Combination of On-line pH and Oxygen Transfer Rate Measurement in Shake Flasks by Fiber Optical Technique and Respiration Activity MOnitoring System (RAMOS)

Abstract

Shake flasks are commonly used for process development in biotechnology industry. For this purpose a lot of information is required from the growth conditions during the fermentation experiments. Therefore, Anderlei et al. developed the RAMOS technology [1, 2], which proviedes on-line oxygen and carbondioxide transfer rates in shake flasks. Besides oxygen consumption, the pH in the medium also plays an important role for the successful cultivation of micro-organisms and for process development. For online pH measurement fiber optical methods based on fluorophores are available. Here a combination of the on-line Oxygen Transfer Rate (OTR) measurements in the RAMOS device with an on-line, fiber optical pH measurement is presented. To demonstrate the application of the combined measurement techniques, Escherichia coli cultivations were performed and on-line pH measurements were compared with off-line samples. The combination of on-line OTR and pH measurements gives a lot of information about the cultivation and, therefore, it is a powerful technique for monitoring shake flask experiments as well as for process development.

Characterization of antibacterial polyethersulfone membranes using the respiration activity monitoring system (RAMOS)

“…Therefore, the results of this experiment are significant for the development of membranes for these purposes. The OTR of the reference culture follows a typical course of cultures in this medium (Scheidle et al, 2007) and peaks after ca. 23.5 h at a height of ca.…”

“…For agar plates 17 g/L agar was added. As a mineral medium Wilms-MOPS synthetic medium was used (Wilms et al, 2001;Scheidle et al, 2007). The medium consists of 20 g/L glucose 5 g/L (NH 4 ) 2 SO 4 ; 0.5 g/L NH 4 Cl; 3 g/L K 2 HPO 4 ; 2 g/L Na 2 SO 4 ; 0.5 g/L MgSO 4 $7H 2 O; 41.85 g/L (0.2 M) 3-(N-morpholino)-propanesulfonic acid (MOPS); 0.1 g/L ampicillin; 0.01 g/L thiamine hydrochloride; 1 mL/L trace element solution ( …”

“…It was used for different applications in process development, media optimization and screening of microorganisms (Stö ckmann et al, 2003;Jeude et al, 2006;Klement et al, 2011). Several publications characterized the growth of the model microorganism E. coli in RAMOS shake flask cultures (Losen et al, 2004;Scheidle et al, 2007;Huber et al, 2011;Scheidle et al, 2011).…”

Optical assessment of impact and recovery of sedimentary pH profiles in ocean acidification and carbon capture and storage research

“…This technology has existed for some time and been successfully implemented in other areas of research and industry (e.g. Kensy et al, 2005;Puskeiler et al, 2005;Scheidle et al, 2007), having been used for sediment profiling (Blossfeld et al, 2010). However, despite its potential and ease-of-use, it has not been implemented in the context of marine sedimentary pH profile acquisition.…”

High-Throughput Workflow for Monitoring and Mining Bioprocess Data and Its Application to Inferring the Physiological Response of Escherichia coli to Perturbations

“…In addition, these major physiological parameters provide information on cellular metabolism. For instances, the trend of pH values may be a qualitative indicator of phenomena such as organic acid production or consumption (50) and the course of pO 2 may point out substrate or oxygen limitations, product inhibitions, or diauxic growth (2). For these reasons, online measurements are favorable for small-scale process monitoring.…”