Effect of Selenium on Lipid and Amino Acid Metabolism in Yeast Cells

Biological Trace Element Research - This article discusses the effect of selenium in aqueous solutions on aspects of lipid and amino acid metabolism in the cell biomass of Saccharomyces cerevisiae...     

Effect of Zinc Sulfate and Zinc Glycine Chelate on Concentrations of Acute Phase Proteins in Chicken Serum and Liver Tissue

Biological Trace Element Research - The aim of the study was to determine how inorganic and organic forms of zinc affect the concentrations of C-reactive protein (CRP), serum amyloid A (SAA),...     

The effects of novel synthetic cytokinin derivatives and endogenous cytokinins on the in vitro growth responses of hemp (Cannabis sativa L.) explants

Plant Cell, Tissue and Organ Culture (PCTOC) - The biotechnological utilization (genetic transformation, gene editing) of industrial hemp (Cannabis sativa L.) has been hampered by a lack of robust...     

Critical swimming speed of sterlet (Acipenser ruthenus): Does intraspecific hybridization affect swimming performance?

We studied the effect of intraspecific hybridization on swimming performance in sterlet, hypothesizing that such hybridization increases the performance by inducing the hybrid vigor. A total of 12 purebred and hybrid crosses were reproduced from Danube (D) and Volga (V) populations of Acipenser ruthenus. Within each cross, one group of fish was exposed to temperature challenges mimicking the temperature variation in the natural environment during summer. Temperature challenges comprised a constant increase from 19°C to 24°C and then return to 19°C within 12 hr (dT<1°C/hr), and were carried out every third day over the experimental period of 20 days. As a control, fish from each cross were kept at a constant temperature of 19°C. Critical swimming speed (U_crit) was assessed on day 0 (29 days post hatch, dph), 10 (39 dph) and 20 (49 dph). The critical swimming speeds ranged from 5.12 cm/s (1.63 TL/s) to 16.44 cm/s (2.4 TL/s) during the experimental period (29–49 dph). There were no significant differences observed in U_crit between repeatedly temperature challenged and control groups, indicating that the temperature challenge did not alter the swimming performance. The critical swimming speed showed positive relationship with total body length. Comparing intraspecific hybrid crosses with purebred crosses, no significant difference in swimming performance was observed. It is thus concluded that swimming performance is a family specific trait. There is no indication that intraspecific hybridization affects swimming performance nor that close‐to‐natural temperature regimes increase swimming performance.     

A novel LED‐based 2D‐fluorescence spectroscopy system for in‐line monitoring of Chinese hamster ovary cell cultivations – Part I

A new two‐dimensional fluorescence sensor system was developed for in‐line monitoring of mammalian cell cultures. Fluorescence spectroscopy allows for the detection and quantification of naturally occurring intra‐ and extracellular fluorophores in the cell broth. The fluorescence signals correlate to the cells’ current redox state and other relevant process parameters. Cell culture pretests with twelve different excitation wavelengths showed that only three wavelengths account for a vast majority of spectral variation. Accordingly, the newly developed device utilizes three high‐power LEDs as excitation sources in combination with a back‐thinned CCD‐spectrometer for fluorescence detection. This setup was first tested in a lab design of experiments study with process relevant fluorophores proving its suitability for cell culture monitoring with LOD in the μg/L range. The sensor was then integrated into a CHO‐K1 cell culture process. The acquired fluorescence spectra of several batches were evaluated using multivariate methods. The resulting batch evolution models were challenged in deviating and “golden batch” validation runs. These first tests showed that the new sensor can trace the cells’ metabolic state in a fast and reliable manner. Cellular distress is quickly detected as a deviation from the “golden batch”.     

Actin‐spectrin scaffold supports open fenestrae in liver sinusoidal endothelial cells

Fenestrae are open transmembrane pores that are a structural hallmark of healthy liver sinusoidal endothelial cells (LSECs). Their key role is the transport of solutes and macromolecular complexes between the sinusoidal lumen and the space of Disse. To date, the biochemical nature of the cytoskeleton elements that surround the fenestrae and sieve plates in LSECs remain largely elusive. Herein, we took advantage of the latest developments in atomic force imaging and super‐resolution fluorescence nanoscopy to define the organization of the supramolecular complex(es) that surround the fenestrae. Our data revealed that spectrin, together with actin, lines the inner cell membrane and provided direct structural support to the membrane‐bound pores. We conclusively demonstrated that diamide and iodoacetic acid (IAA) affect fenestrae number by destabilizing the LSEC actin‐spectrin scaffold. Furthermore, IAA induces rapid and repeatable switching between the open vs closed state of the fenestrae, indicating that the spectrin‐actin complex could play an important role in controlling the pore number. Our results suggest that spectrin functions as a key regulator in the structural preservation of the fenestrae, and as such, it might serve as a molecular target for altering transendothelial permeability.     

Intact cell mass spectrometry as a progress tracking tool for batch and fed-batch fermentation processes

Penicillin production during a fermentation process using industrial strains of Penicillium chrysogenum is a research topic permanently discussed since the accidental discovery of the antibiotic. Intact cell mass spectrometry (ICMS) can be a fast and novel monitoring tool for the fermentation progress during penicillin V production in a nearly real-time fashion. This method is already used for the characterization of microorganisms and the differentiation of fungal strains; therefore, the application of ICMS to samples directly harvested from a fermenter is a promising possibility to get fast information about the progress of fungal growth. After the optimization of the ICMS method to penicillin V fermentation broth samples, the obtained ICMS data were evaluated by hierarchical cluster analysis or an in-house software solution written especially for ICMS data comparison. Growth stages of a batch and fed-batch fermentation of Penicillium chrysogenum are differentiated by one of those statistical approaches. The application of two matrix-assisted laser desorption/ionization time-of-flight (MALDI–TOF) instruments in the linear positive ion mode from different vendors demonstrated the universal applicability of the developed ICMS method. The base for a fast and easy-to-use method for monitoring the fermentation progress of P. chrysogenum is created with this ICMS method developed especially for fermentation broth samples.     

Genes of the extinct Caucasian bison still roam the Białowieża Forest and are the source of genetic discrepances between Polish and Belarusian populations of the European bison,Bison bonasus

European bison (Bison bonasus) populations from both the Polish (PL) and the Belarusian (BY) sides of the Bia?owie?a Forest represent the Lowland genetic line (LB line) – progeny of the Lowland bison (Bison bonasus bonasus) that inhabited western, central, and south‐eastern Europe in historical times. During the species recovery, one of the founders was a descendant of the extinct Caucasian bison (Bison bonasus caucasicus) and its descendants formed the other genetic line – Lowland–Caucasian (LC). There have been justified suspicions that LB European bison in the former Soviet Union had undergone cross‐mating with the LC line. We performed a comparative genetic analyses on European bison from the BY and PL parts of the Bia?owie?a Forest, the LC line and extinct Caucasian bison, based on a set of 19 microsatellite markers and 1512 bovine single nucleotide polymorphism (SNP) markers, polymorphic in at least one of the studied populations. Although genetic variability (mean allele number and expected heterozygosity) for both populations were similar, the F_ST jack‐knifing and principal component analyses PCA revealed highly significant differences between PL and BY bison from the Bia?owie?a Forest. Examining DNA of the extinct Caucasian bison revealed that at least part of the genetic variants found in the BY, but not the PL, population were of Caucasian origin. The results indicate that the contemporary population of European bison from the BY part of the Bia?owie?a Forest should not be regarded as a LB line. The results also suggest that the actual global population size of the LB line European bison is only a half of its official status. Consideration of the presented results are crucial in determining management actions and policy decisions in order to conserve LB line bison within the Bia?owie?a Forest – its natural refuge. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 752–763.