grow at high pH values. Presently, the genus comprises a limited number of species, including T. halophilus, T. koreensis, T. muriaticus, T. osmosphilus and T. solitarius. Based on both physiological and genetic characteristics as well as on the origin of the strains, the species T. halophilus was further subdivided into two subspecies, including T. halophilus subsp. halophilus and T. halophilus subsp. flandriensis for strains isolated from salt-rich and sugar-rich environments, respectively. In this chapter, both phenotypical and genotypical characteristics of the genus are outlined, with a detailed description of each species comprising the genus. In addition, emphasis is put on the industrial relevance of the genus.