| Title | A diversity study of Saccharomycopsis fibuligera in rice wine starter nuruk, reveals the evolutionary process associated with its interspecies hybrid |
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| Author | Mohamed El-Agamy Farh, Yunjoo Cho, Jae Yun Lim, and Jeong-Ah Seo* |
| Address | School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea |
| Bibliography | Journal of Microbiology, 55(5),337-343, 2017, |
| DOI | 10.1007/s12275-017-7115-y |
| Key Words | APL1, asci, Jeju, natural hybridization, nuruk, Sac-charomycopsis fibuligera, thermotolerant |
| Abstract | The amylolytic yeast Saccharomycopsis fibuligera is the pre-dominant yeast in the starter product, nuruk, which is utilized for rice wine production in South Korea. Latest molecular studies explore a recently developed interspecific hybridiza-tion among stains of S. fibuligera with a unique genetic fea-ture. However, the origin of the natural hybridization occur-rence is still unclear. Thus, to respectively distinguish paren-tal and hybrid strains, specific primer sets were applied on 141 yeast strains isolated from different nuruk samples fer-mented in different provinces. Sixty-seven strains were de-fined accordingly as parental species with genome A while 8 strains were defined as hybrid strains. Unexpectedly, another parental species with genome B could not be found among the strain pools yet. Furthermore, it was observed that hybrid strains are phenotypically different from A genome strains; asci containing tetrad ascospores were observed in A genome strains more frequent than in hybrid strains. Nevertheless, hybrid strains were slightly more thermotolerant than A ge-nome strains. Interestingly, all hybrid strains were located only in Jeju province. Based on these sets of data, we specu-lated that the unique climate of Jeju province might play an evolutionary role in the interspecific hybridization between A genome strains, as well as the unculturable allopatric B ge-nome strains. |