In vitro evaluation of probiotic potential and enzymatic profiling of Pichia kudriavzevii Y33 isolated from traditional home-made mango pickle

Abstract

Background: Fermented foods are the results of metabolic activities of various microorganisms. People have traditionally known how to culture desirable microorganisms, primarily lactic acid bacteria, yeasts, and filamentous molds, for the manufacture of edible foods. Yeast isolated from home-made mango pickle from Hamirpur, Himachal Pradesh, was assessed for probiotic properties and their enzymatic profiling.

Results: Four yeast isolates were isolated out of which P. kudriavzevii Y33 was selected on the basis of high acid tolerance as well as broadest antimicrobial activity. The selected isolate was observed to have high acid tolerance at pH 2 and show strong antimicrobial activity against all the pathogens examined. P. kudriavzevii Y33 can also withstand high bile concentration and showed high viability index, i.e., 95% at concentration of 2% of bile. The isolate was able to demonstrate high cholesterol assimilation in medium containing ox bile and taurocholate, at 88.58 and 86.83%, respectively. The autoaggregation ability of isolate increases with increasing the time of incubation and showed 87% of autoaggregation after 24 h of incubation. P. kudriavzevii Y33 exhibited resistance towards different antibiotics, found to be positive for exopolysaccharide production and showed no hemolytic activity. The isolate was observed to produce several enzymes such as β-galactosidase, protease, amylase, phytase, and lipase.

Conclusions: The results of the current study revealed that P. kudriavzevii Y33 has various beneficial qualities that suggest it could be used as probiotics. Enzymes produced by yeast isolate help in improving flavor and mineral availability in the fermented products.

Keywords: Fermented foods; Phytase; Pichia kudriavzevii; Probiotics; Traditional pickle.

Fig. 1

Phylogenetic tree of P. kudriavzevii Y33 based on homology of ITS gene sequences. Toluene showed significantly high cell surface hydrophobicity at p < 0.05 as measured by 2 sided Tukey’s post hoc range test between replications

Fig. 2

a Cell surface hydrophobicity. b Autoaggregation of P. kudriavzevii Y33

Fig. 3

Proteolytic, amylase, phytase, and lipase activity of P. kudriavzevii Y33