Light Nanofilter System Stimulates Algae Growth. (Credit: Flickr @ Daniel Ramirez http://www.flickr.com/photos/danramarch/)A team of researchers from The University of Western Australia has helped develop a nanoparticle light filter system which stimulates the growth of useful microalgal organisms. The resulting microalgal cells and their light-absorbing photopigments provide high value-added chemical compounds which could lead to environmentally sustainable applications including biofuels.
Research Assistant Professor Ela Eroglu and Dr Paul Eggers working with Winthrop Professor Steven Smith, of UWA’s School of Chemistry and Biochemistry and ARC Centre of Excellence in Plant Energy Biology—and with Flinders University clean technology expert Professor Colin Raston—developed a passive way of using minute, reusable gold and silver particles to create an optical nanofilter which harnesses the light wavelengths most beneficial to microalgal pigment formation—the most suitablelight wavelengths for algae growth.
Algae grow in natural light but too much light, or certain wavelengths of light, can inhibit its growth. The researchers used the nanoparticles to “extract” only those wavelengths which the algae could use, resulting in improved growth.
“While commercial application is a long way off, this research shows that algal productivity can be improved using advances in nanotechnology,” Dr Eroglu said.
The research ties in with an increasing worldwide interest in the use of microorganisms, including microalgal cells, for production of bioenergy and biomass. Bioenergy production offers many potential opportunities such as for energy supply to rural communities, while biomass production is useful for animal feed and the chemical and pharmaceutical industries.
In fact, another study showed that the U.S. land and water resources could likely support the growth of enough algae to produce up to 25 billion gallons (94.6 million m3) of algae-based renewable biodiesel a year, one-twelfth of the country’s yearly needs. A Spanish project is even researching ways to turn algae into clean energy using wastewater, saving water and land resources for other purposes.
“Perhaps even more exciting is the potential to use such nanofilters in artificial photosynthesis systems —the ‘Holy Grail’ of Green Chemistry—in which solar energy would be used to split water into oxygen and hydrogen for fuel,” Professor Smith said.
Ela Eroglu, Paul K. Eggers, Matthew Winslade, Steven M. Smith, Colin L. Raston (2013). Enhanced accumulation of microalgal pigments using metal nanoparticle solutions as light filtering devices Green Chemistry, 15, 3155-3159 DOI: 10.1039/c3gc41291a
