Labor Day, Lactobacillus, and Workers in Leather

Let’s hear it for everyone in bacterial businesses.

On Monday, the United States will pay tribute to American workers by giving many the day off. Labor Day is always the first Monday in September, and this year it falls on September 3rd.

Just as you might expect, we at uBiome naturally take our hats off to the American workforce, of which we’re proud to be a part.

And also, just as you might expect, we’re particularly keen to take our hats off to those American workers who work with bacteria, one way or another.

So here it is:

The Ultimate uBiome Labor Day Top Seven List of People Who Work With Bacteria (snappy, huh?)

1. Brewers

Although the most important microorganism in brewing is yeast – actually a microscopic fungus – many brewers also make use of Lactobacillus bacteria.

It consumes sugars in wort, which is the liquid extracted from the mashing process during beer brewing.

During this procedure, lactic acid is produced, lowering the pH of the brew, and leading to the signature tang of German beers like Gose and Berliner Weisse.

Cheers, American brewers. We do like a good signature tang.

2. Bakers

Bakers of bread also depend on yeast.

However, particularly in the production of sourdough bread, bacteria also plays an important part, and just as in brewing, it’s our friends the Lactobacilli that find their way into sourdough culture, leading to a characteristic crusty loaf with a chewy bite and a sharply acidulated tang.

Sourdough bread dates back not just centuries, but millennia. In fact, very early examples have been excavated in Switzerland, dating all the way back to 3700 BCE. Rather stale, we imagine.

May we propose a toast, therefore, to all American bakers?

3. Cheesemakers

There would be no cheese without bacteria.

Alongside milk, rennet, and salt, these four ingredients are all you need to produce cheese.

Some varieties of this tasty dairy product are made with dozens of species of bacteria, and not surprisingly, the species you add can contribute greatly to the smell, taste, and appearance of the end product.

Propionobacter shermanii, for example, digest acetic acid, converting it to sharp, sweaty-smelling propionic acid and carbon dioxide.

The CO2 gives Swiss cheeses such as Emmental their holes, while the propionic acid leads to an underarm-like odor (a good thing, we’re assured, by connoisseurs).

Cheesemakers of America, we think you’re grate.

4. Vaccine-makers

A 21st-century occupation if ever there was one, those who make vaccines are looking into the use of bacterially-produced antigens as an alternative to the use of chicken eggs.

For 60 years, flu vaccine, for example, has traditionally been manufactured using fertilized embryonic eggs.

In fact, every year, hundreds of millions of chicken eggs are used for this purpose.

However, the use of bacteria to create antigens could put an end to this rather awkward-feeling practice.

American vaccine makers: you fine folk are not to be sneezed at.

5. Biofuel technicians

Researchers are using the tools of synthetic biology to manipulate the genes of Escherichia coli so that this very common bacteria can consume vegetation, producing diesel and other hydrocarbons.

E. coli, although a common (and safe) inhabitant of the human gut at low levels, can also be a source of food poisoning, so it’s particularly exciting it can also be turned into a force for good.

Scientists at UC Berkeley have created genetically modified E. coli that consume sugar, and secrete engine-grade diesel.

No refining is necessary: this biofuel simply floats to the top of the fermentation vat where it can be scooped up and used.

US biofuel technicians, you so fire us up.

6. Leather workers

Among all those who work in bacteria-related professions, perhaps leather workers most deserve their day off on Monday.

Converting animal skins into leather requires the use of some harsh chemicals, including those traditionally used for the pretty self-explanatory, but graphic-sounding, “hide unhairing.”

These substances include lime and sodium sulfide, which frankly make for a fairly extreme depilatory preparation. Definitely not something you’d want to use in the bathroom.

But now, scientists in India have uncovered a way to harvest enzymes produced by Bacillus crolab bacteria to enable hide-unhairing to be carried out more safely, and in a more environmentally-friendly way.

Interestingly, the Bacillus crolab were first isolated from soil around a canal, where a meat stall had previously been located.

Finding safer ways to “unhair” has to be good news for those engaged in processing hides.

Leather workers of America, we’ve really taken a shine to you.

7. Lab scientists

Finally, let’s salute those who, like our own team, work with bacteria all day.

Unlike Victorian experimenters, who often simply rolled up their sleeves to work at the kitchen table with little regard for contamination, today’s lab scientists operate with strict procedures and rigorous hygiene controls.

Of course, it’s vital that scientists don’t get contaminated by the substances they’re working with, but in many instances (uBiome’s for example) it’s also critical that there is no contamination in the reverse direction.

Enormous care is taken to ensure that rogue DNA cannot get from one sample to another, nor from the scientist to the sample.

One example of this is that the robots in our lab squirt their way through huge volumes of single-use pipettes.

Each interacts with one sample only, then is disposed of.

Fortunately, the same isn’t true of our lab team, who are quite the opposite.

Completely indispensable.

This Labor Day, laboratory scientists of the US, we raise our (safety) glasses to you.

In fact, whatever work you do, whether it’s paid or unpaid, to do with bacteria or not, our very best wishes – and thanks – to you for next Monday.

More reading

Bacteria in industry

Biofuel from Bacteria

CLRI’s chemical-free method for unhairing skin

Down and Dirty: Ten Most Germy Jobs

Flu vaccine grown in bacteria works like vaccine grown in chicken eggs

Hydrogen, ethanol and cellulase production from pulp and paper primary sludge by fermentation with Clostridium thermocellum

Lactobacillus sanfranciscensis

Serious Cheese: Know Your Microbes

The Biology of… Sourdough

The Microbiology of Malting and Brewing

Understanding Vaccines, Vaccine Development and Production

Yeast and bacteria 101: Brettanomyces, lactobacillus, pediococcus