Identification and biotechnological characterization of lactic acid bacteria isolated from chickpea sourdough in northwestern Argentina

Abstract

Chickpea, a relevant legume worldwide, can be nutritional and functionally improved by fermentation with lactic acid bacteria (LAB). In order to select suitable autochthonous starter cultures, we isolated and identified LAB from kabuli chickpeas cultivated and consumed in northwestern Argentina, and screened their relevant techno-functional properties. Chickpeas were milled and spontaneously fermented with daily back-slopping at 37 °C for 6 days and evolution of microbial populations were followed by plate counting. Phenotypic and genotypic methods including (GTG)5-based PCR fingerprinting and 16S rDNA sequencing were used to differentiate and identify the isolates to species level. A marked increase of LAB counts was observed throughout fermentation raising from 0.88 ± 0.35 log CFU/g of unfermented flours to 9.61 ± 0.21 log CFU/g after 5 backslopping steps with a concomitant pH decline from 6.09 ± 0.05 to 4.40 ± 0.03. Eighteen strains belonging to four LAB genera and six species: Enterococcus durans, E. mundtii, Lactococcus garvieae, Pediococcus pentosaceus, Weissella cibaria and W. paramesenteroides were identified in chickpea sourdoughs. Based on their abilities, Weissella cibaria CRL 2205 (acidification capacity), W. paramesenteroides CRL 2191 (proteolytic activity), Pediococcus pentosaceus CRL 2145 (gallate decarboxylase and peptidase activities), Lactococcus garviae CRL 2199 (α-galactosidase activity) and E. durans CRL 2193 (antimicrobial activity), were selected to design novel fermented chickpea products.