From Big Medical Encyclopedia

HEMOSTATNY METHOD (a synonym hemostat) — a method of management of process of continuous cultivation of microorganisms, at Krom the speed of their growth is proportional to concentration of any substrate, limiting, vital for a microorganism (glucose, oxygen, nitrogen, etc.) at surplus of other components of the environment.

X. m use for studying of physiology of microorganisms and in theoretical researches if necessary to otdifferentsirovat influence of changes of conditions of the environment (concentration of glucose, pH of the environment, partial pressure of oxygen, etc.) on culture from influence of change of growth rate, edge is integral size and reflects the speed of many reactions in a microbic cell. X. m apply in pilot studies at production of preventive drugs against a number of infections. Hemostatny control can be exercised in any device for continuous cultivation of microorganisms.

At continuous cultivation a medium constantly comes to the reactor (reactor), and cultural liquid is removed from it with the same speed. Speed of receipt of the environment and removal of liquid corresponds to the speed of reproduction of microorganisms, and thus in the reactor constant concentration of microbic cells is maintained.

The principle of self-control is the basis for management of continuous cultivation of microorganisms. In these conditions the specific growth rate of microorganisms —

r = where Ah is designated by a gain

of biomass for an infinitesimal time term And/, it is possible to record on any value: from close to zero to a maximum during the time, necessary for the experimenter. The specific growth rate close to zero corresponds to a stationary growth phase — a S-shaped curve when the gain of biomass is equal to quantity of the dying-off cells. If initial velocity of growth of microorganisms is equal to the speed of washing away, then the dynamic equilibrium is established, at Krom microorganisms grow under existing conditions with the maximum specific speed. If the speed of washing away is more than the growth rate, then concentration of biomass falls and concentration of the substrate limiting growth increases. The subsequent increase in the .pitatelny environment of the substrate limiting growth will lead to increase in speed of reproduction. Therefore, X. the m allows to change the growth rate of biomass of microorganisms due to concentration of the substrate limiting growth whereas at periodic cultivation growth rate is caused or high-quality shifts as a part of a medium, or changes such physical. - chemical parameters of a medium, as concentration of hydrogen ions and partial pressure dissolved in the environment of oxygen.

One of forms of hemostatny management is the turbidostatny method: microorganisms of a vyrashchiv

yut in the conditions of continuous cultivation to a certain density, edge it is controlled by means of a photo cell by a feed-back and automatic control of supply of nutrient medium. At a tour-bidostatnom a method of management the principle of a sakhmoregulya-tion also works, but growth rate depends on population density in the reactor, edges causes concentration of metabolites. The Turbidostatny method is applied in cases when cultivation of culture at the growth rate close is necessary to maximum.

Bibliography: Perth Page D. Bases

of cultivation of microorganisms and cells, the lane with English, M., 1978; R and about t of N the island and I. L. and P about z m about about in and I. N. Hemostatnoye cultivation and ingib

rovany growth of microorganisms, M.,

1979. L. G. Zhdanova.