Characterization and technological properties of lactic acid bacteria isolated from traditional argentinean goat' s milk products

TABOADA, N.; NUÑEZ, M., MEDINA, R.B; LÓPEZ ALZOGARAY, S.

FOOD BIOTECHNOLOGY

TAYLOR & FRANCIS INC

Lugar: Londres; Año: 2014 vol. 28 p. 123 - 141

0890-5436

A total of 286 lactic acid bacteria isolated from goat´s dairy products in northwest of Argentina were characterized. The strains were identified according to morphological, physiological, and relevant technological properties. Lactobacilli (109 isolates) were classified into eight species: Homofermentative (L. delbrueckii subsp. bulgaricus, L. helveticus, L. acidophilus) (11%), facultatively heterofermentative (L. plantarum, L. rhamnosus, L. casei) (59%), and obligately heterofermentative (L. brevis, L. fermentum) (30%). Cocci (177 isolates) were classified into five species: E. faecium (47.46%), E. faecalis (7.34%), Leuconostoc (27.12%), S. thermophilus (13.56%), and Pediococcus (4.52%) after identification. S. thermophilus, Pediococcus and facultatively heterofermentative  lactobacilli were the highest acid producers. S. thermophilus, E. faecium, Pediococcus and obligately heterofermentative lactobacilli strains showed the highest percentage of rapid fermentation. The majority of the strains utilized citrate and produced diacetyl and acetoin in goat milk. L. fermentum UNSE200, UNSE212, UNSE204, UNSE199, UNSE236, UNSE224, UNSE218A, and UNSE53A strains, which produce bacteriocins or metabolites similar to bacteriocins, should be carefully evaluated for their potential applications in dairy fermented products. The API-ZYM test was applied to 39 isolates. The enzymatic activity profile was strain specific. Activities values of pediococci (five isolates) strains were lower than in lactobacilli (34 isolates). Eight strains have been initially selected for use as starter or adjunct culture in the manufacture of artisanal  goat cheeses and they were characterized to species level.