Production of volatile organic compounds (VOCs) by yeasts isolated from the ascocarps of black (Tuber melanosporum Vitt.) and white (Tuber magnatum Pico) truffles.
Twenty-nine yeast strains were isolated from the ascocarps of black and white truffles (Tuber melanosporum Vitt. and Tuber magnatum Pico, respectively), and identified using a polyphasic approach. According to the conventional taxonomic methods, MSP-PCR fingerprinting and sequencing of the D1/D2 domain of 26S rDNA, the strains were identified as Candida saitoana, Debaryomyces hansenii, Cryptococcus sp., Rhodotorula mucilaginosa, and Trichosporon moniliiforme. All isolates assimilated L: -methionine as a sole nitrogen source and produced the volatile organic compounds (VOCs), 2-methyl butanol, 3-methyl butanol, methanethiol, S-methyl thioacetate, dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, dihydro-2-methyl-3(2H)-thiophenone and 3-(methylthio)-1-propanol (MTP). ANOVA analysis of data showed significant (P<0.01) differences in VOCs produced by different yeasts, with MTP as the major component (produced at concentrations ranging from 19.8 to 225.6 mg/l). In addition, since some molecules produced by the isolates of this study are also characteristic of truffle complex aroma, it is possible to hypothesize a complementary role of yeasts associated with this ecosystem in contributing to final Tuber spp. aroma through the independent synthesis of yeast-specific volatile constituents.
Buzzini
Pietro
P
Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali, Sezione di Microbiologia Applicata, Università di Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy. pbuzzini@unipg.it
Gasparetti
Chiara
C
Turchetti
Benedetta
B
Cramarossa
Maria Rita
MR
Vaughan-Martini
Ann
A
Martini
Alessandro
A
Pagnoni
Ugo Maria
UM
Forti
Luca
L
D001203:Ascomycota; D004247:DNA / Q000737:chemistry / Q000235:genetics; D016172:DNA Fingerprinting; D004271:DNA, Fungal / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D008715:Methionine / Q000378:metabolism; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000737:chemistry / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D015003:Yeasts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
D004271:DNA, Fungal; D009930:Organic Chemicals; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D004247:DNA; D008715:Methionine