Microbial Community Dynamics during Rearing of Black Soldier Fly Larvae (Hermetia illucens) and Impact on Exploitation Potential

Abstract

The need to increase sustainability in agriculture, to ensure food security for the future generations, is leading to the emergence of industrial rearing facilities for insects. One promising species being industrially reared as an alternative protein source for animal feed and as a raw material for the chemical industry is the black soldier fly ( Hermetia illucens ). However, scientific knowledge toward the optimization of the productivity for this insect is scarce. One knowledge gap concerns the impact of the microbial community associated with H. illucens on the performance and health of this insect. In this review, the first steps in the characterization of the microbiota in H. illucens and the analysis of substrate-dependent dynamics in its composition are summarized and discussed. Furthermore, this review zooms in on the interactions between microorganisms and the insect during H. illucens development. Finally, attention is paid to how the microbiome research can lead to alternative valorization strategies for H. illucens , such as (i) the manipulation of the microbiota to optimize insect biomass production and (ii) the exploitation of the H. illucens -microbiota interplay for the discovery of new enzymes and novel antimicrobial strategies based on H. illucens immunity using either the whole organism or its molecules. The next decade promises to be extremely interesting for this research field and will see an emergence of the microbiological optimization of H. illucens as a sustainable insect for industrial rearing and the exploitation of its microbiome for novel biotechnological applications.

The Intestinal Microbiota of Hermetia illucens Larvae Is Affected by Diet and Shows a Diverse Composition in the Different Midgut Regions

“…Despite the great and exponentially increasing interest in BSF larvae for bioconversion (4-6) and bioremediation (32), several aspects concerning the biology of this insect are still neglected. Surprisingly, there is still a paucity of information on its intestinal microbiota (11), an issue that should be instead considered a priority for an organism that can be used for such purposes. A recent review on the microbial community associated with BSF (11) highlights knowledge gaps and provides suggestions on aspects that still need to be unraveled rather than presenting a summary of the available data.…”

“…On the other hand, an in-depth characterization of BSF larval microbiota and the factors that influence its composition is particularly important. Microbiota composition is known to impact insect health and performance and has to be considered in the effort to optimize biomass yield (11). In addition, the analysis of the microbiota could allow the identification of bacterial species with peculiar and unique characteristics, such as the capacity to degrade complex substrates (e.g., cellulose, hemicellulose, and lignin) (12) or xenobiotics.…”

“…Such evidence implies the presence of potent antimicrobial effectors produced by BSF larvae and their intestinal microbiota. It should be pointed out that the latter is, in turn, implicated in the maintenance of gut homeostasis and supports gut immune functions (11,17,18).…”

Insects as food and feed, a new emerging agricultural sector: a review

“…Research is conducted on the microbial community of the black soldier fly not only for optimising the industrial rearing, but also whether it may yield anti-microbials in feed, that can be used in pharma (De Smet et al, 2018). Health benefits of using the black soldier fly have been shown for pigs (e.g.…”

Potential Benefits and Risks for Soil Health Derived From the Use of Organic Amendments in Agriculture

“…The larvae grown on the (bio)waste can then be used for animal feed production, thus providing a protein source to help alleviate the rising global demand for animal feed [225] and, interestingly, revenues for financially viable waste management systems [224]. In particular, black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) biowaste processing is a treatment technology that received much attention over the last few decades [226][227][228]. Interestingly, a recent study [225] concluded that black soldier fly biowaste treatment offers an environmentally relevant alternative, with very low direct emissions of greenhouse gases and potentially high reduction in global warming potential.…”