Microbial Ecology of Bodre and Shamita Fermentation
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Date
1997-06
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Addis Ababa University
Abstract
'Borde' and 'Shamita' are two of the traditional Ethiopian fermented beverages commonly consumed
in the southern part of the country. They are thick in consistency, consumed while actively
fermenting and have served as meal replacement. The ingredients for 'borde' and 'shamita'
preparation are usually maize (or wheat) and barely, respectively.
The dominant organisms isolated during 'borde' fermentation belonged to the genus Bacillus,
Micrococcus, Lactobacillus, Streptococcus, Staphylo~occus, Saccharmoyces, Rhodotomla and
members of Enterobacteriaceae. With drop in pH of 'borde' from 5.2 to 3.6, the count of some of
these dominant organisms increased markedly while few were inhibited. Likewise, 'shamita'
fermentation was dominated by bacteria of the genus Bacillus, both homo- and hetrofermentative
Lactobacillus, Staphylococcus, }yficrococcus, members of Enterobacteriaceae and yeasts of the
genus Saccharomyces. As the pH dropped from 5.82 to 3.98, increase in counts of certain groups and
decrease in other groups was noted. Members of Enterobacteriaceae were inhibited earlier during
fermentation of both beverages.
The ingredients and equipment used for fermentation contributed to the microbial flora. The major
groups of organisms isolated from equipment (earthen jar) were Micrococcus, Saccharomyces,
RilOdotorula and members of Enterobacteriaceae with counts as high as 10' in most groups. Bacillus
and bacterial spores dominated spices
and heat treated cereal ingredients with spore counts in the range of 2xIO'-9.9xIO' and 2x102-
2.5xIO', respectively. Barley malt contributed almost all of the dominant microbial isolates including
Bacillus, Staphylococcus, Micrococcus, heterofermentative Lactobacillus, Streptococcus, bacterial
spores, Saccharomyces and RllOdotorula.
Nutritionally, the concentration of reducing sugars decreased with time in both beverages; the
availability of soluble protein appeared to increase initially with gradual decrease in the later s'tages
during 'shamita' fermentation (37.2 to 30.6 mg/ml). The difference were not considerable in 'borde'.
The percent ash content appeared higher in 'shamita' than 'borde' with moderate lipolytic activities in
both beverages.
Locally collected 'shamita' samples were found to have microbial similarity to the laboratory brewed
products with slightly higher microbial count in the collected samples.
The low cost of both beverages, the role they playas meal replacement and their popularity among
most economically deprived people make these beverages good candidates for production on a largescale.
But identification of microorganisms responsible for their fermentation and assessment of the
production procedures are among the preliminary steps that need investigation.
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Biology