Qubit Systems produces the only complete experimental package Q-Box NF1LP for measurement of nitrogen fixation in H2 producing legume symbioses. The unique flow-through H2 sensor (Q-S121) measures the production rate of H2 from N2-fixing tissues, allowing in vivo measurement of nitrogenase activity in real time. Measurement of H2 evolution as a means of determining nitrogenase activity overcomes all the problems of the traditional acetylene reduction assay. The Q-Box NF1LP Nitrogen Fixation Package is perfectly safe, non-invasive and allows changes in nitrogenase activity to be observed as they occur.

The Q-Box NF1LP Nitrogen Fixation Package includes:

• Q-S121 Hydrogen Analyzer (0-2000ppm) includes drying column
• Q-S102 O2 Analyzer 9-100% 
• S132 Temperature Sensor
• Q-G267 Pump & Flow Monitor (1L/min)
• Q-G268 Pump & Flow Monitor (2L/min)
• G122 Large Gas Bags (2)
• G132 Plant Growth Pots (4) with lids, fittings and Qubitac
• G161 Nodule Cuvette
• B201 Soybean seeds with Bradyrhizobium japonicum inoculant
• C610 LabQuest mini (2) data interface system
• C901 Logger Pro Software
• C404 Customized Setup Software
• Rugged water-proof case housing all analyzers and sensors
• Q-Box Accessory kit
• Manual
• A248 Battery pack (Optional)

The Nitrogen Fixation Package contains everything required to conduct numerous investigations into the physiology and biochemistry of N2 fixation in an open-flow gas exchange system.  We even supply legume seeds and inoculum! You supply only the computer. Calibration of analyzers is simple, set-up time is minimal and experiments are easy to perform.

Applications:

• Examine the effects of temperature on nitrogenase activity
• Examine the oxygen regulation of N2 fixation
• Measure the nitrogenase electron allocation coefficient
• Examine the relationship between N2 fixation and photosynthate supply
• Determine the effect of N2 fixation inhibition by fertilizers

Data from experiment investigating O2-lability of nitrogenase in an intact soybean plant:

Data showing the effect of temperature on nitrogenase activity:

MCGES – Multichannel Gas Exchange System allows studies of metabolism and physiology of living organisms via measurements of gas exchange. Qubit Systems can provide Gas Exchange Systems customized to your specifications and needs, to study photosynthesis, respiration, transpiration, N2-fixation and other processes.

MCGES-Multichannel Gas Exchange System may be controlled by the C950 Multichannel Gas Exchange Software to measure the flow of gases to the samples, through the sample chambers and to the gas analyzers. The C950 software controls all data acquisition from the sensors and analyzers, graphically displays the data and calculates gas exchange rates as required. Please  Contact QUBIT with your specifications and we will design your gas exchange system.

In a MCGES the reference gas may be supplied to the system from an air pump or from compressed gas tanks or an air compressor. If several gas mixtures are to be used then a gas mixing system is included (G400). Gasses can be humidified and dehumidified using a humidity controller.

In a multichannel system the gas enters the flow controller where it is split between sample channels, the flow in each channel being controlled by needle valves and measured by separate mass flow monitor. Gas Flow Controllers are available for any number of channels in multiples of four (4 (G248), 8 (G245) channels etc).

Gas enters each sample chamber which may or may not be temperature controlled. The structure of the chamber will depend on the organism. At Qubit, we can build chambers to your specifications. The effluent gas from each chamber enters a Gas Switcher (4 channel - G243, 8 channel – G244) that selects one of the channels for analysis, and vents the others to the atmosphere. Alternatively, the gas flow through the non-selected channels may be stopped, sealing that channel.

Gas from the selected channel is analyzed by one or several analyzers that may be arranged in a series or in parallel. Qubit supplies a wide range of analyzers for measuring CO2, O2, water vapor, H2, CH₄, N2O and other gases. Different analyzers are available across a wide range of gas concentrations and offer various features such as on board data acquisitions, rapid response times etc. We also offer gas conditioning columns, such as scrubbers for water and CO2 (A382).

Qubit Systems personnel have been designing gas exchange systems for over 30 years, and have published extensively on the physiology of respiration, photosynthesis and nitrogen fixation. We are committed to providing researchers with the most appropriate gas exchange system for a particular application at the best possible price, and we are always available to provide expert advice freely without obligation.   Contact QUBIT for furhter information.

References:

• M. R. Odiere, K. G. Koski, H. A. Weiler and M. E. Scott. Concurrent nematode infection and pregnancy induce physiological responses that impair linear growth in the murine foetus. Parasitology Vol 137,  p991-1002 (2010).

• Jumbo-Lucioni P, Ayroles JF, Chambers MM, Jorday KW, Leips J, Mackay TFC, DeLuca M. Systems Genetics analysis of body weight and energy metabolism traits in Drosophila melanogaster. BMC Genomics:11 p297- 309 (2010)

Q-S121 H2 Gas Analyzer is a flow through analyzer for measurements of H2 gas in 0-2000ppm range.  Linear response in the low range (0-20ppm) with ppb resolution.  The Q-S121 has a Tin-dioxide (SnO2) semiconductor sensing element.  Q-S121 can be used to measure Nitrogenase activity as H2 evolution in uptake hydogrenase (HUP) minus symbioses of legumes.  The Q-S121 H2 Gas Analyzer may also be used to monitor the hydrogen consumption of organisms that have the HUP enzyme.  This H2 Analyzer is a vital part of the Q-Box NF1LP Nitrogen Fixation Package.

Specifications:

• Range: 0 to 2000 ppm H2
•  Output: 0 to 5 V  analog to digital interface
• output sensitive to O2 concentration and flow rate
• warranty: 1 years

References:

• Catherine A. Osborne, Mark B. Peoples and Peter H. Janssen. Detection of a Reproducible, Single-Member Shift in Soil Bacterial Communities Exposed to Low Levels of Hydrogen. Applied and Environmental Microbiology Vol. 76, Number 5, p1471-1479 (2010).

• Stephanie A. Fischinger, Marieta Hristozkova, Zaman-Allah Mainassara and Joachim Schulze. Elevated CO₂ concentration around alfalfa nodules increases N₂ fixation. J. Exp. Bot. Vol  61, Number 1, p121-130 (2009).

• Mark B. Peoples, Paul D. McLennan and John Brockwell. Hydrogen emission from nodulated soybeans [Glycine max (L.) Merr.] and consequences for the productivity of a subsequent maize (Zea mays L.) crop. Plant and Soil Vol 307, Numbers 1-2, p67-82 ( 2008).

• Jiamila Maimaiti, Ye Zhang, Jing Yang, Yan-Ping Cen, David B. Layzell, Mark Peoples and Zhongmin Dong. Isolation and characterization of hydrogen-oxidizing bacteria induced following exposure of soil to hydrogen gas and their impact on plant growth. Environmental Microbiology Vol 9, Issue 2, p435–444 (2007).

• Y.-P. Cen and  D. B. Layzell. Does oxygen limit nitrogenase activity in soybean exposed to elevated CO₂? Plant, Cell & Environment Vol 27, Issue 10, p1229–1238 (2004).

• Z. Dong, L. Wu, B. Kettlewell, C. D. Caldwell and D. B. Layzell. Hydrogen fertilization of soils – is this a benefit of legumes in rotation? Plant, Cell & Environment Vol 26, Issue 11, p1875–1879 (2003).

• Z. Dong and D.B. Layzell. H2 oxidation, O2 uptake and CO2 fixation in hydrogen treated soils. Plant And Soil Vol 229, Number 1, p1-12 (2001).