Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enzymes find pastures greener

17.04.2002


Chemists put biological catalysts to work in clean industrial solvents.



In a move towards cleaner chemical processing, researchers in Spain and France have worked out how to use enzymes as catalysts using two ’green’ solvents: one to dissolve the enzyme, the other to dissolve the materials it transforms.

In some industrial processes chemists have replaced polluting organic solvents, such as chlorine and benzene, with supercritical carbon dioxide. This is the liquid-like fluid that is made by putting carbon dioxide under moderately high pressure and at temperatures equivalent to a hot bath. Supercritical carbon dioxide dissolves many organic compounds used for chemical synthesis. It decaffeinates coffee, for example.


Another, more recent, green option is the use of ionic liquids - these are salts that are molten at room temperature. They too dissolve many organic compounds, and don’t give off nasty fumes.

Jose Iborra of the University of Murcia in Spain and co-workers have used a combination of supercritical carbon dioxide and ionic liquids to help an enzyme transform some organic molecules1. This is an ideal form of green chemistry, as it uses natural catalysts in clean solvents.

Enzymes are designed to work in water inside cells. But water won’t dissolve many of the organic reagents used in industrial and pharmaceutical chemistry. So many industrial processes that use enzymes as catalysts need organic solvents.

Unfortunately, enzymes typically don’t work well in carbon dioxide. "It reacts with the enzyme," explains chemist Eric Beckman of the University of Pittsburgh. This and other complications stop the enzyme working as a catalyst. Some enzymes, though, work well in ionic liquids. So Iborra’s group devised a two-phase reactor in which the organic starting materials are dissolved in supercritical carbon dioxide and passed through a chamber containing a yeast enzyme dissolved in an ionic liquid.

The enzyme converts the reagents to the desired products, presumably by reactions occurring at the boundary between the two solvents. Product molecules dissolve in the carbon dioxide and are carried out of the reaction chamber. The enzyme, which stays in the ionic solvent, is protected from the worst of the deactivating influence of carbon dioxide.

It’s not a perfect solution - some carbon dioxide can dissolve in the ionic liquid and so can still get at the enzyme. But it’s a lot better than trying to carry out the reaction entirely in carbon dioxide, which deactivates the enzyme quickly.

"It’s an intriguing idea," says Beckman, as using enzymes in supercritical solvents has previously been fraught with difficulties.

References
  1. Lozano, P. , de Diego, T., Carrie, D., Vaultier, M. & Iborra, J. L. Continuous green biocatalytic processes using ionic liquids and supercritical carbon dioxide. Chemical Communications, 2002, 692 - 693, (2002).


PHILIP BALL | © Nature News Service

More articles from Life Sciences:

nachricht Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>