Composition and Diversity of Natural Bacterial Communities in Mabisi, a Traditionally Fermented Milk

Many traditionally fermented milk products such as mabisi involve spontaneousfermentation, which can result in bacterial community composition variation due toselection pressure. The aim of this study was to determine the composition of bacterialcommunities in the different types of mabisi produced across Zambia and identify thefactors that influence their composition. Samples of mabisi were collected across thecountry, and analyzed for pH and bacterial communities using 16S rRNA ampliconsequencing. We found that the bacterial community composition was dominated bymembers of two phyla, i.e., Firmicutes and Proteobacteria, from which the top 10most abundant genera were Lactococcus, Lactobacillus, Streptococcus, Enterobacter,Citrobacter, Klebsiella, Kluyvera, Buttiauxella, Aeromonas, and Acinetobacter. The mostdominant genus was Lactococcus, which was present in all types of mabisi producedfrom all regions. The mabisi products from traditional mabisi production regions (TMPRs)were dominated by lactic acid bacteria (LAB) whereas products from non-TMPRswere dominated by non-LAB species. Tonga mabisi, the most popular type of mabisiproduced in non-TMPRs, had the most complex and diverse bacterial communitycomposition compared to the other types, which included barotse, backslopping,creamy, and thick-tonga mabisi. Other factors that influenced bacterial communitycomposition were geographical location, fermentation duration and pH while the type offermentation container and producer did not. This study provides new insights that canbe applied in starter culture development as well as microbial functionality studies.