E. coli bacteria produce a "green" blue dye
In its traditional form, the textiles industry isn't exactly a poster child for eco-friendliness – this is largely due to the widespread use of toxic synthetic dyes. That's why there's an increasing demand for less harmful, natural alternatives. Just such an alternative has recently been developed by scientists at Utah State University, who discovered that E. coli bacteria can produce a deep blue dye known as indigoidine.
Led by Dr. Jixun Zhan, the researchers started with another type of bacteria that naturally produce the blue pigment, but only in small amounts. To produce usable quantities, Zhan turned to the genetic manipulation of E. coli.
"In the original producing strain, there is only one copy of the biosynthetic gene that synthesizes the pigment," he says. "But in E. coli we can make multiple copies of the gene and induce its expression under a stronger promoter."
The indigoidine is further processed and purified after being produced by the bacteria, to the point that it's even safe for use as a colorant in food products, beverages and cosmetics. Utah State University has secured a patent for the technology, and is now planning on developing it commercially.
Russian scientists are also developing an alternative to synthetic dyes, in the form of a non-toxic ink that produces different colors by altering the nanostructure of the material to which it's applied.
Source: Utah State University