Characterization of Antibacterial Activity and Potential as Probiotic of Lactic Acid Bacteria Isolated from Goat’s Milk in Algeria

Abstract

Lactic acid bacteria (LAB) were isolated from goat's milk in different north west region of Algeria. A total of 233 isolates were identified as LAB. However, only 11 strains showed excellent inhibition zones on agar when Salmonella typhimorium ATCC 13311 was used as an indicator for preliminary detection of antagonistic activity. After elimination of inhibition due to acid and H 2 O 2 , Staphylococcus aureus ATCC 25923 was used for secondary screening for antagonistic activity of these 11 strains. It was found that only 9 strains exhibited a good inhibition zones on agar, and all of them could inhibit E. coli ATCC 25921 and Pseudomonas aeruginosa ATCC 27853 as the third and the forth indicators respectively. Lactococcus lactis subsp. cremoris, Lactobacillus casei subsp. casei, Lactobacillus casei subsp. rhamnosus, Streptococcus salivarius subsp. thermophilus and Lactococcus lactis biovar.diacetylactis were the strains that have a good antibacterial activity, survive in the gastrointestinal conditions and were sensible to the majority of the antibiotics. All isolated strains tolerate pH = 2 and high bile salt concentration.

Biophysicochemical characterization of Pyocin SA189 produced by Pseudomonas aeruginosa SA189

“…Thermostability of pyocin SA189 was determined by exposing the preparations to elevated temperatures, i.e ., from 40 °C to 80 °C for 30 min, and to 100 °C and 121 °C for 15 min. After treatment, the residual activity was determined by AWDA ( Jabeen et al ., 2009 ; Benreguieg et al ., 2013 ). To determine the temperature and duration of the bacteriocin stability, the preparation was stored at temperatures, 0 °C, 4 °C or −20 °C, and their bioactivity was monitored till one year using AWDA.…”

Prophylactic Effect of A Probiotic Strain Lactobacillus Rhamnosus Against Aluminum Chloride-Induced Intoxication in Wistar Rats: Neurobehavioral and Hematobiochemical Studies

“…Two colonies were then transferred to 9ml of semi-skimmed milk and incubated at 30°C for18h. From a standard inoculum, 200ml of sterile semi-skimmed milk is inoculated with 1ml of Lactobacillus rhamnosus (i.e., 10 8 CFU/ml) (Benreguieg et al, 2013;Mahmoudi, 2014), the cultures are incubated, and the resulting coagulate is then stored at 4°C until it is presented to the animals.…”