Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria dye jeans

27.03.2002


Biotech bugs turn indigo blue in a green way.



Jeans dyed blue by bacteria may soon be swaggering down the streets. Researchers have genetically modified bugs to churn out the indigo pigment used to stain denim. The process could be a greener rival to chemical indigo production.

Originally extracted from plants, indigo dye is now made from coal or oil, with potentially toxic by-products. Bacteria have previously been adapted as alternative indigo manufacturers, but a trace by-product renders jeans an unfashionable shade of red.


Walter Weyler and his colleagues of Genencor International in Palo Alto, California tweaked the genes of the bacterium Escherichia coli to eliminate the red pigment1. The final colour is "indistinguishable" from the globally popular deep blue of the chemically made dye, says Doug Crabb, vice president of Genencor.

The bugs offer an environmentally friendly substitute for chemical synthesis: they use sugar as their raw material and create less waste. "Biological indigo would probably be more environmentally friendly," agrees UK environmental consultant Michael Griffiths. But industry is unlikely to use it until it is also as cheap and effective.

Blue bugs

Biotech indigo starts with a chemical called tryptophan, which bacteria produce naturally. Tryptophan is ideal for conversion to indigo because it already contains the ring-structure at the core of the indigo molecule. A few chemical alterations convert tryptophan into the dye.

Bioindigo E. coli have an enzyme from another microbe engineered into them that converts trytophan into the ring-containing indigo precursor indoxyl; this spontaneously turns into indigo when exposed to air.

Weyler and his team tinkered with their E. coli so that they churned out high levels of the raw material tryptophan. The researchers also inserted a gene that cuts down production of the contaminating red pigment. The efficiency of the process still needs to be improved, however, Crabb concedes.

Before the chemical process was invented, people used plants such as woad and dyer’s knotweed to make indigo: soaking their leaves in water releases indigo’s chemical precursors. How these are converted to indigo is still a mystery. Biochemist Philip John of the University of Reading, UK is heading a project to re-introduce indigo- yielding crops into Europe as a natural alternative to chemical synthesis.

Biotech and plant production would both have to be souped-up to feed the world’s obsession with blue jeans: 16,000 tonnes of dye are made annually, almost all of which is used on denim. "There’s no other dye that will give that characteristic colour," explains John, "It’s got to be indigo."

References

  1. Berry, A. et al. Application of metabolic engineering to improve both the production and use of biotech indigo. Journal of Industrial Microbiology & Biotechnology, 28, 127 - 133, (2002).


HELEN PEARSON | © Nature News Service

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>