Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species.

Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR) for detection of khs (kievitone hydratase) and pelA (pectate degrading enzyme) genes.

Results: The recovery rate of yeasts from sausage was 20% (2/10) followed by kareish cheese, processed cheese, and butter 10% (1/10) each as well as raw milk 9% (9/100), and fruit yoghurt 30% (6/20). Different yeast species were recovered, namely, Candida kefyr (5 isolates), Saccharomyces cerevisiae (4 isolates), Candida intermedia (3 isolates), Candida tropicalis (2 isolates), Candida lusitaniae (2 isolates), and Candida krusei (1 isolate). khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa.

Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food.

Keywords: antimicrobial, meat products, milk, pathogenic bacteria, yeasts.

1. Li, Q., Huang, J., Guo, H., Guo, X., Zhu, Y. and Dong, K. (2012) Bactericidal activity against meticillin-resistant Staphylococcus aureus of a novel eukaryotic therapeutic recombinant antimicrobial peptide. Int. J. Antimicrob. Agents, 39: 496-499. [Crossref] [PubMed]

2. Liu, J., Sui, Y., Wisniewski, M., Droby, S. and Liu, Y. (2013) Review: Utilization of antagonistic yeasts to manage postharvest fungal diseases of fruit. Int. J. Food Microbiol., 167: 153-160. [Crossref] [PubMed]

3. Carocho, M., Morales, P. and Ferreira, I.C.F. (2015) Natural food additives: Quo vadis? Trends Food Sci. Technol., 45: 284-295. [Crossref]

4. Sui, Y., Wisniewski, M., Droby, S. and Liu, J. (2015) Responses of yeast biocontrol agents to environmental stress. Appl. Environ. Microbiol., 81: 2968-2975. [Crossref] [PubMed] [PMC]

5. Lim, S.L. and Tay, S.T. (2011) Diversity and killer activity of yeasts in Malaysian fermented food samples. Trop. Biomed., 28(2): 438-443. [PubMed]

6. Fakruddin, M.D., Hossain, M.D.N. and Ahmed, M.M. (2017) Antimicrobial and antioxidant activities of Saccharomyces cerevisae LFSTO62013, a potential probiotic. BMC Complement. Altern. Med., 17: 64. [Crossref] [PubMed] [PMC]

7. Fijan, S. (2014) Microorganisms with claimed probiotic properties: An overview of recent literature. Int. J. Environ. Res. Public Health, 11: 4745-4767. [Crossref] [PubMed] [PMC]

8. Breinig, F., Sendzik, T., Eisfeld, K. and Schmitt, M.J. (2006) Dissecting toxin immunity in virus-infected killer yeast uncovers an intrinsic strategy of self-protection. Proc. Natl. Acad. Sci. USA, 103(10): 3810-3815. [Crossref] [PubMed] [PMC]

9. Young, T.W. (2012) Killer yeasts. In: Rose, A.H., Harrison, J.S., editors. The Yeasts. 2nd ed. Academic Press, London, UK. p131-164.

10. Muccilli, S., Wemhoff, S., Restuccia, C. and Meinhardt, F. (2013) Exoglucanase-encoding genes from three Wickerhamomyces anomalus killer strains isolated from olive brine. Yeast, 30: 33-43. [Crossref] [PubMed]

11. Roostita, R. (1993) Occurrence, Growth and Biochemical Properties of Yeasts in Cheeses and Milk. A Thesis, the University of New South Wales, Australia.

12. Wickerham, L.J. and Burton, K.A. (1948) Carbon assimilation test for the classification of yeasts. J. Bacteriol., 56: 363-371. [PubMed] [PMC]

13. Lodder, J. and Kreger-van Rij, N.J.W. (1970) The Yeasts, a Taxonomic Study. North Holland Publ. Co., Amsterdam.

14. Roostita, L.B., Fleet, G.H., Wendry, S.P., Apon, Z.M. and Gemilang, L.U. (2011) Determination of yeasts antimicrobial activity in milk and meat products. Adv. J. Food Sci. Technol., 3(6): 442-445.

15. Suga, H., Ikeda, S., Taga, M., Kageyama, K. and Hyakumachi, M. (2002) Electrophoretic karyotyping and gene mapping of seven Formae speciales in Fusarium solani. Curr. Genet., 41(4): 254-260. [Crossref] [PubMed]

16. Sambrook, J., Fritscgh, E.F. and Mentiates, T. (1989) Molecular Coloning: A Laboratory Manual. 2nd ed. Cold Spring Harbor Laboratory, New York.

17. Fleet, G.H. (1992) Food spoilage yeasts. In: Spencer, J.F.T. and Spencer, D.M., editors. Yeast Technology. Springer-Verlag, Berlin.

18. Ahmed, A.M. and Ismail, T.H. (2010) Improvement of the quality and shelf-life of minced-beef mixed with soyprotein by Sage (Salvia officinalis). Afr. J. Food Sci., 4(6): 330-334.

19. Ibrahim, J.I., Salama, E., Saad, A. and Helmy, A.A. (2015) Microbial quality of some dairy products in Ismailia city. In: 2nd Conference of Food Safety, Suez Canal University, Faculty of Veterinary Medicine. Vol. 1. p14-21.

20. Viljoen, B.C., Knox, A.M., Jager, P.H. and Lourens-Hattingh, A. (2003) Development of yeast populations during processing and ripening of blue veined cheese. Food Technol. Biotechnol., 41: 291-297.

21. Salomskiene, J. and Macioniene, I. (2009) The influence of contamination yoghurt, quark and semi-hard cheese by yeasts on their sensory properties. Vet. Med. Zootec., 48(70): 72-76.

22. El-Sharoud, W.M., Belloch, C., Peris, D. and Querol, A. (2009) Molecular identification of yeasts associated with traditional Egyptian dairy products. J. Food Sci., 74: 341-346. [Crossref] [PubMed]

23. Seker, E. (2010) Identification of Candida species isolated from bovine mastitic milk and their in vitro haemolytic activity in western turkey. Mycopathologia, 169: 303-308. [Crossref] [PubMed]

24. Wanderley, L., Bianchin, A., Arruda Teo, C.R.P. and Meneghello, F.A. (2013) Occurrence and pathogenicity of Candida spp. in unpasteurized cheese. Braz. J. Biosci., 11: 145-148.

25. Abdelatif, S.S., Elsayed, S.M., Bahout, A.A. and Bayoumi, A.M. (2016) Studies on beneficial yeasts isolated from some Egyptian dairy products. Zagazig Vet. J., 44(1): 75-84.

26. Rajkowska, K., Bska, A.K. and Rygal'a, A. (2012) Probiotic activity of Saccharomyces cerevisiae var. Boulardii against human pathogens. Food Technol. Biotechnol., 50(2): 230-236.

27. Viljoen, B. (2006) Yeast ecological interactions. Yeast-yeast, yeast-bacteria, yeast-fungi interactions and yeasts as biocontrol agents. In: Querol, A. and Fleet, G., editors. The Yeasts Handbook: Yeasts in Food and Beverages. Springer-Verlag, Berlin, Germany. p83-110. [Crossref]

28. Hatoum, R., Labrie, S. and Fliss, I. (2013) Identification and partial characterization of anti listerial compounds produced by dairy yeasts. Probiotics Antimicrob. Proteins, 5: 8-17. [Crossref] [PubMed]

29. Chen, Y., Aorigele, C., Wang, C., Simujide, H. and Yang, S. (2015) Screening and extracting mycocin secreted by yeast isolated from koumiss and their antibacterial effect. J. Food Nutr. Res., 3:52-56. [Crossref]

30. Franca, R.C., Conceicao, F.R., Mendonca, M., Haubert, L., Sabadin, G., de Oliveira, P.D., Amaral, M.G., Silva, W.P. and Moreira, A.N. (2015) Pichia pastoris X-33 has probiotic properties with remarkable antibacterial activity against Salmonella Typhimurium. Appl. Microbiol. Biotechnol., 99: 7953-7961. [Crossref] [PubMed]

31. Fukuda, K., Kichise, H., Kitano, K. and Hara, S. (1991) Cloning and nucleotide sequence of the KHS killer gene of Saccharomyces cerevisiae. Agric. Biol. Chem., 55(8): 1953-1958. [PubMed]

32. Li, D., Chung, K.R., Smith, D.A. and Schardl, C.L. (1995) The Fusarium solani gene encoding kievitone hydratase, a secreted enzyme that catalyzes detoxification of a bean phytoalexin. Mol. Plant Microbe Interact, 8: 388-397. [Crossref]

33. Suga, H., Hasegawa, T., Mitsui, H., Kageyama, K. and Hyakumachi, M. (2000) Phylogenetic analysis of the phytopathogenic fungus Fusarium solani based on the rDNA-ITS region. Mycol. Res., 104: 1175-1183. [Crossref]

34. O'Donnell, K. (2000) Molecular phylogeny of the Nectria haematococca-Fusarium solani species complex. Mycologia, 92: 919-938. [Crossref]