Question - Which of the following is a nitrogen fixing bacterium?

Answered by: Sara Garcia  |  Category: General  |  Last Updated: 22-06-2022  |  Views: 686  |  Total Questions: 14

Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (nonsymbiotic) bacteria, includes the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium. Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or elemental nitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds. Microorganisms that fix nitrogen are bacteria called diazotrophs. Nitrogen-fixing bacteria are microorganisms present in the soil or in plant roots that change nitrogen gases from the atmosphere into solid nitrogen compounds that plants can use in the soil. ADVERTISEMENTS: Let us make in-depth study of the two types of nitrogen fixation. The two types of nitrogen fixation are: (1) Physical Nitrogen Fixation and (2) Biological Nitrogen Fixation. Apart from carbon, hydrogen and oxygen, nitrogen is the most prevalent essential macro-element in living organisms.

Azospirilla are Gram-negative free-living nitrogen-fixing rhizosphere bacteria. They display a versatile C- and N-metabolism, which makes them well adapted to establish in the competitive environment of the rhizosphere. Ammonium, nitrate, nitrite, amino acids and molecular nitrogen can serve as N-sources [11].

Most plants get the nitrogen they need to grow from the soils or water in which they live. Animals get the nitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water.

Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen.

Legume family They contain symbiotic rhizobia bacteria within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. When the plant dies, the fixed nitrogen is released, making it available to other plants; this helps to fertilize the soil.

They are aerobic, free-living soil microbes that play an important role in the nitrogen cycle in nature, binding atmospheric nitrogen, which is inaccessible to plants, and releasing it in the form of ammonium ions into the soil (nitrogen fixation).

Peanuts are a legume with amazing nitrogen-fixing properties. And once the nodules are formed [the bacteria] takes the atmospheric nitrogen from the air and fixes the nitrogen from the air to the plant, from the plant to the soil. ” Left image shows late-season nitrogen-fixing Bradyrhizobium nodules on peanut roots.

We use the term "organic nitrogen" to describe a nitrogen compound that had its origin in living material. The nitrogen in protein and urea is organic nitrogen. Organic nitrogen can enter septic systems as bodily wastes, discarded food material, or as components of cleaning agents.

Definition of nitrogen fixation. : the conversion of atmospheric nitrogen into a combined form (such as ammonia) through chemical and especially biological action (such as that of soil rhizobia)

Denitrifying bacteria, microorganisms whose action results in the conversion of nitrates in soil to free atmospheric nitrogen, thus depleting soil fertility and reducing agricultural productivity.

Nitrification is the process by which ammonia is converted to nitrites (NO2-) and then nitrates (NO3-). This process naturally occurs in the environment, where it is carried out by specialized bacteria. The nitrification process is carried out by two different types of bacteria.

Most plants must rely on the addition of nitrogen to the soil in order to be able to use it. There are a few plants that love nitrogen gas, though; they are able to draw the nitrogen gas from the air and store it in their roots. These are called nitrogen fixing plants.

Explanation: In the nitrogen cycle, denitrifying bacteria convert nitrate ( NO−3 ) found in the soil into nitrogen gas ( N2 ). This process is called denitrification. Denitrifying bacteria allows nitrogen to return to the atmosphere.

Nitrogen-fixing bacteria convert free nitrogen gas into nitrogen compounds. 2. Bacterias that are decomposers recycle nitrogen compounds in the soil by breaking down animal wastes and dead plants and animals. Other bacteria break down nitrogen compounds and release free nitrogen back into the air.

The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes.