Polyether Cyclization Cascade Alterations in Response to Monensin Polyketide Synthase Mutations

The targeted manipulation of polyketide synthases has in recent years led to numerous new-to-nature polyketides. For type I polyketide synthases the response of post-polyketide synthases (PKS) processing enzymes onto the most frequently polyketide backbone manipulations is so far insufficiently studied. In particular, complex processes such as the polyether cyclisation in the biosynthesis of ionophores such as monensin pose interesting objects of research. We present here a study of the substrate promiscuity of the polyether cyclisation cascade enzymes in monensin biosynthesis in the conversion of redox derivatives of the nascent polyketide chain. LC-HRMS/MS²-based studies revealed a remarkable flexibility of the post-PKS enzymes. They acted on derivatized polyketide backbones based on the three possible polyketide redox states within two different modules and gave rise to an altered polyether structure. One of these monensin derivatives was isolated and characterized by 2D-NMR spectroscopy, crystallography, and bioactivity studies.     

Molecular-Cling-Effect of Fluoroethylene Carbonate Characterized via Ethoxy(pentafluoro)cyclotriphosphazene on SiOx/C Anode Materials – A New Perspective for Formerly Sub-Sufficient SEI Forming Additive Compounds

Effective electrolyte compositions are of primary importance in raising the performance of lithium-ion batteries (LIBs). Recently, fluorinated cyclic phosphazenes in combination with fluoroethylene carbonate (FEC) have been introduced as promising electrolyte additives, which can decompose to form an effective dense, uniform, and thin protective layer on the surface of electrodes. Although the basic electrochemical aspects of cyclic fluorinated phosphazenes combined with FEC were introduced, it is still unclear how these two compounds interact constructively during operation. This study investigates the complementary effect of FEC and ethoxy(pentafluoro)cyclotriphosphazene (EtPFPN) in aprotic organic electrolyte in LiNi_0.5Co_0.2Mn_0.3O ∥ SiO_x/C full cells. The formation mechanism of lithium ethyl methyl carbonate (LEMC)-EtPFPN interphasial intermediate products and the reaction mechanism of lithium alkoxide with EtPFPN are proposed and supported by Density Functional Theory calculations. A novel property of FEC is also discussed here, called molecular-cling-effect (MCE). To the best knowledge, the MCE has not been reported in the literature, although FEC belongs to one of the most investigated electrolyte additives. The beneficial MCE of FEC toward the sub-sufficient solid-electrolyte interphase forming additive compound EtPFPN is investigated via gas chromatography-mass spectrometry, gas chromatography high resolution-accurate mass spectrometry, in situ shell-isolated nanoparticle-enhanced Raman spectroscopy, and scanning electron microscopy.     

Biokatalytische Ganzzellproduktion des Sesquiterpens Presilphiperfolan-8β-ol in stoffwechseloptimierten Escherichia coli

Fermentative whole-cell production in Escherichia coli offers the option of producing complex natural products such as terpenes from simple, inexpensive, and sustainable carbon sources. The aim of this study was to develop such a process for the synthesis of presilphiperfolan-8β-ol (PSP). The biosynthetic pathway of this tricyclic sesquiterpene alcohol was successfully introduced into E. coli. The resulting multi-plasmid strain was able to produce farnesyl pyrophosphate in vivo via the mevalonate pathway, which was then converted to PSP by the sesquiterpene cyclase BcBOT2. The product, which is mainly secreted into the culture medium, was identified via GC-MS and quantified via GC-FID. The constructed strain produced 10 mg L⁻¹ PSP in 48 h at 20 °C directly from carbon feedstock.     

Digitale Zwillinge in der Bioprozesstechnik – Chancen und Möglichkeiten

The digitalization of processes is one of the currently dominating topics and missions in both industrial production and scientific research. In biotechnology, these efforts have enormous potential to optimize existing bioprocesses or to develop new bioprocesses for upcoming challenges. In this review, the state-of-art of digitalization in bioprocess engineering is considered, the terms digital twin and digital shadow are characterized, and an outlook on future Lab 4.0 concepts is given.     

Fostering knowledge sharing: Design principles for persuasive digital technologies in open innovation projects

Integrating knowledge is crucial for open innovation, and digital technologies can play a central role because they support knowledge sharing. In open innovation projects, in particular, little is known about the role of technology. Here, the individual behaviour of users is taken into account concerning the extent to which knowledge is shared. Therefore, persuasive technologies offer the potential to foster sharing. In particular, to facilitate the construction of future digital technologies, this study applies a design science research approach to create and analyse artefacts as a research contribution and develop design principles as a step towards a nascent design theory. We present insights from the design and application of three artefacts in different stages of open innovation processes. Results show that digital technologies can be used for various purposes: to build a common understanding, support design phases, communicate ideas and simplify the application of the technology for the user. Our research provides insights into the role of digital technologies for knowledge sharing in open innovation projects, and four design principles are found to facilitate the construction of future persuasive digital technologies for open innovation projects.     

Van der Waals Heteroepitaxy of GaSe and InSe,Quantum Wells,and Superlattices

Bandgap engineering and quantum confinement in semiconductor heterostructures provide the means to fine-tune material response to electromagnetic fields and light in a wide range of the spectrum. Nonetheless, forming semiconductor heterostructures on lattice-mismatched substrates is a challenge for several decades, leading to restrictions for device integration and the lack of efficient devices in important wavelength bands. Here, it is shown that the van der Waals epitaxy of 2D GaSe and InSe heterostructures occur on substrates with substantially different lattice parameters, namely silicon and sapphire. The GaSe/InSe heteroepitaxy is applied in the growth of quantum wells and superlattices presenting photoluminescence and absorption related to interband transitions.