Sergey Pavlovich Kostychev, an outstanding microbiologist and plant physiologist, founder of agricultural microbiology, organizer and first director of the All–Union (now All-Russian) Scientific Research Institute of Agricultural Microbiology (ARRIAM) was born in 1877 in St. Petersburg. After graduating from the Faculty of Physics and Mathematics of St. Petersburg University (1900), S.P. Kostychev began to develop fundamental problems of plant physiology, which were the subject of his master's thesis “Research on anaerobic respiration of plants” (1907), and then his doctoral dissertation “Physiological and chemical research on plant respiration" (1911). As a result of the conducted research, S.P. Kostychev showed that alcoholic fermentation in plants is not the first phase of respiration (as it was believed before), although these processes are associated with intermediate products of carbohydrate conversion. He established a way for plants to restore nitrates to ammonia, and also described the daily dynamics of photosynthesis. The results of these works were summarized in the monographs “Studies on anaerobic respiration of plants“ (1907) and "Physiological and chemical studies on plant respiration" (1910).

S.P. Kostychev combined the development of research on plant physiology with active teaching, working as an assistant at the Department of Botany of the Military Medical Academy (since 1903), a teacher of botany at the Institute of Technology (since 1910), head of the Department of Plant Physiology and Anatomy at Petrograd University (since 1916). 

In parallel with his work on plant physiology, S.P. Kostychev conducted active microbiological research, which he began after being elected professor of the Department of Botany and Microbiology at the Higher Women's (Bestuzhev) Courses (1911). During these years, S.P. Kostychev made a number of important discoveries in the field of biochemistry of microorganisms. His most famous work was on the synthesis of organic acids by fungi, in particular on the formation of citric and oxalic acids of Aspergillus niger. Applying the method of interchangeable crops, S.P. Kostychev created the theory of citric acid formation and developed the conditions necessary for its maximum accumulation. The results obtained served as the basis for the organization of citric acid production in Russia.

Simultaneously with the development of physiological and biochemical work, S.P. Kostychev turned to the study of soil microflora, continuing the research of his father, Pavel Andreevich Kostychev (1845-1895). Occupying the Chair of Agronomy at St. Petersburg University since 1876, P.A. Kostychev proved the leading role of soil microorganisms in the decomposition of plant residues and in the formation of humus. Since 1885, P.A. Kostychev worked at the Ministry of Agriculture and State Property, where he was engaged in organizing research in the field of agricultural microbiology. After the appointment of P.A. Kostychev in 1894 As Director of the Department of Agriculture, this work culminated in the creation of a bacteriological laboratory, which marked the beginning of the development of the national school of agricultural microbiology. 

An important stage in this development was the appointment of S.P. Kostychev as a consultant to the Department of Bacteriology of the Agricultural Scientific Committee in 1918. Already in these years, S.P. Kostychev expressed innovative ideas about the organization of agrocenosis as an integral biosystem based on the activity of microorganisms. This fundamental generalization became possible due to the broadest general biological outlook of S.P. Kostychev, which is obvious from the list of monographs published by him in the period preceding the creation of ARRIAM (On the appearance of life on Earth, 1921; Microbiology and its significance for mankind, 1922; Natural Philosophy and Exact Sciences, 1922; Accumulation of living matter on earth, 1925).

Systemic ideas about the organization of agrocenosis as a biosystem based on close interaction of microorganisms and plants were formulated by S.P. Kostychev as follows:

“... the nutrition of microbes from the root systems of higher plants seems plausible”;

“... there are special microbes in the soil around the roots of each plant, accustomed to the secretions produced by these roots; the plant feels great in community with them.” Kostychev S.P. Selected works on physiology and biochemistry of microorganisms. Vol. 1. — M.: Publishing House of the USSR Academy of Sciences, 1956.

Considering the activity of the soil microflora, S.P. Kostychev came to an important conclusion: “If previously the activity of microorganisms isolated from the soil and producing certain transformations of substances was studied in pure cultures, now it is time to synthesize the acquired results and study the soil as a complex organism, taking into account the importance of bacterial communities, the peculiar physico-chemical environment of soils, conditions of nutrition and competition of microbes in natural conditions". Kostychev S.P. Conclusions of an agronomic nature from the work of the Department of Soil biodynamics // Proceedings of the Institute of Agriculture. Microbiol. 1930. vol. 4, pp. 29-40. 

In 1923, after being elected a full member of the Academy of Sciences with a degree in botany, Sergei Pavlovich Kostychev was appointed head of the Bacteriology Department of the Agricultural Scientific Committee, which in 1930 was transformed into the All-Union Research Institute of Agricultural Microbiology. Developing research on agronomic microbiology, S.P. Kostychev organized and headed the laboratory of soil microbiology, whose work was aimed at studying the composition and functions of soil microflora in various climatic zones of Russia with an emphasis on studying the cycle of nitrogen substances and, in particular, biological nitrogen fixation. 

In his works, S.P. Kostychev relied on the works of S.N. Vinogradsky, who in 1922 organized the Department of Agricultural Microbiology at the Pasteur Institute in Paris, that is, virtually simultaneously with the creation of S.P. Kostychev's Department of Bacteriology in St. Petersburg.  The basic principle of studying soil microflora, according to S.N. Vinogradsky's ideas, was that microbiological processes should be studied in the soil itself or in environments as close to it as possible. Considering these processes, S.N. Vinogradsky refuted the theory of pleomorphism, which assumed unlimited individual variability of bacteria in nature. S.N. Vinogradsky saw the reason for the high diversity of soil microorganisms in the complex organization of their communities, for the study of which special techniques are needed, in many ways different from the existing methods of general microbiology. 

These approaches have been fully confirmed and further original development in the work of the laboratory headed by S.P.Kostychev. In particular, the methods of elective cultures developed by S.N. Vinogradsky were adapted by S.P. Kostychev to solve practical problems related to the creation of microbial preparations. 

The first works of the laboratory led by S.P.Kostychev concerned the study of the soil microflora of the southern coast of Crimea, where, in a subtropical climate, microbiological processes occur with high intensity and are not accompanied by the accumulation of significant amounts of humus. The importance of soil microflora for the root nutrition of plants is clearly manifested on these soils. The study of these soils proved to be very useful in deciphering the results of studies of more humus soils in various regions of Russia, as well as for the development of general methods of soil microbiology, which was continued by numerous students and followers of S.P. Kostychev.

Thus, S.P. Kostychev became the first biologist who used a holistic approach to the study of the soil ecosystem and to the management of the productivity of agrocenosis. The use of this approach has shown a deep relationship between the processes of formation of humus fund of soils and plant nutrition controlled by microorganisms. On this basis, S.P. Kostychev was 

The general goal of the development of agricultural microbiology is formulated – the study of soil biodynamics, which became the basis for the formation of a long-term scientific program of the Institute. It was formulated by S.P. Kostychev in the monograph “Research on soil biodynamics” (1930) and continues to develop productively at the present time. The development of soil-microbiological research allowed N.M. Lazarev, who headed S.P. after his death. Kostycheva (1931) the laboratory of soil microbiology, to summarize the extensive material on nitrogen, carbon and phosphorus exchange of soils and to propose the theory of the bioorganomineral complex, which became the basis of the ecology of soil microorganisms. 

The most important conclusion drawn from the conducted research was that the functional unit of the soil microflora is not a single species or strain, but a microbial consortium. Therefore, microbiological preparations used to improve plant development and to increase soil fertility should be based not on monocultures of microorganisms, but on their communities. The first of these drugs is turfogrunt AMB (autochthonous microflora of group B, developed by N.M. Lazarev) contained a large number of various microorganisms capable of decomposing organic substances, including humus, releasing mobile nitrogen compounds. The drug AMB was used in cases where the soil is depleted of nutrients and does not have enough native microorganisms to maintain its fertility. This preparation was also used to create soils in greenhouses for growing vegetable crops. Among the drugs created later based on multicomponent microbial communities, it is necessary to note the BUG (biologically active soil) developed on the basis of AMB. Currently, it is used not only for the utilization of soil organic substances (plant residues), but also for the decomposition of pesticides (Lisina et al., 2024).  

Further research conducted at ARRIAM by S.P. Kostychev's students and followers confirmed many of his ideas, although not always in the form in which they were originally proposed. For example, the leading role of nitrogen-fixing bacteria in maintaining the nitrogen balance of soils and in plant nutrition has been shown by numerous studies, but the previously assumed leading role of Azotobacter has not been confirmed. Despite this, the drug azotobacterin containing these bacteria was widely used in agricultural production in the 1930s and 1940s to increase plant productivity. 

The leading role of microorganisms in the metabolism of humus substances shown by S.P. Kostychev is also beyond doubt, although the importance of humus-decomposing microbes in plant nutrition, as well as the possibility of using these microbes to increase crop productivity, remain controversial. The role of microbes in humus formation associated with the transformation of plant residues is currently being actively studied.

Thus, the scientific activity of Sergei Pavlovich Kostychev characterizes him as an outstanding biologist who, based on the synthesis of knowledge in microbiology, plant physiology, soil science and ecology, created the national school of agricultural microbiology, which continues to develop productively nowadays. S.P. Kostychev was a talented teacher. His teaching experience is summarized in the textbook “Plant Physiology”, which went through a number of editions during the life and after the death of its author (1924-1933) and is one of the best textbooks not only in Russian, but also in the world practice of teaching plant physiology. One of the main advantages of this textbook is that it fully disclosed the role of microorganisms (nitrogen fixers, mycorrhizal fungi) in plant life.

The activity of S.P. Kostychev is a vivid example of a productive and harmonious combination of fundamental science and its practical applications. The paradigm of agricultural microbiology created by him, based on a holistic approach to the study of soil microbiocenosis, anticipated many of the ideas of systems biology that arose later. It was S.P. Kostychev who first showed that the integrity of agrobiocenosis is ensured by soil and plant-associated microorganisms, which determine the circulation of substances and energy, and, as it turned out later, genetic information. This principle is increasingly being developed in the works based on the methods of metagenomics, transcriptomics, proteomics, metabolomics and bio-informatics, which are currently being conducted at the Institute of Agricultural Microbiology.      

Author: D.B.N. N.A. Provorov

Sources:

Dorosinsky L.M. S.P. Kostychev - organizer and head of soil and microbiological research at the Institute of Agricultural Microbiology (to the centenary of his birth) // Bulletin of ARRIAM, No. 19, Issue 1, 1978. pp. 50-55.

Provorov N.A., Tikhonovich I.A. Agricultural microbiology and symbiogenetics: synthesis of classical ideas and construction of highly productive agrocenoses // Agricultural Biology. 2022. Vol. 57. No. 5. pp. 821-831.

Provorov N.A., Tikhonovich I.A. From agricultural microbiology to symbiogenetics // In the book: St. Petersburg Academic Science: almanac. Issue 1. On the 30th anniversary of the Russian Academy of Sciences, 1991-2021 / Ed. V.A. Rumyantsev, M.I. Orlova. – St. Petersburg: Publishing House of SPbGEU, 2022. pp. 303-308.