Respiration activity monitoring system (RAMOS), an efficient tool to study the influence of the oxygen transfer rate on the synthesis of lipopeptide by Bacillus subtilis ATCC6633

Abstract Background Growing large crop monocultures and heavily using pesticides enhances the chance of evolution of pesticide-insensitive pests and pathogens. To reduce pesticide use in crop cultivation, the application of priming-active compounds (PrimACs) is a welcome alternative. PrimACs strengthen the plant immune system and can thus help to protect plants with lower amounts of pesticides. PrimACs can be identified, for example, by their capacity to enhance the respiratory activity of parsley cells in culture as determined by the oxygen transfer rate (OTR) using the respiration activity monitoring system (RAMOS) or its miniaturized version, µRAMOS. The latter was designed for with suspensions of bacteria and yeast cells in microtiter plates (MTPs). So far, RAMOS or µRAMOS have not been applied to adult plants or seedlings which would overcome the limitation of (µ)RAMOS to plant suspension cell cultures. Results In this work, we introduce a modified µRAMOS for analysis of plant seedlings. The novel device allows illuminating the seedlings and records the respiratory activity in each well of a 48-well MTP. To validate the suitability of the setup for identifying novel PrimAC in Arabidopsis thaliana, seedlings were grown in MTP for seven days and treated with the known PrimAC salicylic acid (SA; positive control) and the PrimAC candidate methyl 1-(3,4-dihydroxyphenyl)-2-oxocyclopentane-1-carboxylate (Tyr020). Twenty-eight h after treatment, the seedlings were elicited with flg22, a 22-amino acid peptide of bacterial flagellin. Upon elicitation, the respiratory activity was monitored. The evaluation of the OTR course reveals Tyr020 as a likely PrimAC. The priming-inducing activity of Tyr020 was confirmed using molecular biological analyses in A. thaliana seedlings. Conclusion We disclose the suitability of µRAMOS for identifying PrimACs in plant seedlings. The difference in OTR during a night period between primed and unprimed plants was clearly distinguishable after elicitation with flg22. Thus, it has been shown, that the µRAMOS device can be used for a reliable screening for PrimACs in plant seedlings.

Download Full-text

An illuminated respiratory activity monitoring system identifies priming-active compounds in plant seedlings

BMC Plant Biology ◽

10.1186/s12870-021-03100-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Judith Loogen ◽

André Müller ◽

Arne Balzer ◽

Sophie Weber ◽

Kathrin Schmitz ◽

...

Keyword(s):

Monitoring System ◽

Respiratory Activity ◽

Oxygen Transfer Rate ◽

Positive Control ◽

Activity Monitoring ◽

Yeast Cells ◽

Respiration Activity ◽

Active Compounds ◽

Amino Acid Peptide ◽

Plant Seedlings

Abstract Background Growing large crop monocultures and heavily using pesticides enhances the evolution of pesticide-insensitive pests and pathogens. To reduce pesticide use in crop cultivation, the application of priming-active compounds (PrimACs) is a welcome alternative. PrimACs strengthen the plant immune system and could thus help to protect plants with lower amounts of pesticides. PrimACs can be identified, for example, by their capacity to enhance the respiratory activity of parsley cells in culture as determined by the oxygen transfer rate (OTR) using the respiration activity monitoring system (RAMOS) or its miniaturized version, µRAMOS. The latter was designed for with suspensions of bacteria and yeast cells in microtiter plates (MTPs). So far, RAMOS or µRAMOS have not been applied to adult plants or seedlings, which would overcome the limitation of (µ)RAMOS to plant suspension cell cultures. Results In this work, we introduce a modified µRAMOS for analysis of plant seedlings. The novel device allows illuminating the seedlings and records the respiratory activity in each well of a 48-well MTP. To validate the suitability of the setup for identifying novel PrimAC in Arabidopsis thaliana, seedlings were grown in MTP for seven days and treated with the known PrimAC salicylic acid (SA; positive control) and the PrimAC candidate methyl 1-(3,4-dihydroxyphenyl)-2-oxocyclopentane-1-carboxylate (Tyr020). Twenty-eight h after treatment, the seedlings were elicited with flg22, a 22-amino acid peptide of bacterial flagellin. Upon elicitation, the respiratory activity was monitored. The evaluation of the OTR course reveals Tyr020 as a likely PrimAC. The priming-inducing activity of Tyr020 was confirmed using molecular biological analyses in A. thaliana seedlings. Conclusion We disclose the suitability of µRAMOS for identifying PrimACs in plant seedlings. The difference in OTR during a night period between primed and unprimed plants was distinguishable after elicitation with flg22. Thus, it has been shown that the µRAMOS device can be used for a reliable screening for PrimACs in plant seedlings.

Download Full-text

Time-Resolved Monitoring of the Oxygen Transfer Rate of Chinese Hamster Ovary Cells Provides Insights Into Culture Behavior in Shake Flasks

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.725498 ◽

2021 ◽

Vol 9 ◽

Author(s):

Nina Ihling ◽

Lara Pauline Munkler ◽

Christoph Berg ◽

Britta Reichenbächer ◽

Johannes Wirth ◽

...

Keyword(s):

Oxygen Transfer ◽

Transfer Rate ◽

Shake Flask ◽

Oxygen Transfer Rate ◽

Carbon Sources ◽

Chinese Hamster ◽

Respiration Activity ◽

Time Resolved ◽

Non Invasive ◽

Shake Flasks

Cultivations of mammalian cells are routinely conducted in shake flasks. In contrast to instrumented bioreactors, reliable options for non-invasive, time-resolved monitoring of the culture status in shake flasks are lacking. The Respiration Activity Monitoring Respiration Activity Monitoring System system was used to determine the oxygen transfer rate (OTR) in shake flasks. It was proven that the OTR could be regarded as equal to the oxygen uptake rate as the change of the dissolved oxygen concentration in the liquid phase over time was negligibly small. Thus, monitoring the oxygen transfer rate (OTR) was used to increase the information content from shake flask experiments. The OTR of a Chinese hamster ovary cell line was monitored by applying electrochemical sensors. Glass flasks stoppered with cotton plugs and polycarbonate flasks stoppered with vent-caps were compared in terms of mass transfer characteristics and culture behavior. Similar mass transfer resistances were determined for both sterile closures. The OTR was found to be well reproducible within one experiment (standard deviation <10%). It correlated with changes in cell viability and depletion of carbon sources, thus, giving more profound insights into the cultivation process. Culture behavior in glass and polycarbonate flasks was identical. Monitoring of the OTR was applied to a second culture medium. Media differed in the maximum OTR reached during cultivation and in the time when all carbon sources were depleted. By applying non-invasive, parallelized, time-resolved monitoring of the OTR, the information content and amount of data from shake flask experiments was significantly increased compared to manual sampling and offline analysis. The potential of the technology for early-stage process development was demonstrated.

Download Full-text

DISTRIBUTION OF OXYGEN TRANSFER RATE IN STIRRED BIOREACTORS WITH SIMULATED BROTHS

Environmental Engineering and Management Journal ◽

10.30638/eemj.2008.034 ◽

2008 ◽

Vol 7 (3) ◽

pp. 199-211 ◽

Cited By ~ 1

Author(s):

Dan Cascaval ◽

Anca-Irina Galaction ◽

Stefanica Camarut ◽

Radu Z. Tudose

Keyword(s):

Oxygen Transfer ◽

Transfer Rate ◽

Oxygen Transfer Rate ◽

Stirred Bioreactors

Download Full-text

Estimation of oxygen transfer rate in sequencing batch reactor

Water Science & Technology ◽

10.2166/wst.1996.0458 ◽

1996 ◽

Vol 34 (3-4) ◽

pp. 413-420

Author(s):

Y. C. Liao ◽

D. J. Lee

Keyword(s):

Dissolved Oxygen ◽

Oxygen Transfer ◽

Transfer Rate ◽

Sequencing Batch Reactor ◽

Batch Reactor ◽

Oxygen Transfer Rate ◽

Intermittent Aeration ◽

Transient Effects ◽

Operational Parameters ◽

Transient Model

Transient model of oxygen transfer rate in a sequencing batch reactor is derived and solved numerically. The dissolved oxygen response under several conditions is analyzed. Effects of operational parameters and liquid bath height are studied. When with short, intermittent aeration periods, the transient effects on oxygen transfer rate may be substantial and should be taken into considerations. An example considering bioreaction is also given.

Download Full-text

Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽

10.3390/fluids6060226 ◽

2021 ◽

Vol 6 (6) ◽

pp. 226

Author(s):

Rashal Abed ◽

Mohamed M. Hussein ◽

Wael H. Ahmed ◽

Sherif Abdou

Keyword(s):

Mass Transfer ◽

Oxygen Transfer ◽

Transfer Rate ◽

Two Phase Flow ◽

Oxygen Transfer Rate ◽

Flow Patterns ◽

Oxygen Mass Transfer ◽

Phase Flow ◽

Two Phase ◽

Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

Download Full-text

Oxygen Supply Method Using Gas-Permeable Film for Wastewater Treatment

Water Science & Technology ◽

10.2166/wst.1993.0169 ◽

1993 ◽

Vol 28 (7) ◽

pp. 243-250 ◽

Cited By ~ 17

Author(s):

Y. Suzuki ◽

S. Miyahara ◽

K. Takeishi

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Oxygen Transfer ◽

Transfer Rate ◽

Oxygen Supply ◽

Oxygen Transfer Rate ◽

High Energy ◽

High Rate ◽

N Removal ◽

High Energy Consumption

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.

Download Full-text

Flow Mixing Enhancement from Balloon Pulsations in an Intravenous Oxygenator

Journal of Biomechanical Engineering ◽

10.1115/1.1894260 ◽

2004 ◽

Vol 127 (3) ◽

pp. 400-415 ◽

Cited By ~ 3

Author(s):

Amador M. Guzmán ◽

Rodrigo A. Escobar ◽

Cristina H. Amon

Keyword(s):

Numerical Simulations ◽

Oxygen Transfer ◽

Fiber Bundle ◽

Transfer Rate ◽

Oxygen Transfer Rate ◽

Three Dimensional ◽

Time Dependent ◽

Fiber Placement ◽

Flow Mixing ◽

Dependent Flow

Computational investigations of flow mixing and oxygen transfer characteristics in an intravenous membrane oxygenator (IMO) are performed by direct numerical simulations of the conservation of mass, momentum, and species equations. Three-dimensional computational models are developed to investigate flow-mixing and oxygen-transfer characteristics for stationary and pulsating balloons, using the spectral element method. For a stationary balloon, the effect of the fiber placement within the fiber bundle and the number of fiber rings is investigated. In a pulsating balloon, the flow mixing characteristics are determined and the oxygen transfer rate is evaluated. For a stationary balloon, numerical simulations show two well-defined flow patterns that depend on the region of the IMO device. Successive increases of the Reynolds number raise the longitudinal velocity without creating secondary flow. This characteristic is not affected by staggered or non-staggered fiber placement within the fiber bundle. For a pulsating balloon, the flow mixing is enhanced by generating a three-dimensional time-dependent flow characterized by oscillatory radial, pulsatile longitudinal, and both oscillatory and random tangential velocities. This three-dimensional flow increases the flow mixing due to an active time-dependent secondary flow, particularly around the fibers. Analytical models show the fiber bundle placement effect on the pressure gradient and flow pattern. The oxygen transport from the fiber surface to the mean flow is due to a dominant radial diffusion mechanism, for the stationary balloon. The oxygen transfer rate reaches an asymptotic behavior at relatively low Reynolds numbers. For a pulsating balloon, the time-dependent oxygen-concentration field resembles the oscillatory and wavy nature of the time-dependent flow. Sherwood number evaluations demonstrate that balloon pulsations enhance the oxygen transfer rate, even for smaller flow rates.

Download Full-text