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Dr Warhol’s Periodic Table of Microbes, The Small Guide to Small Things

89.  Ac. Acetobacter

Love ‘em or hate ‘em, the Acetobacter make the world a more sour place to be.

There are around 4 dozen species of Acetobacter, all share the ability to produce acetic acid from ethanol in the presence of oxygen, and they live all over the world, wherever sweet fermentable things are found. This is great if you want to make vinegar and certain other industrial products. This is bad if you’re trying to make wine. It’s really bad. In fact, one of Louis Pasteur’s claims to fame is that he discovered that Acetobacter was responsible for wine spoilage way back in 1864, thus saving the French wine industry.

Because it specializes in converting ethanol to acetic acid, you can probably guess that Acetobacter is relatively ethanol-tolerant, and thrives in alcoholic environments that hinder many other microbes (it lives in beer and wine, some would call that lucky!). Because it makes acid, it’s not surprising that Acetobacter is relatively acid-tolerant.

Unlike yeast, which ferments in the absence of oxygen, Acetobacter is an obligate aerobe, which is why brewers and vintners are very careful about fermentation locks that exclude oxygen from the fruits and grains.

The best-known species is probably Acetobacter aceti (Dr Pasteur’s microbe), which is used to intentionally make acetic acid from alcohol in industrial quantities, mostly for use in vinegar. Sadly, it’s cheaper to make acetic acid from petrochemicals, but food-grade vinegar mostly comes from fermentation, to the tune of around 500,000 tons per year!

Another noteworthy species is Acetobacter xylinus, which synthesizes cellulose! Imagine that, a microbe that makes the same material as plant cell walls! Each microbe sort of spins a cocoon of cellulose around itself!

Acetobacter cells are Gram negative rods that measure about 0.5 to 0.7 microns wide by 1.8 to 2.0 microns long.

New Jersey Microbe

Met with two New Jersey State Senators, two Assemblymen, a lobbyist, and two senior administrators in NJ colleges. They all think the idea of a State Microbe is great. It will give all people from New Jersey something to be proud of.

More details are coming, so please follow this story!

Happy Birthday Martinus Beijernick

One of the founding fathers of virology and environmental microbiology. Sorry, no Nobel Prize, maybe because he was known to be cranky.

Coined the word virus to describe a non-bacterial agent that can transmit disease, in his case, the tobacco mosaic virus.

Happy Birthday Paul Ehrlich

Nobel Prize in 1908. Developed the concept of The Magic Bullet, or selective chemotherapy.

Discovered Salvarsan, the first antimicrobial for syphilis. Father of chemotherapy. Outstanding immunologist. He named the “mast cell” in blood smears (because it looked like it was well fed on “mast” animal food).

Subject of the Academy Award-nominated movie Dr Ehrlich’s Magic Bullet starring Edward G Robinson in 1940. A great movie, but an example of political correctness of the time; they didn’t want to use the word “syphilis” or mention that Ehrlich was Jewish.

Happy Birthday Emil von Behring

Awarded the first ever Nobel Prize in Physiology or Medicine in 1901. Discovered diphtheria antitoxin. One of the founding fathers of serotherapy, or passive immunization.

Diphtheria is an unpleasant way to die, most often in children. President Cleveland’s daughter Ruth died from diphtheria; there were about 1 million cases and 50,000 deaths in Europe in 1943; the Iditarod dog race commemorates the delivery of diphtheria antitoxin to Nome Alaska.

Vaccines work.

Dr Warhol’s Periodic Table of Microbes, The Small Guide to Small Things

86.  Rn.  Ruminococcus

Fans of South Park will immediately recognize the importance of Ruminococcus as it relates to the story line of the long-running cartoon. Why? Because the South Park school sports teams are known as The Cows, (if you’re really lucky you have your own “Go Cows” T-shirt) and cows are ruminants. Ruminants are herbivores that acquire nutrients by microbial digestion of the plant material in a 4-chambered stomach system. The cow is perhaps the biggest and best-known ruminant, but the group includes goats, sheep, deer, antelope, and kangaroos.  Hippopotamuses are kinda-sorta ruminants; they have only a three chambered stomach, but are way bigger than cows.

Most of the interesting microbial work occurs in the first 2 stomachs, the rumen and reticulum, which are essentially large living fermentation vessels that provide the proper conditions for a happy party of microbes that include bacteria, protozoa, and yeasts. But who needs fermentation anyway? Well, just about any vertebrate, because we all lack cellulase, the enzyme needed to break down cellulose from fibrous plants. To do this we rely on microbes that produce cellulase and a host of other enzymes that extract all the sugars and nutrients trapped in plant tissue.

Ruminococcus is one of the major cellulose-digesting microbes found in ruminants. There are around 20 species, and they are all anaerobes. Understanding cellulose digestion is important to optimize animal nutrition, and can also provide insight for improved methods for extracting biofuels from cellulosic materials.

Ruminococcus cells are Gram positive cocci that are around 1 micron in diameter.

Copyright 2017 Warhol.

Dr Warhol’s Periodic Table of Microbes, The Small Guide to Small Things

83.  Bi.  Bifidobacterium

Everything you always wanted to know about probiotics began with these organisms way back around the turn of previous century, so we’re talking around 1900 not Y2K! All of the current publications and advertising, as well as the endless variety of yogurt products, have their origins in some very old-school microbiology. Bifidobacterium was discovered at the Pasteur Institute as part of the normal intestinal content of breast-fed babies. The Bifidobacterium name comes from the Latin “bifidus” meaning divided into two equal parts by a cleft, as the microbes are typically Y-shaped.

They are one of the lactic acid bacteria, a group that ferments milk products and produces lactic acid. The great Nobel laureate Elie Metchnikoff believed that fermented dairy products (like yogurt and kefir) enabled Russian peasants to achieve amazing longevity and make memorable TV commercials, now viewable on YouTube!

There are more than 60 species of Bifidobacterium; the most commonly found in infants are Bifidobacterium infantis, Bifidobacterium brevi, and Bifidobacterium longum. The Bifids account for about 90% of the fecal flora in infants, but only around 5% in adults. They are believed to aid in intestinal homeostasis, modulation of the gut immune response, and improve the intestinal mucosal barrier. The Bifids and other lactic acid bacteria are generally considered beneficial and otherwise known as “good bacteria”. There is a growing and lively body of research on probiotics, and if you like biochemistry, fermentation, and genetic studies you will be fascinated by these microbes.

When not in the probiotic realm, Bifidobacterium are considered part of the normal flora of the mouth, vagina, and intestinal tract of mammals and other species. Like many other microbes, unique species of Bifidobacterium have been discovered in strange places, so while it is accurate to say these are normal commensal/beneficial organisms in humans, (and they are Y-shaped) some are shaped like stars, are intertwined like snakes, or form chains, and they have been found in marmosets and ring-tailed lemurs (how cute!), bumblebees, pigs, rabbits, milk, feces (of course!), cattle, and gorillas.

Bifidobacterium cells are Gram positive rods that are characterized as Y-shaped, approximately 0.3 to 0.6 microns wide by 0.4 to 1.2 microns long.

Copyright Warhol 2017