Isolement et identification des lactocoques isolé à partir du lait cru de chèvre et caractéristique biotechnologique.

Abstract

The lactic bacteria represent a very heterogeneous group from the phenotypic point of view. This group ischaracterized by commoncriteria: the type of Gram, the absence of catalase on the Whole production of lactic acid. The recently created genus Lactococcus includes Non-haemolytic and homofermentary streptococci Our theme is devoted to the isolation, purification and identification of lactococcus species. Fromtwosamples of goatmilkweisolated 60 isolates with a negative catalase gram-positive homofermental profile from which 30 isolates were selected from this collection of shells based on the resultants of the test Sherman bleu, only 15 representative isolates of the dominat flora Were fully identified by phenotypic methods. The results of the biochemical, physiological and fermentation tests carried out on isolated and Purified strains have made it possible to identify the following species: -V27, V6, V10, Lactococcusplantarum -V13, v16, Lactococcusraffinolactis -V21, v7, v33, v19, v8, Lactococcuslactissubsp. lactis -V31, v9, v25, Lactococcuslactissubsp.lactisbiovar. diacetylactis -V27, v3, Lactococcuslactissubsp. Cremoris The results of the technological aptitude assessment indicate that mostst strains exhibit good proteolytic potency