Penicillin was discovered by accident

In 1928, Alexander Fleming returned from vacation to find mold contaminating a petri dish of bacteria. Around the mold, the microbes had died—an accidental observation that led to the discovery of penicillin.

The 'Penicillin Girls' made mass production possible

In Oxford during the early 1940s, six female technicians—later dubbed the “Penicillin Girls”—worked long hours tending mold cultures and extracting tiny amounts of penicillin.

The same mold behind penicillin also flavors blue cheese

There are over 300 species of Penicillium. The mold that produces the lifesaving antibiotic is a close relative to those used to make blue cheeses like Roquefort and Stilton and to flavor some types of ham.

Oxford scientists turned Fleming’s mold discovery into medicine

In 1939, a team at Oxford—including Howard Florey, Ernst Chain, and Norman Heatley—revived Fleming’s forgotten discovery. Using makeshift equipment like bedpans and milk churns, they purified enough penicillin to prove it could treat deadly infections.

Penicillin production was just behind the atom bomb in wartime priorities

By 1943, the US War Department made penicillin its second-highest priority—just after the Manhattan Project. Producing enough of the antibiotic for the D-Day invasion became a central mission of Allied science and industry.

It took 14 years to deploy penicillin after its discovery

Despite its promise, US production of penicillin remained minimal in 1942—enough to treat fewer than 100 patients nationwide. Within two years, output expanded into millions of doses to supply troops for D-Day.

Penicillin was hailed as a 'wonder drug' upon its release

When penicillin became widely available in the 1940s, newspapers and doctors alike celebrated it as a “wonder drug” that could cure infections once considered fatal.

Penicillin’s pioneers were awarded the Nobel Prize in 1945

Alexander Fleming, Howard Florey, and Ernst Chain received the 1945 Nobel Prize in Physiology or Medicine for discovering and developing penicillin.

Penicillin is considered one of history’s greatest medical breakthroughs

Experts widely rank penicillin’s discovery among the most important advances in medicine. It launched the antibiotic era, transformed once-deadly infections into treatable illnesses.

Penicillin has saved an estimated 500 million lives since its creation

Since its introduction in the 1940s, penicillin and related antibiotics are estimated to have saved around 500 million lives worldwide—making it one of the most consequential medical breakthroughs in human history.

Penicillin’s discoverer predicted antibiotic resistance

Alexander Fleming’s discovery of penicillin revolutionized modern medicine. But the same man who pioneered the development of antibiotics also recognized that bacteria could make sntibiotics obsolete if they were used irresponsibly. This story sheds light on Fleming’s discovery—and on his prophetic warning about antibiotic resistance.

Most penicillin allergy diagnoses are wrong, leading to costlier, less effective treatments and contributing to the growing problem of antibiotic resistance.

Women's wartime suit features silk dyed with CRISPR-modified bacteria

Anna Dumitriu's bioart piece was created to commemorate the 75th anniversary of the first use of penicillin in a human patient and intends to raise awareness about the rapid development of antibiotic-resistant pathogens by using bacteria that have essentially been transformed into their pre-antibiotic era state.

Penicillin supplies were ready for every wounded soldier on D-Day

By June 1944, Allied stockpiles included 2.3 million doses of penicillin—enough to ensure that every soldier wounded during the pivotal Normandy landings could receive treatment.

The invention of cheese likely came from a fruit fly landing in a pail of fermenting milk

The chance encounter around 5,500 years ago laid the groundwork for cultured milk products like yogurt and cheese. Over time, microbes evolved in tandem with goats, sheep, and wheat to give us the wide variety of cheeses that we enjoy today.

Watermelons were once neither red nor sweet

The gargantuan summer picnic staple has a fascinating story: 100 million tons are produced worldwide and they take up the most space of any vegetable crop in the world. But not long ago, the flesh of the melon was white and it had a bitter taste.

In 1951, a small French town was likely overtaken by the fungus that ultimately led to LSD.

Penicillin slashed battlefield pneumonia deaths during World War II

Before antibiotics, bacterial pneumonia killed about 18% of infected soldiers in World War I. By World War II, penicillin cut that death rate to less than 1%.

Cantaloupe’s textured skin boosts the risk of food poisoning

Food safety expert Darin Wetwiler says he prefers to stay clear of this fruit altogether since it’s so hard to keep the textured skin pathogen-free. He advises trying to avoid pre-cut cantaloupe in particular, since consumers won’t know when the fruit was sliced and pathogens on the outside could have been spread to the part we consume during slicing and multiplied.

The food processing techniques developed for World War II, later repurposed for consumers

Research projects funded or sponsored by the military led to the development of active dry yeast to make bread easier to bake and an improved version of dehydrated cheese, which would be used in powdered cheese snacks. Freeze-drying, which had been used to ease the transport of blood plasma to battlefields, where it would be reconstituted with water, was later used on fruit for cereals.

Listen to how the 1902 'poison squad' experiments changed food safety in America

As part of government research, a group of young men were paid to eat standard American food—replete with food additives like borax and formaldehyde—which revealed the dangers of unregulated food. The work was led by the first FDA commissioner, Harvey Wiley, who helped end the "century of the great stomachache."

Microbes are essential to creating the many varieties of cheese, influencing texture and taste

Microbes break down proteins and fats and produce compounds with distinct tastes. These microbes can include bacteria (like the one used to give Swiss its trademark holes), molds (like the ones that give blue cheese its distinctive veining), and countless other tiny organisms.

The pharmaceutical industry evolved, in part, from the discovery of synthetic dyes

In 1856, a chemist accidentally discovered mauveine, the world's first synthetic dye, while trying to make quinine to treat malaria. The synthetic dyes that followed helped reveal germs under microscopes, paving the way for modern imaging techniques and breakthrough treatments, such as antibiotics.

Ancient Romans helped develop modern cheese production techniques

The ancient Romans loved cheese and experimented with different processes to elevate its flavor, like aging. Some of their innovations, like Pecorino Romano, you can still find today. Others, like the smoked goat-milk Caseus, we only know about through historical records.

Monsanto got its start in the early 1900s producing saccharin

The company was originally called Monsanto Chemical Works and was founded in 1901 by John Francis Queeny who was then a wholesale drug buyer. He named the company Monsanto for his wife's maiden name. At first, the company began producing saccharin with borrowed equipment and secondhand machines, aiming to produce domestically what was then being imported from Germany. (Some users may encounter a paywall.)

Maryland required cholera researchers to fly a yellow warning flag—signifying quarantine dangers in the 1970s

University of Maryland Hospital researchers intentionally infected volunteers with the cholera bacterium in the late 1970s to further their understanding of the disease. They proceeded with this work following the recommendation of a US government panel. (Some users may encounter a paywall.)

Pneumonia was once a leading killer before penicillin treatments

In the early 20th century, pneumonia was a top cause of death worldwide, often fatal without effective treatment. Penicillin turned a once deadly infection into one of the most treatable bacterial diseases.

The cholera bacteria was first isolated in 1854—but the discovery was largely ignored

The pathogen was isolated by the Italian physician Filippo Pacini in Florence, Italy, though his discovery was largely ignored in favor of the popular miasma—bad air—theory of disease at the time. The pathogen was separately isolated about three decades later by German microbiologist Robert Koch.

Penicillin ended scarlet fever’s deadly threat to children

Between 1840 and 1883, scarlet fever was among the leading causes of childhood death in the United States, with case fatality rates ranging from 15% to 30%. Today, thanks to antibiotics like penicillin, the mortality rate is below 1%.

Mold growth in space raises the hypothesis of life being brought to Earth

Panspermia suggests that life could be carried throughout the cosmos by asteroids, comets, and other objects, but it requires organisms that can withstand the extreme cold of space travel, stellar radiation, lack of water, and intense heat of planetary impacts. The discovery of mold on the International Space Station and experiments showing it can withstand radiation in outer space-like conditions increase the plausibility of the hypothesis.

How scientists are using molecules found in acidophiles to develop new medical treatments

The Berkeley Pit, an open-pit copper mine in Butte, Montana, that ceased operations in 1982 and is now filled with highly acidic water, is home to various species of fungi and yeast. These extremophiles produce unique compounds that may have anti-inflammatory benefits and have already been used to create an antibiotic for staph infections.

Michael Sveda discovered cyclamate by accident

When this lab researcher brought his hands to his lips to smoke his cigarette in 1937, he tasted something sweet, which he called cyclamate. It was quickly used in diet sodas, but it was banned from the US in 1969 after being linked to rodent bladder cancer in lab experiments.

A New York farmer established the first cheese factory and revolutionized the industry by sourcing milk from local farms.

Multiple sugar substitutes were accidental discoveries when lab workers didn't wash their hands.

Research on bacterial cultures used in yogurt production led to CRISPR's discovery

Scientists learned it was a microbial immune system that could be repurposed to protect dairy cultures from viruses. Today, nearly all yogurt is made with CRISPRized bacteria, as are genetically modified crops like herbicide-resistant corn, wheat, and soy.

Iceberg lettuce was the salad staple people ate for most of the 20th century, popular due to its durability, long shelf life, and mild flavor.