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Characterization of dominant microbiota of a Ghanaian fermented milk product, nyarmie , by culture‐ and nonculture‐based methods
Author(s) -
Obodai M.,
Dodd C.E.R.
Publication year - 2006
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2006.02895.x
Subject(s) - biology , streptococcus thermophilus , lactobacillus helveticus , lactobacillus , food science , fermentation starter , lactobacillus delbrueckii subsp. bulgaricus , fermentation , microbiology and biotechnology , temperature gradient gel electrophoresis , lactococcus , bacteria , lactococcus lactis , 16s ribosomal rna , lactic acid , genetics
Aims: To characterize the predominant micro‐organisms in a Ghanaian traditional fermented dairy product, nyarmie , made from cows’ milk, using both culture‐ and nonculture‐based methods. Methods and Results: Samples of nyarmie were analysed from three production sites in Accra, by determining the counts on selective culture media. The microbial diversity occurring in nyarmie was also evaluated by 16S/18S ribosomal DNA PCR amplification and denaturing gradient gel electrophoresis. Results showed that nyarmie contained lactococci and lactobacilli in the range of 10 8 and 10 10 CFU ml −1 , respectively, and yeasts at around 10 7 CFU ml −1 . The pH ranged between 3·49 and 4·25. The predominant lactic acid bacteria (LAB) in nyarmie were Leuconostoc mesenteroides ssp. mesenteroides , Streptococcus thermophilus , Lactobacillus delbrueckii ssp. bulgaricus , Lact. helveticus , Lact. delbrueckii ssp. lactis and Lactococcus lactis , while Saccharomyces cerevisiae was the predominant yeast species. Lactobacillus delbrueckii ssp. delbrueckii was not detected by cultivation but its predominance was revealed by PCR‐DGGE analysis. Conclusions: The flora in products from different producers varied in the LAB composition present and may result in variations in product quality. Significance and Impact of the Study: Development and use of starter cultures for nyarmie may be beneficial in improving the consistency of product quality.