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Two strains, designated JCM 36746 T and JCM 36749, were isolated from Bengal clock vine ( Thunbergia grandiflora ) and soil, respectively, in Okinawa, Japan. Analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the large subunit rRNA gene sequences revealed identical sequences in both strains, indicating that they belong to the same species. Sequence analysis and physiological characterization identified these strains as representing a novel yeast species in the genus Yamadazyma . The sequence similarities of the concatenated ITS regions and D1/D2 domains indicated that JCM 36746 T and JCM 36749 formed a well-supported distinct from closely related species belonging to the Yamadazyma clade, including Candida dendronema , C. diddensiae , C. germanica , C. kanchanaburiensis , C. naeodendra , C. vaughaniae , Y. akitaensis , Y. koratensis , Y. nakazawae , Y. philogaea , Y. phyllophila , Y. siamensis , Y. ubonensis , and three undescribed species, comprising Candida aff. naeodendra / diddensiae Y151, Candida sp. GE19S08, and Yamadazyma sp. strain NYNU 22830. The sequences of the D1/D2 domains and ITS regions differed in nucleotide substitutions by 1.51% and 2.57% or greater, respectively, from those of the previously described and undescribed related species. In addition, the physiological characteristics of the novel species were distinct from those of the closely related described species. On the basis of these findings, we propose the name Yamadazyma thunbergiae sp. nov. to classify this species within the genus Yamadazyma . The holotype used is JCM 36746 T (ex-type strains CBS 18614 and NBRC 116657). The MycoBank accession number is MB 853823.

Two strains were isolated from flowers and insects in Japan, namely NBRC 115686 T and NBRC 115687, respectively. Based on sequence analysis of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region and physiological characteristics, these strains were found to represent a novel yeast species of the genus Wickerhamiella . Considering pairwise sequence similarity, NBRC 115686 T and NBRC 115687 differ from the type strain of the most closely related species, Wickerhamiella galacta NRRL Y-17645 T , by 65-66 nucleotide substitutions with 12 gaps (11.65-11.83 %) in the D1/D2 domain of the LSU rRNA gene. The novel species differ from the closely related Wickerhamiella species in some physiological characteristics. For example, compared with Wickerhamiella galacta JCM 8257 T , NBRC 115686 T and NBRC 115687 assimilated d-galactose, and could grow at 35 and 37 °C. Hence, the name Wickerhamiella bidentis sp. nov. is proposed to accommodate this species in the genus Wickerhamiella . The holotype is NBRC 115686 T (ex-type strain JCM 35540=CBS 18008).

Background: Various industrial Saccharomyces cerevisiae strains are used for specific processes, such as sake, wine brewing and bread making. Understanding mechanisms underlying the fermentation performance of these strains would be useful for further engineering of the S. cerevisiae metabolism. However, the relationship between the fermentation performance, intra-cellular metabolic states, and other phenotypic characteristics of industrial yeasts is still unclear. In this study, 13 C-metabolic flux analysis of four diploid yeast strains-laboratory, sake, bread, and wine yeasts-was conducted., Results: While the Crabtree effect was observed for all strains, the metabolic flux level of glycolysis was elevated in bread and sake yeast. Furthermore, increased flux levels of the TCA cycle were commonly observed in the three industrial strains. The specific rates of CO 2 production, net ATP regeneration, and metabolic heat generation estimated from the metabolic flux distribution were two to three times greater than those of the laboratory strain. The elevation in metabolic heat generation was correlated with the tolerance to low-temperature stress., Conclusion: These results indicate that the metabolic flux distribution of sake and bread yeast strains contributes to faster production of ethanol and CO 2 . It is also suggested that the generation of metabolic heat is preferable under the actual industrial fermentation conditions., (© 2021 Wiley-VCH GmbH.)