THE NECESSITY FOR MOLECULAR CLASSIFICATION OF BIOCONTROL AGENTS. Papiliotrema terrestris LS28 taxonomic sequences

Plant protection is steadily moving towards a reduced use of chemicals, through the increasing use of microbialbiocontrol agents to mitigate the negative impacts of crop production, and nowadays several microorganisms areactive ingredients of the so-called biofungicides. Some of these commercial products are based on yeasts that areeffective antagonists of different fungal plant pathogens both in the field and during storage. Molecular techniquesapplied in microbial taxonomy are leading to deep revisions of the classification of many microbial groups that hadpreviously been classified on the basis of phenotypic traits. Taxonomic re-classification also includes differentbiocontrol yeasts for which it is desirable to have a clear taxonomic identification, also to rule out a too closephylogenetic proximity to species that are pathogenic to humans and animals. In the last decade, the number ofstudies reporting effective biocontrol activity of basidiomycetous yeasts has significantly increased. Recent taxonomicrevision of the basidiomycete genus Cryptococcus showed that many isolates of C. laurentii were renamed asPapiliotrema laurentii. This revision also affects Cryptococcus spp. that include strains displaying biocontrol activity, asin the case of strain LS28, originally classified as C. laurentii. In this study, we performed comparisons of ITS, D1D2,TEF1 and RPB1 nucleotide sequences of LS28 with those of the type strains of taxonomically related species andfound that the BCA LS28 belongs to the species Papiliotrema terrestris rather than to P. laurentii. We encourage othergroups working on biocontrol to perform molecular characterization of their yeast(s) of interest to encourage furtherstudies on the species that have the highest potential for practical applications and facilitate possible commercialregistration