In Vitro Assessment of Gastrointestinal Tolerance, Antibacterial Activity, and Antioxidant Activity of Bacterial Strains Isolated from Fermented Sap of Acrocomia mexicana

In southern Mexico and other regions of Central America, fermented palm sap is consumed as an alcoholic beverage and represents a potential source of microorganisms with probiotic properties. This study aimed to isolate and identify bacterial strains from the fermented sap of Acrocomia mexicana and evaluate properties associated with probiotic potential, including gastrointestinal tolerance, antibacterial activity, and antioxidant capacity. Strains were identified by biochemical characterization and 16S rRNA gene sequencing. Gastrointestinal tolerance was assessed under simulated gastric and intestinal conditions, while antibacterial and antioxidant activities were determined using the agar diffusion and DPPH radical scavenging assays, respectively. The isolates were assigned to Weissella cibaria, Weissella sp., Enterococcus faecium, Enterococcus sp., Bacillus velezensis, and Bacillus nakamurai. Gastrointestinal tolerance varied among isolates, with B. velezensis, E. faecium, and W. cibaria showing the highest survival, whereas some isolates were not detected after gastric exposure. Antibacterial activity was observed only for E. faecium P1M34 and W. cibaria 1AM1 with inhibition zones of 12.33–16.33 mm against Escherichia coli and Salmonella. Antioxidant activity varied, with B. velezensis showing the highest capacity (~79%). These findings identify isolates for further assessment based on preliminary in vitro screening. Comprehensive strain-specific safety studies are required before considering food applications.