Genome-scale modeling drives 70-fold improvement of intracellular heme production in .

Heme is an oxygen carrier and a cofactor of both industrial enzymes and food additives. The intracellular level of free heme is low, which limits the synthesis of heme proteins. Therefore, increasing heme synthesis allows an increased production of heme proteins.

Dataset for suppressors of amyloid-β toxicity and their functions in recombinant protein production in yeast.

The production of recombinant proteins at high levels often induces stress-related phenotypes by protein misfolding or aggregation. These are similar to those of the yeast Alzheimer's disease (AD) model in which amyloid-β peptides (Aβ42) were accumulated [1], [2]. We have previously identified suppressors of Aβ42 cytotoxicity via the genome-wide synthetic genetic array (SGA) [3] and here we use them as metabolic engineering targets to evaluate their potentiality on recombinant protein production in yeast .

RNA Interference (RNAi ) as a Tool for High-Resolution Phenotypic Screening of the Pathogenic Yeast Candida glabrata.

After its discovery RNA interference (RNAi) has become a powerful tool to study gene functions in different organisms. RNAi has been applied at genome-wide scale and can be nowadays performed using high-throughput automated systems (robotics). The simplest RNAi process requires the expression of two genes (Dicer and Argonaute) to function.

Suppressors of amyloid-β toxicity improve recombinant protein production in yeast by reducing oxidative stress and tuning cellular metabolism.

High-level production of recombinant proteins in industrial microorganisms is often limited by the formation of misfolded proteins or protein aggregates, which consequently induce cellular stress responses. We hypothesized that in a yeast Alzheimer's disease (AD) model overexpression of amyloid-β peptides (Aβ42), one of the main peptides relevant for AD pathologies, induces similar phenotypes of cellular stress. Using this humanized AD model, we previously identified suppressors of Aβ42 cytotoxicity.

Improved production of human hemoglobin in yeast by engineering hemoglobin degradation.

With the increasing demand for blood transfusions, the production of human hemoglobin (Hb) from sustainable sources is increasingly studied. Microbial production is an attractive option, as it may provide a cheap, safe, and reliable source of this protein. To increase the production of human hemoglobin by the yeast Saccharomyces cerevisiae, the degradation of Hb was reduced through several approaches.

Simple Carbohydrate Derivatives Diminish the Formation of Biofilm of the Pathogenic Yeast .

The opportunistic human fungal pathogen relies on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of from yeast-form cells to cells forming hyphae. These compounds, benzyl α-l-fucopyranoside and benzyl β-d-xylopyranoside, inhibit the hyphae formation and adhesion of to a polystyrene surface, resulting in a reduced biofilm formation.

RNAi as a Tool to Study Virulence in the Pathogenic Yeast .

The yeast is a major opportunistic pathogen causing mucosal and systemic infections in humans. Systemic infections caused by this yeast have high mortality rates and are difficult to treat due to this yeast's intrinsic and frequently adapting antifungal resistance. To understand and treat infections, it is essential to investigate the molecular basis of virulence and resistance.

Understand the genomic diversity and evolution of fungal pathogen Candida glabrata by genome-wide analysis of genetic variations.

The yeast Candida glabrata, an opportunistic human fungal pathogen, is the second most prevalent cause of candidiasis worldwide, with an infection incidence that has been increasing in the past decades. The completion of the C. glabrata reference genome made fundamental contributions to the understanding of the molecular basis of its pathogenic phenotypes.

The use of polyhydroxylated carboxylic acids and lactones to diminish biofilm formation of the pathogenic yeast .

The vaginal microbiome of healthy women is a diverse and dynamic system of various microorganisms. Any sudden change in microbe composition can increase the vaginal pH and thus lead to vaginal infections, conditions that affect a large percentage of women each year. The most common fungal strains involved in infections belong to the yeast species .

Improving the Production of Cofactor-Containing Proteins: Production of Human Hemoglobin in Yeast.

Human hemoglobin is an essential protein, whose main function as an oxygen carrier is indispensable for life. Hemoglobin is a cofactor-containing protein with heme as prosthetic group. Same as in humans, heme is synthesized in many organisms in a complex pathway involving two cellular compartments (mitochondria and cytosol), which is tightly regulated.

Improvement of thermotolerance in Lachancea thermotolerans using a bacterial selection pressure.

The use of thermotolerant yeast strains is an important attribute for a cost-effective high temperature biofermentation processes. However, the availability of thermotolerant yeast strains remains a major challenge. Isolation of temperature resistant strains from extreme environments or the improvements of current strains are two major strategies known to date.

Novel Centromeric Loci of the Wine and Beer Yeast Dekkera bruxellensis CEN1 and CEN2.

The wine and beer yeast Dekkera bruxellensis thrives in environments that are harsh and limiting, especially in concentrations with low oxygen and high ethanol. Its different strains' chromosomes greatly vary in number (karyotype). This study isolates two novel centromeric loci (CEN1 and CEN2), which support both the yeast's autonomous replication and the stable maintenance of plasmids.

Alcohol dehydrogenase gene ADH3 activates glucose alcoholic fermentation in genetically engineered Dekkera bruxellensis yeast.

Dekkera bruxellensis is a non-conventional Crabtree-positive yeast with a good ethanol production capability. Compared to Saccharomyces cerevisiae, its tolerance to acidic pH and its utilization of alternative carbon sources make it a promising organism for producing biofuel. In this study, we developed an auxotrophic transformation system and an expression vector, which enabled the manipulation of D.

The wine and beer yeast Dekkera bruxellensis.

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines.

Genome structure and dynamics of the yeast pathogen Candida glabrata.

The yeast pathogen Candida glabrata is the second most frequent cause of Candida infections. However, from the phylogenetic point of view, C. glabrata is much closer to Saccharomyces cerevisiae than to Candida albicans.

Small chromosomes among Danish Candida glabrata isolates originated through different mechanisms.

We analyzed 192 strains of the pathogenic yeast Candida glabrata from patients, mainly suffering from systemic infection, at Danish hospitals during 1985-1999. Our analysis showed that these strains were closely related but exhibited large karyotype polymorphism. Nine strains contained small chromosomes, which were smaller than 0.

The genome of wine yeast Dekkera bruxellensis provides a tool to explore its food-related properties.

The yeast Dekkera/Brettanomyces bruxellensis can cause enormous economic losses in wine industry due to production of phenolic off-flavor compounds. D. bruxellensis is a distant relative of baker's yeast Saccharomyces cerevisiae.

Parallel evolution of the make-accumulate-consume strategy in Saccharomyces and Dekkera yeasts.

Saccharomyces yeasts degrade sugars to two-carbon components, in particular ethanol, even in the presence of excess oxygen. This characteristic is called the Crabtree effect and is the background for the 'make-accumulate-consume' life strategy, which in natural habitats helps Saccharomyces yeasts to out-compete other microorganisms. A global promoter rewiring in the Saccharomyces cerevisiae lineage, which occurred around 100 mya, was one of the main molecular events providing the background for evolution of this strategy.

Heterologous expression of Saccharomyces cerevisiae MPR1 gene confers tolerance to ethanol and L: -azetidine-2-carboxylic acid in Hansenula polymorpha.

Hansenula polymorpha is a naturally xylose-fermenting yeast; however, both its ethanol yield from xylose and ethanol resistance have to be improved before this organism can be used for industrial high-temperature simultaneous saccharification and fermentation of lignocellulosic materials. In the current research, we checked if the expression of the Saccharomyces cerevisiae MPR1 gene encoding N-acetyltransferase can increase the ethanol tolerance of H. polymorpha.

Construction of Hansenula polymorpha strains with improved thermotolerance.

The methylotrophic yeast Hansenula polymorpha has the potential to be used in the process of simultaneous saccharification and fermentation (SSF) of xylan derived xylose at elevated temperatures. To improve parameters of high-temperature resistance and high-temperature fermentation of H. polymorpha, strains carrying deletion of acid trehalase gene (ATH1) and overexpressing genes coding for heat-shock proteins Hsp16p and Hsp104p were constructed.

Production of flavin mononucleotide by metabolically engineered yeast Candida famata.

Recombinant strains of the flavinogenic yeast Candida famata able to overproduce flavin mononucleotide (FMN) that contain FMN1 gene encoding riboflavin (RF) kinase driven by the strong constitutive promoter TEF1 (translation elongation factor 1alpha) were constructed. Transformation of these strains with the additional plasmid containing the FMN1 gene under the TEF1 promoter resulted in the 200-fold increase in the riboflavin kinase activity and 100-fold increase in FMN production as compared to the wild-type strain (last feature was found only in iron-deficient medium). Overexpression of the FMN1 gene in the mutant that has deregulated riboflavin biosynthesis pathway and high level of riboflavin production in iron-sufficient medium led to the 30-fold increase in the riboflavin kinase activity and 400-fold increase in FMN production of the resulted transformants.

Overexpression of pyruvate decarboxylase in the yeast Hansenula polymorpha results in increased ethanol yield in high-temperature fermentation of xylose.

Improvement of xylose fermentation is of great importance to the fuel ethanol industry. The nonconventional thermotolerant yeast Hansenula polymorpha naturally ferments xylose to ethanol at high temperatures (48-50 degrees C). Introduction of a mutation that impairs ethanol reutilization in H.

Overexpression of bacterial xylose isomerase and yeast host xylulokinase improves xylose alcoholic fermentation in the thermotolerant yeast Hansenula polymorpha.

The thermotolerant methylotrophic yeast Hansenula polymorpha is able to ferment xylose to ethanol. To improve characteristics of xylose fermentation, the recombinant strain Delta xyl1 Delta xyl2-ADelta xyl2-B, with deletions of genes encoding first enzymes of xylose utilization (NAD(P)H-dependent xylose reductase and NAD-dependent xylitol dehydrogenases, respectively), was constructed and used as a recipient for co-overexpression of the Escherichia coli xylA gene coding for xylose isomerase and endogenous XYL3 gene coding for xylulokinase. The expression of both genes was driven by the H.

[Construction of the flavinogenic yeast Candida famata strains with high riboflavin kinase activity using gene engineering].

The recombinant strains of the flavinogenic yeast Candida famata, which contain the DNA fragment consisting of the FMN1 gene (encoding the riboflavin kinase, enzyme that converts riboflavin to flavinmononucleotide) driven by the strong promoters (the regulated RIB1 or constitutive TEF1 promoter) were isolated. Riboflavin kinase activity in the isolated transformants was tested. The 6-8-fold increase of the riboflavin kinase activity was shown in the recombinant strains containing the integrated Debaryomyces hansenii FMN1 gene under the strong constitutive TEF1 promoter.