Yeast

About: Yeast is a research topic. Over the lifetime, 31777 publications have been published within this topic receiving 868967 citations. The topic is also known as: yeasts.

Increased tolerance and conversion of inhibitors in lignocellulosic hydrolysates by Saccharomyces cerevisiae

Abstract: During hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance during the fermentation step. Among the microorganisms that have been evaluated for lignocellulosic hydrolysate ethanol fermentation, the yeast Saccharomyces cerevisiae appears to be the least sensitive. In order to overcome the effect of inhibitors, strategies that include improvement of natural tolerance of microorganism and use of fermentation control strategies have been developed. An overview of the origin, effects and mechanisms of action of known inhibitors on S. cerevisiae is given. Fermentation control strategies as well as metabolic, genetic and evolutionary engineering strategies to obtain S. cerevisiae strains with improved tolerance are discussed.

Yeast promoters and lacZ fusions designed to study expression of cloned genes in yeast.

Abstract: Publisher Summary This chapter describes plasmids and methods for constructing fusions of any cloned gene to lacZ for study in yeast. If the gene to be fused to lacZ contains no appropriate Sau3A sites, alternative strategies to the above must be employed. If the DNA sequence of the gene to be fused to lacZ is known, inframe fusions can be made simply by choosing the appropriate gene fragment. The vector sequences that precede the yeast DNA is a yeast gene–lacZ fusion may affect gene regulation. Plasmids may be used to probe the signals that govern the initiation of transcription and translation in S. cerevisiae. These methods provide powerful tools in the analysis of the expression of yeast genes. Further, the plasmids should facilitate the expression in yeast of any cloned gene to produce the native, unfused product.

Comprehensive mass-spectrometry-based proteome quantification of haploid versus diploid yeast.

Abstract: Mass spectrometry is a powerful technology for the analysis of large numbers of endogenous proteins. However, the analytical challenges associated with comprehensive identification and relative quantification of cellular proteomes have so far appeared to be insurmountable. Here, using advances in computational proteomics, instrument performance and sample preparation strategies, we compare protein levels of essentially all endogenous proteins in haploid yeast cells to their diploid counterparts. Our analysis spans more than four orders of magnitude in protein abundance with no discrimination against membrane or low level regulatory proteins. Stable-isotope labelling by amino acids in cell culture (SILAC) quantification was very accurate across the proteome, as demonstrated by one-to-one ratios of most yeast proteins. Key members of the pheromone pathway were specific to haploid yeast but others were unaltered, suggesting an efficient control mechanism of the mating response. Several retrotransposon-associated proteins were specific to haploid yeast. Gene ontology analysis pinpointed a significant change for cell wall components in agreement with geometrical considerations: diploid cells have twice the volume but not twice the surface area of haploid cells. Transcriptome levels agreed poorly with proteome changes overall. However, after filtering out low confidence microarray measurements, messenger RNA changes and SILAC ratios correlated very well for pheromone pathway components. Systems-wide, precise quantification directly at the protein level opens up new perspectives in post-genomics and systems biology.