MAL62 overexpression enhances uridine diphosphoglucose-dependent trehalose synthesis and glycerol metabolism for cryoprotection of baker's yeast in lean dough.
Microb Cell Fact
; 19(1): 196, 2020 Oct 19.
Article
em En
| MEDLINE
| ID: mdl-33076920
ABSTRACT
BACKGROUND:
In Saccharomyces cerevisiae, alpha-glucosidase (maltase) is a key enzyme in maltose metabolism. In addition, the overexpression of the alpha-glucosidase-encoding gene MAL62 has been shown to increase the freezing tolerance of yeast in lean dough. However, its cryoprotection mechanism is still not clear.RESULTS:
RNA sequencing (RNA-seq) revealed that MAL62 overexpression increased uridine diphosphoglucose (UDPG)-dependent trehalose synthesis. The changes in transcript abundance were confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzyme activity assays. When the UDPG-dependent trehalose synthase activity was abolished, MAL62 overexpression failed to promote the synthesis of intracellular trehalose. Moreover, in strains lacking trehalose synthesis, the cell viability in the late phase of prefermentation freezing coupled with MAL62 overexpression was slightly reduced, which can be explained by the increase in the intracellular glycerol concentration. This result was consistent with the elevated transcription of glycerol synthesis pathway members.CONCLUSIONS:
The increased freezing tolerance by MAL62 overexpression is mainly achieved by the increased trehalose content via the UDPG-dependent pathway, and glycerol also plays an important role. These findings shed new light on the mechanism of yeast response to freezing in lean bread dough and can help to improve industrial yeast strains.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Trealose
/
Uridina Difosfato Glucose
/
Proteínas de Saccharomyces cerevisiae
/
Alfa-Glucosidases
/
Farinha
/
Glicerol
Idioma:
En
Revista:
Microb Cell Fact
Assunto da revista:
BIOTECNOLOGIA
/
MICROBIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article