Escherichia coli strains with precise domain deletions in the ribonuclease RNase E can achieve greatly enhanced levels of membrane protein production.

Escherichia coli is one of the most widely utilized hosts for production of recombinant membrane proteins (MPs). Bacterial MP production, however, is usually accompanied by severe toxicity and low-level volumetric accumulation. In previous work, we had discovered that co-expression of RraA, an inhibitor of the RNA-degrading activity of RNase E, can efficiently suppress the cytotoxicity associated with the MP overexpression process and, simultaneously, enhance significantly the cellular accumulation of membrane-incorporated recombinant MPs in bacteria.

The Sugar Metabolic Model of Can Only Be Reliably Transferred to Fungi of Its Phylum.

Fungi play a critical role in the global carbon cycle by degrading plant polysaccharides to small sugars and metabolizing them as carbon and energy sources. We mapped the well-established sugar metabolic network of to five taxonomically distant species (, , , and ) using an orthology-based approach. The diversity of sugar metabolism correlates well with the taxonomic distance of the fungi.

Xylitol production from plant biomass by Aspergillus niger through metabolic engineering.

Xylitol is widely used in the food and pharmaceutical industries as a valuable commodity product. Biotechnological production of xylitol from lignocellulosic biomass by microorganisms is a promising alternative option to chemical synthesis or bioconversion from D-xylose. In this study, four metabolic mutants of Aspergillus niger were constructed and evaluated for xylitol accumulation from D-xylose and lignocellulosic biomass.

Re-routing of Sugar Catabolism Provides a Better Insight Into Fungal Flexibility in Using Plant Biomass-Derived Monomers as Substrates.

The filamentous ascomycete has received increasing interest as a cell factory, being able to efficiently degrade plant cell wall polysaccharides as well as having an extensive metabolism to convert the released monosaccharides into value added compounds. The pentoses D-xylose and L-arabinose are the most abundant monosaccharides in plant biomass after the hexose D-glucose, being major constituents of xylan, pectin and xyloglucan. In this study, the influence of selected pentose catabolic pathway (PCP) deletion strains on growth on plant biomass and re-routing of sugar catabolism was addressed to gain a better understanding of the flexibility of this fungus in using plant biomass-derived monomers.

Engineering of primary carbon metabolism in filamentous fungi.

Filamentous fungi are important industrial cell factories used for the production of a wide range of enzymes and metabolites. Their primary metabolism is a significant source of industrially important compounds, as well as of monomeric building blocks for the production of secondary metabolites and extracellular enzymes. Therefore, large efforts have been made towards the development of suitable strains for the industrial scale production of primary metabolites.

Identification of a gene encoding the last step of the L-rhamnose catabolic pathway in Aspergillus niger revealed the inducer of the pathway regulator.

In fungi, L-rhamnose (Rha) is converted via four enzymatic steps into pyruvate and L-lactaldehyde, which enter central carbon metabolism. In Aspergillus niger, only the genes involved in the first three steps of the Rha catabolic pathway have been identified and characterized, and the inducer of the pathway regulator RhaR remained unknown. In this study, we identified the gene (lkaA) involved in the conversion of L-2-keto-3-deoxyrhamnonate (L-KDR) into pyruvate and L-lactaldehyde, which is the last step of the Rha pathway.

Transcriptome analysis of Aspergillus niger xlnR and xkiA mutants grown on corn Stover and soybean hulls reveals a highly complex regulatory network.

Background: Enzymatic plant biomass degradation by fungi is a highly complex process and one of the leading challenges in developing a biobased economy. Some industrial fungi (e.g.

Genetic engineering of Synechocystis PCC6803 for the photoautotrophic production of the sweetener erythritol.

Background: Erythritol is a polyol that is used in the food and beverage industry. Due to its non-caloric and non-cariogenic properties, the popularity of this sweetener is increasing. Large scale production of erythritol is currently based on conversion of glucose by selected fungi.