Microencapsulation of Lactobacillus cells utilizing the β-glucan-rich cell wall of Saccharomyces cerevisiae for enhanced stability and efficacy

Abstract

Probiotic encapsulation enhances bacterial stability and viability, yet conventional materials like sodium alginate have limitations, particularly in acidic environments. This study explores the use of β-glucan-rich Saccharomyces cerevisiae cell walls, extracted via ultrasound-assisted enzymolysis, as an alternative microencapsulation matrix for probiotics. This study aims to improve encapsulation efficiency, enhance probiotic survival under stress conditions, and offer a sustainable solution for probiotic delivery. Among the tested strains, Levilactobacillus brevis C23 encapsulated in S. cerevisiae cell walls exhibited the highest encapsulation efficiency (90.42 ± 4.53 %) and cell viability (7.52 ± 0.45 log CFU/mL), significantly outperforming sodium alginate encapsulation (p < 0.05). Encapsulation in S. cerevisiae cell walls provided superior heat resistance (up to 65 °C) and enhanced survival in simulated gastrointestinal conditions, with viable counts of 2.266 ± 0.095 log CFU/mL in gastric juice (120 min) and 4.557 ± 0.086 log CFU/mL in intestinal juice (240 min). Fourier-transform infrared spectroscopy (FTIR) confirmed successful probiotic encapsulation. At the same time, storage studies showed that encapsulated cells maintained viability above 6 log CFU/mL for eight weeks at 4 °C, though viability decreased at 25 °C. These findings demonstrate the potential of S. cerevisiae cell walls as an effective and sustainable encapsulation matrix, offering enhanced probiotic protection for food and pharmaceutical applications.

Keywords: Lactic acid bacteria; Microencapsulation; β-Glucan.