Note Candida kunwiensis sp. nov., a yeast associated with flowers and bumblebees Soon Gyu Hong, 1 Kyung Sook Bae, 1 Michel Herzberg, 2 Andreas Titze 2 and Marc-Andre ´ Lachance 3 Correspondence Kyung Sook Bae ksbae@mail.kribb.re.kr 1 Korean Collection for Type Cultures, Korea Research Institute of Bioscience & Biotechnology, no. 52, Oun-dong, Yusong, Taejon 305-333, Republic of Korea 2 Plant Ecology, Department of Biology, Philipps University, Marburg, Karl-von-Frisch-Straße, 35043 Marburg, Germany 3 Department of Plant Sciences, University of Western Ontario, London, Ontario, Canada N6A 5B7 A novel asexual ascomycetous yeast, Candida kunwiensis (SG99-26 T =KCTC 17041 T =CBS 9067 T ), was isolated from sweet potato (Ipomoea batatas) flowers in Korea and from the body surface of pollinating bumblebees in Germany. Comparative analysis of the D1/D2 domain of 26S rDNA of all available sequences for ascomycetous yeasts showed that the novel species was phylogenetically related to the genus Metschnikowia, but the sequence similarity was low. Morphologically and physiologically, C. kunwiensis in many ways resembles Metschnikowia pulcherrima, but can be distinguished from this species by its ability to assimilate lactic acid and its inability to produce pulcherrimin. Certain yeast species with affinities to the genus Metschnikowia occur in flowers, fruits and associated vector insects (Miller & Phaff, 1998). Metschnikowia hawaiiensis (Lachance et al., 1998b, 1990), Metschnikowia continentalis (Lachance et al., 1998b), Metschnikowia lochheadii, Metschnikowia drosophilae (Lachance et al., 2001a) and Candida ipomoeae (Lachance et al., 1998a) occur on morning glories (Ipomoea spp.) and insects, including drosophilids, beetles and bees, found on these flowers (Lachance et al., 2001b). Other yeasts isolated from flowers include Metschnikowia gruessii, Metschnikowia lunata, Metschnikowia pulcherrima, Metschnikowia reukaufii (Miller & Phaff, 1998) and Metschnikowia koreensis (Hong et al., 2001). In the course of an isolation programme of yeasts from various natural sources in Korea, a strain (SG99-26 T ) of ascomycetous affinity was isolated from flowers of Ipomoea batatas Lam. Comparison of the sequence of the D1/D2 domain of the 26S rDNA with sequences from all currently recognized ascomycetous yeasts and comparison of physio- logical profiles indicated that strain SG99-26 T represented a novel yeast species. Independently, a study of yeasts associated with pollinating bumblebees in Germany yielded various strains of a yeast with the same D1/D2 sequences as that of strain SG99-26 T . Here, we describe the Korean strain and German strains as representing a novel yeast species, for which the name Candida kunwiensis is proposed. This novel species has a close phylogenetic relationship with the genus Metschnikowia. The origins of the novel strains discussed in this report are given in Table 1. Morphological and physiological characte- ristics were examined by the conventional techniques described by Yarrow (1998). For strain SG99-26 T , the assimilation of carbon sources was examined at 25 ˚ C on a rotary shaker (120 r.p.m.) at 7-day intervals for 21 days. The utilization of nitrogen sources was examined by auxano- graphy for 7 days. Urease activity was tested in Christensen’s urea agar (Christensen, 1946). The determination of the coenzyme Q system was carried out as described by Yamada (1998) using an HPLC apparatus equipped with a Spherisorb S5 ODS2 column (Waters). The DNA base content (G+C mol%) was determined by the thermal denaturation method (T m ) using 0?16SSC solution. The G+C content was calculated using the equation G+C mol%=51?0+2?08 (T mx 2T mr ), where a DNA preparation from Escherichia coli KCTC 2443 (K-12; G+C content, 51?0 mol%) was included as a reference (T mr ) (Owen & Pitcher, 1985). The German strains were characterized nutritionally by replica plating. All the novel strains are maintained in liquid nitrogen in the yeast collection of the Department of Plant Sciences, University of Western Ontario, Canada. The D1/D2 domain of the nuclear 26S rDNA of strain SG99-26 T was amplified and sequenced using the primer The GenBank accession number for the partial 26S rDNA sequence of Candida kunwiensis SG99-26 T is AF389527. 02200 G 2003 IUMS Printed in Great Britain 367 International Journal of Systematic and Evolutionary Microbiology (2003), 53, 367–372 DOI 10.1099/ijs.0.02200-0