Pannida Khunnamwong

Wickerhamiella siamensis f.a., sp. nov., an endophytic and epiphytic yeast species isolated from sugar cane leaf.

Six strains representing a novel yeast species were isolated from tissue (DMKU-SE106(T), DMKU-SE110, DMKU-SE112 and DMKU-SE132) and the external surface (DMKU-SP335 and DMKU-SP406) of sugar cane leaves collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region, the six strains were found to represent a single novel species of the genus Wickerhamiella although the formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the six strains differed from each other by 0-2 and 2-3 nt substitutions, respectively. The novel species was related most closely to Candida infanticola but with 4.5-4.6% nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and 6.6-7.1% nucleotide substitutions in the ITS region. The name Wickerhamiella siamensis f.a., sp. nov. is proposed. The type strain is DMKU-SE106(T) ( =BCC 61185(T) =NBRC 109697(T) =CBS 13331(T)).

Occultifur tropicalis f.a., sp. nov., a novel cystobasidiomycetous yeast species isolated from tropical regions.

Five strains representing a single novel anamorphic yeast species were isolated from sugar cane. Two strains were from tissue (DMKU-SE38, DMKU-SE59(T)) and two from the external surface (DMKU-SP385, DMKU-SP403) of leaves collected in Thailand and the fifth (IMUFRJ 52020) from the rhizoplane of sugar cane in an organically cultivated field in Brazil. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were classified as representing a single species of the genus Occultifur. The sequences of the D1/D2 region of the LSU rRNA genes and the ITS regions of the five strains were either identical or differed from each other by only one nucleotide substitution. The novel species was related most closely to Occultifur brasiliensis f.a. CBS 12687(T) but with 0.7-1.0% nucleotide substitutions (4-6 nt) in the D1/D2 region of the LSU rRNA gene and 2.5-2.7% nucleotide substitutions (14-15 nt) in the ITS region. The name Occultifur tropicalis f.a., sp. nov. is proposed. The type strain is DMKU-SE59(T) ( =BCC 61184(T) =NBRC 109696(T) =CBS 13389 (T)).

Papiliotrema siamense f.a., sp. nov., a yeast species isolated from plant leaves

Two strains representing a novel species were isolated from the external surface of a sugar cane leaf (DMKU-SP85(T)) and tissue of a rice leaf (DMKU-RE97) collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, the two strains were determined to represent a novel species of the genus Papiliotrema although sexual reproduction was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the two strains were identical, but differed from those of the type strain of Cryptococcus nemorosus by 0.6 % nucleotide substitutions (four nucleotide substitutions out of 597 nucleotides) in the D1/D2 region of the LSU rRNA gene and 1.8 % nucleotide substitutions (nine nucleotide substitutions out of 499 nucleotides) in the ITS region. The name Papiliotrema siamense f.a., sp. nov. is proposed. The type strain is DMKU-SP85(T)( = BCC 69499(T) = CBS 13330(T)).

Description of Diutina gen. nov., Diutina siamensis, f.a. sp. nov., and reassignment of Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida ranongensis, Candida rugosa and Candida scorzettiae to the genus Diutina.

Three strains (DMKU-RE28, DMKU-RE43T and DMKU-RE123) of a novel anamorphic yeast species were isolated from rice leaf tissue collected in Thailand. DNA sequence analysis demonstrated that the species forms a sister pair with Candida ranongensis CBS 10861T but differs by 24-30 substitutions in the LSU rRNA gene D1/D2 domains and 30-35 substitutions in the ITS region. A phylogenetic analysis based on both the small and the large rRNA gene subunits confirmed this connection and demonstrated the presence of a clade that also includes Candida catenulata, Candida mesorugosa, Candida neorugosa, Candida pseudorugosa, Candida rugosa and Candida scorzettiae. The clade is not closely affiliated to any known teleomorphic genus, and forms a well-separated lineage from currently recognized genera of the Saccharomycetales. Hence, the genus Diutina gen. nov. is proposed to accommodate members of the clade, including Diutina siamensis f.a. sp. nov. and the preceding seven Candida species. The type strain is DMKU-RE43T ( = CBS 13388T = BCC 61183T = NBRC 109695T).

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

Strain DMKU-CE23T representing a novel yeast species was isolated from tissue of a corn leaf (Zea may L.) collected in Thailand. A phylogenetic analysis based on the combined sequences of the internal transcribed spacer (ITS) region and the D1/D2 region of the LSU rRNA gene indicated that strain DMKU-CE23T belongs to the Yamadazyma clade and is clearly distinct from other related species. It therefore represents a novel species of the genus Yamadazyma although the formation of ascospores was not observed. The strain of novel species was most closely related to the type strain of Yamadazyma epiphylla but with 5.1 % nucleotide substitutions in the ITS region and 3.7 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene. The name Yamadazyma endophytica f.a., sp. nov. is proposed. The type strain is DMKU-CE23T (=CBS 14163T=TBRC 5174T).

Occultifur plantarum f.a., sp. nov., a novel cystobasidiomycetous yeast species

Nine strains representing a single anamorphic novel yeast species in dispersed tropical and subtropical habitats were isolated from sugarcane leaf tissue (DMKU-SE24, DMKU-SE45T, DMKU-SE129 and DMKU-SE134) and corn leaf tissue (DMKU-CE36) in Thailand, phylloplane and rhizoplane of sugarcane in Brazil (IMUFRJ 52018 and IMUFRJ 52019), bromeliad leaf tissue in Brazil (IMUFRJ 51954) and plant leaf in Japan (IPM31-24). These strains showed identical or only 1 nt substitution in the sequences of the D1/D2 region of the LSU rRNA gene and 0-5 nt substitutions in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions showed that the eight of these strains represented a single species in the genus Occultifur that was distinct from related species. Occultifur kilbournensis was the most closely related species, but with 0.9-1.2 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 2.4-2.6 % nucleotide substitutions in the ITS region. They are therefore considered to represent a novel species of the genus Occultifur although the formation of basidia was not observed. The name Occultifur plantarum f.a., sp. nov. is proposed. The type strain is DMKU-SE45T (=CBS 14554T=TBRC 6561T).

Cryptotrichosporon siamense sp. nov., a ballistoconidium-forming yeast species in Trichosporonales isolated in Thailand

Two strains, which formed pink colonies and produced ballistoconidia and represented a novel anamorphic yeast species, were isolated from peat (DMKU-SPS1-2) and fern leaf (ST-145) collected in Thailand. Analysis of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) regions showed that the two strains were identical to the sequences of the D1/D2 domains of the LSU rRNA gene and differed by two nucleotide substitutions in the ITS regions. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions confirmed that the two strains represented a single species in the genus Cryptotrichosporon that was distinct from the other known species of the genus. Cryptotrichosporon argae (CBS 14376T) was the most closely related species, but with 2.2 % nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene, and 6.8-8.0 % nucleotide substitutions in the ITS regions. Therefore, the two strains were assigned as a novel species, for which we propose the name Cryptotrichosporon siamense sp. nov. The type is DMKU-SPS1-2T. The MycoBank number of the novel species is MB82336.

Saturnispora kantuleensis f.a., sp. nov., a novel yeast species isolated from peat in a tropical peat swamp forest in Thailand

Two strains (DMKU-PPS4-5T and DMKU-EPS3-4) representing a single novel anamorphic yeast species were isolated from two peat samples collected in Kan Tulee peat swamp forest, Surat Thani Province, Thailand. The strains differed by two nucleotide substitutions in the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and only one nucleotide substitution in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the D1/D2 regions showed that the two strains represented a single species in the genus Saturnispora and were clearly distinct from other related species. Saturnispora sekii was the most closely related species, but with 1.7-2.1 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 3.1-3.3 % nucleotide substitutions in the ITS region. They therefore represent a novel species of the genus Saturnispora, although the formation of ascospores was not observed. The name Saturnispora kantuleensis f.a., sp. nov. is proposed. The type strain is DMKU-PPS4-5T (=CBS 15217T=TBRC 7762T).

Candida kantuleensis sp. nov., a d-xylose-fermenting yeast species isolated from peat in a tropical peat swamp forest

Three strains (DMKU-XE11T, DMKU-XE15 and DMKU-XE20) representing a single novel anamorphic and d-xylose-fermenting yeast species were obtained from three peat samples collected from Khan Thulee peat swamp forest in Surat Thani province, Thailand. The strains differed from each other by one to two nucleotide substitutions in the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and zero to one nucleotide substitution in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions showed that the three strains represented a single Candida species that was distinct from the other related species in the Lodderomyces/Candida albicans clade. The three strains form a subclade with the other Candida species including Candida sanyaensis, Candida tropicalis and Candida sojae. C. sanyaensis was the most closely related species, with 2.1-2.4 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 3.8-4.0 % nucleotide substitutions in the ITS region. The three strains (DMKU-XE11T, DMKU-XE15 and DMKU-XE20) were assigned as a single novel species, which was named Candida kantuleensis sp. nov. The type strain is DMKU-XE11T (=CBS 15219T=TBRC 7764T). The MycoBank number for C. kantuleensis sp. nov. is MB 824179.

Papiliotrema phichitensis f.a., sp. nov., a novel yeast species isolated from sugarcane leaf in Thailand

AbstractStrain DMKU-SP105T representing a novel yeast species was isolated from the external surface of a sugarcane leaf (Saccharum officinarum L.) collected from a sugarcane plantation field in Phichit province, Thailand. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, the strain DMKU-SP105T differed by 7–16 substitutions in the D1/D2 region of LSU rRNA gene and 6–22 substitutions in the ITS region from a group of related species, Papiliotrema aspenensis, Papiliotrema odontotermitis, Papiliotrema rajasthanensis and Papiliotrema laurentii. A phylogenetic analysis based on the concatenated sequences of ITS region and the D1/D2 region of the LSU rRNA gene indicated that strain DMKU-SP105T belongs to the laurentii clade of Papiliotrema in the Tremellales and is distinct from other related species in the clade. It therefore represents a novel species of the genus Papiliotrema although the formation of basidiospores was not observed. The name Papiliotrema phichitensis f.a., sp. nov. is proposed. The type is DMKU-SP105T (= CBS 13390T = BCC 61187T = NBRC 109699T).