Lactobacillus gasseri from human milk with probiotic potential and some technological properties

In the current study, Lactobacillus gasseri MA-4 strain from human breast milk was evaluated for its probiotic potential and some technological properties. The strain was also evaluated for its virulency. The antimicrobial activity was tested against a wide range of clinical-human and food pathogenic bacteria, Candida species and various fish pathogens. High tolerance was observed by MA-4 strain for some essential parameters such as low pH, bile salts, artificial stomach and small intestine fluids conditions. The autoaggregation and coaggregation abilities of the strain were recorded as 95% and 45-55% respectively. The nisin sensitivity against nine different nisin concentrations (1.25-150 -mu g/mL) was only observed at 100 and 150 mu g/mL. The strain exhibited high resistance to sodium benzoate (0.1% w/v), a commonly used food presevative. The supernatant of the strain showed high cholesterol assimilation ability with 75.66% at the 1% bile concentration. DPPH free radical reducing and the iron ion chelating activity of MA-4 strain were determined as 39.20% and 15.60% respectively. Amylase and beta-1,3-1,4-glucanase (lichenase) enzymes activities were also obtained qualitatively. Consequently, MA-4 strain may be considered as a good candidate for probiotic cultures, biotherapeutic and bio-protective agents.