Applied Biology in Saharan Areas
Volume 3, Numéro 3, Pages 27-43

Comparison Of Maldi Tof Ms Profiling And 16s Rrna Gene Identification Of Presumptive Lactic Acid Bacteria Isolated From The Traditional Algerian Date Product “btana”.

Authors : Abekhti Abdelkader . Cnockaert Margo . Aerts Maarten . Daube Georges . Vandamme Peter . Tahri Assia . Taminiau Bernard .

Abstract

The present study sat the purpose to compare the accuracy of identification of 68 strains lactic acid bacteria originating from Btana samples (Bouchegroun, Sali, Algeria) Btana by means of 16s RNA sequencing and Matrix-assisted laser desorption ⁄ ioni-zation time-of-flight mass spectrometry (MALDI-TOFMS) MALDI TOF. Dilution of Btana samples were cultured on MRS, M17 and MSE media. For MALDI TOF identification, a cell extract was prepared from each isolates then coated with matrix of 1 μL of a 0.5% (w/v) alpha-cyano-4-hydroxycinnamic acid solution (α-CHCA). The best quality spectra was selected then compared against an in-house (LMG) built reference database. Five assigned cluster identified as Weissella paramesenteroides, Weissella cibaria/confuse, Leuconostoc citreum, Leuconostoc pseudomesenteroides, and Lactobacillus plantarum and one AAB species Gluconobacter cerinus. A representative strain of each cluster was selected for identification by 16S rRNA gene analysis. Sequences comparison with Genbank database confirmed accurately the strain’s identity made already by MALDI-TOF. According to API 50 CHL essay, 7 carbohydrates (D-glucose, D-fructose, D-mannose, N-acetyl glucosamine, D-maltose, D-lactose, D-saccharose were systematically used by the five LAB strains. Which support that the identified species are adapted to the high sugar environment of Btana.

Keywords

Btana ; date fruit ; traditional food ; lactic acid bacteria ; high sugar food ; MALDI-TOF MS