Compartment-specific metabolome analysis reveals the tight link between IgG1 formation and necessarily high mitochondrial shuttle activities in Chinese Hamster Ovary cells

Chinese hamster ovary (CHO) cells are the dominating host for the production of pharmaceutical proteins, in particular monoclonal antibodies (mABs). Although production titers improved more than 100 fold during the last 2 decades, similar enhancements of cell specific productivities are less pronounced. They demand for detailed subcellular studies to identify promising metabolic engineering targets. In this context, our study focused on compartment specific metabolome analysis to measure metabolic patterns in the cytosol and in the mitochondrion during cell cultivation. Thereof, in vivo shuttle activities were calculated and correlated with cell specific IgG1 formation rates. The compartment-specific metabolome and labelling analysis (13C) distinguishes between cytosol and mitochondrion. Metabolomics and instationary 13C metabolic flux analysis build on preliminary own studies of 13C analytics (Teleki et al., Anal Biochem 2015; Teleki et al. Metab Eng 2017) and compartment-specific metabolomics (Matuszczyk et al., Biotechnol J 2015; Pfitzenmaier et al., Biotechnol J 2016). Further development and optimization has been performed finally reaching the current status that allows monitoring compartment-specific flux distributions and shuttle activities during the course of cell cultivation. Studying multiple periods of an IgG1 production process the crucial role of the mitochondrion not only as a provider of ATP but also as an essential part of metabolism was unraveled. 13C flux analysis disclosed the time-variant activities of the mitochondrial shuttles that are tightly linked to mitochondrial and cytosolic metabolism. Clear evidence was found that mAB production strongly depends on sufficient NADPH supply provided by cytosolic malic enzyme activity and malate export from the mitochondrio

Nanomagnetic Particle Production: Effect of Carbon and Iron Sources

Production of nanomagnetic particles via microbial processes offers the advantage of better biocompatibility for medical applications. However, this process is not widely applied due to the difficulties in cultivating magnetotactic bacteria in the lab. This research explored the possibilities of cultivating magnetotactic bacteria in order to produce nanomagnetic particles in the lab and in particular to find the carbon and iron sources to get the optimum yield of nanomagnetic particles. Experiments were performed as semiaerobic-batch-magnetotactic-bacteria cultivations. The carbon source in the media was varied as: sodium lactate, sodium acetate, and sodium pyruvate. As for the iron source, either Fe-citrate or Fe-quinate was used. Bacterial cell growth was monitored using the turbidometry-gravimetry method, substrate concentration was measured using high performance liquid chromatography (HPLC), while the cellular iron content was measured using electron dispersive X-ray spectroscopy (EDS) and transmission electronic microscopy (TEM). It was observed that cell growth did not correlate with the production of nanomagnetic particles. The bacteria grew best on sodium pyruvate and Fe-quinate, however, the best yield of nanomagnetic particles was obtained from the cultivation with sodium acetate and Fe-quinate. The obtained TEM images confirmed the presence of nanomagnetic particles

PENGEMBANGAN SISTEM APLIKASI TELEMEDICINE PELAYANAN DAN PERAWATAN ANAK

PENGEMBANGAN SISTEM APLIKASI TELEMEDICINE PELAYANAN DAN PERAWATAN ANAK