Identification of yeasts associated with the fermented fish, adjuevan, of Ivory Coast by using the molecular technique of PCR-denaturing gradient gel electrophoresis (DGGE)
Diversity of yeasts was investigated by using a molecular technique employing variable regions of 26S rDNA profiles generated by PCR-denaturing gradient gel electrophoresis (DGGE) in the salted and fermented traditional fish named "adjuevan". This fermented fish was produced in Ivory Coast at ambient temperature (28 to 30°C) following two traditional fermentation methods. Fermentation according to Method 1 was made in jars covered with plastics and stones for 5 days then dried for three days on racks or nets. For Method 2, fermentation and fish drying took place on racks or nets simultaneously for at least 10 days. PCR-DGGE and DNA sequencing was used to compare yeasts from both methods of production, and they were identified as Kluyveromyces marxianus, Hansenula anomala, Saccharomyces cerevisiae, Candida tropicalis, Candida zeylanoides, Pichia fermentans, Debaromyces hansenii, Hanseniaspora osmophilic, and Rhodotorula glutinis which had not been previously described in fermented fish. Yeast diversity was higher for Method 1, while the predominance strains of Debaromyces sp. and Candida sp. with Kluyveromyces sp. were higher for Method 2. This study showed the presence of yeast species and their participation in the fermentation of adjuevan. D. Hansenii and K. marxianus could be used as starter cultures for the standardisation of the fermented fish, adjuevan.