An Investigation of the Yeast Flora of Marine Fish from Scottish Coastal Waters and a Fishing Ground off Iceland

Abstract

A total of 189 yeast isolates was obtained from samples taken from the gills, faeces, skin and mouths of fish caught in the Clyde Estuary, North Sea and Gletty Bank off the east coast of Iceland. The isolates comprised 6 genera, Debaryomyces, Torulopsis, Candida, Rhodotorula, Pichia and Cryptococcus, and 17 species. Debaryomyces kloeckeri comprised almost half the isolates (47·7%), followed by Torulopsis inconspicua (12·8%) and Candida parapsilosis (10·1%). Most of the isolates agreed closely with the description of a type species but some differences were noted.The incidence of yeast occurrence was highest on the fish skin, followed by those from the gills and mouth, and then, in considerably lower proportions, from the faeces. No notable differences were observed in the species isolated from these locations.Without exception D. kloeckeri was the predominant species in every geographical location of sampling, whereas both the occurrence and the proportion of isolates of other species varied in each area. All 16 types of fish sampled yielded yeasts and there were no indications that a characteristic yeast flora exists for each type of fish.