Essential oils (EO) from aromatic and medicinal plants generally perform a diverse range of biological activities because they have several active constituents that work in different mechanisms of action. EO from Citrus peel have an impressive range of food and medicinal uses, besides other applications. EO from Citrus reticulata, C. sinensis and C. deliciosa were extracted from fruit peel and analyzed by GC-MS. The major constituent of EO under evaluation was limonene, whose concentrations were 98.54%, 91.65% and 91.27% for C. sinensis, C. reticulata and C. deliciosa, respectively. The highest potential of inhibition of mycelial growth was observed when the oil dose was 300 μL. Citrus oils inhibited fungus growth in 82.91% (C. deliciosa), 65.82% (C. sinensis) and 63.46% (C. reticulata). Anti-Sclerotinia sclerotiorum activity of 90% pure limonene and at different doses (20, 50, 100, 200 and 300 μL) was also investigated. This monoterpene showed to be highly active by inhibiting 100% fungus growth even at 200 and 300 μL doses. This is the first report of the in vitro inhibitory effect of natural products from these three Citrus species and its results show that there is good prospect of using them experimentally to control S. sclerotiorum, in both greenhouse and field conditions.

Six yeast strains representing two novel Wickerhamiella species were isolated from plants and insects collected in Costa Rica, Brazil, and French Guiana. They belong to a subclade containing Wickerhamiella domercqiae and Wickerhamiella bombiphila, and differ by approximately 12 % in the D1/D2 sequences of the large subunit rRNA gene from these species. The intergenic spacer (ITS) regions of the two novel species differ by around 19 and 27 %, respectively, from those of W. domercqiae. The novel species exhibit 5 % divergence in the D1/D2 sequences among them (around 4 % in the ITS). The names Wickerhamiella dianesei f.a., sp. nov. and Wickerhamiella kurtzmanii f.a., sp. nov. are proposed to accommodate these species, for which a sexual cycle has not been observed. Wickerhamiella dianesei was isolated from the stingless bee, Trigona fulviventris, collected in an Asteraceae flower in Costa Rica, and from leaves of Sabicea brasiliensis (Rubiaceae) and a flower of Byrsonima crassifolia (Malpighiaceae) in Brazil. Wickerhamiellsa kurtzmanii was isolated from a flower of Ipomoea batatoides (Convolvulaceae) in Costa Rica, the surface of a fruit of B. crassifolia in Brazil, and flowers in French Guiana. The type strains are Wickerhamiella dianesei UWOPS 00-107.1T (=CBS 14185=NRRL Y-63789; Mycobank number MB 827008) and Wickerhamiella kurtzmanii UWOPS 00-192.1T (=CBS 15383=NRRL Y-63979; MB 827011).

Background: This work studied the occurrence, density, and diversity of yeast species associated with the leaves and fruits of Sabicea brasiliensis and Anacardium humile. Methods: Fragments of leaves and fruits were subjected to maceration and placed under agitation in peptone water. One hundred µL aliquots of each of the decimal dilutions were plated on YM chloramphenicol agar medium. The different morphotypes were identified through sequence analysis of the 26S rDNA. Results: A total of 83 yeast isolates were recovered from the organs sampled, 40 from fruits and 19 from the leaves of S. brasiliensis, while 14 were recovered from fruits and 10 from the leaves of A. humile. The isolates were identified as belonging to two phyla, six classes, eight orders, and eight families. Most isolates, at 71 (84.3%), belong to Ascomycota, with Saccharomycetes dominant in fruits and Dothideomycetes in leaves. The remaining 12 (15.7%) isolates belong to the phylum Basidiomycota. The most frequent genera were Aureobasidium, Candida, Rhodotorula, and Wickerhamiella. The Wickerhamiella isolates made possible the subsequent description of a new species within this genus. Conclusions: Our data reveal the yeast species that inhabit different Cerrado plant organs and indicate that these hosts can be considered an important habitat for yeast diversity, including new and/or previously unreported species in this biome.