Particles occur in almost all processes in chemical and life sciences. The particle size and shape influence the process performance and product quality, and in turn they are influenced by the flow behavior of the par...Particles occur in almost all processes in chemical and life sciences. The particle size and shape influence the process performance and product quality, and in turn they are influenced by the flow behavior of the particles during production. Monitoring and controlling such characteristics in multiphase systems to obtain sufficient qualities will greatly facilitate the achievement of reproducible and defined distributions. So far, obtaining this information inline has been challenging, because existing instruments lack measurement precision, being unable to process overlapping signals from different particle phases in highly concentrated multiphase systems. However, recent advances in photo-optics made it possible to monitor such features(particle size distribution(PSD), aspect ratio and particle concentration) with advanced image analysis(IA) in real-time. New analysis workflows as well as single feature extractions from the images using multiple image analysis algorithms allowed the precise real-time measurements of size, shape and concentration of particle collectives even separated from each other in three phase systems. The performances, advantages and drawbacks with other non-photo-optical methods for assessing the particle size distribution are compared and discussed.展开更多
Bioprocess scale-down simulators are used to investigate the phenomena occurring in industrial scale cultivations. The aim is to simulate the large-scale conditions, characterized by long mixing times introducing loca...Bioprocess scale-down simulators are used to investigate the phenomena occurring in industrial scale cultivations. The aim is to simulate the large-scale conditions, characterized by long mixing times introducing local gradients into the bioreactor, in laboratory scale bioreactor. We have expanded the current physiological knowledge about the consequences of such cultivation conditions from well-known mixed-acid fermentation to amino acid metabolism. Several interesting deviations were observed for amino acids derived from pyruvate when a STR-PFR scale-down simulator and a regular STR fed-batch cultivation were compared. In this article we show that the cultivation of Escherichia coli K-12 substrain W3110 in a scale-down two-compartment bioreactor has consequences on the free amino acid pools. Repeated occurrence of high glucose zones affects the biosynthesis of amino acids derived from pyruvate. This is interesting since the pyruvate based amino acids are precursors of the branched chain amino acid pathway, which is further disturbed by an unbalanced regulation caused by a frameshift mutation in the ilvG gene of E. coli K-12 strains. As a consequence the formation of non-typical amino acid norvaline was detected in the two compartment bioreactor cultivation.展开更多
Hydrolysis at changing hydraulic retention time,recirculation,bedding straw content in the feed,bioaugmentation and the impact of those changes on gradient formation in the liquid phase in plug-flow reactors(PFRs)was ...Hydrolysis at changing hydraulic retention time,recirculation,bedding straw content in the feed,bioaugmentation and the impact of those changes on gradient formation in the liquid phase in plug-flow reactors(PFRs)was examined.The pH-value,conductivity and oxidation-reduction potential(ORP)were monitored at three spots along the PFRs to study potential correlations to process performance during a total process time of 123 weeks.The on-line monitoring showed good correlations to acidogenesis:namely,the pH and ORP to the acidification,to butyric(and lactic)acid concentration and to the acid yield.The ORP(measured at the inlet)showed the most stable correlation to acidogenesis under dynamic operation,while the conductivity(at the outlet)correlated to the acid concentration in dependence on the feedstock.Multiple measurement spots as used in this study allow to gain more information about acidogenic fermentation than a single spot,simplifying process control and automation attempts with recalcitrant feedstock.展开更多
基金financially supported by the grants for the project "Smart Process Inspection" (funding code ZF4184501CR5) from the "Zentrales Innovationsprogramm Mittelstand" (ZIM)
文摘Particles occur in almost all processes in chemical and life sciences. The particle size and shape influence the process performance and product quality, and in turn they are influenced by the flow behavior of the particles during production. Monitoring and controlling such characteristics in multiphase systems to obtain sufficient qualities will greatly facilitate the achievement of reproducible and defined distributions. So far, obtaining this information inline has been challenging, because existing instruments lack measurement precision, being unable to process overlapping signals from different particle phases in highly concentrated multiphase systems. However, recent advances in photo-optics made it possible to monitor such features(particle size distribution(PSD), aspect ratio and particle concentration) with advanced image analysis(IA) in real-time. New analysis workflows as well as single feature extractions from the images using multiple image analysis algorithms allowed the precise real-time measurements of size, shape and concentration of particle collectives even separated from each other in three phase systems. The performances, advantages and drawbacks with other non-photo-optical methods for assessing the particle size distribution are compared and discussed.
文摘Bioprocess scale-down simulators are used to investigate the phenomena occurring in industrial scale cultivations. The aim is to simulate the large-scale conditions, characterized by long mixing times introducing local gradients into the bioreactor, in laboratory scale bioreactor. We have expanded the current physiological knowledge about the consequences of such cultivation conditions from well-known mixed-acid fermentation to amino acid metabolism. Several interesting deviations were observed for amino acids derived from pyruvate when a STR-PFR scale-down simulator and a regular STR fed-batch cultivation were compared. In this article we show that the cultivation of Escherichia coli K-12 substrain W3110 in a scale-down two-compartment bioreactor has consequences on the free amino acid pools. Repeated occurrence of high glucose zones affects the biosynthesis of amino acids derived from pyruvate. This is interesting since the pyruvate based amino acids are precursors of the branched chain amino acid pathway, which is further disturbed by an unbalanced regulation caused by a frameshift mutation in the ilvG gene of E. coli K-12 strains. As a consequence the formation of non-typical amino acid norvaline was detected in the two compartment bioreactor cultivation.
基金financially supported by the Fachagentur für Nachhaltige Rohstoffe e.V.(FNR),grant number 22039818.
文摘Hydrolysis at changing hydraulic retention time,recirculation,bedding straw content in the feed,bioaugmentation and the impact of those changes on gradient formation in the liquid phase in plug-flow reactors(PFRs)was examined.The pH-value,conductivity and oxidation-reduction potential(ORP)were monitored at three spots along the PFRs to study potential correlations to process performance during a total process time of 123 weeks.The on-line monitoring showed good correlations to acidogenesis:namely,the pH and ORP to the acidification,to butyric(and lactic)acid concentration and to the acid yield.The ORP(measured at the inlet)showed the most stable correlation to acidogenesis under dynamic operation,while the conductivity(at the outlet)correlated to the acid concentration in dependence on the feedstock.Multiple measurement spots as used in this study allow to gain more information about acidogenic fermentation than a single spot,simplifying process control and automation attempts with recalcitrant feedstock.
