Characterization of Lactobacillus Isolated from the Microflora of Different Fermentation Processes and Doderlein Flora

Abstract

Lactobacillus contribute to the organoleptic quality of foods during the fermentation process in which they are involved. They also have the ability to inhibit the growth of undesirable germs by producing metabolites such as bacteriocins. The aim of this study was to isolate and identify the different Lactobacillus species from various fermentation processes and from the Doderlein flora. Lactobacillus were isolated from raw cow milk, curdled milk, cassava ferment (Magnan) and Doderlein flora on MRS agar. Strains were identified by mass spectrometry (MALDI-TOF). 213 Lactobacillus strains were isolated and identified from the different matrices. The main species isolated from raw cow's milk and curdled milk were Lactobacillus plantarum (31.58%), Lactobacillus casei (26.31%), Lactococcus lactis (21.05%), Lactobacillus delbrueckii spp bulgaricus (31%), Lactobacillus helveticus (30%) and Lactobacillus fermentum (25%) respectively. In the cassava ferment, Lactobacillus plantarum (37.5%), Lactobacillus rhamnosus (25%) and Lactobacillus reuteri (25%) were the most isolated species. The main species of Doderlein flora were Lactobacillus acidophilus (50%) and Lactobacillus plantarum (25%). This study showed a diversity of Lactobacillus present and involved in the different fermentation processes of foods and Doderlein flora (Commensal flora of the vagina). The qualitative and quantitative proportions of the different Lactobacillus species depend on the matrix. These Lactobacillus can potentially produce substances (bacteriocins) that inhibit the growth of pathogenic bacteria and multi-resistant bacteria.