Deoxynivalenol (DON) Accumulation and Nutrient Recovery in Black Soldier Fly Larvae (Hermetia illucens) Fed Wheat Infected with Fusarium spp.

Abstract

Fusarium head blight (FHB) is one of the most significant causes of economic loss in cereal crops, resulting in a loss of $50–300 million for Canadian agriculture. The infected grain (containing Fusarium-damaged kernels (FDKs)) is often both lower in quality and kernel weight, and it may be unsuitable for human and animal consumption due to mycotoxin presence. However, it still contains a considerable amount of nutrients. A method to recover the nutrients without the mycotoxins should be beneficial for the agricultural economy. In this study, our objective was to examine recovery methods of the nutrients in relation to mycotoxin accumulation in the insect. The FDKs were fermented with Aspergillus oryzae and/or Lactobacillus plantarum (solid-state fermentation (SSF)). The SSF kernels were then provided to 50 young, black soldier fly larvae (BSFL) for 12 days. Weight gain, chemical composition, and mycotoxin bioaccumulation of BSFL and spent feed were evaluated. After 12 days of insect culture, the BSFL grew 5–6 times their initial weight. While the overall weights did not significantly vary, the proteins and lipids accumulated more in SSF FDK-fed insects. During the active growth period, the larval biomass contained deoxynivalenol (DON), a mycotoxin, at detectable levels; however, by day 12, when the larvae were in the pre-pupal stage, the amount of DON in the insect biomass was nearly negligible, i.e., BSFL did not accumulate DON. Thus, we conclude that the combination of BSFL and SSF can be employed to recover DON-free nutrients from FHB-infected grain to recover value from unmarketable grain.

Staphylococcus aureus in Substrates for Black Soldier Fly Larvae (Hermetia illucens) and Its Dynamics during Rearing

“…The fact that certain fungi can produce mycotoxins may cause safety problems for BSFL rearing. The fate of mycotoxins in substrates for BSFL rearing has already been a topic of research, for instance in references 44 – 47 , and is still under investigation.…”

Rethinking organic wastes bioconversion: Evaluating the potential of the black soldier fly (Hermetia illucens (L.)) (Diptera: Stratiomyidae) (BSF)

“…For example, when BSF larvae were reared on the experimental substrate spiked with heavy metals, Cd and Pb bioaccumulated in the BSF biomass, with the bioaccumulation factor (concentration in the organism divided by the concentration in the substrate) of 6.1-9.5 and 1.2-2.6, respectively, exceeding the statutory thresholds for animal feed (Purschke et al, 2017;Tschirner and Simon, 2015;van der Fels-Klerx et al, 2016b), while no bioaccumulation was observed for chromium (Cr), nickel (Ni), As, zinc (Zn), and mercury (Hg) (Diener et al, 2015;Purschke et al, 2017). Similarly, no bioaccumulation of mycotoxins (aflatoxins B1/B2/G2, deoxynivalenol, ochratoxin A, zearalenone) (Bosch et al, 2017;Camenzuli et al, 2018;Gulsunoglu et al, 2019;Lalander et al, 2016;Meijer et al, 2019;Purschke et al, 2017), pesticides (chlorpyrifos, chlorpyrifos-methyl, pirimiphos-methyl, azoxystrobin, propiconazole) (Bosch et al, 2017;Gulsunoglu et al, 2019;Lalander et al, 2016;Purschke et al, 2017), and pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) (Lalander et al, 2016) have been observed in BSF biomass. The concentration of pesticides and pharmaceuticals decreased in the residual substrate, which was attributed to degradation of these compounds by microorganisms associated with BSF larvae.…”

Chemical safety of black soldier fly larvae (Hermetia illucens), knowledge gaps and recommendations for future research: a critical review

“…So far, no influence of exposure to mycotoxins, shown in Table 2, has been observed on larval growth performance or survival rate, probably due to limited accumulation of various mycotoxins, resulting in concentrations below the maximum/guidance values prescribed by the European feed law. In fact, the mycotoxin concentration in the residue (which is the remaining substrate along with excretion products of the BSFL) is in general even reduced compared to the substrate due to the presence of BSFL, except in one case of zearalenone (Bosch et al, 2017;Gulsunoglu et al, 2019;Leni et al, 2019;Purschke et al, 2017). Zearalenone can increase in the residue, possibly by the extractability of the compound.…”