Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov., isolated from flowers in French Guiana

Abstract

Analysis of yeasts isolated from various biotopes in French Guiana led to the identification of two strains isolated from flowers and designated CLIB 1634 and CLIB 1707. Comparison of the D1/D2 domain of the large subunit (LSU D1/D2) rRNA gene sequences of CLIB 1634 and CLIB 1707 to those in the GenBank database revealed that these strains belong to the Starmerella clade. Strain CLIB 1634 was shown to diverge from the closely related Starmerella apicola type strain CBS 2868 with a sequence divergence of 1.34 and 1.30 %, in the LSU D1/D2 rRNA gene and internal transcribed spacer (ITS) sequences respectively. Strain CLIB 1634 and Candida apicola CBS 2868 diverged by 3.81 and 14.96 % at the level of the protein-coding gene partial sequences EF-1α and RPB2, respectively. CLIB 1707 was found to have sequence divergence of 3.88 and 9.16 % in the LSU D1/D2 rRNA gene and ITS, respectively, from that of the most closely related species Starmerella ratchasimensis type strain CBS 10611. The species Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov. are proposed to accommodate strains CLIB 1634 (=CBS 15247) and CLIB 1707 (=CBS 15257), respectively.

Candida metrosideri pro tempore sp. nov. and Candida ohialehuae pro tempore sp. nov., two antifungal-resistant yeasts associated with Metrosideros polymorpha flowers in Hawaii

“…Flowers have been increasingly recognized as unexplored reservoirs of yeast diversity due to the production of nutrient-rich exudates, such as floral nectar or stigmatic secretions, in which microbes can thrive [1][2][3]. Study of yeast diversity in flowers has led during the last decade to the discovery of more than 50 new species of ascomycetes yeasts, dispersed across different continents [2,[4][5][6][7][8][9][10][11][12][13][14]. Additionally, the taxonomic status of several flower-inhabiting yeast species still remains unclear because their phylogenetic affiliation is not yet satisfactorily resolved by available multilocus sequences, and/or they seem unable to produce sexual structures under standard laboratory conditions, making accurate classification challenging.…”

Towards a better understanding of the role of nectar-inhabiting yeasts in plant–animal interactions

“…Flowers and their animal visitors are being increasingly recognized as a rich source of undescribed fungal species [19,29,43]. For example, the study of these habitats has led to the discovery of more than 50 new yeast species during the last decade, most of which were classified within the ascomycetous genera Metschnikowia, Wickerhamiella, Starmerella and Kodamaea [43,[51][52][53][54][55][56][57][58][59][60]. In contrast, descriptions of new species of mycelial fungi obtained from flowers are much scarcer (but see, for example, [61]).…”

Metabolome Exploration by High-Resolution Mass Spectrometry Methodologies of Two New Yeast Species: Starmerella reginensis and Starmerella kourouensis

“…Both S. reginensis and S. kourouensis have been isolated from flowers in the tropical environment of French Guiana, near the towns of Regina and Kourou, respectively. 4 There are more and more studies on the organoleptic properties of microorganisms for food and health, so a method to screen all secondary metabolites, or natural products, of a microorganism is of great interest. Among the approximate 200,000 compounds recorded in the Dictionary of Natural Products, only 9.99% are from fungal organisms, making fungal species an original and interesting biological source to explore.…”

“…Yeasts were routinely grown on modified YPD agar medium (1% yeast extract, 1% peptone, 1% glucose, and 1.4% agar) at 26.5 °C. 4 Strains were streaked from an overnight culture on a 10 cm diameter Petri dish on a solidified synthetic medium: YNB agar medium (6.7% yeast nitrogen base, 1% peptone, 1% glucose, and 1.4% agar) and then incubated for 3 days at 26.5 °C. Culture medium samples without yeasts were also prepared as control samples.…”

“…The first studied Starmerella, Starmerella bombicola, was a teleomorph, that is to say, a synonym of Candida bombicola, able to produce sophorolipids useable as biosurfactants. Starmerella yeasts have been described as osmotolerant and fermentative, and they use few carbon compounds to live and grow and may be collected from flowers and associated beetles. , These non-Saccharomyces yeasts are considered useful in the preparation of alcoholic beverages, such as wine, to enhance sensorial complexity and the aroma profile or to reduce potential ethanol content . For example, Starmerella bacillaris is one member of the fermenting coffee berry microflora; its impact on wine aroma profiles has been explored via analyses by chromatographic techniques or mass spectrometry. − Some strains of S.…”