Small Things Considered

Luddites, Rejoice!

Those who are underwhelmed by modern technology do not stand alone. A fungus made an "indestructible" CD inoperable by growing on its edge, devouring aluminum and polycarbonate, and making short shrift of the “information pits,” whatever they are. This particular CD had resided in Belize under conditions of high humidity and temperature—"extreme weather conditions" according to the inventor of the CD. But with global warming, who knows!

Leaving aside further temptation to dwell on the frailties of modern technology, the microbiology here is not without interest. 

Talmudic Question #12

by Miguel Vicente

All living creatures are born, grow, reproduce and finally die. Consequently, as many flow without discontinuity from one cell to the next (Escherichia coli in the gut), a number of them do not grow (Salmonella enterica inside some phagosomes), others fail to reproduce (Mycobacterium tuberculosis in latent infection) and, finally, some do not even die (Bacillus subtilis after sporulation) are bacteria alive?

Help on the Taxonomic Front

I daresay that most of us feel frustrated and thwarted in the attempt to bring order in the chaotic thicket of microbial taxonomy.  In our bewilderment we wonder, for example,  if the concept of species will - Cheshire Cat-like - fade from view.  Now the American Academy of Microbiology has issued a colloquium report  entitled Reconciling Microbial Systematics and Genomics.  It lays out with welcome clarity the issues emerging from modern methodologies. This document relies on the weight of authority, as the participants are old hands at this business.  A light in the darkness?

The Proper Study of Man Is Bacteria

It is of more than passing interest to know which infectious diseases did  beset ancient humans.  Such information may illuminate behavioral and cultural patterns difficult to obtain from other sources.  Thanks to modern technology, it is possible to identify microbial DNAs found in ancient human remains. 

Talmudic Question #11

Can you think of any group of living organisms that is not host to some virus?

Arms and the Fungus

Electron microscope section of the
tip of a Haptoglossa gun cell,
courtesy of Dr. E. Jane Robb.

Arma virumque cano (“I sing of the arms and the man”). So starts Virgil’s Aeneid. I have wondered why anyone would want to sing the praise of armaments, as this is not my cup of tea. There is, however, biological weaponry that I think deserves our admiration. One of the most elaborate examples is the mechanism found in Haptoglossa, an enigmatic fungus that has been provisionally classified with the oomycetes or water molds. An entire fungal cell is injected into a passing nematode or rotifer, there to develop at the expense of the host. Mechanisms for injecting biologically active material are not uncommon; they are seen in pathogenic bacteria, viruses, jellyfish, and stinging nettles, among others. But it is a rare organism that possesses the intricate machinery required to actively introduce a whole cell into a fast-moving and unsuspecting host.

A Unified View By Providers and Consumers of Scientific Grants

The NIH and the American Society for Microbiology have jointly issued a document (pdf) entitled “Basic Research on Bacteria. The Essential Frontier.”  Readers of this blog may find this an enlightened manifesto that makes a lucid case for the subtitle of the report.  This is not surprising, considering that it was assembled by some 60 outstanding scientists from academia and the Federal Government.  It would be too optimistic to hope that such a report will alter the funding situation overnight, but in the long run it can only help.  In the meanwhile, it makes for good reading.

Talmudic Question #10

Do we know for sure that there are only three domains of life (Bacteria, Archaea, Eukarya)?

Life Without Sunshine

Vulcan's Forge by Luca
Giordano (1632-1705)

In 1998, a respected astronomer and physicist turned geologist, Thomas Gold, wrote a highly influential book, The Deep Hot Biosphere, in which he argued that there is abundant microbial life in the water within the pores, cracks and fissures of the rocks beneath our feet. Furthermore, Gold advanced the provocative notion that hydrocarbons within the Earth were not derived from fossils but rather were created early in the life of the planet by chemical and physical processes below the crust, including radiation. (His 1992 paper summarizing some of these ideas is available.) Taken together, these views suggest that there exists an immense and hospitable underground environment for microbes, complete with liquid water, an energy source (hydrocarbons and hydrogen), and livable temperatures (down to about 10 Km at which point it becomes too hot for even the most extreme of thermophiles). Gold postulated that not only is there life in the neighborhood of Vulcan’s furnace, but that there might be as much biomass there as on land and sea combined. Not only would this life not need the sun as an energy source, but unlike the communities thriving around the deep sea vents, it could be independent of all photosynthetically produced products (e.g., oxygen), as well.

But how would one go about studying the deep hot biosphere?

Talmudic question #9

Given that spores are so effective in ensuring survival of bacteria, why don't all species make them?
(Courtesy of Sabrina Perrino, who thought of this in class about five minutes after I did)