Bacteria that use caffeine as food discovered

Updated: May 25, 2011, 00:00 AM IST

Washington: For the first time, scientists have discovered a new bacteria that use caffeine as its food, a finding they say holds promise for cheaper versions of some
life-saving drugs used to treat asthma and blood arrhythmias.

Researchers at the University of Iowa in the US found that the bacterium called Pseudomonas putida CBB5 uses some digestive enzymes to break down the caffeine, which allows it to live and grow.

"We have isolated a new caffeine-degrading bacterium, which breaks caffeine down into carbon dioxide and ammonia," said Ryan Summers, a doctoral student who led the research.

According to Summers, the compounds formed during the caffeine break down are natural building blocks for many drugs used to treat asthma, improve blood flow and stabilize heart arrhythmias.

Currently it`s very difficult to synthesise these drugs chemically. But using CBB5 enzymes would allow for easier pharmaceutical production, thus lowering their cost, he said.

Another potential application of bacteria-generated enzymes would be the decaffeination of coffee and tea as an alternative to harsh chemicals currently used, he added.

Caffeine itself is composed of carbon, nitrogen, hydrogen and oxygen, all of which are necessary for bacterial cell growth.

Within the caffeine molecule are three structures, known as methyl groups -- composed of one carbon and three hydrogen atoms.

This bacterium is able to effectively remove these methyl groups (a process known as N-demethylisation) and essentially live on caffeine, the researchers found.

Summers and his colleagues have identified the three enzymes responsible for the N-demethylization and the genes that code for these enzymes.

Further testing showed that the compounds formed during break down of caffeine are natural building blocks for drugs used to treat asthma, improve blood flow and stabilise heart arrhythmias.

"This work, for the first time, demonstrates the enzymes and genes utilised by bacteria to live on caffeine," Summers added.

The new findings were presented at a meeting of the American Society for Microbiology in New Orleans.