AUTHOR=Garcia Estefânia F. , Luciano Winnie A. , Xavier Danilo E. , da Costa Whyara C. A. , de Sousa Oliveira Kleber , Franco Octávio L. , de Morais Júnior Marcos A. , Lucena Brígida T. L. , Picão Renata C. , Magnani Marciane , Saarela Maria , de Souza Evandro L. 

TITLE=Identification of Lactic Acid Bacteria in Fruit Pulp Processing Byproducts and Potential Probiotic Properties of Selected Lactobacillus Strains

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01371

DOI=10.3389/fmicb.2016.01371

ISSN=1664-302X

ABSTRACT=<p>This study aimed to identify lactic acid bacteria (LAB) in byproducts of fruit (<italic>Malpighia glabra</italic> L., <italic>Mangifera indica</italic> L., <italic>Annona muricata</italic> L., and <italic>Fragaria vesca</italic> L.) pulp processing. Fifty strains of LAB were identified using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequence (16S rRNA) analysis. Species belonging to <italic>Lactobacillus</italic> genus were the predominant LAB in all fruit pulp processing byproducts. The average congruency between the MALDI-TOF MS and 16S rRNA in LAB species identification reached 86%. Isolates of <italic>L. plantarum, L. brevis, L. pentosus, L. lactis</italic> and <italic>L. mesenteroides</italic> were identified with 100% congruency. MALDI-TOF MS and 16S rRNA analysis presented 86 and 100% efficiency of LAB species identification, respectively. Further, five selected <italic>Lactobacillus</italic> strains (<italic>L. brevis</italic> 59, <italic>L. pentosus</italic> 129, <italic>L. paracasei</italic> 108, <italic>L. plantarum</italic> 49, and <italic>L. fermentum</italic> 111) were evaluated for desirable probiotic-related properties and growth behavior on two different cultivation media. The exposure to pH 2.0 sharply decreased the counts of the different <italic>Lactobacillus</italic> strains after a 1 or 2 h incubation, while varied decreases were noted after 3 h of exposure to pH 3.0. Overall, the exposure to pH 5.0 and to bile salts (0.15, 0.30, and 1.00%) did not decrease the counts of the <italic>Lactobacillus</italic> strains. All tested <italic>Lactobacillus</italic> strains presented inhibitory activity against <italic>Staphylococcus aureus, Salmonella</italic> Typhimurium, <italic>Salmonella</italic> Enteritidis, <italic>Listeria monocytogenes</italic> and <italic>Escherichia coli</italic>, and presented variable susceptibility to different antibiotics. The selected <italic>Lactobacillus</italic> strains presented satisfactory and reproducible growth behavior. In conclusion, MALDI-TOF MS and 16S rRNA analysis revealed high efficiency and congruency for LAB species identification, and the selected <italic>Lactobacillus</italic> strains may be candidates for further investigation of novel probiotic strains.</p>