A nitrogen fixation package is a piece of research equipment for studying
nitrogen fixation
Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmo ...
in plants. One product of this kind, the Q-Box NF1LP made by Qubit Systems, operates by measuring the
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
(H
2) given off in the nitrogen-fixing chemical reaction enabled by
nitrogenase
Nitrogenases are enzymes () that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria. These enzymes are responsible for the reduction of nitrogen (N2) to ammonia (NH3). Nitrogenases are the only fa ...
enzymes.
Principle of operation
Nitrogen is produced by bacteria, which have an
endo-symbiotic relationship with the
legume host.
In this relationship, the plant shares its
carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...
s with the bacteria so that the bacteria can thrive, and the plant benefits by having excess nitrogen made available. The bacteria's creation of nitrogen also creates hydrogen, which is what the unit measures to determine the nitrogen produced.
Measurement of H
2 evolution as a means of determining nitrogenase activity is an alternative technique to
acetylene reduction assay,
and allows real-time monitoring of changes in nitrogenase activity.
Product description
Q-Box NF1LP is an experimental package using an open-flow
gas exchange
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a ...
system for measurement of nitrogen fixation in H
2-producing legume symbioses. A flow-through H
2 sensor (Q-S121) measures the production rate of H
2 from N
2-fixing tissues, allowing in vivo measurement of nitrogenase activity in real time. Measurements of nitrogenase activity on up to three plants is possible, i.e. a four-channel system including a reference sample.
Operation
Nitrogen fixation packages must be used in a laboratory-type environment. This can be a temporary laboratory set up in the field, as long as it is under stable, uncontaminated conditions. The product must be supplied with many potted samples of the plants and of the neighbouring soil, taken from separate areas on the farm or field under study.
The tests rely on the availability of the
Herbaspirillum bacteria in the soil.
This bacterium is found at the root of most legumes, which is where they produce nitrogen.
To test soil properly, it must be free of added nitrogen fertilizers, which have harmful effects on the Herbaspirillum bacteria needed for fixation.
Applications
Different aspects of nitrogen fixation can be examined with these products, such as effects of temperature on the fixation process, the regulation of the process by
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...
, and the inhibition of nitrogen fixation by an over-abundance of
fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s.
References
External links
* {{cite web, title=Q-Box NF1LP Nitrogen Fixation Package - Qubit Biology Inc., url=http://www.qubitbiology.com/plant-and-soil/q-box-nf1lp-nitrogen-fixation-package/, publisher=Qubit Biology Inc., accessdate=11 January 2016, language=en-US
Microbiology equipment
Nitrogen cycle