GENOMIC POTENTIAL FOR EXOPOLYSACCHARIDE BIOSYNTHESIS IN LEUCONOSTOC MESENTEROIDES ISOLATED FROM PEQUI PEEL (CARYOCAR BRASILIENSE CAMB.)

Lactic acid bacteria (LAB) isolated from native fruits of the Brazilian Cerrado have potential for producing compounds of biotechnological interest, including exopolysaccharides (EPS), which are used in the food industry for their technological properties. This study aimed to investigate genes associated with EPS biosynthesis in Leuconostoc mesenteroides (C5PB), isolated from pequi (Caryocar brasiliense Camb.) peel, and relate the genomic results to phenotypic evaluation using different carbon sources. Taxonomic identification of the isolate was performed using the Type (Strain) Genome Server (TYGS), while genome annotation was conducted using Bakta through the Galaxy platform. EPS production potential was qualitatively evaluated on MRS agar plates prepared with glucose, lactose, and sucrose as carbon sources, followed by incubation at 37 °C for 48 h. Cultures exhibiting fibrous or mucoid characteristics were considered indicative of potential EPS production. Genomic analysis identified three regions annotated as dextransucrases (BEBKIO-01405, BEBKIO-09155, and BEBKIO09885), enzymes involved in extracellular glucan synthesis from sucrose. Sequences annotated as glycosyltransferase EpsH (BEBKIO-03565), and an exopolysaccharide biosynthesis-associated protein (BEBKIO-03590) were also identified and are related to the formation of these polymers. In the phenotypic evaluation, the isolate exhibited mucoid colonies in the tested media, with these characteristics being more evident in the sucrose-containing medium. This result is relevant because sucrose serves as a substrate for dextransucrases during extracellular glucan synthesis. EPS produced by LAB may act as thickening and stabilizing agents, contributing to the viscosity, texture, and stability of food products. The presence of candidate genes involved in EPS biosynthesis, together with the phenotypic results, indicates the potential of L. mesenteroides (C5PB) for applications in food biotechnology. These findings also contribute to the knowledge of LAB isolated from pequi peel and their potential technological applications, while supporting the sustainable use of by-products from the Brazilian Cerrado.

Acknowledgments: The author acknowledges the Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG) for the doctoral scholarship granted through the Excellence Scholarship Program (Public Call No. 44/2025).