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Due to their critical influence on manufacturing accuracy, machine tool feed drives and the monitoring of their condition has been a research field of increasing interest for several years already. Accurate and reliable estimates of the current condition of the machine tool feed drive’s components ball screw drive (BSD) and linear guide shoes (LGSs) are expected to significantly enhance the maintainability of machine tools, which finally leads to economic benefits and smoother production. Therefore, many authors performed extensive experiments with different sensor signals, features and components. Most of those experiments were performed on simplified test benches in order to gain genuine and distinct insights into the correlations between the recorded sensor signals and the investigated fault modes. However, in order to build the bridge between real use cases and scientific findings, those investigations have to be transferred and performed on a more complex test bench, which is close to machine tools in operation. In this paper, a condition monitoring test cycle is developed for such a test bench. The developed test cycle enables the recording of a re-producible data basis, on which models for the condition monitoring of BSDs and LGSs can be based upon.

Economic data acquisition and storage have been key enablers to pave the way for data-driven predictions of machine downtimes. Regarding industrial robots, such predictions can maximize the robot’s availability and effective life span. This paper focuses on the comparison of different data-driven models for robot fault prediction and classification by applying them to a data set derived from a robot test bed and illuminates the data transformation process from raw sensor data to domain knowledge motivated robot health indicators.

Enzymes catalyzing asymmetric carboligation reactions typically show very high substrate specificity for their nucleophilic donor substrate components. Structure-guided engineering of the thermostable transketolase from Geobacillus stearothermophilus by directed in vitro evolution yielded new enzyme variants that are able to utilize pyruvate and higher aliphatic homologues as nucleophilic components for acyl transfer instead of the natural polyhydroxylated ketose phosphates or hydroxypyruvate. The single mutant H102T proved the best hit toward 3-methyl-2-oxobutyrate as donor, while the double variant H102L/H474S showed highest catalytic efficiency toward pyruvate as donor. The latter variant was able to complement the auxotrophic deficiency of Escherichia coli cells arising from a deletion of the dxs gene, which encodes for activity of the first committed step into the terpenoid biosynthesis, offering the chance to employ a growth selection test for further enzyme optimization.

A structure‐guided engineering of fructose‐6‐phosphate aldolase was performed to expand its substrate promiscuity toward aliphatic nucleophiles, i.e., unsubstituted alkanones and alkanals. A "smart" combinatorial library was created targeting residues D6, T26 and N28 that form a binding pocket around the nucleophilic carbon atom. Double‐selectivity screening was executed by high‐performance TLC that allowed simultaneous determination of total activity as well as a preference for acetone versus propanal as competing nucleophiles. While any mutation of N28 resulted in inactivation of the enzyme, D6 turned out to be the key residue that enabled activity with non‐hydroxylated nucleophiles. Altogether 25 single‐ and double‐site variants (D6X and D6X/T26X) were discovered that show useful synthetic activity and a varying preference for ketone or aldehyde as the aldol nucleophiles. Remarkably, all of the novel variants had completely lost their native activity for cleavage of fructose 6‐phosphate., This project received funding from the European Union’s Horizon 2020 research and innovation program under grant no. 635595 (CarbaZymes), the Spanish Ministerio de Economía y Competitividad (MINECO), and the Fondo Europeo de Desarrollo Regional (FEDER) (grant no. CTQ2015-63563-R to P.C.).

Application of aldolases for the asymmetric synthesis of multifunctional chiral products is hampered by their reputed strict nucleophile (=aldol donor) specificity owing to a mechanistic requirement for creating a carbanion nucleophile in aqueous medium. Here we report that a minimalist engineering can extensively broaden the substrate scope of native d-fructose-6-phosphate aldolase (FSA) from Escherichia coli, for which hydroxyacetone is the most proficient substrate, to accept an unprecedented wide variety of alternative nucleophiles. By single- or double-space-generating mutations using simple conservative Leu to Ala replacement of active site residues, we found enzyme variants to efficiently convert larger ketols and bioisosteric ether components with up to seven skeletal atoms, including linear and branched-chain structures. All reactions occurred with full retention of the natural d-threo diastereospecificity. These FSA variants open new avenues toward the synthesis of novel product families that hitherto were inaccessible by biological catalysis., This work was funded by the Bundesministerium für Bildung und Forschung (BMBF grant 0315775B PT-J to W.-D.F.) and the Ministerio de Economı́a y Competitividad (MINECO) (grant CTQ2012-31605 to P.C.), within the transnational Eurotrans-Bio framework, as well as by student exchange funds from the DAAD (grant PPP-50749958 to W.-D.F.), Acciones Integradas (MINECO; grant AIB2010DE-00405 to P.C.), and COST action CM1303 Systems Biocatalysis.