Ammonia-oxidizing archaea and ammonia-oxidizing archaea enrichment culture method in fresh water pond

Abstract

The invention provides an ammonia-oxidizing archaea enrichment culture method in a fresh water pond. The method comprises steps of enrichment culture and separation purification. Ammonia-oxidizing archaea provided by the invention is extracted from the fresh water pond, in an enrichment culture process, urea in an ammonia-oxidizing archaea enrichment culture medium is adopted as a nitrogen source,in a heating process, the urea is not volatilized and is kept at a stable state in a water solution, a primary concentration value can be still maintained after high-temperature treatment, direct high-temperature sterilization can be implemented, and thus the opportunity of living contaminants in a culture process can be reduced. In an enrichment culture process of the invention, calcium carbonate in the ammonia-oxidizing archaea enrichment culture medium is adopted as an adhesion matrix, the adhesion matrix is large in specific surface area, the ammonia-oxidizing archaea can be adhered to and grown on the adhesion matrix, microorganism loss in a culture medium replacement process can be reduced, in addition, the pH value of the culture medium can be buffered and stabilized at about 7.0,and thus stable growth of the ammonia-oxidizing archaea can be facilitated; and in addition, the calcium carbonate can also provide an inorganic source, namely carbonate ions for living bodies.

Description

technical field [0001] The invention belongs to the technical field of aquaculture environment microorganisms, and in particular relates to an ammonia-oxidizing archaea and a method for enriching and culturing the ammonia-oxidizing archaea in freshwater ponds. Background technique [0002] In the past 100 years, people have always believed that the oxidation of ammonia nitrogen is completely performed by ammonia oxidizing bacteria, but in the past 10 years, the discovery of ammonia oxidizing archaea has completely changed this understanding. Archaea, also known as archaea, archaea or archaea, archaea, is a single-celled microorganism, which is another biological classification domain, or a kingdom, completely different from bacteria. They have many similarities to bacteria in that they lack a nucleus and any other membrane-bound organelles, while other features resemble eukaryotes, such as the presence of repetitive sequences and nucleosomes. Due to the harsh requirements f...

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Problems solved by technology

Freshwater ponds are ecosystems completely different from oceans and soils, and are greatly disturbed by human factors. During the breeding season, freshwater ponds receive a large amount of feed every day, and the concentrations of organic matter and ammonia nitrogen in water bodies and sediments are much higher than those in oceans. Pond water is strongly disturbed by light, and the existing culture methods for marine and soil habitats may not be suitable for the cultivation of ammonia-oxidizing archaea in pond habitats

[0004] Moreover, the existing ammonia-oxidizing archaeal culture methods often use ammonium chloride as the nitrogen source of the medium, and the ammonium salt is used as NH in the solution. 3 -N and NH 4 + -N two material states exist, and their ratio will decrease with the decrease of the pH of the solution, and increase with the increase of the pH, and the higher concentration of NH 3 -N and very low concentrations of NH 3 -N is not conducive to the growth of ammonia oxidizing archaea

During the culture process, due to the continuous consumption of protons, the pH of the medium tends to decrease over time, which in turn leads to the NH in the medium solution 3 -Uncertainty in N concentration, erratic growth rate of ammonia-oxidizing archaea

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