Featured Research

from universities, journals, and other organizations

Scientists Learning To Create Nanomaterials Based On Micro-algae Patterns

Date:
December 7, 2006
Source:
Georgia Institute of Technology
Summary:
Researchers at the Georgia Institute of Technology have developed a technique to study how unicellular micro-algae, known as diatoms, create their complex cell walls. Researchers hope to learn how diatoms assemble these nanometer-patterned, intricate micro-architectures to find better methods for creating nanomaterials in the laboratory.

Researchers hope to find better methods for creating nanomaterials based on intricate cell-wall patterns assembled by diatoms, such as Thalassiosira pseudonana.
Credit: Image courtesy of Nils Kröger

Researchers at the Georgia Institute of Technology have developed a technique to study how unicellular micro-algae, known as diatoms, create their complex cell walls. Researchers hope to learn how diatoms assemble these nanometer-patterned, intricate micro-architectures to find better methods for creating nanomaterials in the laboratory.

"Diatoms are nature's most gifted nanotechnologists," said Nils Kröger, an assistant professor in Georgia Tech's School of Chemistry and Biochemistry and the School of Materials Science and Engineering. "We want to learn how diatom cell walls are produced because human technology can't make something that intricate by self-assembly processes and under ambient conditions."

Diatoms are single-celled organisms that frequently appear as a brown, slippery coating on submerged stones and as phytoplankton in the open ocean. Tiny pores in the cell wall allow diatoms to exchange nutrients with the environment and remain at the surface of the water to absorb sunlight for photosynthesis. Diatom photosynthesis is responsible for 20 percent of the world's organic carbon. The pores allow diatoms to be lightweight, but their cell wall gives them a strong mechanical structure. The strength of the cell wall comes from amorphous silica, or silicon dioxide (SiO2) -- virtually the same material as glass.

Diatom cell walls show an enormous diversity in form, most of them amazingly beautiful and ornate, depending on specific biomolecules produced by the diatom, Kröger explained. Previous research has shown that uniquely modified proteins called silaffins and extremely long polyamine chains play a role in the structural design of the cell wall. Kröger hypothesizes that the structure of the diatom silica critically depends on the type of silaffin present within the diatoms' silica-producing organic matrix. Therefore, he expects that changing the "silaffin equipment" of a diatom cell should result in novel silica nanostructures.

Kröger and collaborator Nicole Poulsen, a postdoctoral researcher in the School of Chemistry and Biochemistry, have developed a technique to genetically engineer diatoms. The process allows insertion of mutated or foreign genes into the genome of the diatom Thalassiosira pseudonana. Kröger believes this technique will enable the creation of diatoms with novel silica structures. He will describe the technique in an invited presentation on Dec. 12 at the fall meeting of the American Geophysical Union.

Genetic manipulation of diatoms will increase the understanding of their cellular biochemistry and potentially enable the use of these organisms for the production of commercially valuable compounds and materials, Kröger said. But inserting a gene through the strong silica cell wall is difficult. The wall must be penetrated, but not broken, and the foreign gene must be accepted into the diatom's genome, he explained.

To insert the genes, such as those that encode different silaffins, through the diatom cell wall, Kröger and Poulsen use a technique called microparticle bombardment. DNA-coated tungsten particles are "shot" on the diatoms under high heliumpressure, thus enabling them to penetrate the strong diatom cell wall. The diatom incorporates the introduced DNA into its genome, and selection of the transfected cells is achieved using the antibiotic nourseothricin. When new genes are introduced with the technique developed by Kröger and Poulsen, they can be expressed constantly or be turned on and off when necessary. Specific details of the technique were published in the October 2006 issue of the Journal of Phycology.

Kröger and Poulsen established this technique for the diatom Thalassiosira pseudonana because it is currently the only diatom species with a completely sequenced genome.

"Knowing the genome sequence and having established a method for genetic modification of this organism means we can, in principle, analyze the function of every gene and the protein that it encodes," Kröger said. "This will eventually enable us to identify the key cellular biomolecules involved in creating the strong, intricately patterned diatom cell walls."

The research has been supported by a grant from the Office of Naval Research and the Defense Advanced Research Projects Agency.


Story Source:

The above story is based on materials provided by Georgia Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Georgia Institute of Technology. "Scientists Learning To Create Nanomaterials Based On Micro-algae Patterns." ScienceDaily. ScienceDaily, 7 December 2006. <www.sciencedaily.com/releases/2006/12/061207083806.htm>.
Georgia Institute of Technology. (2006, December 7). Scientists Learning To Create Nanomaterials Based On Micro-algae Patterns. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2006/12/061207083806.htm
Georgia Institute of Technology. "Scientists Learning To Create Nanomaterials Based On Micro-algae Patterns." ScienceDaily. www.sciencedaily.com/releases/2006/12/061207083806.htm (accessed July 30, 2014).

Share This




More Matter & Energy News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) — A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Stranded Whale Watching Boat Returns to Boston

Stranded Whale Watching Boat Returns to Boston

Reuters - US Online Video (July 29, 2014) — Passengers stuck overnight on a whale watching boat return safely to Boston. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Baluchistan Mining Eyes an Uncertain Future

Baluchistan Mining Eyes an Uncertain Future

AFP (July 29, 2014) — Coal mining is one of the major industries in Baluchistan but a lack of infrastructure and frequent accidents mean that the area has yet to hit its potential. Duration: 01:58 Video provided by AFP
Powered by NewsLook.com
Easier Nuclear Construction Promises Fall Short

Easier Nuclear Construction Promises Fall Short

AP (July 29, 2014) — The U.S. nuclear industry started building its first new plants using prefabricated Lego-like blocks meant to save time and prevent the cost overruns that crippled the sector decades ago. So far, it's not working. (July 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins