The necessity for molecular classification of basidiomycetous biocontrol yeasts

The field of plant protection is steadily reducing the use of chemicals by increasing the use of microbial biocontrol agents. At present, several microorganisms are active ingredients of the so-called biofungicides and some of these are based on yeasts. Molecular techniques applied in microbial taxonomy are leading to extensive revisions of the classification of many microbial groups, including various yeasts used for biocontrol. Recent taxonomic revision of the basidiomycete genus Cryptococcus resulted in C. laurentii (Kufferath) Skinner (Tremellales) being renamed as Papiliotrema laurentii, including strains displaying biocontrol activity, such as strain LS28. In this study, we performed comparisons of ITS, D1D2, TEF1, and RPB1 nucleotide sequences of LS28 with the corresponding genes of the type strains of taxonomically related species. We found that the yeast strain LS28 belongs to the species P. terrestris (Tremellales) (Crestani et al. Int J Syst Evol Microbiol 59:631–636, 2009) rather than P. laurentii. We encourage other groups working on biocontrol to perform molecular characterization of their yeast(s) of interest to identify the species that have the highest potential for practical applications and facilitate possible commercial registration.