Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have developed a new technique for identifying the many species of microorganisms. They have explained about their method in the journal of Applied Environmental Microbiology. Microbiology has many applications and one such is the ability to identify species useful for cleaning up contamination, to identify pathogens and distinguish harmless bacteria from potential bioterror weapons.
Daniel (Niels) van der Lelie, lead author of the study said that it is very important to understand the role of microbes in global cycles, their metabolic capabilities and identify potential threats to human health. He said that culturing technique to identify microbes are very time consuming and error prone. On the other hand sequencing entire genomes is labor intensive and costly. So scientists were looking out for new techniques that could identify key segments of genetic code that are short enough to be sequenced rapidly and can readily distinguish among species.
The Brookhaven team has developed the single point genome signature tagging. Enzymes that recognize specific sequences in the genetic code are used to chop the microbial genomes into small segments. These contain identifier genes common to all microbial species, plus enough unique genetic information to tell the microbes apart.
This unique genetic information can identify all community members down to the genus level, and most to the species level. Sequencing is expensive and because of this 10 to 30 of them are glued together to sequence all at one time, making this a highly efficient, cost-effective technique.
Then the sequence is matched with the already existing database sequence. Still if there is no match to be found then van der Lelie said that it is considered as a brand new species. It can differentiate between closely related strains of Bacillus cereus, a pathogenic soil microbe, and Bacillus anthracis, the bacterial cause of anthrax. It can also identify the group of species which can deliver good results in cleaning up radiological contamination.
This study represents just one application of genome signature tagging. Further research could greatly speed the process of identifying genes that could be turned on and off in different types of cells.