Molecular Identification of Lactic Acid Bacteria Isolated from Fermented Coconut Yoghurt through Uncontrolled Fermentation

Abstract

This study aimed to identify and characterize Lactic Acid Bacteria obtained from uncontrolled
fermentation of coconut milk using molecular biology tools. Healthy coconut fruit was
aseptically processed to obtain the milk which was afterwards allowed to ferment spontaneously
under laboratory condition. Using standard microbiological methods Lactic Acid Bacteria
(LAB) were isolated from the fermenting milk during fermentation. The LAB isolates were
subjected to presumptive tests and subsequently to molecular analyses to confirm their
identities. Genomic DNA of each LAB was extracted using commercial kits, 16S rRNA gene
of the extracted DNA was amplified by Polymerase Chain Reaction (PCR) and the product
sequenced by Sanger method. Similarity and phylogenetic relationship of the resulting
sequences with reference strains’ sequences in National Centre for Biotechnology Information
database were compared using BLAST. Isolated Lactic Acid Bacteria were identified as
Lactobacillus acidophilus, Limosilactobacillus reuteri, Leuconostoc mesenteroides, and
Lactococcus lactis, with each exhibiting 100.00% homology to 16SrRNA gene sequence of
reference strains. This study demonstrates the effectiveness of the selective isolation method
and highlights the potential benefits of LAB in developing a non-dairy yoghurt from coconut
milk. Further research is recommended to the use of these LAB isolates as starters for controlled
fermentation of coconut milk to develop various fermented foods from this process. Also, the
probiotic properties and functional characteristics of the isolated LAB species could be further
explored.