Nanotechnology has potential to mitigate pathogens

When laymen, myself included, hear about nanotechnology, we might envision microscopic robots being injected into our bodies to assist doctors in diagnosing a disease or fixing an internal wound of some sort, but nanotech has been used in the agricultural industry for some time and is now looked at as an innovative frontier for the aquaculture business to battle microbes, lowering antibiotic use, while making the fish farming sector more sustainable, say proponents.

Nanobio – nanotech

            Unlike genetically modified organisms (GMOs) where living things whose genetic material (DNA) is changed in ways unlike those that occur naturally, nanobio and nanotech involves the creation and manipulation of particles at a nanometer level (which is one hundred thousandth the diameter of a single strand of your hair) to produce new materials.

            Rather than introduce a substance from another organism, the changes are made within the existing organism. Scientists who participate in food nanotechnology move and put together molecules to create foods that provide more nutrition, have a longer shelf life, destroy disease and even taste better.

Post-doctoral researcher, Candice Lavelle, Physiological Sciences University of Florida, was

awarded a grant from the National Institute of Food and Agriculture (NIFA) Fellowship Program “Food, Agriculture, Natural Resources and Human Sciences Education and Literacy Initiative” and is using the two-year funding to research nanomaterials for use in the aquaculture industry.

Mitigating fish pathogens

            “There are many areas in which nanotechnology can potentially be applied to help the aquaculture sector,” she explained. “I chose to focus on the use of nanotechnology to mitigate pathogens because cultured fish are commonly susceptible to disease, which can result in devastating losses in productivity. Currently, the use of pharmaceuticals to remediate pathogenic infections is highly regulated in fish intended for human consumption and can also lead to generation of resistant pests.”

            Lavelle said her research centers on utilizing novel materials, called nanomaterials, to remediate challenges that face the aquaculture industry. There are many areas in which nanotechnology can potentially be applied to help the aquaculture sector. 

            The need to develop non-chemical means for mitigating pathogenic outbreaks in aquaculture operations has sparked new interest by investors, governments, and researchers. For instance, virus removal by nanomaterials has been the subject of several studies.

            The report, “Nanotechnology as a novel tool for aquaculture industry: A review,” looked at silver nanoparticles used as a new method to use against pathogens and bacteria. The properties of silver nanoparticles are attractive and beneficial to the aquaculture industry, according to the authors of the report. The silver nanoparticle synthesis methods are the physical and chemical methods and the problem with chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed during the process.

            To overcome this, the authors of the report surmised, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The main uses of silver nanoparticles in the aquaculture include diagnostic applications and therapeutic applications, they write.

            In most applications it is the immunostimulator and antimicrobial properties of silver nanoparticles that are being looked at. In addition to these applications, silver nanoparticles may be used in many practices such as fish packaging, prevention of biofouling, DNA nanovaccines and DNA biosensors.

            “Our approach is to construct carbon nano material-based filters that are highly absorptive to select viruses,” said Lavelle. “These devices could eventually be placed strategically into water systems of aquaculture facilities to remove pathogens before they have a chance to infect the fish. One advantage of this approach is that the filters will be designed in such a way so the nanomaterials will not come in contact with the fish, minimizing any potential side-effects.”

Potential to solve many issues

            Other areas that nanotechnology is being explored for use in the aquaculture industry are drug delivery, other aspects of water treatment, and food packaging, she explained.  “The key is finding the right materials to perform each of these tasks efficiently while also minimizing toxicity in the fish and workers,” Lavelle explained. “Nanomaterials are made from a wide variety of materials with differing degrees of safety therefore research into all of these areas is expanding and should result in some exciting products and applications in the near future.”

            In a recent article in The Hans India newspaper, scientist P. Swain reported stated during his presentation “The Application of Nanotechnology in Aquaculture and Fisheries”, that “though the application of nanotechnology in aquaculture is still at an infant stage, it has the potential to solve many of the problems associated with aquaculture.”

            He said that at present research has initiated in the application of metal and metal oxide nanoparticles for control of bacterial bio film, fungal infection, and algal blooms for immuno-modulation as feed additives, development of antimicrobial, anti-algae and antifouling coating for water remediation, enrichment of micronutrient content of fish fillets and improving the color of fish. The scientist said that by using nanotechnology feed consumption is reduced.

            Though the nanotech industry is just beginning to make a push into the aquaculture sector, the possibilities are vast for improving fish health, growth, and quality of fish farmed in marine water where a lot of the controversial antibiotic and other chemical use has been a problem.

—Erich Luening