Candida oceani sp. nov., a novel yeast isolated from a Mid-Atlantic Ridge hydrothermal vent (−2300 meters)

Abstract

A novel species in the genus Candida was obtained from deep-sea hydrothermal fields on the Mid-Atlantic Ridge. Strains Mo39, MARY089 and CBS 5307, respectively, isolated from an unidentified deep-sea coral collected near Rainbow hydrothermal vent, from water samples near Menez Gwen hydrothermal field and from the stomach of a marine fish are considered as a novel taxon. Sequence similarities in the D1/D2 region of the 26S rRNA gene indicated that strains Mo39, MARY089 and CBS 5307 have for closest neighbors Candida spencermartinsiae, Candida taylorii, Candida atmosphaerica and Candida atlantica. The strains, respectively, differ from C. spencermartinsiae, C. taylorii, C. atmosphaerica andCandida atlantica by 4, 4.3, 4.3 and 4.7% in the D1/D2 domain. Strains Mo39, MARY089 and CBS 5307 were differentiated from others by differences in the ability to assimilate D: -Gluconate and in the ability to grow at relatively high temperature. Only strain Mo39 displays an optimal growth at 3% sea salts, indicating that this strain is clearly adapted to live in marine conditions. Sequence similarities between strains Mo39, MARY089 and CBS 5307 and related species and differences in the ability to utilize specific carbon compounds revealed that these strains represent a hitherto unknown species. Sexual reproduction was not observed in strains Mo39, MARY089 and CBS 5307. An anamorphic name Candida oceani sp. nov. is proposed for the type strain Mo39(T) (= CBS 11857(T) = DSM 23777(T)) and the two other strains MARY089 and CBS 5307. To our knowledge, this is the first description of a micro-eukaryotic organism including a strain isolated from a deep-sea coral near a hydrothermal ecosystem.

Yamadazyma endophytica f.a. sp. nov., an ascomycetous yeast species isolated from leaf tissue

“…In the latest edition of The Yeasts, a Taxonomic Study, six ascosporogenous species (Yamadazyma philogaea, Y. akitaensis, Y. mexicana, Y. nakazawae, Y. scolyti, Y. triangularis) and 23 asexual species assigned to the genus Candida were placed in the Yamadazyma clade . Since then, additional species of the genus Candida in this clade have been found Nakase et al, 2008;AmIn et al, 2011;Buddie et al, 2011;Burgaud et al, 2011;Groenewald et al, 2011) and many novel species of the genus Yamadazyma have been discovered and described such as Yamadazyma terventina, Y. siamensis, Y. phyllophila, Y. paraphyllophila, Y. ubonensis, Y. insecticola, Y. epiphylla, Y. riverae, Y. dushanensis and Y. kitorensis (Ciafardini et al, 2013;Kaewwichian et al, 2013b;Junyapate et al, 2014;Jindamorakot et al, 2015;Lopes et al, 2015;Wang et al, 2015;Nagatsuka et al, 2016). In addition, three known species of the genus Candida were transferred to the genus Yamadazyma as novel combinations, namely Yamadazyma olivae, Y. tumulicola and Y. takamatsuzukensis (Nagatsuka et al, 2016).…”

Astonishing Fungal Diversity in Deep‐Sea Hydrothermal Ecosystems: An Untapped Resource of Biotechnological Potential?

“…Salinity was another structuring parameter for yeasts that separates halophiles from halotolerant and nonhalophilic taxa. One hydrothermal vent taxon described above, Candida oceani, was found to be a halophile (Burgaud et al, 2011). This seems to indicate that halophilic strains are endemic deep-sea marine fungi, while others may be ubiquitous but adapted taxa that occur at hydrothermal vents as a result of sedimentation or other natural phenomena such as the circulation of water masses.…”

“…Culture-based analyses led to the isolation of many known, but also novel, yeast species (Burgaud et al, 2010;Burgaud et al, 2011;Gadanho and Sampaio, 2005;Nagahama, Hamamoto, and Horikoshi, 2006) and also many filamentous fungi . The only two cultured endemic fungal species from hydrothermal vents described to date have been yeasts belonging to higher fungi -one basidiomycete and one ascomycetenamed Rhodotorula pacifica (Nagahama, Hamamoto, and Horikoshi, 2006) and Candida oceani (Burgaud et al, 2011), respectively.…”

“…The only two cultured endemic fungal species from hydrothermal vents described to date have been yeasts belonging to higher fungi -one basidiomycete and one ascomycetenamed Rhodotorula pacifica (Nagahama, Hamamoto, and Horikoshi, 2006) and Candida oceani (Burgaud et al, 2011), respectively. R. pacifica was isolated from sediment samples collected at a depth of 991 m at north-west Pacific Ocean, while C. oceani was isolated from two sites: (i) from water samples near Menez Gwen hydrothermal field at 825 m (Gadanho and Sampaio, 2005); and (ii) from deep-sea coral near the Rainbow hydrothermal vent at 2300 m depth (Burgaud et al, 2011). However, many novel fungal species have not yet been described.…”

Cold-Adapted Yeasts in Deep-Sea Environments

“…Although sampling sites are often selected with a bias toward interesting geographic locations, such as hydrothermal vents, and may not fully represent the diversity of yeast present in general deep-sea environments, the most frequently isolated yeast species from deep-sea environments belong to the genera Rhodosporidium, Rhodotorula, and Candida (Table 7.1). Some novel species of the genera Rhodotorula and Candida have been found in deep-sea environments (Nagahama et al 2001b(Nagahama et al , 2003a(Nagahama et al , b, 2006Burgaud et al 2011). Yeast species of the genera Clavispora, Cryptococcus, Dioszegia, Dipodascus, Kluyveromyces, Pichia, Pseudozyma, Sporidiobolus, Sporobolomyces, and Trichosporon have also been isolated from deep-sea environments.…”