Dataset Information

Metabolically engineered bacteria for producing hydrogen via fermentation.

ABSTRACT: Hydrogen, the most abundant and lightest element in the universe, has much potential as a future energy source. Hydrogenases catalyse one of the simplest chemical reactions, 2H(+) + 2e(-) ? H(2), yet their structure is very complex. Biologically, hydrogen can be produced via photosynthetic or fermentative routes. This review provides an overview of microbial production of hydrogen by fermentation (currently the more favourable route) and focuses on biochemical pathways, theoretical hydrogen yields and hydrogenase structure. In addition, several examples of metabolic engineering to enhance fermentative hydrogen production are presented along with some examples of expression of heterologous hydrogenases for enhanced hydrogen production.

SUBMITTER: Vardar-Schara G

PROVIDER: S-EPMC3864445 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Metabolically engineered bacteria for producing hydrogen via fermentation.

Vardar-Schara Gönül G Maeda Toshinari T Wood Thomas K TK

Microbial biotechnology 20080301 2

Hydrogen, the most abundant and lightest element in the universe, has much potential as a future energy source. Hydrogenases catalyse one of the simplest chemical reactions, 2H(+) + 2e(-) ↔ H(2), yet their structure is very complex. Biologically, hydrogen can be produced via photosynthetic or fermentative routes. This review provides an overview of microbial production of hydrogen by fermentation (currently the more favourable route) and focuses on biochemical pathways, theoretical hydrogen yiel ...[more]

PMID: 21261829

Similar Datasets

Project description:Saccharomyces cerevisiae is an established cell factory for production of terpenoid pharmaceuticals and chemicals. Numerous studies have demonstrated that deletion or overexpression of off-pathway genes in yeast can improve terpenoid production. The deletion of YPL062W in S. cerevisiae, in particular, has benefitted carotenoid production by channeling carbon toward carotenoid precursors acetyl coenzyme A (acetyl-CoA) and mevalonate. The genetic function of YPL062W and the molecular mechanisms for these benefits are unknown. In this study, we systematically examined this gene deletion to uncover the gene function and its molecular mechanism. RNA sequencing (RNA-seq) analysis uncovered that YPL062W deletion upregulated the pyruvate dehydrogenase bypass, the mevalonate pathway, heterologous expression of galactose (GAL) promoter-regulated genes, energy metabolism, and membrane composition synthesis. Bioinformatics analysis and serial promoter deletion assay revealed that YPL062W functions as a core promoter for ALD6 and that the expression level of ALD6 is negatively correlated to terpenoid productivity. We demonstrate that ΔYPL062W increases the production of all major terpenoid classes (C10, C15, C20, C30, and C40). Our study not only elucidated the biological function of YPL062W but also provided a detailed methodology for understanding the mechanistic aspects of strain improvement.IMPORTANCE Although computational and reverse metabolic engineering approaches often lead to improved gene deletion mutants for cell factory engineering, the systems level effects of such gene deletions on the production phenotypes have not been extensively studied. Understanding the genetic and molecular function of such gene alterations on production strains will minimize the risk inherent in the development of large-scale fermentation processes, which is a daunting challenge in the field of industrial biotechnology. Therefore, we established a detailed experimental and systems biology approach to uncover the molecular mechanisms of YPL062W deletion in S. cerevisiae, which is shown to improve the production of all terpenoid classes. This study redefines the genetic function of YPL062W, demonstrates a strong correlation between YPL062W and terpenoid production, and provides a useful modification for the creation of terpenoid production platform strains. Further, this study underscores the benefits of detailed and systematic characterization of the metabolic effects of genetic alterations on engineered biosynthetic factories.

Project description:BACKGROUND:Glycyrrhetinic acid (GA) is the most important ingredient in licorice due to its outstanding anti-inflammatory activity and wide application in the medicine and cosmetics industries. Contemporary industrial production of GA by acid hydrolysis of glycyrrhizin which was extracted from Glycyrrhiza plants, is not environment-friendly and devastates farmland since the Glycyrrhiza rhizomes grow up to 10 m underground. RESULTS:In this study, GA was produced through metabolically engineering Saccharomyces cerevisiae by introducing the entire heterogeneous biosynthetic pathway of GA. Codon optimized CYP88D6 and CYP72A154, combined with ?-AS (?-amyrin synthase encoding gene) and the NADPH-cytochrome P450 reductase gene of Arabidopsis thaliana were introduced into S. cerevisiae. The resulting strain (Y1) produced 2.5 mg/L of ?-amyrin and 14 ?g/L of GA. The cytochrome b5 from G. uralensis (GuCYB5) was identified and the introduction of this novel GuCYB5 increased the efficiency of GA production by eightfold. The joint utilization of the GuCYB5 gene along with 10 known MVA pathway genes from S. cerevisiae were overexpressed in a stable chromosome integration to achieve higher GA production. Using the combined strategy, GA concentration improved by 40-fold during batch fermentation. The production was further improved to 8.78 mg/L in fed-batch fermentation, which was increased by a factor of nearly 630. CONCLUSIONS:This study first investigated the influence of carbon flux in the upstream module and the introduction of a newly identified GuCYB5 on GA production. The newly identified GuCYB5 was highly effective in improving GA production. An integrated strategy including enzyme discovery, pathway optimization, and fusion protein construction was provided in improving GA production, achieving a 630 fold increase in GA production. The metabolically engineered yeast cell factories provide an alternative approach to glycyrrhetinic acid production, replacing the traditional method of plant extraction.

Dataset Information

Metabolically engineered bacteria for producing hydrogen via fermentation.

Publications

Metabolically engineered bacteria for producing hydrogen via fermentation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets