Headline Dec 23, 2014/

''' COFFEE ''' : 

WASTE NOT - WANT NOT '''

COFFEE is a big business.  One grave consequence is a lot of  caffeine-rich waste which cannot be thrown away  willy-nilly.

Because  caffeine is a pollutant.

It inhibits both the germination of seedlings and the growth of adult plants. so it must be collected and dumped at approved sites.

This is a pity for two reasons. One is that it increases the cost of a cup of coffee. The other is that the waste is rich in nutrients.

If it could be decaffeinated, it might be used as animal feed   -thus adding to coffee companies'  revenues rather than subtracting from them. But that would require a cheap way to decaffeinate it.

Which is what Jeffrey Barrick of the University of Texas at Austin and his colleagues hope they have found. Their research published in  Synthetic Biology, suggests the answer lies with genetically modified bacteria.

The idea of using a bacteria to decaffeinate waste is not new.

Past studies showed that a species called  Pseudomonous putida can chew the molecules up. But it does in small quantities, and no one knew enough about it to work out how to increase its efficiency.

Dr Barrick thought the best way round this way to take the  caffeine chewing mechanism out of   P.putida  and put it  into  Esccherichia coli, a species biologists are good at manipulating.

He and his colleagues therefore extracted the cluster of  E.putida's genes that encode the  caffeine-chewing  enzymes and transferred them into  E.coli. And not just any old  E. coli.

The strain they picked lacked a gene from the pathway the bud usually uses to synthesise guanine,  one of the four chemical bases that act as a genetic code in DNA.

This was to test whether the transfer had worked, because the transplanted biochemical pathway turns caffeine into xanthine, a molecule  E.coli can make into guanine without the missing gene.

Since nothing can reproduce without  guanine  in its  DNA, the researchers had merely to sit back and see if their engineered bugs multiplied in the presence of caffeine. 

Sadly, they didn't.

An examination of the problem showed that the transferred gene cluster was missing a crucial piece.

That, they fixed using a patch from a third species  janthinobacterium. Then they tried again. This time the bacteria bred like  billy-o

The next step will be to see if what works in the lab also works on an industrial scale. If it does,  then coffee companies should see their costs reduced. 

And other producers of waste-  That require specialised  disposal,  will have new line of inquiry to pursue.  

With respectful dedication to the billions of  Coffee-Drinkers the world over. See Ya all on !WOW!  -the World Students Society Computers-Internet-Wireless:

''' Brewing Solutions '''

'''Good Night and God Bless

SAM Daily Times - the Voice of the Voiceless