Global Research Journal of Education

Global Research Journal of Microbiology Vol.3(2) pp.13 –17 June 2013.

Available online http://www.globalresearchjournals.org/journal/grjm

Copyright ©2013 Global Research Journals

 

Full Length Research.

 

MICROBIAL DYNAMICS DURING CUCUMBER FERMENTATION

By 

JOSIAH A. LENNOX¹ AND PROFESSOR B.J.O. EFIUVWEVWERE² 

¹DEPARTMENT OF MICROBIOLOGY, FOOD AND INDUSTRIAL UNIT,

UNIVERSITY OF CALABAR,CALABAR, CROSS RIVER STATE

²DEPARTMENT OF MICROBIOLOGY, FOOD AND INDUSTRIAL UNIT,

 UNIVERSITY OF PORT HARCOURT, RIVERS STATE

Corresponding Author’s E-mail: lenasime@gmail.com 

 

Abstract

            Cucumber (cucumis sativus) is one of the primary  vegetables often fermented to obtain pickles. The cucumber pickle is an example of a product of a mixed microbial fermentation in which desirable and undesirable bacteria and fungi interact and compete during the initial stages of the fermentation. The harvested cucumbers were subjected to fermentation in 10%(w/v) NaCl solution. The changes in microflora of the fermenting  cucumber in brine solution were studied for 15 days. The results showed initial counts of 4.2 x 10⁶cfu/ml, 1.4 x 10³cfu/ml, 5.0 x 10⁶cfu/ml and 1.2 x 10³cfu/ml for lactic acid bacteria (LAB), fungi, indicator organisms and salmonella-shigella respectively in the fermenting brine solution. There was sharp increase in counts of LAB and indicator organisms in the brine on the 3^rd day and thereafter they started to decline but the indicators were finally inhibited by the 12^th day. The salmonella-shigella  showed very slight  increase on the 3^rd day but finally inhibited by the 12^th day. The fungi counts fluctuated and reached their peak on the 6^th day, but were finally inhibited also by the 15^th day. LAB persisted to the end of the fermentation with the total count of 2.1x10cfu/ml. The results of the cucumber fruit showed a different pattern. There were no growth of salmonella-shigella within the fruit for the period of fermentation. On the third day of fermentation only LAB and indicator organisms grew with counts of 5x10³cfu/g and 3x10³cfu/g respectively. The indicator organisms were inhibited within the cucumber by the 6^th day. The aerobic plate counts (APC) and lactic acid bacteria (LAB) maintained steady colony counts of 3.7 log₁₀ cfu/g to 4.3log₁₀cfu/g and 5.0 log₁₀cfu/g to 3.6log₁₀cfu/g respectively to the end of the fermentation period. The changes in the microbial flora in the brine and fruit could have been due to the competitive nature of the microorganisms in any environment. The fermentation process has proved to be effective in eliminating pathogenic organisms and other contaminants and also preserved the produce.

Keywords: Fermentation, pickles, microbial, enteropathogenic microflora.