Aislamiento y caracterización de cepas nativas de Lactobacillus spp. para su uso como probióticos en la industria láctea

Abstract

The use of starters to elaborate dairy products is a current practice in the industry. In our Country we import these starters from foreign companies dedicated to make and sale it, and most of them include probiotic bacterias. Probiotics can be defined as microorganisms that after be consumed in adequate amount, can give some advantageous effect to the host. In this study a strain of Lactobacillus was isolated from a human. The identification was done through gram stain, catalase test, aerobic and anaerobic growth, and an API 50 CH test. In order to prove the probiotic properties of the strain, studies of pH resistance, bile salts tolerance and an in vitro gastric model were conducted. The results indicate that the isolate correspond to a native strain of Lactobacillus acidophilus phenotipically characterized with a 97% of confidence. What is more, because it capability to resist the exposure to a pH similar than the stomach, to growth in a medium with bile salts and to survive to the simultaneous action of pepsine and gastric juice, it would be able to survive the passage through the digestive tube. These characteristics allow us to classify it as a probiotic strain.