Yeast diversity during tapping and fermentation of palm wine from Cameroon

• Published in: Food microbiology 2009-06, Vol.26 (4), p.415-420
• Main Authors: Stringini, Marzia, Comitini, Francesca, Taccari, Manuela, Ciani, Maurizio
• Format: Article
• Language: English
• Subjects: acetic acid bacteria; Biological and medical sciences; biotypes; Cameroon; Candida; Colony Count, Microbial - methods; DGGE; Elaeis guineensis; Electrophoresis, Agar Gel; Fermentation; Fermented food industries; food analysis; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; Hanseniaspora uvarum; lactic acid bacteria; Molecular typing; multiple strain starters; Mycological Typing Techniques; natural fermentation; Palm wine; Phylogeny; Pichia fermentans; Polymerase Chain Reaction; quantitative analysis; Saccharomyces cerevisiae; Saccharomyces cerevisiae - classification; Saccharomyces cerevisiae - isolation & purification; semi-continuous fermentation; species diversity; Species Specificity; tree tapping; Vitaceae; Wine - microbiology; wine yeasts; wines; Wines and vinegars; Yeast diversity; Yeasts - classification; Yeasts - isolation & purification; Zygosaccharomyces bailii
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2009.02.006

In the present study, we have investigated the occurrence of yeast flora during tapping and fermentation of palm wine from Cameroon. The yeast diversity was investigated using both traditional culture-dependent and culture-independent methods. Moreover, to characterize the isolates of the predominant yeast species ( Saccharomyces cerevisiae) at the strain level, primers specific for δ sequences and minisatellites of genes encoding the cell wall were used. The results confirm the broad quantitative presence of yeast, lactic acid bacteria and acetic acid bacteria during the palm wine tapping process, and highlight a reduced diversity of yeast species using both dependent and independent methods. Together with the predominant species S. cerevisiae, during the tapping of the palm wine the other species found were Saccharomycodes ludwigii and Zygosaccharomyces bailii. In addition, denaturing gradient gel electrophoresis (DGGE) analysis detected Hanseniaspora uvarum, Candida parapsilopsis, Candida fermentati and Pichia fermentans. In contrast to the progressive simplification of yeast diversity at the species level, the molecular characterization of the S. cerevisiae isolates at the strain level showed a wide intraspecies biodiversity during the different steps of the tapping process. Indeed, 15 different biotypes were detected using a combination of three primer pairs, which were well distributed in all of the samples collected during the tapping process, indicating that a multistarter fermentation takes place in this particular natural, semi-continuous fermentation process.