The Golden Age of Microbiology


There were a few questions that kept European scientists up at night from 1850 to 1900:

  • Is Spontaneous Generation a real thing?
  • What ferments our precious wine?
  • How do we get sick?
  • How can we not get sick?

Scientists would compete during this time for fame, recognition, and status to answer these questions. Some names popped out of this that you’ll recognize such as Pasteur and Koch. However, some names are remembered because of the falsehood of their proposed answers like Needham and Buchner. Even though some of the ideas these men had about microbes during the Golden age were wrong, though, they served to spawn even more questions and fields of science.

Do Microbes Spontaneously Generate?

Redi of the late 1600s experimented with nasty meat and maggots and flies. He showed the world of science that the flies do not pop out of meat, but need to first be lain as eggs by other flies. Basically that animals come from other animals. After Leeuwenhoek discovered microbial life using nifty little microscopes, the world wanted to know once again; do these little animal-like things come from parent animal-like things?

-After all, microbes would appear in fresh rainwater only a few days after being collected.

A man named Needham set out to solve this mystery. After boiling beef and vegetable broth into a clear substance, he poured the liquid into a flask and sealed it shut. The microbes still appeared. He was convinced that this was proof of spontaneous generation. Another man names Spallanzani came along and doubted his experiment was done correctly, he repeated it. However, this time Spallanzani boiled the broth longer and sealed the flask tighter. No microbes appeared.

Critics, however, were not convinced by Spalanzani’s work and continued to believe that microbial life could in fact spontaneously generate.

Louis Pasteur joined the conversation. He created a special glass flask with a “swan-neck” tube at the end. The S shape allowed air into the larger chamber of the flask of broth without allowing dust and potential microbes. Even 18 months later, the broth remained free of microbes. This proved that the allowance of contaminated air into the broth made it easy for microbes to breed in the broth. So they did have parents all along!

What Causes Fermentation?

Pasteur was now a science rockstar in Europe. Wine growers were having difficulty fermenting their wine because of acid that ruined its taste. He observed yeast cells budding in grape juice. After some experiments, he saw that these yeast cells would only appear if some were first added, like in the case with other microbes. Bacteria caused the acidity to develop while yeast did the fermentation by digesting the sugars in the grape juice.

This new found knowledge meant that microbes could be used to help create things. Biotechnology rose from this because wine was such a valuable commodity if microbes could be used to make it then what else could they do for humans? Louis Pasteur is also known as the father of Pasteurization (crazy, right?). This is the process of boiling substances until they become sterile. This is almost the opposite of using microbes to produce food, it’s the process of boiling the foods out of it.

Buchner was a man who was into the same sort of microbe science stuff. Although, he argued that the live stuff, yeast, didn’t ferment the grape juice but it was in fact done by enzymes. This is true, but it’s the yeast that produces the enzymes. These are the cell’s produced proteins that catalyze chemical reactions that ferment the wine. His work began the field of biochemistry and the study of metabolic reactions.

What Causes Disease?

Before the 1800’s, diseases were not understood, like, at all. People knew that if you were close in proximity to someone who was sick you would have a better chance of also getting sick. This was explained by everything from bad omens and bodily fluids. And in the case of bodily fluids, which is the closest to right the explanations got, the cure was to simply bleed the person out. As you may and hopefully know, this does not help.

Today we know that diseases are caused by genetic, environmental and germy factors. Robert Koch was a doctor in Germany that would see animals on farms die of a disease called Anthrax. After carefully examining the blood of each infected animal, he noticed that everyone shared small rod-shaped bacteria.

This was the first bacteria proven to be the cause of a disease.

He then turned his attention to other diseases. Most were more difficult than Anthrax because of their size, Anthrax is bigger than most infectious bacteria. He would smear the blood or pus of the diseased victims onto a slice of potato or gelatin as a food medium so the colonies of bacteria would grow.

Gram is another guy who contributed a  ton to the investigations of bacteria. Since most microbes are colorless and hard to identify, he decided to create dyes that would allow easier interpretation of these species. His process involves a series of dyes that leave some bacteria pink and others purple. This is still the most widely used method of staining when taking the first steps to identify a species.

How Can We Prevent Infection and Disease?

Some methods of limiting and preventing infection and disease were discovered before we understood that microorganisms were the cause of these diseases. In the middle of the nineteenth century, things like water treatment, pest control, and personal hygiene were becoming widely practiced. Medical personnel and health care facilities lacked appropriate cleanliness and disinfection was absent. Healthcare-associated infections were rampant since surgeons would go straight from working inside or corpses straight to delivering babies without washing their hands, this was the reason why diseases like gangrene and puerperal fever.

Ignaz Semmelweis was a physician in the obstetric ward when he observed women giving birth and dying more often if the doctors had just come from working on corpses. Since this was before germ theory, he hypothesized that these diseases were caused by ‘cadaver particles’. He suggested to doctors that they wash their hands in chlorinated lime water, which successfully lowered mortality rates in these women. Although it was a success, doctors apparently disliked having to wash more than having new mothers die. They discontinued the practice and Semmelweis was eventually admitted to a sanitarium where he died of the very diseases he was trying to help others from.

Lister modified and advanced the practice of sanitation he was a surgeon that had the first-hand experience in what a lack of antiseptic technique. He began spraying wounds, dressings and surgical incisions with phenol. Death reduced by two thirds.

Florence Nightingale contributed to cleanliness in the health care setting during the Crimean war. There, she started the practice of changing bedding, clothes, and dishes that wounded soldiers used in the hospital. Additionally, she documented how these improvements lowered rates of infection and brought these acts back to England where nursing was revolutionized.


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