African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5093

Full Length Research Paper

Identification of acetic acid bacteria isolated from Tunisian palm sap

Malek Ghariani
  • Malek Ghariani
  • Institut National des Sciences Applique´es et de Technologie (INSAT), Boulevard de la terre, BP 676 1080 Tunis, Tunisia.
  • Google Scholar
Moktar Hamdi
  • Moktar Hamdi
  • Institut National des Sciences Applique´es et de Technologie (INSAT), Boulevard de la terre, BP 676 1080 Tunis, Tunisia.
  • Google Scholar
Luciano Beneduce
  • Luciano Beneduce
  • Department of Sciences of Agriculture, Food and Environment (SAFE) University of Foggia, via Napoli, 25 71122 Foggia, Italy.
  • Google Scholar
Vittorio Capozzi
  • Vittorio Capozzi
  • Department of Sciences of Agriculture, Food and Environment (SAFE) University of Foggia, via Napoli, 25 71122 Foggia, Italy.
  • Google Scholar
Salvatore Massa*
  • Salvatore Massa*
  • Department of Sciences of Agriculture, Food and Environment (SAFE) University of Foggia, via Napoli, 25 71122 Foggia, Italy.
  • Google Scholar


  •  Received: 13 August 2016
  •  Accepted: 25 November 2016
  •  Published: 21 April 2017

Abstract

Date palm sap (Phoenix dactylifera L.), called Lagmi, is a sugary substrate that readily ferments through the activity of native microflora that consists mainly of yeasts, lactic acid bacteria and acetic acid bacteria (AAB). The aim of this work was to perform a preliminary step in the isolation and identification of AAB species from different samples of palm sap collected in Southern Tunisia, in order to use them as a starter in vinegar production. AAB were isolated on GEY agar from the fresh palm sap (day (D) 0) and following spontaneous fermentation at room temperature after 3 (D3) and 7 days (D7). A preliminary phenotypic identification of 18 isolates was made by means of Gram, catalase, oxidase and ethanol oxidation to acetic acid, and then further to CO2 and H2O. Subsequently, genotypic identification was conducted by sequencing the gene coding for 16SrRNA and a phylogenetic analysis was obtained based on 16S rRNA sequences. Isolates were identified as Acetobacter tropicalis (11 strains), Acetobacter pasteurianus (3 strains), Acetobacter senegalensis (1 strain), Acetobacter indonesiensis (1 strain), Acetobacter cerevisiaie (1 strain), and Gluconacetobacter liquefacienes (1 strain). The application of selected strains as pure starter cultures for the production of vinegar from palm sap is under investigation in our laboratory.

Key words: Date palm sap, Lagmi, acetic acid bacteria (AAB), starter, vinegar.