2021 10 Goncharov Biuret What to be afraid of
The biuret molecule contains large fragments of two molecules of urea (carbamide). Hence the name – bi (two) + urea (urea). When urea is heated to a high temperature, not only biuret is formed, but also other substances – triuret, for example. In the soil, biuret does not “live” for long – it is broken down by bacteria, actinomycetes and some micromycetes. The same microorganisms break down not only the biuret contained in carbamide, but also the biuret formed during the breakdown of S-triazine molecules (atrazine, simazine, terbutrine, prometrine). The active destructor of biuret is the nitrogen-fixing bacteria Rhizobium leguminasorum. This is what the enzyme biurethhydralase (BiuH) of rhizobia looks like There are many types of microorganisms in the soil that break down both biuret and triuret. In “live” soil with active microbe, detoxification occurs very quickly – several tens of kilograms of biuret are split in the soil in 3-4 weeks. If we transplant the bacterial gene responsible for the production of the enzyme biureth hydrolase into plants, the plants not only neutralize the toxic substance, but use it as a source of mineral nitrogen. Some plants are inherently resistant to high doses of biuret. For example, some conifers grow in soils with a very high biuret content. Moreover, biuret as a nitrogen fertilizer is useful not only for conifers, but also for soil microflora. Symptoms of the toxic effect of biuret are not picturesque – when foliar application, the leaves turn yellow and do not restore their green color. New leaves grow “as expected”.