American Journal of Food Science and Health
Articles Information
American Journal of Food Science and Health, Vol.3, No.4, Aug. 2017, Pub. Date: Aug. 1, 2017
Screening of Thermotolerant Yeasts in the Sudan
Pages: 75-82 Views: 117 Downloads: 77
Authors
[01] Iman Mohammed Ali, Food Science and Rural Development Department, Faculty of Agriculture, Omdurman Islamic University, Omdurman, Sudan.
[02] Sara El Kheir Mustafa, Nutrition and Food Technology Department, Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan.
[03] Fatin Hassan Farahat, Food Science and Rural Development Department, Faculty of Agriculture, Omdurman Islamic University, Omdurman, Sudan.
[04] Abdel Mutalab Mohammed Khater, Food Science and Rural Development Department, Faculty of Agriculture, Omdurman Islamic University, Omdurman, Sudan.
Abstract
A total of Seventy four (74) thermotolerant yeast strains were isolated from 67 food samples taken from different areas in the Sudan. Among the collected yeasts 47 isolates were regarded as thermophilic, 5 isolates regards as extremely thermopilic because they grow at 20°C and 49°C. The yeasts described as extremely thermophilic were identified to the genus and species level according to Lodder and Barnett. Three isolates were assigned to species Saccharomyces cereivisae and two isolates were assigned as Kluyveromyces ssp. The optimum growth temperature ranged between 30°C and 40°C. The extremely thermophilic yeast isolates were used in fermentation tests for the production of ethanol. The isolate identified as Kluyveromces sp gave final ethanol concentrations in the mash of 6% (w/v). This amount represented a yield of 83% of the theory. The other isolates gave ethanol concentrations of 3% to 2.5% (w/v) representing yields of only 50% of the theory. This indicates that these isolates area not suitable for ethanol production. Being thermotolerant they could be of interest for single cell protein production.
Keywords
Thermotoleant Yeast, Thermophilic Yeast, Saccharomyces cereivisae
References
[01] Agab, M. A. Studies of some Aspects of Heat Resistance in Yeast. Ph.D. Thesis, Tu, Belfast. (1883).
[02] Hamad, S. H. Screening of Yeasts Associated with Food from the Sudan and their Possible Application for Single Cell Protein and Ethanol Production. Ph.d. thesis, Ing. Berlin. (1986).
[03] Abdelgadir, M. and Mustafa, M. M. Yeasts Causing Spoilage in Carbonated Beverages in the Sudan, J. Food Sci. Technol. (1978);10: 55-61.
[04] Baerwald, G. and Hamad, S. H. The Presence of Yeasts in Sudanese Can Sugar Factories, Zuckerind. (1984);109: 1014-1017.
[05] Barnett, J. A.; Payne, R. A.; and Yarrow, D. Yeasts: Characteristics and Identification. (ed.) Cambridge.(1983).
[06] Lodder, J. The Yeasts: Taxonomic Study. 2nd (ed.) north Holland, Publ. comp. Amsterdam, London. (1970).
[07] Barnett, J. A.; Payne, R. A.; and Yarrow, D. Yeasts Characteristics and Identification, 2nd (ed.) Cambridge University. Press London, New York, Melbourne.(1990).
[08] Kiss, I. Testing Methods in Food Microbiology. Amsterdam, Oxford, New York and Tokyo. (1984).
[09] Van Der Walt, J. P. and Yarrow, D. Methods for Isolation, Maintenance, Classification and Identification of Yeat. In N. J. W. Kregere Van Rig, ed. The yeast a taxonomic study. Elsevier science publisher. B. V. Amsterdam. (1984): 45-103.
[10] Agab, M. A. Isolation of Yeast Strains Suitable for Ethanol and Microbial Protein Production from Sugar Cane Molasses, M. Sc. Thesis, University of Khartoum, Faculty of Agriculture, Sudan.(1978).
[11] Caputi, A. Jr. and Wright, D. Collaborative Study of the Determination of Ethanol in Wine by Chemical Oxidation. J. AOAC. (1969); 52 (1): 85-91.
[12] Arthur, H. and Watson, K. Thermal Adaptation in Yeasts. J. Bacteriol. (1976); 128: 56-68.
[13] Einsele, A. Biomass from Higher N-Alkanes, Ico. Cif. (1983): 19-43.
[14] Barnett, J. A.; Payne, R. A.; and Yarrow, D. Yeasts Characteristics and Identification, 2nd (ed.) Cambridge University. Press London, New York, Melbourne. (1990).
[15] Hacking, A. J.; Taylor, L. W. F.; and Hanas, C. M. Selection of Yeast able to Produce Ethanol from Glucose at 40°C. appl. Microbial. Biotechnol. (1984);19: 361-363.
[16] Ibrahim, H. H. A. Ethanol Production from Sugar Cane Molasses, M.Sc. thesis, University of Khartoum, Faculty of Agriculture, Sudan. (1993).
[17] Ali, I. A. M. Ehanol Production from Molasses by Yeast Fermentation. M.Sc. Thesis, University of Khartoum, Faculty of Agriculture. Sudan. (1987).
600 ATLANTIC AVE, BOSTON,
MA 02210, USA
+001-6179630233
AIS is an academia-oriented and non-commercial institute aiming at providing users with a way to quickly and easily get the academic and scientific information.
Copyright © 2014 - 2017 American Institute of Science except certain content provided by third parties.