Researchers at the California Polytechnic State University cracked open a piece of Dominican amber and extracted material from the abdomen of a bee encased therein. The amber is dated at 25 and 40 million years based on the microscopic fossils found in the geographic strata in which the amber was found. Within two weeks, bacteria subsequently identified as Bacillus sphericus grew in the culture. A comparison of the DNA of ancient and modern bacteria appeared to confirm that the bacteria had indeed grown from the ancient spores. Morphological, enzymatic and biochemical identification methods were used to make a specific identification.
Bacillus is an ancient genus of bacteria that is known to form endospores.
The spores are protected from the effects of heat, radiation, pressure and environmental contamination by a thick, protective protein coat. Bacteria can remain in this dehydrated cryptobiotic state for millions of years, said Dr. Raul Cano, a microbiologist at Cal Poly. Bacillus species form symbiotic relationships with numerous bee species. While the bees provide a home for the bacteria, the bacteria aid metabolic processes within the bees. When facing starvation, the bacteria undergo transformation to spore form, he explained.