Aflatoxin- Scourge of Stored Grains: How Black Soldier Fly Could Remediate Issue

I recently had a nice email exchange with a colleague in Switzerland about topics of interest on the BSF- and he suggested I circle back around and discuss in-depth some of the benefits of BSF in terms of bioremediation. Specifically, he mentioned aflatoxin, heavy metals, and bacteria. So, I wanted to touch on each of these topics in separate posts as my previous discussion on these topics was fairly limited. And to my colleague in Switzerland- thank you for the suggestion!

​So, for today- I will discuss aflatoxin. 

Overview: Aflatoxin is a major concern for stored products globally. This particular toxin is produced a species of fungi (Aspergillus flavus and Aspergillus parasiticus) commonly occurring in the same environment as the stored grains (e.g., maize & peanut) when grown. When the grain is stored in an environment where humidity and temperature are high, the fungi produce the toxin- aflatoxin. As you will read in the link with aflatoxin, it is a carcinogen to people as well as livestock. As such, methods have been developed for detecting the presence of the fungus and the toxin. 

This is all well and good for developed nations; however, such methods can be expensive and difficult to get into place in developing nations. Even from the most basic sense, excluding impact on human and livestock directly, economically, the impact is massive as well. Watch this video to learn about aflatoxin in Africa.

Here is an article that discusses this topic as well:

Health economic impacts and cost-effectiveness of aflatoxin reduction strategies in Africa: Case studies in biocontrol and postharvest interventions
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So what does this have to do with BSF? Great question- that has been addressed in a publication discussed briefly in a previous post. 

Bosch, G., H. J. van der Fels-Klerx, T. C. de Rijk, and D. G. A. B. Oonincx. 2017. Aflatoxin B1 and accumulation in black soldier fly larvae (Hermetia illucens) and yellow mealworms (Tenebrio molitor). Toxins 185.

Synopsis: As you can read, the article focuses on two species- one of which is the BSF. In this particular study they addressed two questions; 1) does concentration of aflatoxin impact life-history of the insect, and 2) could the insect be used to remediate the toxin? 

So what did they find? 1) Aflatoxin did not impact the development or survivorship of the BSF; 2) the BSF did not bioaccumulate the aflatoxin. 

Does this matter? Most definitely! This finding is huge- especially if you consider the amount of stored grain contaminated with aflatoxin that cannot be used as animal or human food. 

"Worldwide, approximately 25% of food crops are affected by mycotoxins causing a loss of nearly 1 billion tonnes of foodstuff per year."

Big Picture- what does this mean? Given so much stored grain is impacted, finding a solution for recycling these nutrients is massive as the production of insect biomass (protein) that can then be utilized to feed livestock, poultry, or aquaculture could reduce the economic burden of such waste as well as increase job opportunities, decrease protein deficiencies in developing nations and decrease long-term health impacts due to consumption of aflatoxin.

As always- I hope this information is useful. Until next time- good luck and happy BSF farming!

Author

Jeff Tomberlin, PhD, BSF choreographer 
Twitter: @FliesFacility
Director, EVO Conversion Systems
evoconsys.com