Dominant Lactic Acid Bacteria and Their Antimicrobial Profile from Three Fermented Milk Products from Northern Namibia

L. N. Heita^*, A. Cheikhyoussef^*

Science, Technology and Innovation Division, Multidisciplinary Research Centre, University of Namibia, Private Bag 13301, 340 Mandume Ndemufayo Avenue, Pionierspark, Windhoek, Namibia.

DOI: 10.4236/jbm.2014.29002                

Abstract

The present study focused on the isolation, identification and antimicrobial profile of the dominant lactic acid bacteria from three traditional fermented milk products namely: Omashikwa, Mabisi and Mashini Ghamushikwa from the north-central and north-eastern parts of Namibia. The microbiological and antimicrobial activities of these products fluctuate from one region to another depending on the local indigenous microflora. Omashikwa and Mashini Ghamushikwa fermentation processes involves the addition of Boscia albitrunca root (Omunkuzi) and butter churning. The root contributes to the flavor of the product, increasing the milk fermentation rate and churning. Mabisi is produced by letting the milk to ferment naturally until the water is separated from the whey. The water is then decanted, and the whey is shaken until it is smooth without removal of fat. A total of 180 isolates of Lactic acid bacteria (LAB) were obtained and identified based on their phenotypical characterization. Cell free supernatants (CFS) of the 180 LAB isolates were evaluated for antimicrobial activities against selected food borne pathogens; Escherichia coli ATCC 25,922, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATTC 10,876, Candida famata and Geotrichum klebahnii using the well diffusion assay. Twenty LAB isolates having the highest inhibitory effects were selected for biochemical identification using API 50 kit and these were identified as being; Lactobacillus plantarum (53%), Lactobacillus rhamnosus (29%), Pediococcus pentosaceus (6%), Lactobacillus paracasei ssp. paracasei (6%) and Lactococcus lactic ssp. lactis (6%). Pediococcus pentosaceus showed the highest inhibitory effect on all the indicator strains. This study provides an insight into LAB diversity of unstudied Namibian fermented milk products and reports a potential production of antimicrobial compounds which is significant in the standardization of protective starter cultures which can be used to control fermentation process and shelf life extension of dairy products in Namibia.

Keywords

Namibia, Traditional Fermented Milk, Lactic Acid Bacteria, Omashikwa, Mabisi, Mashini ghamushikwa

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Steinkraus, K.H. (2002) Fermentations in World Food Processing. Comprehensive Reviews in Food Science and Food Safety, 1, 23-32. http://dx.doi.org/10.1111/j.1541-4337.2002.tb00004.x
[2]	Chandan, R.C. and Shah, N.P. (2013) Functional Foods and Disease Prevention. In: Chandan, R.C. and Kilara, A., Eds., Manufacturing Yogurt and Fermented Milks, John Wiley & Sons, Oxford, 411-431. http://dx.doi.org/10.1002/9781118481301.ch20
[3]	Amenu, D. (2013) Antimicrobial Activity of Lactic Acid Bacteria Isolated from “Ergo”, Ethiopian Traditional Fermented Milk. Current Research in Microbiology and Biotechnology, 1, 278-284.
[4]	Khalid, K. (2011) An Overview of Lactic Acid Bacteria. International Journal of Biosciences, 1, 1-13.
[5]	Reis, J.A., Paula, A.T., Casarotti, S.N. and Penna, A.L.B. (2012) Lactic Acid Bacteria Antimicrobial Com-pounds: Cha- racteristics and Applications. Food Engineering Reviews, 4, 124-140. http://dx.doi.org/10.1007/s12393-012-9051-2
[6]	Robertson, A., Tirado, C., Lobstein, T., Jermini, M., Knai, C., Jensen, J.H., Ferro-Luzzi, A. and James, W.P.T. (2004) Food and Health in Europe: A New Basis for Action. European Series, WHO Regional Publications, Geneva.
[7]	Bille, P.G., Ozuuko, A.T.R. and Ngwira, T. (2002) Sensory Properties of Traditionally Fermented Buttermilk (Omashikwa) Processed in Namibia. Journal of Food Technology in Africa, 7, 52-54. http://dx.doi.org/10.4314/jfta.v7i2.19244
[8]	Bille, P.G., Buys, E. and Taylor, J.R.N. (2007) The Technology and Properties of Omashikwa, a Traditional Fermented Buttermilk Produced by Small-Holder Milk Producers in Namibia. International Journal of Food Science and Technology, 43, 620-624. http://dx.doi.org/10.1111/j.1365-2621.2006.01381.x
[9]	Bille, P.G. (2013) Effect of Boscia albitrunca (Omukunzi) Root on the Bacteriology and Viscosity of Omashikwa, Traditional Fermented Buttermilk from Namibia. African Journal of Food, Agriculture, Nutrition and Development, 13, 7927-7943.
[10]	Jans, C., Bugnard, J., Njage, P.M.K., Lacroix, C. and Meile, L. (2012) Lactic Acid Bacteria Diversity of African Raw and Fermented Camel Milk Products Reveals a Highly Competitive, Potentially Health-Threatening Predominant Microflora. LWT-Food Science and Technology, 47, 371-379. http://dx.doi.org/10.1016/j.lwt.2012.01.034
[11]	Li, W., Mutuvulla, M., Chen, X.H., Jiang, M. and Dong, M. (2012) Isolation and Identification of High Viscosity-Producing Lactic Acid Bacteria from a Traditional Fermented Milk in Xinjiang and Its Role in Fermentation Process. European Food Research and Technology, 235, 497-505. http://dx.doi.org/10.1007/s00217-012-1779-7
[12]	Cheikhyoussef, A. (2011) Pilot Study on the Indigenous Knowledge Systems on Foods and Beverages in Selected Areas in Karas Region, Namibia. University of Namibia, Windhoek.
[13]	Cheikhyoussef, A., Pogori, N., Chen, H.Q., Tian, F.W., Chen, W., Tang, J. and Zhang, H. (2009) An-timicrobial Activity and Partial Characterization of Bacteriocin-Like Inhibitory Substances (BLIS) Produced by Bifi-dobacterium infantis BCRC 14602. Food Control, 20, 553-559. http://dx.doi.org/10.1016/j.foodcont.2008.08.003
[14]	Harris, L.J., Daeschel, M.A., Stiles, M.E. and Klaenhammer, T.R. (1989) Antimicrobial Activity of Lactic Acid Bacteria against Listeria monocytogenes. Journal of Food Protection, 52, 384-387.
[15]	Lewus, C.B. and Montville, T.J. (1991) Detection of Bacteriocins Produced by Lactic Acid Bacteria. Journal of Microbiological Methods, 13, 145-150. http://dx.doi.org/10.1016/0167-7012(91)90014-H
[16]	da Silva Sabo, S., Vitolo, M., González, J.M.D. and de Souza Oliveira, R.P. (2014) Overview of Lactobacillus plantarum as a Promising Bacteriocin Producer among Lactic Acid Bacteria. Food Research International, 64, 527-536. http://dx.doi.org/10.1016/j.foodres.2014.07.041
[17]	Todorov, S.D., LeBlanc, J.G. and Franco, B.D.G.M. (2012) Evaluation of the Probiotic Potential and Effect of Encapsulation on Survival for Lactobacillus plantarum ST16Pa Iso-lated from Papaya. World Journal of Microbiology and Biotechnology, 28, 973-984. http://dx.doi.org/10.1007/s11274-011-0895-z
[18]	Moraes, P.M., Perin, L.M., Ortolani, M.B.T., Yamazi, A.K., Vi?osa, G.N. and Nero, L.A. (2010) Protocols for the Isolation and Detection of Lactic Acid Bacteria with Bacteriocinogenic Potential. LWT-Food Science and Technology, 43, 1320-1324. http://dx.doi.org/10.1016/j.lwt.2010.05.005
[19]	Rodriguez, E., Gonzalez, B., Gaya, P., Nunez, M. and Medina, M. (2000) Diversity of Bacteriocins Produced by Lactic Acid Bacteria Isolated from Raw Milk. International Dairy Journal, 10, 7-15. http://dx.doi.org/10.1016/S0958-6946(00)00017-0