Money may not grow on trees, but gold can. In a remarkable experiment, Indian scientists have developed a form of gold using a micro-organism from a fig tree as the 'factory'.
But before rushing to try cultivating fig trees and converting the gold into ornaments, here is a word of caution : The scientists have been able to use the micro- organism to churn out gold nanoparticles 8,000 times smaller than the human hair.
And therein lies the beauty of the new gold. Being so small , it can have easy access to the cells. Gold being bio- friendly , researchers can piggy - back drug molecules into the very heart of cranky cells that cause diseases and repair them.
The technology can also be used in developing nanomaterials and nanoelectronics.
The research group took a micro- organism called Rhodococcus from a fig tree, and exposed it to a liquid containing gold ions ( which are electrically charged gold particles).
They found that the micro- organism caused the gold ions to gain electrons , thereby forming gold nanoparticles within the micro - organism's cells.
The new work has been done by researchers from the National Chemical Laboratory (NLC ) and the Armed Forces Medical College ( AFMC ), both in Pune and published in the recent issue of Nanotechnology, the journal of the Institute of Physics.
The journal has hailed the experiment as " green chemistry " because following the biosynthesis of gold nanoparticles in Rhodococcus, its cells continued to multiply normally , as the metal ions used were not toxic to the cells . This eco- friendly step is important as more gold would be formed as the cells multiply.
" This (the nanoparticles) is much more uniform than the particles formed using other biological methods. Having uniformly sized particles will be needed if we are to use this method in biodiagnosis using gold nanoparticles or to deliver therapeutic drugs," he added .
Such gold nanoparticles of uniform size can also be useful in labelling proteins , nucleicacids and other biomolecules.
These nanoparticles are more conecntrated and more uniform in size than particles biosynthesised by previous methods that used a fungus , according to the paper published by Nanotechnology.
Although the exact reaction that causes the gold to form is not yet fully known, the group believes that the Rhodococcus species gives better results because it is a certain type of micro-organism ( an actinomycete) that shows characteristics of both bacteria and fingi, rather than just being a fungus.
The group will soon be looking into making the nanoparticles on a large scale, which could be attained by genetically modifying actinomycetes to produce more of the enzymes which cause the gold to form.
