A rough translation of his mentor’s summary goes like this:
“He found a new way of life”.
Sergei Winogradsky, born in Kyiv, Ukraine in 1856, is now known as the father of microbial ecology. It was his ideas that led to our modern concept of “ecosystems”, and his research was rooted in the water and soil that surrounds us. And it all started with… sulphur.
But let’s start at the beginning. From a young age, Winogradsky seems to have been both imaginative and pragmatic. An example? I love the anecdote about how, after receiving a gold medal for academic excellence as a teenager, he immediately went ahead and sold the gold.
Like many of us today, it took a while for Winogradsky to decide which field in which he would spend his life – studied music and law as a young man – but he eventually landed in the St. Petersburg laboratory of Andrei Famintsyn, “a world-famous and charismatic botanist”. There, Winogradsky investigated how light could impact the growth of the Spirogyra algae. He learned how to use microscopic techniques to monitor the growth of his study subject, and at this time he steadily became interested in the new field of microbiology. He was especially impressed with the work of Louis Pasteur, and in fact he would end his career at the Pasteur Institute, after being forced to flee Russia in 1917 - a journey remarkably similar to that of fellow Ukrainian scientist Elie Metchnikoff, who I wrote about last week on Microbial Mondays.
But back to the early days of Winogradsky’s career. For his Master of Science degree, Winogradsky moved on from studying how light impacted the growth of algae, to studying how food could impact the growth of a different microbe. This time, Winogradsky turned his eye to Candida vini – then known as Mycoderma vini – a type of fungus that was known for wreaking havoc in the sugar beet industry. Winogradsky set out to see what would happen if he “fed” this fungus, or yeast, different diets. What would happen if he added or subtracted specific nutrients from this yeast’s food, or if he gave it more or less access to oxygen? Would the fungus grow more, or less? And would the way it looked change?
In brief, the answer was “yes”: his research demonstrating that changes in oxygen and nutrients could change the growth patterns of Mycoderma vini earned him the title of Master of Science in 1883. The story goes that, with his successful achievement of the Master of Science degree, he was invited to train for a professorship at St. Petersburg University, but he declined since “he had never and was never to be impressed with academia.” As an academic, this made me giggle and nod with recognition. Academia can be a strange place.
Instead, Winogradsky got married, and moved back to sunnier locales in Ukraine – namely Crimea. However, Mr. and Mrs. Winogradsky were not to stay there long. The tense political climate in Russia after the assassination of Tsar Alexander II pushed the young scientist to move to a more liberal-minded location. The couple settled in Strasbourg, where Winogradsky turned to studying a new microbe: Beggiatoa.
This third microbe was a bacterium, and was known for accumulating “sulphur granules”. What are sulphur granules? Well, when scientists looked inside Beggiatoa bacteria, they could see that the bacteria would store pellets of sulphur inside themselves – as long as that bacteria was in its natural environment of sulphurous springs. The scientists at the time had also noticed that other bacteria who lived in sulphur springs also had similar sulphur granules. If all of these different types of bacteria were accumulating sulphur, there must be a reason, right? So, what role could these pellets of sulphur play in the lives of these microscopic bacteria? Why were they storing all this sulphur?
And thus, Winogradsky set out to investigate what was up with these sulphur granules.
Right off the bat, he figured out a few key facts. Firstly, he noticed that when he looked at Beggiatoa freshly retrieved from sulphur springs, the bacteria were loaded up with sulphur granules, But if he kept the bacteria alive for a while and deprived them from sulphur, those granules would disappear. Secondly, he saw that it was a specific type of sulphur that Beggiatoa was accumulating. When he fed his bacterial cells a compound that was two parts hydrogen and one part sulphur (H2S), they thrived, and stuffed themselves full with sulphur. But, when he fed the bacteria a compound that contained “oxidized” sulphur – basically, sulphur attached to oxygen, which is known as “sulphate” – the bacteria would die. So, it was clear that these sulphur granules were important for the wellness of these bacteria. But… Why?
That is precisely where Winogradsky made a giant intellectual leap. He knew that Beggiatoa started out with H2S. And he knew that when deprived of sulphur, all that H2S stored in granules in the bacterial cells would disappear. But where was it going? And why? He made a guess. Could these bacteria be using sulphur to “breathe”?
Winogradsky guessed that, kind of like how when we humans breathe, we inhale oxygen and exhale carbon dioxide, these bacteria might be “inhaling” H2S and “exhaling sulphuric acid. And indeed, his experiments proved him correct. In essence, this was the discovery of a whole new way of life, which became known as “chemolithotrophy”: the ability that some bacteria, like Beggiatoa, have, to use molecules like sulphur to breathe – in contrast to us mammals, who use the molecule carbon in our respiration (from carbohydrates).
This idea from Winogradsky led eventually to the “entire concept of sulfur and nitrogen cycles in nature”, and helped scientists develop the idea that materials like oxygen, nitrogen, and sulphur are recycled in natural ecosystems – and that microbes are important in those cycles. In fact, these ideas helped foster the whole concept “ecosystems”. It was a revolution in science that still impacts us today.
~Alex
Some addendums:
The main source for this article can be found here.
You might have noticed that again, I am writing about a Ukrainian scientist. This is one of my small ways to try to stand with Ukraine. Another way is this fundraiser, My boyfriend and I will cycle 850km from March 11-13: the approximate distance from Kyiv to the Kremlin. With this ride, we are raising money via the Giro555 appeal, announced by 11 collaborating Dutch charities, to stand with and support Ukraine. We would be so grateful if you would consider donating. The donation site accepts credit cards (so it's internationally friendly) and donations are tax deductible. We will also be sharing our planned route on Komoot, and we'll post pictures on Instagram to prove we've done it. Thanks for your consideration, and as always for your readership!