European Journal of Biological Research, vol.11, no.4, pp.480-492, 2021 (Peer-Reviewed Journal)
Since yeasts can survive under variable environmental conditions using different food sources
they have a wide distribution in nature. Fruits are suitable living spaces for yeasts and other microorganisms
due to their high and different sugar contents. Strawberry fruit as well as other fruits are very sensitive to
pathogenic fungi. Due to their residues on fruits, limitations on the use of fungicides have led to increased use
of microorganisms with antagonistic effects as biological control agents. The biological agents to be used are
selected mainly from the microorganisms found in the natural microbiota of the fruit. Therefore, in this study
yeast biota on strawberry fruit collected from fungicide treated (Klorzon and Topas) and organic fields was
determined using molecular identification methods. In addition, extracellular enzyme profiles of the identified
yeast species were determined by the APIZYM-based system. There was no difference in the diversity of
yeast species on strawberries collected from fungicide treated and organic fields, but the yeast density on
organic strawberries was greater than fungicide treated fruits. The identified yeast species on fruits were
determined as Metschnikowia pulcherrima (61.7%), Hanseniaspora uvarum (34.0%) and Wickerhamomyces
pijperi (4.3%). W. pijperi yeast species was reported on strawberry fruit in our study first time. It was
determined that H. uvarum and W. pijperi yeast species showed no α-glucosidase enzyme activity. All yeast
strains showed industrially important β-glucosidase enzyme activity.