Ferdinand Cohn

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Wrocław, Poland
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Wrocław, Poland

Ferdinand Cohn was a German biologist who was born in Breslau, Germany, in the nineteenth century. He is most known for being the founder of the fields of bacteriology and microbiology. At the age of 16, he enrolled at the University of Breslau to study botany. He was not permitted to take his final examination, however, due to his Jewish origin. As a result, he transferred to the more liberal University of Berlin, where he earned his doctorate at the age of nineteen. He then returned to Breslau to take up a teaching position at Breslau University, where he remained until his retirement. He rose to prominence as a researcher, however. He began his research with algae and discovered that protoplasm possessed all of life’s essential traits. He then went on to prove that those unicellular organisms had sexual processes. Later, he focused on bacteria and divided them into four categories. Another of his significant accomplishments was the finding of endospores in Bacillus subtilis. He produced around 150 research publications during his lifetime. The University of Breslau became a cutting-edge center for plant physiology and microbiology under his leadership.

Childhood and Adolescence

Ferdinand Cohn was born on January 24, 1828, in Wroclaw’s Jewish district. The town was known as Breslau at the time of his birth, and it was part of the Prussian Province of Silesia under the German Kingdom. He was the oldest of three sons born to his parents.

When I was younger. Ferdinand was quiet, reserved, and sensitive. Issak Cohn, his father, was a wealthy merchant who noticed his son’s aptitude early in childhood and made every effort to develop it. Ferdinand had a bleak recollection of his very studious boyhood.

Ferdinand started school at the age of four. He enrolled at Maria Magdalena Gymnasium in 1835. He made rapid progress in the beginning. Unfortunately, he experienced hearing loss at the age of ten, and his progress slowed significantly after that. It also caused him severe distress.

In 1842, he overcame his emotional obstacles and enrolled at the University of Breslau. He began by studying philosophy but was soon persuaded to turn to botany by German botanist Heinrich Goppert. He was not permitted to sit the final degree examination because he was a Jew.

As a result, in October 1846, he transferred to the more liberal University of Berlin, where he got his doctorate in botany on November 13, 1847, at the age of 19. He studied botany for two more years in Berlin under well-known experts of the day.

Christian Ehrenberg was one of them, and he introduced Ferdinand to the study of microscopic animals and plants. In 1848, the March Revolution erupted. Ferdinand was sympathetic to their beliefs, even though he did not actively participate. His career in Berlin was sealed by this attitude, and he returned to Breslau in 1849.

Ferdinand Julius’s Career

Ferdinand Julius Cohn became a Privatdozent at the University of Breslau in 1850. For botanists, this was an exciting moment. Matthias Schleiden had formed his cell theory and Hugo von Mohl had discussed protoplasm in plant cells not long earlier.

Cohn was so taken with these innovative ideas that he decided to concentrate on unicellular algae. He also felt that in order to get insight into the cellular structure of higher organisms, one must first understand the cellular structure of simpler organisms.

The third key aspect was that Cohn’s botany professor at Breslau, Heinrich Goppert, had instructed him to focus on algae in 1848. He thought Cohn would be able to add to the study of Silesia’s cryptogamous plants’ flora.

Cohn began his research on the unicellular algae Protococcus pluvialis in 1850, with a focus on protoplasm. His father was so taken with his zeal that he bought him a powerful microscope, which the University of Breslau lacked. It quickly became his primary research instrument.

He believed that, like any other plant, microscopic creatures’ stages of growth could only be studied by closely studying them. As a result, he examined each stage of their development using his microscope. His descriptions of the life cycles of various algal species are still relevant today.

He eventually came to the opinion that protoplasm contained the fundamental properties of all life, and that protoplasm in plants and the “sarcode” in animals were extremely similar, if not identical. He also came to the conclusion that bacteria are plants, not animals, in 1854.

Cohn noticed the production of spermatozoa in Sphaeroplea annulina, a kind of green algae, in 1855 and tracked their passage to the eggs. In 1856, he noticed the same thing in Volvox globator, another green algal species. As a result, he established the algae’s sexuality.

He was named outstanding professor of botany in 1859. He released an important work on plant contractile tissues the following year. He had previously stated that contractility was not limited to animal tissue, and he emphasized this point in this study.

Another notable publication on his experimental research of phototropism in microscopic creatures was published in 1865. After a protracted fight, he was finally able to create a separate Institute for Plant Physiology at the University of Breslau in 1866. Since 1847, it had been a primary focus for him.

The Institute first opened its doors in a former prison. It contained a small, basic marine aquarium, where Cohn discovered a new species of infusoria and published a paper about it.

This was also the time when he started growing marine plants and discovered that red algae from the Oscillaria family could live in conditions that no other plant could. Cohn produced another study in 1867 in which he proposed that these algae were the planet’s initial inhabitants.

He also speculated that these red algae may have influenced the evolution of the rest of the plant world. He then started classifying these lower organisms. Despite the fact that he was not totally successful, it was an innovative try.

From 1868 onwards, Cohn focused on microbes. He looked at their morphology and divided bacteria into four groups and six genera based on that. However, he stressed that morphology alone could not be used as a criterion; biochemical characteristics were also crucial.

Cohn launched a new publication, Beiträge Zur Biologie der Pflanzen (Contributions to Plant Biology), in 1870, principally to disseminate the Institute of Plant Physiology’s research. This journal afterward published a number of groundbreaking bacteriology papers.

Cohn was raised to the rank of full professor in 1872. In the same year, he attempted to bring order to the chaos created by the use of random names in bacteria research.

He began by classifying bacteria before categorizing them into four types based on their exterior appearance. He went on to say that there were six genera of bacteria under these four groupings, none of which had anything to do with fungus.

He then proceeded to demonstrate that bacteria cannot withstand temperatures beyond 80°C. However, he was unsure about Bacillus subtilis because it was more heat resistant. He was able to explain it afterward, though.
He also discovered that prolonged exposure to subzero temperatures does not destroy germs. When the temperature is raised, they become active and become stagnant.

Cohn met Robert Koch, an obscure doctor, in 1876. Cohn was quick to see his potential and not only assisted him in publishing his anthrax research but also in obtaining a position at the Imperial Health Office. In the same year, he released his Bacillus subtilis treatise. It is his final significant work.

Cohn’s Major Projects

Cohn’s most notable contribution is the development of a systematic study of the life cycles of microorganisms such as bacteria and algae. In Bacillus subtilis, he is well known for discovering the development and germination of endospores.

Scientists couldn’t figure out how Bacillus subtilis could resurface in such a short time after the container had been properly boiled because germs can’t survive at such high temperatures. They started to suspect it was because germs could self-replicate.

Cohn dismissed the theory as a fallacy, claiming that the Bacillus could survive boiling temperatures by producing thermo-resistant spores. They returned to their usual reproductive stages after that.

Achievements and Awards

The Royal Netherlands Academy of Arts and Sciences awarded Ferdinand Cohn the Leeuwenhoek Medal in 1885.
The Linnean Society of London bestowed the Gold Medal on him in 1895. It is the world’s oldest active biological society, having been founded in 1788.

He was also made a corresponding member of Rome’s Accademia di Lincei, Paris’s Institut de France, and London’s Royal Society.

Personal History and Legacy

Ferdinand Cohn married Pauline Reichenbach in 1867.
He died on 25 June 1898, in Breslau.

Estimated Net worth