Tag: Microalgae

Concept for self-sustained oxygen mask wins competition

Concept for self-sustained oxygen mask wins competition

Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have developed a concept for a self-sustained oxygen mask that uses the ability of microalgae to convert carbon dioxide into oxygen. This could form the basis for a portable microalgae-biomaterial hybrid device that enables prolonged oxygen supply and water absorption. With this concept, the HZDR team is one of the winners in a competition organized by the journal Nature Reviews Bioengineering. The task was to develop medical innovations for resource-limited regions.  

Life-saving medical devices such as oxygen masks are often dependent on limited or expensive resources, such as medical oxygen. In addition, many important devices and treatments require expensive and complex components, which hinders their development and local manufacturing. Solutions that work in resource-poor and disadvantaged regions of the world are, therefore, urgently needed. This is why the journal Nature Reviews Bioengineering has called on young bioengineers to find a simple solution to this problem.

Oxygen masks are usually dependent on an external oxygen supply, whether in the form of oxygen tanks or capsules. For the competition “The ultimate bioengineering challenge”, Xuan Peng, Xinne Zhao and Željko Janićijević from the Department of Nano-Microsystems for Life Sciences at HZDR´s Institute of Radiopharmaceutical Cancer Research have designed the idea for a self-sustained oxygen mask made of lightweight, biocompatible materials that enables prolonged oxygen supply and water collection in resource-poor areas.

The main challenge in designing a self-sustained oxygen mask was to reduce carbon dioxide and water vapor while increasing the oxygen content in the inhaled air. The scientists’ idea is based on photosynthesis, in which light energy (from the Sun) is converted into chemical energy. This energy is then used to build up energy-rich organic substances from carbon dioxide and water and release oxygen. For photosynthesis, they use microalgae, which are considered excellent converters of carbon dioxide to oxygen and can survive even under harsh environmental conditions. 

Read more on HZDR website

Image: Schematic illustration of how a self-sustained oxygen mask works.

Credit: HZDR / A. Grützner

Multitasking microalgae fight pollution

Multitasking microalgae fight pollution

Microalgae for pollution removal is the topic of two recent studies by MAX IV users. The storage mechanism of phosphorous in the algae was investigated in detail contributing to method development for pollution removal from wastewater. The phosphorous-containing algae can, in turn, be used to soak up metal pollutants.

Phosphorous is used as a fertiliser to enhance crop yields in agriculture. It is needed to feed a growing population but can also become a pollutant if uncontrolled. Agriculture and wastewater treatment processes are the primary sources of phosphate pollution and eutrophication, causing oxygen depletion and loss of aquatic life. 

It is known that microalgae can take up and store phosphorous from water sources. In recent studies, researchers have investigated the storage process in more detail to optimise it and find uses for the algae after they have done their cleaning. Imaging with X-rays revealed the granules that form when microalgae store phosphorous.

“We found that the granules are composed of an interesting polyphosphate compound, inositol hexaphosphate, also known as phytic acid. This compound is found in plant seeds such as grains, nuts or pulses. It is interesting that algae can also store phosphate [editors note: a chemical compound of phosphorous] in this form. The storage is triggered by first starving the algae of phosphate and then giving them a surplus,” says Prof Richard Haverkamp from Massey University in New Zealand, one of the researchers behind the study.

The phytic acid has further uses for pollution removal, so the microalgae seem to come with a bonus.

“Because phytic acid is known to react with some metal ions, we can use the existing knowledge about phytic acid reactions with metals to predict which metal ions might be able to be absorbed readily by these algae containing phosphate granules. We have just started investigating this as a way to clean up water polluted with these metals or to remove valuable metals from aqueous sources,” prof Haverkamp continues.

The researchers scanned the whole microalgae through the X-ray beam to measure the phosphate content using a method called Scanning Transmission X-ray Microscopy (STXM). 

“STXM has the ability to provide images with elemental and chemical information on the features present in the image. So whereas in transmission electron microscopy it is possible to see an object that we can label a granule, in STXM we can image that object but can also measure that it contains phosphorus and that this phosphorus is a specific compound of phosphorus,” says Prof Haverkamp.

The researchers saw the phosphate-rich granules with better than 60 nanometres resolution. They complemented the analysis by studying a sample where the microalgae cells were mixed together to investigate the form of phosphorous compounds in larger detail. However, phytic acid was the only phosphorus compound found. They studied two different kinds of algae. 

Read more on MAXIV website

Image: Algae (green) with the phosphate granules (blue).