When microbiologist Raúl Cano announced in May that he had revived bacteria that were between 25 million and 40 million years old, he became the subject of intense public interest, even more intense scientific skepticism, and a Dave Barry column. (You wait, the humorist wrote. One of these nights, Dr. Cano’s germs are going to escape from their petri dishes and start creeping forward, zombie-like, with their little bacterial arms sticking straight out in front of them, and heaven help the laboratory security guard who stands in their way.)
Cano, who works at California Polytechnic State University in San Luis Obispo, found his ancient research subjects in the belly of a bee that long ago got stuck in the resin flowing from a tree in the Dominican Republic. When that resin hardened, it became amber. The bee died almost immediately, but inside its stomach lived a species of symbiotic bacterium much like the species Bacillus sphaericus that is found in Dominican bees today.
The bacterium survived for millions of years without air or nutrients, Cano claims, by going into a state of suspended animation. In times of stress, a number of microbes knit themselves a strong, protective protein coat called a spore and slow all their cellular processes until they are effectively (but not actually) dead. Once they sense the presence of sufficient nutrients--a sort of bacterial all’s-well signal--they resurrect themselves.
But as Cano found, they don’t rouse easily. Even after he had dissected out the bee’s stomach and put its contents on a petri dish, he still needed to find the precise recipe of metal ions, amino acids, and other ingredients that would allow the bugs to awaken and grow. Cano likens the task to reintroducing food to a starving person. Usually you can’t feed him fettuccine Alfredo, he says. You have to give him bread and water and then just sort of work him up to fettuccine.
Cano originally reported that he had revived just one sleeping species, but he says he’s now found over 2,000. Among them are several other Bacillus species, several species of the Actinomyces bacterium, and even some 20- to 35-million-year-old yeast.
He’s also recovered microorganisms from dozens of other insects, including flies, ants, wasps, beetles, and termites. To look for commercial uses for the aged bugs, Cano has helped found a biotech corporation called Ambergene. Already, he says, he has isolated a unique antibiotic from the Actinomyces. He’s used the yeast, meanwhile, to brew a beer he calls Jurassic Ale (a misnomer, since the yeast actually lived more than 100 million years after the Jurassic Period ended, in the latter half of the Tertiary). Aptly named or not, Cano says, the beer is not too shabby.
His critics, however, are not quite ready to raise a glass to him. They say it’s impossible for any living creature to have survived for so long. Instead of an ancient microbe, they argue, Cano has simply found a modern contaminant.
Cano maintains that he carried out his sterilization procedures to almost ridiculous extremes and carefully searched the amber for any cracks. He compared the DNA of the recovered bug with that of today’s B. sphaericus and concluded they were not close enough to be contemporaries. Similar comparisons were done with other molecular fingerprints. All, he says, led to the same conclusion: the bugs are old.
Cano firmly believes in the hardiness of microbes. It is obvious that microorganisms are really inveterate survivors, he says. They’ve been surviving and struggling through changing environments for three and a half billion years. So they must know how to do it.