Review: Diversity of Microorganisms in Global Fermented Foods and Beverages

Abstract

Culturalable and non-culturable microorganisms naturally ferment majority of global fermented foods and beverages. Traditional food fermentation represents an extremely valuable cultural heritage in most regions, and harbors a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are of interest to food microbiologists. The application of culture-independent technique has thrown new light on the diversity of a number of hitherto unknown and non-cultural microorganisms in naturally fermented foods. Functional bacterial groups (“phylotypes”) may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt has been made to review the microbiology of some fermented foods and alcoholic beverages of the world.

Microbial and Chemical Diversity of Traditional Non-Cereal Based Alcoholic Beverages of Sub-Saharan Africa

“…Recovery of microbes from substrates involves classical extensive sampling, incubation in media of choice depending on the purpose of the study, and then subsequent selection of colonies for further characterization. There are a number of reviews giving comprehensive details on how microbes involved in fermentation are isolated [11,[95][96][97]. Herein we outline some of the identification methods available and their advancements.…”

“…are among several species of non-conventional yeast strains isolated from fermented foods and alcoholic beverages elsewhere in the world [11]. A list of yeasts species responsible for fermentation of alcoholic beverages in the Sub-Saharan region is shown in Table 2.…”

“…Z. mobilis is a natural ethanologen which possess desirable characteristics such as high specific productivity, high alcohol tolerance, a broad pH range for production (pH 3.5 to 7.5) and it is generally regarded as safe (GRAS) [84]. The bacterium is mostly utilized for biofuel production [85] although it has also been isolated from some alcoholic beverages such as pulque [11,54] and palm wine [86] where it is responsible for the production of ethanol, CO 2 , acetaldehyde and H 2 S [87]. C. acetobutylicum ferments sugars into a mixture of organic solvents namely acetone, butanol, and ethanol [88,89] while K. pneumonia produces ethanol, lactate, and acetate [90].…”

“…The pitfall of culture-dependent methods however, it that they underestimate the species richness of non-culturable microorganisms that may play major roles in production of fermented beverages. Examples of culture-dependent identification methods include DNA extraction from cultured microbes and the use of species-specific PCR primers for species level identification [11].…”

“…The fermentative microbes and chemical profiles of the resulting alcoholic beverages are well known. These include; chikokivana, a spirit produced from a mixture of maize meal, and millet malt popular in Zimbabwe [9], togwa of Tanzania, produced from sorghum, maize, and millet [10,11], burukutu, and pito-both popular indigenous alcoholic beverages of Nigeria produced from sorghum The mass production of non-cereal-based alcoholic beverages of Sub-Saharan Africa relies on uncontrolled spontaneous fermentation and exploits inexpensive substrates that are available in the locality, viz. palm tree fruits (Arecaceae family) and exudates, sugarcane (Saccharum officinarum), banana pulp (Musa acuminata), watermelons (Citrullus lanatus), Hyphaene petersiana (mokolwane/moxao) ( Figure 1), marula fruit (Sclerocaryabirrea) (Figure 2), Grewia flava (mogwana) (Figure 3), Grewia occidentalis (moretlwa), Grewia flavascens (mokgomphatha), Popowiaobovata, Balanites aegyptiaca, Berchemia discolor, Ziziphus mauritiana (masau), Kedrostis hirtella (mogakangwaga), Khadia acutipetala, cassava (Manihot esculenta), and honey [5,9,29,30].…”