Antisense-Mediated Inhibition of Acid Trehalase (ATH1) Gene Expression Promotes Ethanol Fermentation and Tolerance in Saccharomyces cerevisiae

Abstract

Acid trehalase gene (ATH1) expression was decreased using the antisense-RNA technique in Saccharomyces cerevisiae. The 500 bp DNA fragments containing anti-ATH1 gene between +1 and +500 were amplified using PCR and fused to yeast ADH1, CYC1 and ATH1 promoters. Yeast cells harboring the recombinant plasmids had a low activity of acid trehalase and promoted ethanol fermentation compared to the control yeast cells harboring the vector plasmid only. The recombinant yeast had a high viability with 8% (v/v) ethanol.

The three trehalases Nth1p, Nth2p and Ath1p participate in the mobilization of intracellular trehalose required for recovery from saline stress in Saccharomyces cerevisiae

“…In our experiments, the recovery improvement was not due exclusively to the elevated trehalose level because the single Dnth1 mutant began the recovery period with a similar level of trehalose as the Dath1 mutant, but it did not show any growth improvement. The fast recovery phenotype we observed for the Dath1 mutant could be due to a rise in fermentative metabolism in concordance with previously published data (Jung & Park, 2005).…”

Saccharomyces cerevisiae KNU5377 Stress Response during High-Temperature Ethanol Fermentation

“…PGK1, TDH, ADH, ZWF1, HSP104, HSP82, HSP42, HSP30, HSP26) are upregulated under ethanol stress (van Voorst et al, 2006), of which 58 are co-regulated by these transcription factors (Ma and Liu, 2010b). For example, inhibition of acid trehalase (ATH1) gene (Jung and Park, 2005) or overexprression of transcription factor MSN2 (Sasano et al, 2012) and Ras-cAMP pathway inhibitor 1 (RPI1) (Puria et al, 2009) promotes ethanol fermentation and tolerance in S. cerevisiae. Under ethanol stress, Msn2/4 triggers a so-called environmental-stress response, inducing gene expression through a stress response element (STRE) and activating transcription of downstream genes (Ma and Liu, 2010a).…”

Progress in Metabolic Engineering of Saccharomyces cerevisiae

“…The same holds for RNA interference. Recent attempts to control gene expression with antisense RNA were made in yeast metabolic engineering (31,153 (389). The importance of RNA techniques for yeast metabolic engineering will undoubtedly increase in the future.…”

“…In fact, the final ethanol concentration reaches about 20% in sake mash (173). Genetic engineering has identified several factors which may contribute to the higher ethanol tolerance of sake yeast, such as ergosterol (127), unsaturated fatty acids (154,155), palmitoyl coenzyme A (palmitoyl-CoA) (251), trehalose (153), inositol (90), and L-proline (341). However, in many cases researchers merely showed that the deletion of a certain gene causes a decrease in ethanol tolerance (90,127).…”

“…Examples of real improvements in ethanol tolerance for sake or other industrial yeasts via rational metabolic engineering are rare. Successful improvements were achieved by decreasing intracellular trehalose degradation or increasing L-proline accumulation (153,339,341). A diploid sake yeast engineered for proline accumulation showed a slight reduction in fermentation time (19 versus 22 days) compared to the wild type (339).…”