Facing the challenges – A miniaturized platform for integrated process development of products from microbial hosts

The recent developments within the biopharmaceutical market change the demands and requirements that have to be addressed. The venture of biosimilars and biobetters based on the off-patent situation enhances the need for acceleration of process development with high flexibility for new products. The trend toward PAT and continuous processing raises the need for better process understanding and integrated process development which challenges both - up and downstream processing. Bacterial systems offer high advantages and flexibility for high yield overexpression but often end up in very complex processes during product recovery. Often overexpression in E.coli is therefore limited to soluble fractions which means a severe limitation and restricts the opportunity to succeed. This talk present a HTS platform to evaluate the entire process of proteins expressed in E. coli as inclusion bodies – directly connecting DoE screening in upstream development to the subsequent downstream process including cell disruption, IB preparation and protein capture. This fast and material saving platform method provides a high-quality evaluation of fermentation screenings and reduces the initial barrier and reservation for IB processes opening potential for new products. As additional benefit you will generate valuable knowledge and gain better understanding of your process on the way

A Subtle Interplay Between Three Pex11 Proteins Shapes De Novo Formation and Fission of Peroxisomes

The organization of eukaryotic cells into membrane-bound compartments must be faithfully sustained for survival of the cell. A subtle equilibrium exists between the degradation and the proliferation of organelles. Commonly, proliferation is initiated by a membrane remodeling process. Here, we dissect the function of proteins driving organelle proliferation in the particular case of peroxisomes. These organelles are formed either through a growth and division process from existing peroxisomes or de novo from the endoplasmic reticulum (ER). Among the proteins involved in the biogenesis of peroxisomes, peroxins, members of the Pex11 protein family participate in peroxisomal membrane alterations. In the yeast Saccharomyces cerevisiae, the Pex11 family consists of three proteins, Pex11p, Pex25p and Pex27p. Here we demonstrate that yeast mutants lacking peroxisomes require the presence of Pex25p to regenerate this organelle de novo. We also provide evidence showing that Pex27p inhibits peroxisomal function and illustrate that Pex25p initiates elongation of the peroxisomal membrane. Our data establish that although structurally conserved each of the three Pex11 protein family members plays a distinct role. While ScPex11p promotes the proliferation of peroxisomes already present in the cell, ScPex25p initiates remodeling at the peroxisomal membrane and ScPex27p acts to counter this activity. In addition, we reveal that ScPex25p acts in concert with Pex3p in the initiation of de novo peroxisome biogenesis from the ER

High intraspecific variation of the cell surface physico-chemical and bioadhesion properties in Brettanomyces bruxellensis

Brettanomyces bruxellensis is the most damaging spoilage yeast in the wine industry because of its negative impact on the wine organoleptic qualities. The strain persistence in cellars over several years associated with recurrent wine contamination suggest specific properties to persist and survive in the environment through bioadhesion phenomena. In this work, the physico-chemical surface properties, morphology and ability to adhere to stainless steel were studied both on synthetic medium and on wine. More than 50 strains representative of the genetic diversity of the species were considered. Microscopy techniques made it possible to highlight a high morphological diversity of the cells with the presence of pseudohyphae forms for some genetic groups. Analysis of the physico-chemical properties of the cell surface reveals contrasting behaviors: most of the strains display a negative surface charge and hydrophilic behavior while the Beer 1 genetic group has a hydrophobic behavior. All strains showed bioadhesion abilities on stainless steel after only 3 h with differences in the concentration of bioadhered cells ranging from 2.2 × 102 cell/cm2 to 7.6 × 106 cell/cm2. Finally, our results show high variability of the bioadhesion properties, the first step in the biofilm formation, according to the genetic group with the most marked bioadhesion capacity for the beer group. © 2023 The Author

Persistent Nav1.1 and Nav1.6 currents drive spinal locomotor functions through nonlinear dynamics

Summary: Persistent sodium current (INaP) in the spinal locomotor network promotes two distinct nonlinear firing patterns: a self-sustained spiking triggered by a brief excitation in bistable motoneurons and bursting oscillations in interneurons of the central pattern generator (CPG). Here, we identify the NaV channels responsible for INaP and their role in motor behaviors. We report the axonal Nav1.6 as the main molecular player for INaP in lumbar motoneurons. The inhibition of Nav1.6, but not of Nav1.1, in motoneurons impairs INaP, bistability, postural tone, and locomotor performance. In interneurons of the rhythmogenic CPG region, both Nav1.6 and Nav1.1 equally mediate INaP. Inhibition of both channels is required to abolish oscillatory bursting activities and the locomotor rhythm. Overall, Nav1.6 plays a significant role both in posture and locomotion by governing INaP-dependent bistability in motoneurons and working in tandem with Nav1.1 to provide INaP-dependent rhythmogenic properties of the CPG

Archéorient et l'Oasi-WWF : aux frontières de l'imagerie acoustique

https://archeorient.hypotheses.org/2363

Archéorient et l'Oasi-WWF : aux frontières de l'imagerie acoustique

https://archeorient.hypotheses.org/2363

The M-current works in tandem with the persistent sodium current to set the speed of locomotion

International audienceThe central pattern generator (CPG) for locomotion is a set of pacemaker neurons endowed with inherent bursting driven by the persistent sodium current (INaP). How they proceed to regulate the locomotor rhythm remained unknown. Here, in neonatal rodents, we identified a persistent potassium current critical in regulating pacemakers and locomotion speed. This current recapitulates features of the M-current (IM): a subthreshold noninactivating outward current blocked by 10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone dihydrochloride (XE991) and enhanced by N-(2-chloro-5-pyrimidinyl)-3,4-difluorobenzamide (ICA73). Immunostaining and mutant mice highlight an important role of Kv7.2-containing channels in mediating IM. Pharmacological modulation of IM regulates the emergence and the frequency regime of both pacemaker and CPG activities and controls the speed of locomotion. Computational models captured these results and showed how an interplay between IM and INaP endows the locomotor CPG with rhythmogenic properties. Overall, this study provides fundamental insights into how IM and INaP work in tandem to set the speed of locomotion

Co-évolution d’une ville et de sa lagune : avancées du projet IMU-Orbetello

Contexte Jusqu’au 19e siècle, la plupart des ports était construits le long des segments les plus abrités des côtes, souvent à l’intérieur d'estuaires ou de lagunes. Ces pépinières de ports favorables en menacent cependant le développement ultérieur, car ces milieux évoluent vite, au gré des déplacements du trait de côte et des cours de rivières, soumettant les bassins portuaires à l’érosion et au comblement. L’expansion même des ports et des villes portuaires, entravée par le carcan estuar..

Kv1.2 Channels Promote Nonlinear Spiking Motoneurons for Powering Up Locomotion

International audienceGraphical Abstract Highlights d Neonatal and adult bistable motoneurons display delayed spike-frequency acceleration d Delayed spike-frequency acceleration reflects slow inactivation of Kv1.2 channels d Kv1.2 channels are highly expressed in axon initial segments of motoneurons d Slow inactivation of Kv1.2 channels amplifies motor outputs upon locomotion onset In Brief Bos et al. demonstrate that slow inactivation of Kv1.2 channels is critical in shaping nonlinear firing properties in mammalian spinal cord. It provides a potent gain control mechanism in spinal motoneurons and has a behavioral role in enhancing locomotor drive during the transition from immobility to steady-state locomotion

Activation of 5-HT 2A receptors restores KCC2 function and reduces neuropathic pain after spinal cord injury

International audienc