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Mitochondrial‐morphology‐targeted breeding of industrial yeast strains for alcohol fermentation
Author(s) -
Kitagaki Hiroshi
Publication year - 2009
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1042/ba20090032
Subject(s) - brewing , yeast , saccharomyces cerevisiae , fermentation , mitochondrion , fis1 , biology , biochemistry , mitochondrial fusion , gene , mitochondrial dna
Since mitochondrial genes are repressed under high glucose and low O 2 , and these conditions correspond to the conditions in which yeast cells are exposed during alcohol fermentation, the existence and structure of yeast mitochondria during alcohol fermentation have not been elucidated. Yeast mitochondria can be observed throughout brewing of sake (Japanese rice wine) and fragment during brewing. Furthermore, it has been revealed that Fis1 [fission 1 (mitochondrial outer membrane) homologue ( Saccharomyces cerevisiae )], which is a transmembrane protein with its C‐terminal anchor embedded in the outer membrane of mitochondria, is required for fragmentation of yeast mitochondria during sake brewing. By utilizing this knowledge, a fis1 disruptant of a sake yeast strain has been generated that has a networked mitochondrial structure throughout sake brewing. It transpired that this strain produces a high content of malate, which imparts a crisp acidic taste, during sake brewing. This strategy is a useful and a completely novel strategy towards developing a new yeast strain which produces a high content of malate in sake, and mitochondrial morphology has now emerged as a promising target for the breeding of practical industrial strains.