A green way of coloring denims blue

A new research study led by the University of California, Berkeley engineering Professor John Dueber has shown that indigo dye, widely used in denim to give its trademark color can be produced using "green" technology.

The current chemical process for dyeing jeans is "environmentally hazardous, not only from the chemicals required for indigo synthesis but also in the excess of a chemical to dissolve indigo to enable dyeing," says Dueber.

Indigo dyeing is an ancient technique widely used nowadays to achieve the blue color tone of our denim jeans. Dueber and colleagues have used genetically engineered bacteria to produce a compound called indoxyl, a precursor to the actual indigo dye. But indoxyl is unstable by itself. To address this problem, the researchers mimic a pathway found in the Japanese indigo plant. "We have taken inspiration from the plants from which indigo was historically harvested to remove the need for all of these chemicals to develop a far more sustainable dyeing process," adds Dueber. The researchers incorporated an enzyme into the engineered bacteria that adds a sugar molecule to indoxyl, stabilizing it in the form of a colorless molecule, indican.

Indican is not only stable but is water-soluble thereby making it the perfect candidate to store for the long-term! And this entire process avoids the more toxic steps present in chemically producing dyes.

Dueber says that this study was conceptualized at an International Genetically Engineered Machines competition aimed at empowering undergraduates. This is a worldwide contest where undergraduates tinker with bacteria to help solve unique problems - a field known as synthetic biology. "The undergraduate team was mentored by a graduate student, Zachary Russ, and did a fantastic job setting the foundation that was followed-up another graduate student, Tammy Hsu," says Dueber. The researchers were initially attracted to how the sugar group could be added or removed from the indoxyl in a fast manner within the bacteria. And all you had to do to make sure the sugar group was added to indoxyl was to follow the color! That turned out to be a cheap means to view this protection.

But how does indican become indigo required to dye the denim? At the time of dyeing, the sugar molecule is removed from indican using a second enzyme producing indoxyl that spontaneously oxidizes into the indigo dye. Dueber says, "We demonstrated our dyeing process by first applying indican to a scarf garment followed by application of a solution containing the second enzyme. Multiple cycles can be performed to achieve darker shades of indigo color. "

This process has only been demonstrated in the lab, and the researchers estimate that scaling it to meet the total, immense indigo demand of the denim markets will take a long time.

However, a "green" technology to produce indigo dye has a huge potential towards producing environmentally friendly dyes in the future. In current times, where spent dye materials are dumped into rivers, sustainable ways of producing dye materials highlighted in Dueber's study could ultimately prevent environmental hazards and have a positive ecological impact in future.

 

Image credit:https://pixabay.com/en/pocket-daisy-jeans-flowers-textile-2324242/


Write a comment ...
Post comment
Cancel

Why Hillary Is Good For Your Health

Hillary the hawk at Stachus
Passing through the basement floor at Stachus these days you might not be sure if you can trust your eyes, as Hillary the Harris Hawk is likely to...

Oh dear, Obikes

Obike Muenchen
So far since launch, 6800 Obikes bikes have been positioned in Munich. More and more of these bicycles-for-rent are being deliberately damaged. Not...

Winter Tollwood 2017

Tollwood Winter Festival
Tollwood Winter Festival 2017 is currently taking place at the Theresienwiese in Munich.
This year's festival motto is: "We, all. Let's stand up and...

Engineering Jobs Fair in Munich

Munich Engineering Jobs - accepting CVs
The Association of German Engineers (VDI) is hosting its annual engineering recruitment fair on Thursday 16th November in Munich. The day-long event...

Second S-Bahn weekend maintenance closures

SBahn delays
For the second - and last - time of the year, the S-Bahn Stammstrecke (main line) will be out of service due to repair and maintenance works.

The...

Follow-Up on the Unterfoehring shooting

A 26-year-old female police officer was severely injured three months ago during a routine check at the Unterföhring S-Bahn station. The suspected...

Institutionalist Ciudadanos won the election, but pro independence parties retain majority

Ines Arrimadas, leader of Ciudadanos with 37 seats obtained most of the support from voters (25,3), but it wasn´t enough to break a majority of pro...

DB Sprinter Hits Technical Issues

It should have been the glorious end of a long and expensive journey; after more than 25 years of planning, political discussions, building halts and...

Is an Executive MBA Worth it?

Chicago Booth MBA
The Future of Business Education: Is an Executive MBA Worth it? Join Chicago Booth in Munich for a candid panel discussion and audience Q&A with...

Rosenheimerplatz Knife Attack - multiple victims

UPDATE: Munich police have now confirmed the man being held is in fact their prime suspect and the emergency situation is now over. UPDATE: a man...

Munich Top City for IT and Engineering

Munich top city for engineering jobs
Back in 2014, a study by the European Commission confirmed that Munich is the city that offers Information and Communication Technology (ICT)...

Munich Students Win Hyperloop Contest

Elon Musk, founder of Tesla and the aerospace company SpaceX, launched the "Hyperloop Pod Competition" in 2015. The Hyperloop is the concept of a...

Advertise with The Munich Eye
Public Service Advertisements
Shades of Love
Advertisements
Spanish Finca for rent Web Site Optimisation
Newspaper sudoku