Bach, Aleksei Nikolaevich
Bach, Aleksei Nikolaevich
(b. Zolotonosha [now in Ukrainian S.S.R.], Russia, 17 March 1857; d. Moscow, U.S.S.R., 13 May 1946)
biochemistry, Physical chemistry
Bach’s father, a technician in a distillery, stimulated his son’s interest in science. During his years in a Gymnasium in Kiev (1867–1875), Bach, under the influence of the ideas of the writer and revolutionary Dmitrii Ivanovich Pisarev, decided to dedicate himself to the natural sciences and to their dissemination for the good of society. In 1875 he enrolled in the natural science section of the Department of Physics and Mathematics of Kiev University, where he specialized in chemistry. In 1878 he was expelled from the university and exiled to Belozersk for three years for participating in student political activities. Allowed to resume his studies at the university in 1882, Bach devoted even more energy than before to the political struggle, and soon became one of the leaders of the Kiev branch of the Narodnaja Volja (“People’s Will”) party. Inspired by revolutionary propaganda, Bach wrote the pamphlet “Tsar’-golod” (“Tsarhunger”; 1883), one of the first statements of Marxist economic theory to be published in Russian. (Before 1917 this pamphlet had sold 100,000 copies, including translations into the languages of several Russian peoples.) In 1883, fearing arrest, Bach went into hiding; the utter defeat of the Narodnaja Volija by the tsarist government forced him to flee to France in 1885.
From 1885 to 1894 Bach lived in Paris, where he collaborated on the journal Moniteur scientifique, a collaboration that enabled him to establish close contact with French scientific circles. As a result, Paul Schützenberger invited him in 1890 to work in his laboratory at the Collège de France. There Bach completed his first investigations of the chemical mechanism of the assimilation of carbon by plants, the results of which Schützenberger regularly reported to the Paris Academy of Sciences. In the same year Bach married Aleksandra Aleksandrovna ChervenVodali, a teacher who had later become a pediatrician. In 1891 Bach traveled to the United States at the behest of the Brussels Society of Maltose, in order to introduce an improved method of fermentation into Chicago’s distilleries.
Bach moved to Switzerland in 1894, residing there until he returned to Russia in 1917. In the laboratory that he built in his home in Geneva, Bach conducted his investigations into slow oxidation and biological oxidation, investigations culminating in the peroxide theory of oxidation and the theory of biological oxidation.
In 1916 Bach was elected chairman of the Société de Physique et d’Histoire Naturelle de Genève, and in the following year he was awarded the doctorate honoris causa by Lausanne University.
After the February 1917 revolution Bach returned to his homeland. In Moscow he met Maxim Gorky, at whose request he wrote a series of articles that were later published as Istorija narodnogo khozjajstva (“The History of the National Economy”). Bach renewed his scientific research in the spring of 1918 in Moscow, first at Blumenthal’s chemical and bacteriological institute and later at the chemical laboratory of the chemical industry section of the Higher Soviet National Economy. He was made director of this laboratory upon the recommendation of Lev Yakovlevich Karpov, a renowned chemist and prominent Communist and statesman. Owing to a significant degree to Bach’s efforts, the laboratory became a major scientific center and, in 1922, was renamed the L.Y. Karpov Institute of Physics and Chemistry. Many prominent chemists, including Aleksandr Ivanovich Oparin, began their scientific careers there under Bach’s guidance. At this instituteh—as well as at the National Commissariat of Health’s Biochemistry Institute, which was founded in 1920 on Bach’s recommendation-wide-ranging investigations of oxidation and the problems of biological catalysis, as well as many applied studies into the biochemical methods of processing raw material, were carried out.
In 1927 Bach was chosen a member of the Central Executive Committee of the U.S.S.R. and was awarded the Lenin Prize. The following year the All-Union Association of Scientists and Technicians was organized at his urging. He was chosen a member of the Academy of Sciences of the U.S.S.R. in 1929, and in 1935 he and Oparin organized the Institute of Biochemistry, with Bach as director, within the Academy of Sciences. This institute became the coordinating center of Soviet biochemistry. Bach participated in the preparation of the scientific publications Zhurnal fizicheskojkhimii (“Journal of Physical Chemistry”), Acta physicochimical URSS, and Biokhimija (“Biochemistry”) and of the Bol’shaja sovetskaja èntsiklopedija (“Great Soviet Encyclopedia”) and the Bol’shaja meditsinskaja èntsiklopedija (“Great Medical Encyclopedia”). In 1939 Bach was chosen the first academician-secretary of the newly created chemical sciences section of the Academy of Sciences. From 1932 until his death, he was the permanent president of the Dmitrii Ivanvich Mendeleev All-Union Chemical Society.
During World War II Bach organized the research of the evacuated institutes of the Academy of Sciences. In 1942–1943, in Frunze, Kirghiz S.S.R., he directed the study of the exploitational possibilities of local biological raw materials. Bach was awarded the State Prize for his work in biochemistry in 1941 and, in 1945, the title Hero of Socialist Labor—the highest distinction for civilians in the U.S.S.R.—was conferred upon him. In 1943 Bach was chosen an honorary member of the Imperial Society of the Chemical Industry (London) and of the American Chemical Society. Annual memorial “Bach readings” on the fundamental questions of biochemistry are held in the Soviet Union on his birthday.
Bach’s most important works are studies of carbon assimilation by plants and of slow oxidation and biological oxidation. These investigations are the basis of his works on enzymology (oxidizing and hydrolytic enzymes) and on technical biochemistry (the regulating principles of industrial biochemical processes). Research into the assimilation of carbonic acid preceded the development of the theory of slow oxidation: Bach proposed that in plants carbonic acid decomposes into H2CO3, and not CO2+H2O; that this process is completed in several stages; and that during this process hydrogen peroxide and peroxides of organic compounds must be formed as intermediary products. On this basis he formed the conclusion that the oxygen formed during photosynthesis is the oxygen of water, and not of carbonic acid, as would follow from the hypotheses concerning the assimilation of carbonic acid proposed by Adolph von Baeyer and E. Erlenmeyer.
The supposition of the existence of conjugate oxidation-reduction reactions and of the formation of intermediary peroxides during the assimilation of carbonic acid led Bach to deal with biological oxidation. Inasmuch as there was no satisfactory general theory of oxidation, he first developed one. His work on slow oxidation, and later on biological oxidation. continued the development of the idea concerning the necessary activation of oxygen in the process of oxidation that had been stated in 1845 by Christian Friedrich Schönbein. “O roli perekisej v protsessakh medlennogo okislenija” (“On the Role of Peroxides in the Process of Slow Oxidation”) stated the foundations of a new theory of slowly proceeding oxidation processes and was published in the Zhurnal Russkago fiziko-khimicheskago obshchestva in 1897. This paper was presented to the Paris Academy of Sciences by Schützenberger in 1897 and published in the Comptes rendus the same year. Almost simultaneously there appeared, in the Berichte der Deutschen chemischen Gesellschaft, an article by Karl Engler and Wilhelm Wild, “Die sogennante Activirung des Oxygens and über Superoxybildung,” which developed a theory analogous to Bach’s and independent of it. The theory of slow oxidation was later named the Bach-Engler peroxide theory of oxidation.
At the heart of the peroxide theory lies the notion that the energy necessary for the activation of oxygen is introduced by the oxidized substance itself. Before Bach, the activation process was considered either the result of the break-up of an oxygen molecule into separate atoms, as was envisaged by Rudolph Clausius, Felix Hoppe-Seyler, and Jacobus van’t Hoff, or the result of the severance of only one bond in the oxygen molecule and the formation of hydrogen peroxide, as Moritz Traube proposed. Bach significantly widened the limits of Traube’s hypothesis, thus formulating a new theory of slow oxidation.
(1) In slow combustion processes the oxygen molecule O=O partially dissociates under the influence of the free energy of the substance being oxidized and enters into the reaction in the form—O—O—.
(2) All substances capable of being oxidized, independent of their chemical nature, annex such —O—O—groups, initially forming a peroxide, either
(3) Peroxides formed in such manner contian half of the annexed oxygen in a weakly bonded, “active” state, and therefore easily lose this to other substances.
Thus, slow oxidation can be represented schematically as a two-stage process:
(1) A + O = AO2
(2) AO2 + A = 2AO.
Having advanced a correct presentation of the influence of the oxidized substance on oxygen, Bach could not explain the nature of this influence. An explanation became possible only after the development of the theory of free organic radicals. It was subsequently demonstrated that during oxidation the free valence of such a radical influences the oxygen molecule. With this correction, Bach’s views are at the base of the modern chain theory of oxidation processes.
Bach subsequently extended the peroxide theory to processes of biological oxidation, focusing attention on the following facts: oxidation processes in organisms proceed with great intensity; the organic substances that serve as food or enter into the composition of the body are practically indifferent to free oxygen; and the oxygen that is separated from the blood’s oxyhemoglobin is found in a passive state. According to Bach, these facts attested to the existence in organisms of the sources-biological catalysts-of the activation of oxygen: enzymes (whose existence was considered far from indisputable at the time) and unsaturated organic compounds. In order successfully to apply the peroxide theory in the explanation of biological oxidation, it was necessary to prove not only the presence of peroxides in living cells but also the existence of mechanisms that would defend the cell from their harmful influence. Bach’s most important work on biological oxidation during the Geneva period of his career was specifically directed to the solution of these problems. In 1902, with R. Chodat, he investigated the action of hydrogen peroxide on a cell, a new reaction for the assay of hydrogen peroxide in green plants (the system potassium bichromate-aniline-oxalic acid) that he had proposed. During the next two years he investigated the formation of peroxides in plants. According to the peroxide theory of biological oxidation proposed by Bach in 1904, the oxidation of biological substances proceeds according to the following schema:
The proposition that at the base of these processes are two consecutively coordinated enzymatic reactions is the most important statement in such an interpretation of biological oxidation. Such an approach was altogether new in the description of metabolic chemical processes. The representation introduced by Bach made note of new means for elucidating the general order of chemical processes in organisms. Although the peroxide mechanism has been confirmed only for the action of lipoxydase, and although it has been found that the more important oxidation-reduction processes are achieved with the aid of mechanisms other than peroxide mechanisms, Bach’s theory played a positive role in the development of the concepts involved in biological oxidation by stimulating Otto Warburg’s successful search for the enzymatic mechanisms of oxidation. Experimental investigations of the conditions under which many oxidation processes are achieved enabled Bach to draw conclusions that were subsequently used in various industrial processes.
Bach carried out fundamental investigations in industrial biochemistry after his return to the Soviet Union. These were inspired by work on the reconstruction and development of the Soviet food industry in the 1920’s and 1930’s. Many recommendations for the improvement of the baking of bread and for the drying and preservation of grain and flour were worked out with Bach’s help. Original investigations aimed at the creation of new methods for the processing of tea, wine, tobacco, and raw-vitamin materials (tea leaves, pine needles, etc.) were carried out. The methods of industrial biochemistry developed by Bach are widely used in many countries.
I. Original Works. Articles by Bach are “O roli perekisej v protsessakh medlennogo okislenija” (“On the Role of Peroxides in the Process of Slow Oxidation”), in Zhurnal Russkago fiziko-khimicheskago obschchestva, 29 , no.2 (1897), 375; “Untersuchungen über die Rolle der Peroxyde in der Chemie der lebenden Zelle, I. Ueber das Verhalten der lebenden Zelle gegen Hydroperoxyde,” in Berichte der Deutschen chemischen Gesellschaft, 35 (1902), 1275, with R. Chodat; and “Khimizm dykhatel’nykh protsessov” (“The Chemical Mechanism of Respiratory Processes”), in Zhurnal Russkago fiziko-khimicheskago obshchestva, 44 , no.2 (1912), 1–74. His sobranie trudoy po khimii i biokhimii (“A Collection of Works on Chemistry and Biochemistry”; Moscow, 1950). A.I. Oparin and A.N. Frumkin, eds., includes a detailed bibliography of his works.
II.Secondary Literature. Works on Bach are Aleksei Nikolaevich Bach, in the series Materialy k bibliografii uchenykh SSSR (“Materials Toward the Bibliography of Scientists of the U.S.S.R.”), A.N. Nesmejanov, ed. (Moscow-Leningrad, 1946); L.A. Bach and A.I. Oparin, Aleksei Nikolaevich Bach. Biograficheskij ocherk (“Aleksei Nikolaevich Bach. Biographical Essay”; Moscow, 1957); B.E. Bykhovsky, Razvitie biologii v SSSR (“The Development of Biology in the U.S.S.R.”; Moscow, 1957); J.I. Gerassimov, ed., Razvitie fizicheskoj khimii v SSSR (“The Development of Physical Chemistry in the U.S.S.R.”; Moscow, 1967); L.A. Orbeli, ed., Trudy soveshchanija, posvjashchennoogo 50-letiju perekisnoj teorii medlennogo okislenija i roli Bacha v razvitii otechestvennoj biokhimii (“Works of the Conference Dedicated to the Fiftieth Anniversary of the Peroxide Theory of Slow Oxidation and to Bach’s Role in the Development of National Biochemistry”; Moscow-Leningrad, 1946); and “Trudy konferentsii, posvjashchennoj 40-letiju perekisnoj teorii Bacha-Ènglera” (“Works of the Conference Dedicated to the Fortieth Anniversary of the Bach-Engler Peroxide Theory”), in M.B. Neyman, ed., Problemy kinetikii kataliza (“Problems of Kinetics and Catalysis”), IV (1940).
Aleksei Nikolaevich Shamin