Lactic Acid Bacteria Isolation from Spontaneous Sourdough and Their Characterization Including Antimicrobial and Antifungal Properties Evaluation

Elena Bartkiene; Vita Lele; Modestas Ruzauskas; Konrad J Domig; Vytaute Starkute; Paulina Zavistanaviciute; Vadims Bartkevics; Iveta Pugajeva; Dovile Klupsaite; Grazina Juodeikiene; Ruta Mickiene; João Miguel Rocha

doi:10.3390/microorganisms8010064

Lactic Acid Bacteria Isolation from Spontaneous Sourdough and Their Characterization Including Antimicrobial and Antifungal Properties Evaluation

Microorganisms. 2019 Dec 30;8(1):64. doi: 10.3390/microorganisms8010064.

Authors

Elena Bartkiene^{1

2}, Vita Lele^{1

2}, Modestas Ruzauskas^{3

4}, Konrad J Domig⁵, Vytaute Starkute^{1

2}, Paulina Zavistanaviciute^{1

2}, Vadims Bartkevics^{6

7}, Iveta Pugajeva⁶, Dovile Klupsaite², Grazina Juodeikiene⁸, Ruta Mickiene¹, João Miguel Rocha⁹

Affiliations

¹ Department of Food Safety and Quality, Veterinary Academy, Lithuanian University of Health Sciences, Mickeviciaus str. 9, LT-44307 Kaunas, Lithuania.
² Institute of Animal Rearing Technologies, Veterinary Academy, Lithuanian University of Health Sciences, Mickeviciaus str. 9, LT-44307 Kaunas, Lithuania.
³ Microbiology and Virology Institute, Veterinary Academy, Lithuanian University of Health Sciences, Mickeviciaus str. 9, LT-44307 Kaunas, Lithuania.
⁴ Department of Anatomy and Physiology, Veterinary Academy, Lithuanian University of Health Sciences, Mickeviciaus str. 9, LT-44307 Kaunas, Lithuania.
⁵ Institute of Food Science, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Wien, Austria.
⁶ Department of Chemistry, University of Latvia, Jelgavas iela 1, LV-1004 Riga, Latvia.
⁷ Institute of Food Safety, Animal Health and Environment BIOR, Lejupesiela 3, LV-1076 Riga, Latvia.
⁸ Department of Food Science and Technology, Kaunas University of Technology, Radvilenu str. 19, LT-50254 Kaunas, Lithuania.
⁹ REQUIMTE-Rede de Química e Tecnologia, Laboratório de Química Verde (LAQV), Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto (FCUP), Rua do Campo Alegre, s/n. P-4169-007 Porto, Portugal.

Abstract

This research effort aimed at isolating and phenotypically characterizing lactic acid bacteria (LAB) isolates from a spontaneous rye sourdough manufactured following traditional protocols, as well as at evaluating their antimicrobial and antifungal properties as key features for future industrial applications. Thirteen LAB strains of potential industrial interest were isolated and identified to species-level via PCR. Most of the sourdough isolates showed versatile carbohydrate metabolisms. The Leuconostoc mesenteroides No. 242 and Lactobacillus brevis No. 173 demonstrated to be gas producers; thus, revealing their heterofermenter or facultative homofermenter features. Viable counts higher than 7.0 log₁₀ (CFU/mL) were observed for Lactobacillus paracasei No. 244, Lactobacillus casei No. 210, L. brevis No. 173, Lactobacillus farraginis No. 206, Pediococcus pentosaceus No. 183, Lactobacillus uvarum No. 245 and Lactobacillus plantarum No. 135 strains, after exposure at pH 2.5 for 2 h. Moreover, L. plantarum No. 122, L. casei No. 210, Lactobacillus curvatus No. 51, L. paracasei No. 244, and L. coryniformins No. 71 showed growth inhibition properties against all the tested fifteen pathogenic strains. Finally, all LAB isolates showed antifungal activities against Aspergillus nidulans, Penicillium funiculosum, and Fusarium poae. These results unveiled the exceptionality of spontaneous sourdough as a source of LAB with effective potential to be considered in the design of novel commercial microbial single/mixed starter cultures, intended for application in a wide range of agri-food industries, where the antimicrobial and antifungal properties are often sought and necessary. In addition, metabolites therefrom may also be considered as important functional and bioactive compounds with high potential to be employed in food and feed, as well as cosmetic and pharmaceutical applications.

Keywords: Lactobacillus; Leuconostoc; Pediococcus; antifungal activity; antimicrobial activity; carbohydrate metabolism; inhibition of bacterial pathogens; lactic acid bacteria; spontaneous sourdough.