Candida ruelliae sp. nov., a novel yeast species isolated from flowers of Ruellia sp. (Acanthaceae)

Abstract

Two novel yeast strains designated as 16Q1 and 16Q3 were isolated from flowers of the Ruellia species of the Acanthaceae family. The D1/D2 domain and ITS sequences of these two strains were identical. Sequence analysis of the D1/D2 domain of large-subunit rRNA gene indicated their relationship to species of the Candida haemulonii cluster. However, they differ from C. haemulonii by 14% nucleotide sequence divergence, from Candida pseudohaemulonii by 16.1% and from C. haemulonii type II by 16.5%. These strains also differ in 18 physiological tests from the type strain of C. haemulonii, and 12 and 16 tests, respectively, from C. pseudohaemulonii and C. haemulonii type II. They also differ from C. haemulonii and other related species by more than 13% sequence divergence in the internal transcribed spacer region. In the SSU rRNA gene sequences, strain 16Q1 differs by 1.7% nucleotide divergence from C. haemulonii. Sporulation was not observed in pure or mixed cultures on several media examined. All these data support the assignment of these strains to a novel species; we have named them as Candida ruelliae sp. nov., and designate strain 16Q1(T)=MTCC 7739(T)=CBS10815(T) as type strain of the novel species.

Candida aurissp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital

“…The antifungal drug sensitivity of JCM15448 T was different from that of the closely related antifungal drug‐resistant yeast C. pseudohaemulonii isolated from a clinical specimen (9). JCM15448 T and C. ruelliae grew at 42 °C, but C. haemulonii , C. pseudohaemulonii and C. heveicola did not (1, 9, 10, 11). No pseudohyphae were produced after 59 days on slide culture on cornmeal agar at 25 °C.…”

“…No pseudohyphae were produced after 59 days on slide culture on cornmeal agar at 25 °C. C. haemulonii , C. pseudohaemulonii and C. ruelliae produce pseudohyphae (1, 9, 10). C. heveicola does not form pseudohyphae, and maximum growth temperature is 37 °C (11).…”

“…JCM15448 T did not assimilate galactose, l ‐sorbose, cellobiose, l ‐arabinose, ethanol, glycerol, salicin or citrate as carbon sources. However, C. ruelliae can assimilate these carbon sources (10). Therefore, JCM15448 T can be discriminated morphologically from these closely related species.…”

Pullulan production by an osmotolerant Aureobasidium pullulans RBF-4A3 isolated from flowers of Caesulia axillaris

“…Amplification and sequencing of the Internal Transcribed Spacer region (ITS1, 5.8S rDNA and ITS2 regions) of rRNA gene cluster and the D1/D2 domain of LSU rRNA gene were done as described earlier (Saluja & Prasad, 2008). Processing of the samples for loading onto an ABI 3130 xl Genetic Analyzer sequencer was performed according to the instructions of the manufacturer (Applied Biosystems).…”

Fermentation behavior of osmophilic yeast Candida tropicalis isolated from the nectar of Hibiscus rosa sinensis flowers for xylitol production

“…There are several new species of the genus Candida which are reported to be associated with flowers and insects including Candida hawaiiana and Candida kipukae (Lachance et al 2003), Candida picachoenolis and Candida pimensis (Suh et al 2004), Candida ruelliae (Saluja and Prasad 2008). Miller and Phaff (1998) reported that the species isolated from terrestrial habitats are typically associated with flowers or fruits and are transmitted to new niches by insects.…”