Phenotypic and functional screening of Weissella ghanensis A0210 and Gluconobacter frateurii MP0210 strains isolated from agro-industrial fruit waste
Abstract
Abstract The growing demand for functional foods has driven research into microorganisms with probiotic potential from sustainable and unconventional sources. In this context, agro-industrial fruit byproducts represent promising matrices for exploring phenotypic screening of bacterial strains with functional relevance. This study aimed to perform an exploratory phenotypic screening of bacterial strains from agro-industrial byproducts of tropical fruits, focusing on probiotic-related and technological traits. Samples were cultured in De Man, Rogosa, and Sharpe (MRS) medium, and isolates were identified using MALDI-TOF MS mass spectrometry. Weissella ghanensis A0210 and Gluconobacter frateurii MP0210 were evaluated for tolerance to acidic pH, resistance to bile salts, hemolytic activity, biofilm formation, antimicrobial susceptibility, and antagonistic activity against pathogenic bacteria. For W. ghanensis A0210, titratable acidity increased from 0.4% to 1.4% within 24 hours, accompanied by a decrease in pH, confirming its fermentative profile. The strain exhibited resistance to amoxicillin, cefaclor, lincomycin, and norfloxacin, while remaining susceptible to erythromycin, rifampicin, and gentamicin. In antagonism assays, W. ghanensis A0210 inhibited all tested pathogens, with the highest inhibitory activity observed against Salmonella sp. and Enterococcus faecalis. In addition, the strain showed survival under resistance to simulated gastrointestinal conditions and moderate biofilm formation; however, its β-hemolytic activity restricts its direct application as a probiotic. In contrast, G. frateurii MP0210 showed lower tolerance and adhesion capacity, yet demonstrated potential for fermentative and biotechnological applications. Overall, the findings support the relevance of agro-industrial fruit residues as sources of microbial biodiversity and highlight the importance of initial functional assessments to guide future safety and application-oriented studies.