Identification of bottom-fermenting yeast genes expressed during lager beer fermentation.

It has been proposed that bottom-fermenting yeast strains of Saccharomyces pastorianus possess at least two types of genomes. Sequences of genes of one genome [S. cerevisiae (Sc)-type] have been found to be highly homologous (more than 90% identity) to S. cerevisiae S288C sequences, while those of the other [Lager (Lg)-type] are less so. To identify and discriminate Lg-type from Sc-type genes expressed during lager beer fermentation, normalized cDNA libraries were constructed and analysed. From approximately 22 000 ESTs, 3892 Sc-type and 2695 Lg-type ORFs were identified. Expression patterns of Sc- and Lg-type genes did not correlate with particular cell functions in KEGG classification system. Moreover, 405 independent clones were isolated that have no significant homology with sequences in the S288C database, suggesting that they include the bottom-fermenting yeast-specific (BFY) genes. Most of BFY genes have significant homology with the S. bayanus genome.

Yoshida S ，Hashimoto K ，Shimada E ，Ishiguro T ，Minato T ，Mizutani S ，Yoshimoto H ，Tashiro K ，Kuhara S ，Kobayashi O ... -  《YEAST》

Expression profiling of the bottom fermenting yeast Saccharomyces pastorianus orthologous genes using oligonucleotide microarrays.

Minato T ，Yoshida S ，Ishiguro T ，Shimada E ，Mizutani S ，Kobayashi O ，Yoshimoto H ... -  《-》

Diversity of the HO gene encoding an endonuclease for mating-type conversion in the bottom fermenting yeast Saccharomyces pastorianus.

Two types of HO gene were cloned, sequenced and characterized from the bottom fermenting yeast Saccharomyces pastorianus. The HO gene present on the 1500 kb chromosome was designated Sc-HO (S. cerevisiae-type HO), because the nucleotide sequence of its promoter region and the open reading frame (ORF) was almost identical to that of the S. cerevisiae laboratory strain HO gene (Lab-HO). The other HO gene, designated Lg-HO (Lager-fermenting-yeast specific HO), showed 64% and 83% homology with the promoter and ORF of the Lab-HO at the nucleotide sequence level, respectively, and was located on the 1100 kb chromosome. Analysis of the 4 kb DNA fragment amplified from S. bayanus type strain indicated that the nucleotide sequence of S. bayanus-HO is almost identical to that of the Lg-HO. The SSB1 gene located downstream of the HO gene in S. cerevisiae was also found in the 3' distal region of the Sc-HO, Lg-HO and S. bayanus HO genes. These results showed that the genetic arrangement around the HO loci both of S. pastorianus and S. bayanus is identical to S. cerevisiae. Southern analysis has revealed that Saccharomyces sensu stricto contain four types of HO genes; S. paradoxus-type HO, the Sc-HO, the Lg-HO and S. uvarum-type HO genes. This HO gene diversity provides useful information for the classification of strains belonging to Saccharomyces sensu stricto. The S. pastorianus Sc-HO, Lg-HO and S. bayanus-HO Accession Nos in the DDBJ Nucleotide Sequence Database are AB027449, AB027450 and AB027451, respectively.

Tamai Y ，Tanaka K ，Umemoto N ，Tomizuka K ，Kaneko Y ... -  《YEAST》

Identification and characterization of amidase- homologous AMI1 genes of bottom-fermenting yeast.

Yoshida S ，Hashimoto K ，Tanaka-Kanai K ，Yoshimoto H ，Kobayashi O ... -  《YEAST》

Chromosomal location of Lg-FLO1 in bottom-fermenting yeast and the FLO5 locus of industrial yeast.

Ogata T ，Izumikawa M ，Kohno K ，Shibata K ... -  《-》