From Big Medical Encyclopedia

REACTORS MICROBIOLOGICAL — the tanks from glass, stainless steel, titanium or aluminum intended for cultivation of microorganisms for the purpose of obtaining microbic weight or products of microbic metabolism — antibiotics, enzymes, amino acids, toxins, etc.

Industrial R. of m (reactors) are instrumented for measurement and attemperation, pressure, pH and air consumption; the maximum capacity of R. of m makes 100 m 3 . For hypodispersion of substrates and creation homogeneous physical. - chemical conditions in cultural liquid R.'s most in m is supplied with the mechanical stirrer, chippers and other devices. Hashing can be carried out also as a result of aeration of cultural liquid by air.

Products mikrobiol. synthesis are characterized by strict specificity therefore material is of great importance, from to-rogo the industrial reactor is executed. So, e.g., the ordinary reactor from stainless steel since surplus of ions of iron adversely influences an exit of diphtheritic toxin is not suitable for cultivation of causative agents of diphtheria. In total R. m have the general technical characteristics providing course of process in the set, optimal conditions for receiving standard products. These requirements are met released in the USSR a lab. AN of KUM-2 installations, Joint stock company-3, AK-10, FS-4, FU-6, FU-30.

Sterilization of the environment in R. of m is most effective at continuous steam sterilizations (see). Cleaning and air sterilization, given for aeration, are based on destruction of microorganisms or their delay on system of filters. The greatest distribution was gained by a method of filtering through fibrous or porous materials, among to-rykh broad use found materials on the basis of the basalt superfine fibers (BSTV) produced by the domestic industry. In the constructive relation corrugated filters of cartridge type thanks to the big surface of filtering and reliability of consolidation have advantage.

For the automatic control and regulation of key parameters of cultivation — temperature, the partial pressure of oxygen (pO 2 ), carbon dioxide gas (pCO 2 ) and the sizes pH use sensors of primary information. Speed of rotation of a mixer of R. of m is controlled by means of a tachometer. Measurement of the partial pressure dissolved in the environment of oxygen is based on a polyarografichesky method (see. Polyarografiya ). Oxygen consumption can also be controlled by measurement of amount of oxygen in the air which is coming to R. of m and coming out it. In this case R. is completed with m gas analyzer (see). As oxygen is consumed by microorganisms with high speed at its extremely low solubility, in the course of cultivation it can be the major limiting factor. Excess of oxygen leads, in turn, to suppression of growth and reproduction of microorganisms.

Measurement of partial pressure of carbon dioxide gas in cultural liquid is carried out by means of the sensor having big inertance. As a rule, the partial pressure of carbon dioxide gas influences process in wider interval of the changes; e.g., for development of such bacteria as the pneumococcus and meningokokk, is required to 5 — 10% of carbon dioxide gas. At the same time accumulation of carbon dioxide gas in the environment at cultivation can slow down process of growth and reproduction of microorganisms even at concentration of the dissolved oxygen above critical.

Measurement of pH is carried out by glass electrodes. The device for regulation of pH allows to enter automatically into cultural liquid acid and alkaline components, to change their quantity, to choose optimum doses of titrant.

The majority of processes of biosynthesis proceeds with formation of strong foaming of cultural liquid that complicates full use of capacity of R. of m, can break sterility, reduces specific growth rate and an exit of biomass. For fight against foam there are chemical, mechanical and physical methods of a penogasheniye. As a rule, use mechanical and chemical methods. Systems of an automatic penogasheniye are based on precautionary operation of the defoaming agent and work according to the set program. Other methods are based on control of level of foam and the automatic delivery of the defoaming agent. Timely to stop process of cultivation, especially in the period of the greatest fiziol. activities of microbic population, it is necessary to measure concentration of biomass. Measurement is conducted in flowing a ditch nefelometricheskpm by method (see. Nefelometriya ).

In the course of cultivation add components of a medium (carbohydrates, nitrogenous food, phosphorus, etc.), using various dispensing pumps: peristaltic, plunger, membrane.

Modern R. can be included by m in program regulation using managing COMPUTERS (see. Electronic computer ), to-rye make calculation of variables of process and use them for the analysis, control and management. COMPUTERS can adjust optimal conditions of process by means of the mathematical model put in her memory.

Bibliography: Viyestur U. E., M. Sh. Kristapsons and E. S Blade of grass-on. Cultivation of microorganisms (Bioengineering bases), M., 1980; Kanterev. M ikramme. A. The analysis of laboratory installations for cultivation of microorganisms, M., 1973; The Theory and practice of continuous cultivation of microorganisms, under the editorship of. And. JI. Rabotnova, page 139, M., 1980.

L. G. Zhdanova.