In Vitro evaluation of probiotic properties of lactic acid bacteria strains isolated from juçara fruit native to the Atlantic Forest

Lactic acid bacteria (LAB) are the microorganisms most commonly used as probiotics. Since probiotic benefits are strain-dependent, there is a continuous need for research into new cultures with probiotic properties. Fruits such as juçara (Euterpe edulis Martius), a palm species from the Atlantic Forest threatened with extinction, are rich niches for microorganisms, including LAB. This study investigated the probiotic properties of Lactococcus lactis J7 and Leuconostoc pseudomesenteroides JF17 strains isolated from juçara fruits native to the Atlantic Forest. Probiotic characteristics, such as tolerance to simulated gastrointestinal fluids or juices, hydrophobicity, autoaggregation, coaggregation properties, inhibition of pathogenic microorganisms, and technological properties were evaluated. The survival rate of L. lactis J7 and L. pseudomesenteroides JF17 decreased after exposure to simulated gastrointestinal conditions; however, L. lactis J7 was more resistant, maintaining viability at the end of the enteric phase of 6.07 ± 0.16 log CFU mL-1. The J7 strain also exhibited the highest values in hydrophobicity (12.55 ± 0.52%), autoaggregation (25.63 ± 0.75%), and coaggregation capacity with E. coli ATCC 25922 (21.52 ± 0.98%) and S. Enteritidis ATCC 13076 (22.68 ± 1.01%). Both J7 and JF17 strains demonstrated antimicrobial activity, confirmed by the multilayer agar plate system. Additionally, the growth of the strains was temperature-dependent, and they were able to thrive in high concentrations of sodium chloride (6%). Thus, L. lactis J7 is a promising probiotic candidate for the development of functional products. Nevertheless, further studies using animal models are necessary to explore the properties of these probiotic bacteria. Novel strains isolated from fruits should be studied to broaden the application of probiotic microorganisms in the development of foods and medicines.