Starch, Seaweed and Shrimp Shells - Gifts to Agriculture

Published: 25 September 2013

In more than a dozen countries, irradiated natural polymers are being used to create products that improve medicine, industry, environmental protection, cosmetics and agriculture. Polymers are the cellulose in plants and trees; the starch in bread, corn and potatoes. The shells of shrimps, crabs and other crustaceans are made of a polymer called chitin; and seaweeds are made of the polymers carrageenan and alginate. These and other natural polymers are the perfect building blocks from which to develop new materials because they are abundant, inexpensive, biodegradable, locally available and renewable. Because radiation breaks chemical bonds and creates new ones, it is used to process these natural polymers, turning them into vastly different, useful products. In Vietnam scientists are using the polymer chitin/chitosan found in shrimp shells to make sprays and additives that prevent and cure plant diseases and promote plant growth. Oligochitosan [OL-EE-GO-KITE-O-SAN], a yellow or brown liquid derived from processed and irradiated shrimp shells, helps plants grow faster and bigger, and improves plants' immunity to diseases and fungal infection. According to Nguyen Quoc Hien, researcher at the Vietnam Atomic Energy Institute, the effectiveness of oligochitosan has led to widespread adoption in Vietnam's agricultural sector, and has almost eliminated the use of toxic fungicides across the country. One teardrop worth of liquid oligochitosan dissolved in one litre of water can be used to prevent diseases in plants.<br /><br />
 (Photo: Biologist Le Quang Luan adds oligochitosan to a water distribution system for plants in a greenhouse) The widespread use of non-toxic products like oligochitosan, which leave no harmful residue behind, is ultimately better for consumers, and opens up greater possibilities for national agricultural exports. Oligochitosan has even been proven to extend the shelf life of fruits like mangos and oranges, keeping them firm and attractive to consumers for longer periods. Oligochitosan and its associated products like Gold Nano and Silver Nano, which are made from the same base polymers but with the addition of gold or silver particles before irradiation, are being used in a number of other ways. They can be added to the feed given to farmed fish, chicken and shrimp to improve the animals' immune systems, survival chances, and propensity for weight gain. They can also be used to clean up water in aquaculture and kill bacteria where infection is already present. Some scientists have even found evidence that these natural polymers may promote health and well-being in humans. Silver Nano has already been commercialized as a wound sterilization spray for children in Vietnam. Conducting research using mice, Le Quang Luan, Head of the Biology Department at the Vietnam Atomic Energy Institute's Centre for Nuclear Techniques, says there is evidence that gold nanoparticles distributed in special oligosaccharides (like oligochitosan and oligobetaglucan - a natural polymer product derived from yeast, mushrooms or oats) can eliminate, or significantly reduce the damaging effects of radiation on cells inside the body. If the results remain consistent after further research, this could have a profound effect on quality of life of cancer patients undergoing radiation treatment. Luan has also been researching the effectiveness of Gold Nano for disease diagnosis and treatment delivery, because when injected, Gold Nano unerringly finds and attaches itself to cancerous formations inside the body. The IAEA has been promoting radiation processing of natural polymers for the last 30 years, and over the last decade, interest in the technology has grown faster in Asia and the Pacific than in any other region in the world, bringing with it the potential for significant benefits to industry, economic growth, health, agriculture and the environment. 'This research is being conducted in approximately two dozen IAEA Member States, most of them in Asia. And we hope that other countries and regions will embrace this clean, safe and beneficial technology,' says Radiation Chemist Agnes Safrany, of the IAEA Radioisotope Products and Radiation Technology Section. <br /><br />© IAEA   <br /><br /> <br /><br /><br /><br />© IAEA