Ivanovsky Dmitry Iosifovich (1864-1920) - an outstanding microbiologist and physiologist, who left a noticeable mark in science. At the end of the 19th century, he suggested the presence of special microorganisms - viruses that cause a number of plant diseases. His theory was confirmed in 1939.
Biography
Ivanovsky Dmitry Iosifovich was the son of the landowner Joseph Antonovich Ivanovsky, who owned the estate in the Kherson province. However, the future scientist was born in the village of Niza, St. Petersburg province. He received his primary education at the gymnasium of the city of Gdov, and then continued his studies at the Larino gymnasium, which he graduated with a gold medal in the spring of 1883.
In August of the same year he entered St. Petersburg University at the Department of Natural Sciences of the Faculty of Physics and Mathematics. Among his teachers were the great Russian scientists I.M.Sechenov, N.E. Vvedensky, D.I. Mendeleev, V.V. Dokuchaev, A.N. Beketov, A.S. Famintsyn.
First research
In 1887, Ivanovsky and Polovtsev, a fellow student of the Department of Plant Physiology, were instructed to investigate the causes of the disease that affected the tobacco plantations of Ukraine and Bessarabia. In 1888 and 1889, they studied the disease under the name Wildfire and concluded that the disease was not contagious. This work determined the future scientific interests of Ivanovsky.
On May 1, 1888, having defended his thesis “On Two Diseases of Tobacco Plants,” Dmitry Iosifovich Ivanovsky graduated from St. Petersburg University with a Ph.D. On the recommendation of two professors A.N. Beketov and K. Ya. Gobi, he stayed at the university to prepare for a teaching career. In 1891, the biologist joined the Botanical Laboratory of the Academy of Sciences.
Virus discovery
In 1890, a new disease appeared on tobacco plantations in the Crimea, and the Directorate of the Department of Agriculture invited Ivanovsky to study it. In the summer, the scientist left for Crimea. The first results of his research on mosaic disease were published in 1892. This was the first document containing factual evidence of the existence of new infectious pathogenic organisms - viruses.
January 22, 1895 Dmitry Iosifovich Ivanovsky defended his master's thesis "Study of alcohol", in which he studied the vital activity of yeast in aerobic and anaerobic conditions. Thus, he received a master's degree in botany and was subsequently assigned to a course of lectures on the physiology of lower plants. He soon became an assistant professor.
New milestones
By this time, Ivanovsky married E.I. Rodionova, their son Nikolai was born. In October 1896, he entered the Technological Institute as an instructor in plant anatomy and physiology, working there until 1901. During this period, Dmitry Iosifovich was engaged in a deep study of the etiology of tobacco disease.
In August 1901, the great Russian scientist moved to Warsaw and in October was appointed extraordinary professor at the University of Warsaw. His work Mosaic Disease in Tobacco, which summarized studies of the etiology of mosaic disease, was published in 1902. In 1903, he presented the book as a doctoral dissertation and defended it in Kiev. The microbiologist received a doctorate and the title of professor.
Unrecognized Genius
Having defended his doctoral dissertation, Dmitry Iosifovich Ivanovsky refused to study viruses. Apparently, he made such a decision because of the extraordinary complexity of the problem itself, as well as the indifference and misunderstanding that most scientists showed to his work. Neither his contemporaries, nor Ivanovsky himself properly appreciated the consequences of their discovery. Either his work went unnoticed, or simply ignored. A possible reason for this was the researcher's extraordinary modesty: he did not make his discoveries widely publicized.
In Warsaw, Ivanovsky studied plant photosynthesis with respect to green leaf pigments. The choice of this topic was caused by his interest in chlorophyll-bearing structures (chloroplasts) in plants that arose during work on a mosaic disease. In the course of these studies, the biologist studied the absorption spectra of chlorophyll in the living sheet and in solution. He found that chlorophyll in solution is rapidly destroyed by light. The scientist also suggested that the yellow pigments of the leaves - xanthophyll and carotene - act as a screen to protect the green pigment from the damaging effects of ultraviolet rays.
Achievements
The main merit of Dmitry Iosifovich Ivanovsky, of course, is the discovery of viruses. He discovered a new type of source of pathogens, which MV Beyerink rediscovered in 1893 and called the "virus." The microbiologist found that the juice of the diseased plant remains infected after filtration, although the bacteria visible under the microscope were filtered.
The scientist believed that this pathogen has the form of discrete particles - extremely small bacteria. His point of view here differed from the point of view of Beyerink, who considered the virus to be “contagious living fluid” (Contagium vivum fluidum). Ivanovsky repeated the experiments of Beyerink and became convinced of the correctness of his own conclusions. After analyzing the arguments of Ivanovsky, Beyerink agreed with the opinion of the Russian scientist.
Bibliography
Original works of Dmitry Iosifovich Ivanovsky:
- "News of microorganisms in the soil" (1891).
- "On two diseases of tobacco" (1892).
- "Studies on alcohol fermentation" (1894).
- The dissertation "Mosaic disease in tobacco" (1902).
- "Plant Physiology" (1924).
The works of the scientist were collected in "Selected Works" (Moscow, 1953).