Nutrient media are individual substances or their mixtures used to excrete different cultures (micro- and macroorganisms) in a laboratory. Standard biovariants of these environments can not be counted, but each of them must meet a strict set of requirements for them.
Nutrient media should be, first of all, sterile, since if the culture medium has extraneous bacteria, this can become a significant obstacle to the development and growth of the microbe that is being investigated. Environments for chemical research should have the right level of moisture to achieve the necessary environment for microbes. In addition, a suitable nutrient medium must have a reducing oxidation potential. One of the main requirements for nutrient media is the mandatory presence of an optimal concentration of hydrogen ions. Thus, it is easy to conduct research on a variety of microorganisms in laboratories.
Basic requirements for nutrient media:
nutritiousness. The presence in their composition of all components necessary for providing a full range of nutritional and energy needs in an easily digestible form. Cultivation of some organisms is accompanied by additional growth factors (vitamins and amino acids that can not be produced by the cell) into the medium;
optimal number of hydrogen ions. Microbes are able to assimilate nutrients only from medium with normal pH reaction, the quality of which necessarily affects the permeability of the shell;
buffering. In the nutrient medium, components capable of neutralizing the metabolic products must be present. Due to this, acids and alkalis, appearing during the growth of organisms, will not affect the pH level in any way;
isotonicity for the microbial cell (equality of osmotic pressures in both the medium and the cell itself);
sterility. Nothing should hinder the growth of the microbe under investigation, influence its qualities and environmental characteristics;
optimum moisture and consistency;
accurate oxidation-reduction potential;
unification (consistency of volumes of all ingredients);
transparency, facilitating the monitoring of the process of tracking the development of culture.
There are various classifications of these substances, depending on which indicator is taken as the basis. Thus, nutrient media are distinguished by:
consistency, or density (dense, liquid and semi-liquid);
composition (simple, such as agar, broth, gelatin, and complex, developed according to the formula "simple medium + vitamins, amino acids, trace elements, etc.");
purpose (special, basic, elective, canning and differential-diagnostic).
Nutrient medium: important aspects and stages of preparation
The dishes, in which preparation of the nutrient medium is expected, should be free from foreign products, especially alkaline ones. It is best to use glass, as well as aluminum and enameled containers. Before cooking, the dishes should be thoroughly washed and dried. In the very process, it is important to follow the sequence of the main actions.
The main stages of creation: cooking, pH determination, clarification, filtration, spilling, sterilization, biological and chemical control.
Characteristics of the medium
Today, the nutrient media is divided into synthetic, natural and artificial. Components for the preparation of a synthetic nutrient medium are inorganic or organic compounds. Natural nutrient media are most often prepared from natural ingredients such as bone meal, meat, or blood clots. At the heart of the preparation of an artificial nutrient medium is a specific formulation, through which the necessary substance is prepared.
According to their main purpose, nutrient media are special, basic, elective, canning, and also differential-diagnostic. In addition, nutrient media can be not only simple or complex, but also liquid, dry or semi-liquid.
Buy culture media
Choosing the dishes for the preparation of nutrient medium, you should pay special attention to its sterility and the lack of alkalis and any other chemical reagents. Buy a variety of nutrient media at a very affordable price you can at any time from the company Agar.ua.
The Agar.ua company offers a huge selection of nutrient media for the most comfortable conduct of laboratory tests.