#bacteria appreciation posts

[touba]

"Bacterial colonies learn. The response of the P. vortex bacteria to non-lethal levels of the antibiotic Septrin. The normal growth pattern in the absence of the antibiotic is shown in panel A. The effect of the first exposure is shown in panel B. The response in a second encounter is shown in panel C. The antibiotic stress induces the bacteria to intensify chemotactic attraction and form larger vortices. This clever strategy protects the bacteria since, as in larger vortices, the antibiotic is diluted by lubricating fluid they excrete. The bacteria enhance their repellent chemotactic signaling to push the vortices away from the antibiotic more rapidly. The 'higher complexity for greater adaptability' behavior is manifested in the fact that the growth pattern in panel B is less complex than that in panel A. Learning from experience is exemplified in panel C. Upon second encounter with the antibiotic the colony expands faster and the pattern is more complex."

-- Eschel Ben-Jacob, Yoash Shapira, and Alfred I. Tauber, "Smart Bacteria," from Chimeras and Consciousness

[touba]

Images from the laboratory of Eshel Ben-Jacob, professor of physics and astronomy at Tel Aviv University, as part of research in collaboration with Herbert Levine, professor at UC San Diego. Click through to view the images in full detail; more images can be viewed here.

From "The Science Behind the Art":

These images are part of a series of remarkable patterns that bacteria form when grown in a petri dish. While the colors and shading are artistic additions, the image templates are actual colonies of tens of billions of these microorganisms. The colony structures form as adaptive responses to laboratory-imposed stresses that mimic hostile environments faced in nature. They illustrate the coping strategies that bacteria have learned to employ, strategies that involve cooperation through communication...In a sense, the strikingly beautiful organization of the pattern reflects the underlying social intelligence of the bacteria...These images remind us never to underestimate our opponent.

[touba]

"A petri dish at the University of Bayreuth in Germany holds swirls of artificial spider silk. Natural dragline silk, which forms the spokes and outer ring of a spider's web, is tougher than steel fiber of the same diameter. The synthetic version cannot quite match that strength, but its durability and pliability make it ideal for fine sutures, replacement tendons, and tough yet lightweight textiles. To produce the silk, engineers equipped E.coli bacteria with the spider genes responsible for silk production. Each liter of bacterial culture produces just a few hundredths of an ounce of silk in three hours."

Photograph (click through for a closer look) by Martin Jehninchen, as featured in the September 2011 issue of Discover Magazine *.

[touba]

Photographs from Caleb Charland's series Biographs, 2009.

"These pictures began by accident. I was curious to see what would happen if I allowed bacteria to grow on the surface of film. I was interested in relinquishing the control of image making to a natural process...As I proceeded with the experiment, I was amazed to see what the bacteria were doing. The bacterial growth patterns were re-depositing the image particles, revealing a life cycle traced in silver...What began as a photograph had become a biograph, a trace of life, an index of an existence."

-- Caleb Charland, from "About Biographs"

[touba]

Listeria monocytogenes (left) and Listeria innocua (right), both on Oxford Agar. Listeria bacteria are the causative agents of listeriosis, a relatively rare food-borne illness.

Oxford Agar "is selective and diagnostic and used for the detection of Listeria. The selective and inhibitory components included in the medium are lithium chloride, acriflavin, colistin sulphate, cefotetan, cycloheximide and phosphomycin. Gram-negative and most Gram-positive bacteria are inhibited. The medium contains ferrous ions and aesculin, the latter of which Listeria hydrolyses producing black zones under and around the colonies." (source)

[touba]

Panspermia is the hypothesis that life exists throughout the universe, distributed by meteoroids, asteroids and planetoids. Panspermia proposes that life that can survive the effects of space, such as extremophile bacteria, become trapped in debris that is ejected into space after collisions between planets that harbor life and Small Solar System Bodies. Bacteria may travel dormant for an extended amount of time before colliding randomly with other planets or intermingling with protoplanetary disks. If met with ideal conditions on a new planets' surfaces, the bacteria become active and the process of evolution begins. Panspermia does not necessarily suggest that life originated only once and subsequently spread through the entire universe, but instead that once started, it may be able to spread to other environments suitable for replication.

source

[touba]

A petri dish containing bacteria with the "Genesis gene" incorporated into their genomes from Genesis, an installation by Eduardo Kac. The synthetic "Genesis gene" was created by the artist by translating a sentence from the Bible into Morse Code, then translating the Morse Code into a DNA sequence; the gene was then cloned in plasmids containing fluorescent proteins and introduced into the bacteria by the process of transformation.