Occurrence and Importance of Yeasts in Indigenous Fermented Food and Beverages Produced in Sub-Saharan Africa

Abstract

Indigenous fermented food and beverages represent a valuable cultural heritage in sub-Saharan Africa, having one of the richest selections of fermented food products in the world. In many of these indigenous spontaneously fermented food and beverages, yeasts are of significant importance. Several factors including raw materials, processing methods, hygienic conditions as well as the interactions between yeasts and other commensal microorganisms have been shown to influence yeast species diversity and successions. Both at species and strain levels, successions take place due to the continuous change in intrinsic and extrinsic growth factors. The selection pressure from the microbial stress factors leads to niche adaptation and both yeast species and strains with traits deviating from those generally acknowledged in current taxonomic keys, have been isolated from indigenous sub-Saharan African fermented food products. Yeasts are important for flavor development, impact shelf life, and nutritional value and do, in some cases, even provide host-beneficial effects. In order to sustain and upgrade these traditional fermented products, it is quite important to obtain detailed knowledge on the microorganisms involved in the fermentations, their growth requirements and interactions. While other publications have reported on the occurrence of prokaryotes in spontaneously fermented sub-Saharan food and beverages, the present review focuses on yeasts considering their current taxonomic position, relative occurrence and successions, interactions with other commensal microorganisms as well as beneficial effects and importance in human diet. Additionally, the risk of opportunistic yeasts is discussed.

Fungi and Aflatoxin Levels in Traditionally Processed Cassava (Manihot esculenta Crantz) Products in Homa Bay County, Kenya

“…The occurrence of diverse groups of yeasts in the products could, therefore, be associated with the breaking down of starch to increase the nutritional value of fermented and nonfermented cassava. The high prevalence of Candida and Saccharomyces in the products is consistent with studies elsewhere that reported them as the most dominant yeasts in many foods in sub-Saharan Africa [ 25 , 26 ]. Reports have shown that S. cerevisiae is the dominant yeast in the fermentation of most indigenous food products in sub-Saharan Africa [ 27 , 28 ].…”

“…e high prevalence of Candida and Saccharomyces in the products is consistent with studies elsewhere that reported them as the most dominant yeasts in many foods in sub-Saharan Africa [25,26]. Reports have shown that S. cerevisiae is the dominant yeast in the fermentation of most indigenous food products in sub-Saharan Africa [27,28].…”

Biochemical and molecular characterization of yeasts isolated from Nigerian traditional fermented food products

“…Galactomyces geotrichum was also isolated from the fermented food products. Galactomyces geotrichum has been listed as among the yeasts that occur in African fermented food products in a review by Johansen et al (2019). Therefore, this present work has confirmed the biodiversity of yeasts that are associated with Nigerian traditional fermented food products.…”

Probiotic potential of Saccharomyces cerevisiae and Kluyveromyces marxianus isolated from West African spontaneously fermented cereal and milk products

“…predominant microbial communities of African spontaneously fermented foods from cereals and milk (Akabanda et al, 2013;Hayford, Petersen, Vogensen, & Jakobsen, 1999;Jespersen, 2003;Johansen et al, 2019;Owusu-Kwarteng et al, 2012). Yeast species such as Kluyveromyces marxianus and Saccharomyces cerevisiae have been recently identified in sorghum-and maize-based mawè, a fermented food in Benin (Houngbédji et al, 2018).…”