Where does the nitrogen in the protein come from? (Kop)

Nitrogen, which is a daily nutrient, is found in protein in the form of amino acids we know well, such as eggs, milk, soy milk, meat, etc. that are abundant in our table.
but where does the nitrogen in these proteins come from? The microbial cycle cycle survives many tiny life forms that we can't see with the naked eye in the soil beneath us, and scientists call them microbes, which had been breeding on Earth for hundreds of millions of years before we appeared, most of them surviving by feeding rotting plant carcasses, and some of them inhabiting living plants and animals.
although they are small, they are surprisingly numerous, with hundreds of millions of microbes in a small pile of soil (Figure 1), so their life activities are not to be underestimated.
the transformation of chemical elements such as carbon, nitrogen and phosphorus in the soil is done by them, and from this point of view, soil microbes can be said to be geoengineers.
nitrogen is an essential nutrient for the growth of plants and animals, it is mainly in the air in a gaseous form, through three processes, namely, biological nitrogen fixation process, nitrification process and anti-nitrification process, to complete its reincarnation, and for plant roots absorption and utilization, and then, to supply animals and humans (Figure 2);
the first journey: nitrogen molecules become amino acids and proteins in the atmosphere stored rich gaseous nitrogen molecules, but unfortunately these nitrogen molecules are inert, plants and animals themselves can not be directly used;
generally speaking, nitrogen fixation bacteria can be divided into three groups, namely, self-contained nitrogen fixation bacteria, symbiotic nitrogen fixation bacteria and endogenous nitrogen fixation bacteria.
self-contained nitrogen fixation bacteria are bacteria that can perform nitrogen fixation independently in the soil.
because the nitrogen fixation enzyme of nitrogen fixation bacteria is very sensitive to oxygen molecules, its activity must be carried out under oxygen-free conditions.
self-contained nitrogen fixation bacteria over hundreds of millions of years, has evolved a nitrogen fixation enzyme anti-oxygen protection mechanism, can carry out aerobic life while fixing nitrogen in the air.
these nitrogen fixers maintain strong respiration to maintain the low-oxygen environment around nitrogen fixers in the cytoplasm, and their cells also contain an ferrite protein that binds to nitrogen fixers, increasing the stability of the latter. In addition to
, the outer layer of the cell wall of the self-contained nitrogen fixation bacteria has a thin layer of membrane or viscose, which can also prevent oxygen molecules from spreading to the cell.
some of the rod-like bacteria known as rhyma bacteria can coexist with legumes, form a root tumor in the thin roots of the legumes and fix nitrogen in the air to supply nitrogen nutrients in the pod, so nutritionists often recommend that we eat more beans to meet the human body's need for protein.
this type of root tumor can cause the root line of the bean plant abnormal growth, and these little guys can be in the body table whip movement, actively looking for the legume plant, from the root hair of the bean plant to the root to form a root tumor (Figure 3), and in the root tumor into branched polymorphic cells, we call it a bacteriological body.
other non-soplant plants also have some nitrogen fixation capacity of bacteria, these plant endogenous nitrogen fixation bacteria can usually be fixed in healthy plants, and host plants joint nitrogen fixation, these are mostly soil bacteria genus, through the plant root wound invasion of a variety of geminiplants and naked plants, resulting in plant cells into abnormally growing tumor cells, hair cancer, hair roots or slugs and so on.
the second leg of the journey: after the protein morphs into nitrous nitrogen plants and animals die, the protein in the body is degraded by microorganisms to ammonia nitrogen, which is transformed into nitrous nitrogen by nitricization.
nitrification can be divided into two stages: ammonia nitrogen oxidation as nitrous nitrogen ammonia oxidation stage, nitrous nitrogen oxidation for nitrosinus nitrogen nitric oxidation stage;
more than 100 years, it is generally believed that ammonia oxidation in the soil is mainly by some chemical energy self-cultivation type of deformation bacteria - that is, ammonia oxidation bacteria catalyzed, including nitrositized monocytobacteria, nitrositus bacteria, nitrosinus and nitric acid bacteria.
in the soil, the self-fed ammonia oxidizing bacteria currently known belong to the genus nitrosized monocytobacteria and the genus nitrous, respectively, is a single-source evolutionary cluster of beta-deformation bacteria, different from the ammonia oxidation bacteria in the ocean.
self-fed ammonia oxidizing bacteria are difficult to isolate and culture in the laboratory, and scientists can only use microbial molecular ecology to decode the 16SrRNA gene or the ammonia monooxidase-encoded gene to infer its distribution and number in the ecosystem.
around 2004, the understanding of ammonia oxide micro-organisms changed, scientists using a newly invented macrogenomic technology found that some of the ancient bacteria living in the ocean's genome contained genes similar to bacteria encoding ammonia monooxidase, and in 2005, scientists isolated the culture from the water of the aquarium in Seattle, USA, to a medium-sized ammonia oxide bacteria, completely subverting people's understanding of ammonia oxide microorganisms.
2006, Dr. Reiner and Professor Sgelbo, from the University of Bergen in Norway, reported in the British journal Nature that their findings found that the number of ancient bacteria with ammonia oxidation in the soil could be up to 3,000 times higher than that of ammonia-oxidizing bacteria.
followed, numerous studies confirmed that the bacteria were widely distributed in lakes including land, sea and freshwater, and that the number of individuals was much higher than that of ammonia oxidizing bacteria.
the third leg of the journey: nitrous nitrogen and nitrogen anti-nitrification, as the name suggests, is the opposite of nitrification nitrogen conversion process, is the nitrification of nitrogen to gas nitrogen process.
anti-nitrification reduces nitrates to gaseous products, which is an important link in the reincarnation of nitrogen elements in soil.
this process is very complex: NO3? , NO2 ? , NO , N2O , N2O , N22, from nitrate to nitrogen release, requires 4 continuous reaction steps, by the anti-nitrification bacteria secretion of nitrate reductase, nitrite reductase, nitric oxide (NO) reductase and nitrous oxide (N2O) reductase four enzyme seises catalysis.
it was initially found that antinitonizing bacteria can only survive in an oxygen-free environment, but it has recently been found that many microorganisms in oxygen-based environments can store nitrate reductase in their cell circumference;
the main factors that affect the action of denitrification are no longer oxygen, but organic matter and nitrate content.
when providing a substrate for anti-nitrification, nitrification and de-nitrification usually couple.
a wide variety of microorganisms involved in anti-nitrification, and more than 80 genus bacteria and some paleontologist, fungi, and linebacteria have been found to be involved in the anti-nitrification effect.
the three processes in the natural state after breaking the balance are balanced, but if humans release excess nitrogen into the atmosphere and soil, that balance is broken.
these microorganisms inhabit the soil, originally living in peace with humanbeing, nothing;
in response to the growing demand for agricultural and animal products, the use of fertilizer in agricultural production has increased rapidly over the past hundred years, with the spread of domestic cars and the burning of petroleum fuels, nitrogen input to the ecosystem has increased rapidly.
the increase of atmospheric nitrogen deposition has become an important global climate change issue, the ecological problem brought about by the increasing amount of sedimentation is becoming more and more serious, atmospheric nitrogen deposition will increase the nitricization of ammonium root ions and the loss of nitric acidion, which will lead to forest soil acidification, nutritional imbalance, tree development decline, biodiversity reduction and productivity reduction.
scientists who applied nitrogen fertilizer to existing forests to simulate atmospheric nitrogen deposition, found that long-term excessive nitrogen deposition could have a negative impact on soil microbes, such as changing the type of microbiome, the number and ability of individual micro-organisms, and also changing the ability and rate of decomposition of soil microbes to plant leaves and roots.
European scientists have found that the minimum critical load of forest nitrogen saturation is 10 kg of nitrogen per hectare per year, but most of the forest nitrogen inputs in central Europe are currently 25 to 60 kg per year, far exceeding the average annual demand for nitrogen nutrients in forests.
in North America, nitrogen intakes in some forest ecosystems amount to 40 kg per hectare per year.
surveys by Chinese scientists are also not optimistic, with annual rainfall carrying nearly as much nitric ions and sedimentation as developed countries such as the United States and Japan, while the concentration of ammonium root ions in rainfall is higher, and the amount of sediment is higher, four times and 3.7 times higher in the United States and Japan, respectively.
A study of pine forests in Harvard Forest by U.S. scientists found that the total amount of microorganisms was 68 percent lower than that of uncast nitrogen forest and 59 percent in broad-leaved forests, and similar phenomena were found in two nitrogen-saturated woodlands in western Virginia, where the total microbial population and fungal/bacterial ratio decreased with increased nitrogen levels.
, in a large grassland field in the north of England, a significantly lower rate of fungal/bacterial biomass in grasssoil sorating nitrogen fertilizer than in non-nitrogen-applying soils was also found.
scientists from the U.S. Department of Environmental Protection's National Health and Environmental Impact Laboratory found that microbes closely related to nitrogen, especially in high-dose nitrogen-treated soils, found a large number of micro-organisms with monoxyamase genes, which are an important type of nitrification microorganism, not found in forested soils withnoone-enriched nitrogen fertilizer;
these changes in the microbiome are likely to affect the reincarnation of nitrogen, which in turn affects our table food.
Source: Science Academy WeChat Public.