Neuroreceptor Inhibition by Clozapine Triggers Mitohormesis and Metabolic Reprogramming in Human Blood Cells.

The antipsychotic drug clozapine demonstrates superior efficacy in treatment-resistant schizophrenia, but its intracellular mode of action is not completely understood. Here, we analysed the effects of clozapine (2.5-20 µM) on metabolic fluxes, cell respiration, and intracellular ATP in human HL60 cells.

Pseudomonas putida KT2440 endures temporary oxygen limitations.

The obligate aerobic nature of Pseudomonas putida, one of the most prominent whole-cell biocatalysts emerging for industrial bioprocesses, questions its ability to be cultivated in large-scale bioreactors, which exhibit zones of low dissolved oxygen tension. P. putida KT2440 was repeatedly subjected to temporary oxygen limitations in scale-down approaches to assess the effect on growth and an exemplary production of rhamnolipids.

Comprehensive Analysis of Anaplerotic Deletion Mutants Under Defined d-Glucose Conditions.

Wild-type ATCC 13032 is known to possess two enzymes with anaplerotic (C4-directed) carboxylation activity, namely phosphoenolpyruvate carboxylase (PEPCx) and pyruvate carboxylase (PCx). On the other hand, C3-directed decarboxylation can be catalyzed by the three enzymes phosphoenolpyruvate carboxykinase (PEPCk), oxaloacetate decarboxylase (ODx), and malic enzyme (ME). The resulting high metabolic flexibility at the anaplerotic node compromises the unambigous determination of its carbon and energy flux in wild type.

Parallelized disruption of prokaryotic and eukaryotic cells via miniaturized and automated bead mill.

The application of integrated microbioreactor systems is rapidly becoming of more interest to accelerate strain characterization and bioprocess development. However, available high-throughput screening capabilities are often limited to target extracellular compounds only. Consequently, there is a great demand for automated technologies allowing for miniaturized and parallel cell disruption providing access to intracellular measurements.

A closer look at : online monitoring via scattered light enables reproducible phenotyping.

Background: Filamentously growing microorganisms offer unique advantages for biotechnological processes, such as extraordinary secretion capacities, going along with multiple obstacles due to their complex morphology. However, limited experimental throughput in bioprocess development still hampers taking advantage of their full potential. Miniaturization and automation are powerful tools to accelerate bioprocess development, but so far the application of such technologies has mainly been focused on non-filamentous systems.

Identification of modifications procuring growth on xylose in recombinant Saccharomyces cerevisiae strains carrying the Weimberg pathway.

The most prevalent xylose-assimilating pathways in recombinant Saccharomyces cerevisiae, i.e. the xylose isomerase (XI) and the xylose reductase/xylitol dehydrogenase (XR/XDH) pathways, channel the carbon flux through the pentose phosphate pathway and further into glycolysis.

Elucidating cellular mechanisms of Saccharomyces cerevisiae tolerant to combined lignocellulosic-derived inhibitors using high-throughput phenotyping and multiomics analyses.

A robust cell factory that can tolerate combined inhibitory lignocellulosic compounds is essential for the cost-effective lignocellulose-based production of second-generation bioethanol and other bulk chemicals. Following high-throughput phenotyping of a yeast genomic overexpression library, we identified a Saccharomyces cerevisiae mutant (denoted AFb.01) with improved growth and fermentation performance under combined toxicity of acetic acid and furfural.

pH fluctuations imperil the robustness of C. glutamicum to short term oxygen limitation.

The presence of complex gradients for, e.g., nutrients, oxygen or pH in industrial scale fed batch processes are a major challenge for process performance.

Comprehensive and accurate tracking of carbon origin of LC-tandem mass spectrometry collisional fragments for C-MFA.

In recent years the benefit of measuring positionally resolved C-labeling enrichment from tandem mass spectrometry (MS/MS) collisional fragments for improved precision of C-Metabolic Flux Analysis (C-MFA) has become evident. However, the usage of positional labeling information for C-MFA faces two challenges: (1) The mass spectrometric acquisition of a large number of potentially interfering mass transitions may hamper accuracy and sensitivity. (2) The positional identity of carbon atoms of product ions needs to be known.

The contest for precursors: channelling L-isoleucine synthesis in Corynebacterium glutamicum without byproduct formation.

L-Isoleucine is an essential amino acid, which is required as a pharma product and feed additive. Its synthesis shares initial steps with that of L-lysine and L-threonine, and four enzymes of L-isoleucine synthesis have an enlarged substrate specificity involved also in L-valine and L-leucine synthesis. As a consequence, constructing a strain specifically overproducing L-isoleucine without byproduct formation is a challenge.

Studies on substrate utilisation in L-valine-producing Corynebacterium glutamicum strains deficient in pyruvate dehydrogenase complex.

The pyruvate dehydrogenase complex was deleted to increase precursor availability in Corynebacterium glutamicum strains overproducing L: -valine. The resulting auxotrophy is treated by adding acetate in addition glucose for growth, resulting in the puzzling fact of gluconeogenic growth with strongly reduced glucose uptake in the presence of acetate in the medium. This result was proven by intracellular metabolite analysis and labelling experiments.

Analysing overexpression of L-valine biosynthesis genes in pyruvate-dehydrogenase-deficient Corynebacterium glutamicum.

L-valine biosynthesis was analysed by comparing different plasmids in pyruvate-dehydrogenase-deficient Corynebacterium glutamicum strains in order to achieve an optimal production strain. The plasmids contained different combinations of the genes ilvBNCDE encoding for the L-valine forming pathway. It was shown that overexpression of the ilvBN genes encoding acetolactate synthase is obligatory for efficient pyruvate conversion and to prevent L-alanine as a by-product.

Influence of L-isoleucine and pantothenate auxotrophy for L-valine formation in Corynebacterium glutamicum revisited by metabolome analyses.

The effect of different amounts of supplemented L-isoleucine and pantothenate has been analysed with the auxotrophic strain Corynebacterium glutamicum DeltailvA DeltapanB, showing that the final biomass concentration of this preliminary L-valine production strain can be controlled by the amount of added L-isoleucine. One gramme cell dry weight is formed from 48 micromol L-isoleucine. Different amounts of available pantothenate affect the intracellular pyruvate concentration.