The COMPARATIVE IDENTIFICATION APPROACH FOR GUM-PRODUCING LACTOBACILLI IN PALM WINE

Abstract

Introduction: Species of lactobacilli are responsible for the consistency and soluble white colouration of palm wine through the production of gum. Phenotypic and physiological characteristics as basis for identification of lactobacilli is often with low level of discrimination.

Objection:  This study aimed at comparative identification approach of gum-producing lactobacilli using amplified ribosomal DNA restriction analysis (ARDRA) and API kit 50 CHL.

Methodology: Four hundred colonies of lactobacilli isolated from seventy-two fresh palm wine samples and two hundred were used for genomic DNA extraction, 16S rDNA analysis and digestion of amplicons with two endonucleases: Hae III and Bash 12361.

Results: Twenty ARDRA pattern group were generated and representatives of each were randomly chosen for sequence and API kit analysis. The size of the amplified products (̴ 1500 bp), digested amplicons (100 - 1000 bp) and the ARDRA profiles; A-T. ARDRA screening revealed unique patterns among the two hundred isolates, with the same pattern for some of the isolates. The 16S rDNA gene sequence analysis showed that the isolates were divide into 20 groups of three genera: Lactobacillus (65%), Leuconostoc (30%), and Lactococcus (5%) whereas API kit identified two genera; Lactobacillus (75%) and Leuconostoc (25%). Gene sequence similarity of all the representative isolate for 16S rDNA (99 - 100%) while API kit (74.8 – 99.9%) with 55% overall similarity in bacterial identified. ARDRA showed higher similarities in identification and discrimination of bacterial species or between closely related groups isolated from palm wine compared to API kit.

Conclusion: ARDRA is a good tool for lactobacilli identification based on the results from this study.