Ivanovsky Dmitry Iosifovich (1864-1920) - an outstanding microbiologist and physiologist who left a noticeable mark on science. As early as 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 an estate in the Kherson province. However, the future scientist was born in the village of Nizy, St. Petersburg province. He received his primary education at the gymnasium of the city of Gdov, and then continued his studies at the Larinsky 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 studies
In 1887, Ivanovsky and Polovtsev, a fellow student in the department of plant physiology, were instructed to investigate the causesdisease that affected the tobacco plantations of Ukraine and Bessarabia. In 1888 and 1889 they studied this disease under the name "Wildfire" and concluded that the disease was not contagious. This work determined Ivanovsky's future scientific interests.
On May 1, 1888, having defended his thesis “On two diseases of tobacco plants”, Dmitry Iosifovich Ivanovsky graduated from St. Petersburg University, receiving 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.
Discovery of viruses
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 the Crimea. The first results of his research on mosaic disease were published in 1892. It was the first document containing actual evidence of the existence of new infectious pathogens - viruses.
January 22, 1895 Dmitry Iosifovich Ivanovsky defended his master's thesis "Research of alcohol", in which he studied the vital activity of yeast in aerobic and anaerobic conditions. Thus, he received the degree of master of botany and was subsequently appointed to a course of lectures on the physiology of lower plants. He soon became an assistant professor.
New milestones
By nowIvanovsky married E. I. Rodionova, they had a son, Nikolai. In October 1896, he entered the Institute of Technology 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 on the etiology of mosaic disease, was published in 1902. In 1903 he submitted the book as a doctoral dissertation and defended it in Kyiv. The microbiologist received a PhD and a professorship.
Unrecognized genius
Having defended his doctoral thesis, Dmitry Iosifovich Ivanovsky refused to study viruses. Apparently, he made this decision because of the extraordinary complexity of the problem itself, as well as the indifference and misunderstanding that most scientists showed towards his work. Neither his contemporaries nor Ivanovsky himself properly assessed the consequences of his discovery. Either his work went unnoticed or simply ignored. A possible reason for this was the researcher's extraordinary modesty: he did not give wide publicity to his discoveries.
In Warsaw, Ivanovsky studied plant photosynthesis in relation to green leaf pigments. The choice of this topic was inspired by his interest in the chlorophyll-bearing structures (chloroplasts) in plants, which arose during his work on mosaic disease. During these studies, the biologiststudied the absorption spectra of chlorophyll in a living leaf 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 pathogen source, which M. W. Beijerinck rediscovered in 1893 and called "virus". The microbiologist determined that the sap of the diseased plant remained infected after being filtered, although the bacteria visible under the microscope had been filtered out.
The scientist believed that this pathogen was in the form of discrete particles - extremely small bacteria. His point of view here differed from that of Beyerink, who considered the virus to be a "contagious living fluid" (Contagium vivum fluidum). Ivanovsky repeated Beyerink's experiments 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 by Dmitry Iosifovich Ivanovsky:
- "News about microorganisms in the soil" (1891).
- "On the Two Diseases of Tobacco" (1892).
- "Studies on the fermentation of alcohol" (1894).
- Dissertation "Mosaic disease in tobacco" (1902).
- Plant Physiology (1924).
The works of the scientist were collected in "Selected Works"(Moscow, 1953).
