Little information exists on yeasts involved in camel milk fermentation in the remote arid and semi-arid regions despite spontaneous nature of the fermentations. Yeast species present throughout the distribution process of raw and naturally fermented camel milk (suusac) were therefore studied. Identification was done using API 20C AUX, Restriction Fragment Length Polymorphism (RFLP) of intergenic spacers ITS1 and ITS2 using restriction endonucleases HhaI, HinfI and HaeIII and RAPD with (GTG)5, (GAC)5, (GACA)4 microsatellite primers and an M13 core sequence. DNA sequence analysis of either ITS1 or ITS2 or the 26S rRNA gene was performed. API enabled the identification of 80 (47%) yeasts isolates and resulted in either incorrect identification or inability to identify the others. RFLP, RAPD and sequence analysis enabled complete identification to species and some differentiation at strain level with RAPD allowing more discrimination within species. There were 21 yeast species belonging to the genera Rhodotorula, Cryptococcus, Candida, Saccharomyces, Trichosporon, Geotrichum and Issatchenkia. The most frequently isolated yeasts were Saccharomyces cerevisiae (19%), Candida inconspicua (12%), Trichosporon mucoides (11%), Candida famata (11%), Rhodotorula mucilaginosa (8%), Candida lusitaniae (6%), Cryptococcus laurentii (5%), Cryptococcus albidus (5%), Candida guilliermondii (5%) and Trichosporon cutaneum (5%). Lowest log cfu mL-1 for the identified yeasts were 2.4 for C. tropicalis and highest were 7.6 (range; 2.4-8.5) for C. famata and 8.0 (range; 2.6-8.5) for C. guilliermondii. A combination of phenotypic and molecular methods for proper yeast identification is recommended. Due to the high diversity and numbers of yeasts, their role in the fermented camel milk should be studied to enable exploitation of useful yeasts and prevention of contamination by detrimental yeasts.
P.M.K. Njage, S. Dolci, C. Jans, J. Wangoh, C. Lacroix and L. Meile, 2011. Characterization of Yeasts Associated with Camel Milk using Phenotypic and Molecular Identification Techniques. Research Journal of Microbiology, 6: 678-692.