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The present study assessed the growth and fish performance of juvenile red sea bream fed four isonitrogenous (46–48%) and isolipidic (15%) diets containing 45% fishmeal (control) and 15%, 30%, and 45% defatted black soldier fly (BSF) Hermetia illucens meal for 67 days. Subsequent analyses showed that there were no significant differences in the growth parameters, nutrient digestibility, and body composition of fish among all treatments. Although no significant difference was observed in fish growth, low growth was observed when the fish meal was totally replaced with the BSF meal. Higher alpha diversity of intestinal microbiota was observed in fish fed the BSF meal-based diet compared to that of the control. In the treatment groups fed the BSF meal, elevations in the presence of microbial genera that produce digestive enzymes, such as chitinase (Nocardia, Vibrio, Paenibacillus, Photobacterium), lipase (Paenibacillus, Photobacterium), and trypsin-like serine protease (Bacillus, Paenibacillus) and vitamin B group [biotin (Vibrio, Paenibacillus, Bacillus), cobalamin (Pseudomonas, Bacillus, Propionibacterium), and pyridoxin (Photobacterium)], were observed. We also found an increasing trend of bacteria producing antioxidative enzymes, such as superoxide dismutase and catalase (Nocardia, Pseudomonas, Photobacterium) in the BSF groups. These results suggested that the BSF meal could replace 67% of fishmeal without causing a negative impact on growth and lead to beneficial effects on the intestinal microbiota of the red sea bream. [ABSTRACT FROM AUTHOR]

The black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae) plays a significant role at the larval stage in the circular economy due to its ability to convert organic waste into valuable products for energy, food, feed, and agricultural applications. Many data are available on larval development and biomass generation, but basic research on this species is lacking and little is known about adult biology, in particular about the cues involved in sexual recognition. In the present study, using various instruments (stereomicroscope, scanning and transmission electron microscope, hyperspectral camera and spectrophotometer), wing ultrastructure of both sexes was analysed, reflectance and transmission spectra of the wings were measured and behavioural bioassays were carried out to measure male response to specific visual stimuli. The collected data showed the existence of sexual dimorphism in the wings of H. illucens due to iridescent structural colouration generated by a multilayer of melanin located in the dorsal lamina of the central part of the wing. Wing sexual dimorphism is particularly evident regarding the strong emission of blue light of female wings. Blue colour induces in males a strong motivation to mate. The obtained results can help to improve and optimize the breeding techniques of BSF. [ABSTRACT FROM AUTHOR]

A major roadblock towards the realisation of a circular economy are the lack of high-value products that can be generated from waste. Black soldier flies (BSF; Hermetia illucens) are gaining traction for their ability to rapidly consume large quantities of organic wastes. However, these are primarily used to produce a small variety of products, such as animal feed ingredients and fertiliser. Using synthetic biology, BSF could be developed into a novel sustainable biomanufacturing platform to valorise a broader variety of organic waste feedstocks into enhanced animal feeds, a large variety of high-value biomolecules including industrial enzymes and lipids, and improved fertiliser. This perspective describes how insects, such as Hermetia illucens, which are already used to process organic wastes at industrial scales, could be developed as a synthetic biology platform for sustainable biomanufacturing and bioremediation. [ABSTRACT FROM AUTHOR]

New approaches to managing the cabbage root fly (Delia radicum L.) are needed because pesticide regulations continue to limit the availability of effective control products. Soil amendment with black soldier fly (Hermetia illucens L.) frass has recently been shown to reduce D. radicum survival. In a greenhouse experiment, soil from a field on which brassicaceous plant species had repeatedly been grown (brassica field soil) was mixed with frass at ratios of 1, 2 or 5 g/kg. In a second greenhouse experiment, 5 g/kg were added to (a) brassica field soil, (b) soil from a different field on which non-brassicaceous species had been rotated (crop rotation field soil) or (c) blocks of potting soil that were later transplanted to unamended field soil. Brussels sprouts (Brassica oleracea L.) plants were grown in amended soil and were infested with D. radicum larvae after 4 weeks. While amendment with 1 or 2 g/kg did not affect D. radicum performance compared with unamended soil, 5 g/kg reduced D. radicum survival and pupal biomass in brassica field soil. In crop rotation field soil, amendment with 5 g/kg reduced pupal biomass but did not reduce D. radicum survival. Amendment with 5 g/kg had no effect on D. radicum performance in potting soil. In general, D. radicum survival was lower in brassica field soil than in either other soil, irrespective of soil amendment. The effects of black soldier fly frass on D. radicum appear to depend on soil type. [ABSTRACT FROM AUTHOR]

Recently, much research has been oriented towards the influence of different food wastes and agricultural by-products on the final larval biomass and chemical composition of the insect species Hermetia illucens L. (Diptera: Stratiomyidae). However, there is a gap in the literature regarding the possible relationship between the feeding substrate of H. illucens larvae and chitin. In this context, in the present study, larvae of H. illucens derived from two populations (i.e., UNIPI and UTH), were reared on different diets composed of fruits, vegetables, and meat. Based on the results, the larval survival was high for all diets tested. Larval growth in terms of weight gain, larval length, and feed conversion ratio (FCR) depended on the composition of each diet. The chitin and chitosan composition of larvae, reared on different substrates, did not reveal significant differences. Given the fact that the feeding substrate represent a significant cost in the industrial production of insects, its correlation with a high value product (i.e. chitosan) is important. On the other hand, as the prepupal stage of H. illucens is currently used as animal feed, the metabolization of chitin by farmed animals when the larvae or prepupae were offered as feed could have adverse effects. Thus, depending on the final product that is to be produced, industries could benefit from the establishment of a suitable diet. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae have been proven to reduce greenhouse gas emissions in the treatment of organic waste. However, the microbial mechanisms involved have not been fully understood. The current study mainly examined the dynamic changes of carbon and nitrogen, greenhouse gas emissions, the succession of microbial community structure, and changes in functional gene abundance in organic waste under larvae treatment and non-aeration composting. Thirty percent carbon and 55% nitrogen in the organic waste supplied were stored in larvae biomass. Compared to the non-aeration composting, the larvae bioreactor reduced the proportion of carbon and nitrogen converted into greenhouse gases (CO2, CH4, and N2O decreased by 62%, 87%, and 95%, respectively). 16S rRNA sequencing analysis indicated that the larvae bioreactor increased the relative abundance of Methanophaga, Marinobacter, and Campylobacter during the bioprocess, enhancing the consumption of CH4 and N2O. The metagenomic data showed that the intervention of larvae reduced the ratio of (nirK + nirS + nor)/nosZ in the residues, thereby reducing the emission of N2O. Larvae also increased the functional gene abundance of nirA, nirB, nirD, and nrfA in the residues, making nitrite more inclined to be reduced to ammonia instead of N2O. The larvae bioreactor mitigated greenhouse gas emissions by redistributing carbon and nitrogen and remodeling microbiomes during waste bioconversion, giving related enterprises a relative advantage in carbon trading. [ABSTRACT FROM AUTHOR]

The edible fungus industry is one of the pillar industries in the Yunnan–Guizhou Plateau, China. The expansion of the planting scale has led to the release of various mushroom residues, such as mushroom feet, and other wastes, which are not treated adequately, resulting in environmental pollution. This study investigated the ability of black soldier fly (Hermetia illucens L.) larvae (BSFL) to degrade mushroom waste. Moreover, this study analyzed changes in the intestinal bacterial community and gene expression of BSFL after feeding on mushroom waste. Under identical feeding conditions, the remaining amount of mushroom waste in Pleurotus ostreatus treatment group was reduced by 18.66%, whereas that in Flammulina velutipes treatment group was increased by 31.08%. Regarding gut microbial diversity, compared with wheat bran-treated control group, Dysgonomonas, Providencia, Enterococcus, Pseudochrobactrum, Actinomyces, Morganella, Ochrobactrum, Raoultella, and Ignatzschineria were the most abundant bacteria in the midgut of BSFL in F. velutipes treatment group. Furthermore, Dysgonomonas, Campylobacter, Providencia, Ignatzschineria, Actinomyces, Enterococcus, Morganella, Raoultella, and Pseudochrobactrum were the most abundant bacteria in the midgut of BSFL in P. ostreatus treatment group. Compared with wheat bran-treated control group, 501 upregulated and 285 downregulated genes were identified in F. velutipes treatment group, whereas 211 upregulated and 43 downregulated genes were identified in P. ostreatus treatment group. Using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we identified 14 differentially expressed genes (DEGs) related to amino sugar and nucleotide sugar metabolism in F. velutipes treatment group, followed by 12 DEGs related to protein digestion and absorption. Moreover, in P. ostreatus treatment group, two DEGs were detected for fructose and mannose metabolism, and two were noted for fatty acid metabolism. These results indicate that feeding on edible mushroom waste can alter the intestinal microbial community structure of BSFL; moreover, the larval intestine can generate a corresponding feedback. These changes contribute to the degradation of edible mushroom waste by BSFL and provide a reference for treating edible mushroom waste using BSFL. [ABSTRACT FROM AUTHOR]

People are increasingly using black soldier fly larvae (BSFL) as a sustainable waste management solution. They are high in protein and other essential nutrients, making them an ideal food source for livestock, poultry, and fish. Prior laboratory studies with BSFL developed on pure mushroom root waste (MRW) showed poor conversion efficiency compared to a regular artificial diet. Therefore, we mixed the nutrient-rich soybean curd residues (SCR) with MRW in different ratios (M2–M5). Pure mushroom root waste (M1, MRW 100%) had the lowest survival rate (86.2%), but it increased up to 96.9% with the SCR percentage increasing. M1 had the longest developmental period (31.1 days) and the lowest BSFL weight (7.4 g). However, the addition of SCR reduced the development time to 22.0 and 21.5 days in M4 (MRW 40%, SCR 60%) and M5 (MRW 20%, SCR 80%), respectively, and improved the larval weight to 10.9 g in M4 and 11.8 g in M5. Other groups did not have as much feed conversion ratio (FCR) (8.4 for M4 and M5), bioconversion (M4 5.4%; M5 5.9%), or lipid content (M4 25.2%; M5 24.3%). These mixtures did. Compare this to M1. We observed better results, with no significant differences between the M4 and M5 groups and their parameters. In the present study, our main target was to utilize more MRW. Therefore, we preferred the M4 group in our nutritional and safety investigation and further compared it with the artificial diet (M7). The heavy metals and essential amino acids (histidine 3.6%, methionine 2.7%, and threonine 3.8%) required for human consumption compared to WHO/FAO levels showed satisfactory levels. Furthermore, fatty acids (capric acid 1.9%, palmitic acid 15.3%, oleic acid 17.3%, and arachidonic acid 0.3%) also showed higher levels in M4 than M7. The SEM images and FT-IR spectra from the residues showed that the BSFL in group M4 changed the structure of the compact fiber to crack and remove fibers, which made the co-conversion mixture better. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effects of black soldier fly larval (BSFL) meal as a fish meal (FM) replacement on the growth performance, survival, immune responses, and resistance to Vibrio parahaemolyticus infection in Pacific white shrimp fed a low FM diet. Four experimental diets were formulated: control (with 12% FM), 2, 5, and 10% BSFL meal. In Experiment 1, shrimp postlarvae were divided into four groups, corresponding to the four diets; they were fed four times daily for 45 days. In Experiment 2, the surviving shrimp from Experiment 1 were challenged with V. parahaemolyticus by immersion at a concentration of 105 CFU/mL and were fed with the same diets for another 7 days to evaluate the disease resistance. Results demonstrated that the 5 and 10% BSFL meal-fed shrimp had significantly increased body weight, decreased hepatopancreatic and intestinal Vibrio spp. count, and improved immune parameters. The survival rates of all BSFL meal groups after the bacterial challenge were at least 60%, which were significantly higher than the control (50%). In short, 5–10% BSFL meal can partially replace FM in the shrimp feed without compromising health conditions and disease resistance. [ABSTRACT FROM AUTHOR]

The article presents the results of studying the viscosity of chitosan-melanin complex solutions from the insect Hermetia illucens and the process of gelation in these solutions in the presence of crosslinking reagents. Chemically cross-linked nanofibers were obtained from solutions of the chitosan-melanin complex in dilute solutions of acetic acid by the method of spinneretless electrospinning. The presence of 14% melanin made it possible to reduce the concentration of acetic acid in the spinning composition. [ABSTRACT FROM AUTHOR]

The rising food waste generation induces major issues of food security, pollution, and depletion of resources and arable land, thus calling for novel recycling practices such as converting food waste into fuels. Here we review the production of dihydrogen, thereafter named 'hydrogen,' and biodiesel from food waste, with focus on food waste composition and hydrolysis, hydrogen production and biodiesel production. Hydrogen production is done by dark fermentation and photofermentation. Biodiesel is produced by production of lipid-rich biomass using food waste and transesterification. We discuss lipids accumulation in oleaginous microorganisms and in black soldier fly larvae. Upscaling of hydrogen and biodiesel production is also presented. Optimal hydrogen yield ranges from 1 to 7 mol H2/mol hexose. After fermentation, the residual glucose should be less than 10% and volatile fatty acids should be less than 40%. Biomass lipids containing less than 1% polyunsaturated fatty acids is ideal for biodiesel production. [ABSTRACT FROM AUTHOR]

Liquid biofuels like biodiesel and bioethanol are crucial in the transition to low-carbon and high-energy alternatives to fossil fuels. One significant by-product of biodiesel production is glycerol, which accounts for about 10% of the total conversion output. While waste glycerol poses challenges due to its impurities and contaminants, it also holds potential as a metabolic resource for essential cellular components in microorganisms. Crude glycerol production is reviewed, highlighting relevance in current biodiesel technologies and its biochemical composition. To efficiently utilize waste glycerol, co-valorization with low-cost substrates through biocircular platforms using various microorganisms or insects for second and third-generation oxy-biofuels has been explored. Among these, the black soldier fly larvae have demonstrated higher competitiveness for lipid contents (35–43%), making them a promising organism for recycling waste glycerol into biodiesel production, alongside microalgae and oleaginous yeast. The microbial biodiesel productivity from oleaginous yeast is notably higher (3546 kg ha−1 y−1) than soybean biodiesel (562 kg ha−1 y−1), while microalgal biodiesel productivity surpasses palm biodiesel by more than 25 times. Remarkably, black soldier fly larvae biodiesel productivity was reported to be ~ 1.7 times higher than microalgae and an impressive ~ 43 times higher than palm biodiesel. Despite their potential for biodiesel production, waste glycerol from biodiesel industry still represents a challenge because of high impurities, high viscosity, and limited direct applications in existing processes. To further enhance energy sustainability and address the challenge of waste glycerol, biocircular platforms are discussed for waste glycerol utilization with domestic wastewater sludge, lignocellulosic biomass, and protein-rich wastes. These platforms offer opportunities to create other sustainable agricultural products while minimizing their environmental footprint. [ABSTRACT FROM AUTHOR]

Biowaste treatment with Black Soldier Fly (BSF) larvae is an alternative option for organic waste valorization. Its environmental impacts should be assessed and compared with conventional treatment options. The research aims to evaluate the treatment of organic fraction of municipal solid waste (OFMSW) with BSF larvae through a life cycle assessment (LCA). This study employed data inventories from literature and aimed to provide a wide range of production parameter values to identify the potentialities of BSF treatment in the best-case and worst-case scenarios. The SimaPro9, the database Ecoinvent3.5, and the impact assessment method IMPACT 2002+ have been employed for the analysis. A sensitivity analysis of relevant parameters was conducted, considering the avoided impacts that can be obtained thanks to the exploitation of larvae proteins for bioplastics or fishmeal production. Research findings highlight six main environmental impact indicators: respiratory inorganics (kg PM2.5-eq), ozone layer depletion (kg CFC-11-eq), terrestrial ecotoxicity (kg TEG soil), land occupation (m2 organic arable), global warming (kg CO2-eq), and non-renewable energy (MJ primary). The most relevant process generating impacts is BSF breeding, followed by boiling, storage, and OFMSW treatment. The environmental performance is better when the conventional fishmeal substituted, thanks to BSF larvae production, is made from areas 10,000 km far, implementing a 100% renewable energy scenario, reducing the energy consumption by 50%, increasing the lifespan of the equipment to 15 years, and products are employed locally. The current study represents the first attempt to evaluate the global higher or lower environmental impact scenario related to OFMSW treatment through BSF larvae. [ABSTRACT FROM AUTHOR]

The present study investigated the potential use of defatted black soldier fly (Hermetia illucens) meal as a protein source in the formulated feed for juvenile lobsters, Panulirus ornatus. A total of 160 heads of juvenile lobsters with initial weight of 0.24 ± 0.01 g and initial length of 21.77 ± 0.32 mm were distributed evenly into 16 rectangular fiberglass aquaria and kept individually for 8 weeks of the feeding experiment. Four formulated feeds containing defatted BSF meal as fishmeal replacements at 0%, 25%, 35%, and 50% and total dietary protein to energy ratio of ~ 26 g CP MJ−1 were prepared and assigned as BSF0, BSF25, BSF35, and BSF50, respectively. Fishmeal is technically a suitable aquafeed ingredient in terms of crude protein, moisture, and amino acid compositions. The partially substituted defatted BSF meal has higher crude lipid and ash content than fishmeal. At the end of week 8 of feeding trial, the specific growth rate, length increment, survival rate, and moulting rate of juvenile lobster were not significantly (P > 0.05) affected by the fishmeal replacement. The fishmeal replacement with the defatted BSF meal did not significantly (P > 0.05) alter the whole-body proximate composition of the juvenile lobster. However, it significantly (P < 0.05) affected the superoxidase dismutase of juvenile lobsters. The cytokine cell expression analysis indicated that up to 35% of fishmeal replacement increased the inflammatory cytokine cells (Interleukin 8 and 17) of juvenile lobster, while an adverse impact was observed on juvenile lobster receiving 50% of fishmeal replacement by BSF meal. Histopathological analysis showed that the hepatopancreas cells of juvenile lobsters were damaged following fishmeal replacement beyond 35%. The present study indicated that up to 35% of defatted BSF meal can be used as fishmeal replacement in the formulated feed of juvenile lobster. [ABSTRACT FROM AUTHOR]

The nutrient profile of Black soldier fly (Hermetia illucens) larva meal (BSFLM) may change with the source and the effects of BSFLM on broiler chicken may depend on its dietary level. Four samples of BSFLM, procured from 3 different sources, were analysed for nutrient profile. One of those, a partially-defatted BSFLM, was evaluated in male broiler chicken diet at 0, 2.5 and 5.0% (expt. 1), and at 0, 5.0, 7.5 and 10.0% levels (expt. 2). Each of the experimental diets was fed to 12 replicates of 6 chickens each in expt. 1 (n = 216) and 15 replicates of 25 chickens each in expt. 2 (n = 1500). The nutrient profile varied greatly amongst the BSFLM samples (crude protein: 49.8 to 59.6%, crude fat: 12.0 to 38.4%, lysine: 2.4–4.7%, methionine: 2.3–4.6%, lauric acid: 15.2–62.4%). Body weight gain (BWG) and feed intake (FI) of broilers increased linearly in the groups fed BSFLM upto 5.0% during 0–3 weeks of age (expt. 1), whereas the feed conversion ratio (FCR) linearly increased during 3 to 5 weeks. At higher levels of BSFLM (7.5 and 10% in diet) (expt. 2), significantly depressed BWG and FI, and increased FCR were observed. Dressing yield, breast weight and abdominal fat content linearly increased with BSFLM level in diet (expt. 2), while other organ weights, serum biochemical profile and PHA-P response were unaffected (expt. 1). It is concluded that the nutrient profile of BSFLM varied with the source and it could be used upto 5% in the diet of broiler chickens with beneficial effects on growth during the early life. [ABSTRACT FROM AUTHOR]

Aims: In terrestrial ecosystems, deposition of insect frass and cadavers in the soil influences soil characteristics, including microbial community composition, with consequences for plant growth and development. Insect frass and exuviae are also a major residual stream from insect production for food and feed, that may be used as soil amendment. However, only few studies have thoroughly examined the effect of soil amendment with insect frass and exuviae on rhizosphere microbial communities and plant growth. Methods: We studied the effects of soil amendment with frass and/or exuviae originating from three insect species, Tenebrio molitor, Acheta domesticus, and Hermetia illucens, at three different concentrations, compared to synthetic fertiliser. At several time points we analysed the rhizosphere bacterial community and assessed multiple plant-growth parameters of a brassicaceous plant. Results: Soil amendment with frass and/or exuviae improved plant growth at least as well as synthetic fertiliser, A. domesticus exuviae having the strongest impact. The origin (insect species), type (frass or exuviae) and concentration of soil amendment influenced the effects on plant traits. The rhizosphere bacterial community differed between amended and unamended soil. Bacterial genera that contain plant growth-promoting species were more abundant in the rhizosphere of plants grown in amended soil. Conclusions: Addition of insect frass and/or exuviae to the soil differentially affects the bacterial rhizosphere community and promotes plant growth in these soils, underlining their unique roles in the aboveground-belowground feedback loop, and their potential use as soil amendment in circular agriculture. [ABSTRACT FROM AUTHOR]

As the problem of antimicrobial resistance is constantly increasing, there is a renewed interest in antimicrobial products derived from natural sources, particularly obtained from innovative and eco-friendly materials. Insect lipids, due to their fatty acid composition, can be classified as natural antimicrobial compounds. In order to assess the antibacterial efficacy of Hermetia illucens lipids, we extracted this component from the larval stage, fed on different substrates and we characterized it. Moreover, we analyzed the fatty acid composition of the feeding substrate, to determine if and how it could affect the antimicrobial activity of the lipid component. The antimicrobial activity was evaluated against Gram-positive Micrococcus flavus and Gram-negative bacteria Escherichia coli. Analyzing the fatty acid profiles of larval lipids that showed activity against the two bacterial strains, we detected significant differences for C4:0, C10:0, C16:1, C18:3 n3 (ALA), and C20:1. The strongest antimicrobial activity was verified against Micrococcus flavus by lipids extracted from larvae reared on strawberry, tangerine, and fresh manure substrates, with growth inhibition zones ranged from 1.38 to 1.51 mm, while only the rearing on manure showed the effect against Escherichia coli. Notably, the fatty acid profile of H. illucens seems to not be really influenced by the substrate fatty acid profile, except for C18:0 and C18:2 CIS n6 (LA). This implies that other factors, such as the rearing conditions, larval development stages, and other nutrients such as carbohydrates, affect the amount of fatty acids in insects. Key points: • Feeding substrates influence larval lipids and fatty acids (FA) • Generally, there is no direct correlation between substrate FAs and the same larvae FAs • Specific FAs influence more the antimicrobial effect of BSF lipids [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSFL) are considered a sustainable ingredient in livestock feed. However, addressing issues related to feed substrate and intestinal microbiota is essential to ensure optimal larval development. The aim of this study was to assess and elucidate the contribution of substrate nutrients and intestinal microbes to protein and fat synthesis in BSFL. The results showed that larvae that were fed high-quality feed (chicken feed) had high fat biomass, while larvae that were fed medium-quality feed (wheat bran) had high protein biomass. These results indicate that the original nutritional content of the feed cannot fully explain larval growth and nutrient utilization. However, the phenomenon could be explained by the functional metabolism of intestinal microbes. Chicken feed enhanced the fatty acid metabolism of middle intestine microorganisms in larvae within 0–7 days. This process facilitated larval fat synthesis. In contrast, wheat bran stimulated the amino acid metabolism in posterior intestine microorganisms in larvae within 4–7 days, leading to better protein synthesis. The findings of this study highlight the importance of the microbial functional potential in the intestine in regulating protein and lipid synthesis in BSFL, which is also influenced by the type of feed. In conclusion, our study suggests that both feed type and intestinal microbes play a crucial role in efficiently converting organic waste into high-quality insect protein and fat. Additionally, a mixed culture of chicken feed and wheat bran was found to be effective in promoting larval biomass while reducing feed costs. Key points: • Intestinal microbes explain BSFL growth better than feed substrates. • Chicken feed promotes fatty acid synthesis in the middle intestine • Wheat bran promotes amino acid synthesis in the posterior intestine. [ABSTRACT FROM AUTHOR]

The CRISPR/Cas9 system is the most straightforward genome-editing technology to date, enabling genetic engineering in many insects, including the black soldier fly, Hermetia illucens. The white gene plays a significant role in the multifarious life activities of insects, especially the pigmentation of the eyes. In this study, the white gene of H. illucens (Hiwhite) was cloned, identified, and bioinformatically analysed for the first time. Using quantitative real-time polymerase chain reaction (qPCR), we found that the white gene was expressed in the whole body of the adult flies, particularly in Malpighian tubules and compound eyes. Furthermore, we utilised CRISPR/Cas9-mediated genome-editing technology to successfully generate heritable Hiwhite mutants using two single guide RNAs. During Hiwhite genome editing, we determined the timing, method, and needle-pulling parameters for embryo microinjection by observing early embryonic developmental features. We used the CasOT program to obtain highly specific guide RNAs (gRNAs) at the genome-wide level. According to the phenotypes of Hiwhite knockout strains, the pigmentation of larval stemmata, imaginal compound eyes, and ocelli differed from those of the wild type. These phenotypes were similar to those observed in other insects harbouring white gene mutations. In conclusion, our results described a detailed white genome editing process in black soldier flies, which lays a solid foundation for intensive research on the pigmentation pathway of the eyes and provides a methodological basis for further genome engineering applications in black soldier flies. [ABSTRACT FROM AUTHOR]

We characterise in detail the larval and pupal cuticle of the black soldier fly Hermetia illucens L. (Diptera: Stratiomyidae), a key insect species in circular economy. In particular, we focus on ultrastructure using scanning and transmission electron microscopy, material characterization and composition (elements and minerals) with confocal laser scanning microscope, energy dispersive X-ray microanalysis, powder X-ray diffraction and mechanical properties with nanoindentation measurements. Calcium carbonate crystallizes on the epicuticle as blocks of calcite in the pupal cuticle. Calcium carbonate granules are stored in two specialised Malpighian tubules. CaCO3 is already present in the cuticle of young larval instars, but it is mainly in the form of amorphous calcium carbonate while the amount of calcite increases during larval development. The presence of calcite leads to cuticle hardening. Larval and pupal cuticles contain large amounts of resilin which guarantee cuticle flexibility. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSFL) bioconversion system is emerging as an effective approach for organic waste pollution treatment. Co-digestion of different organic matters with BSFL can be an effective way to realize the innovative biowaste circular economy. In this study, organic waste mixture of chicken manure and sewage sludge was chosen as substrate for BSFL growth. The bacterial biodiversity and nutrients quality of BSFL residue were evaluated through gene sequencing and other characterizations to confirm their application potential as biofertilizers. The dominant bacteria in BSFL residue were Firmicutes (75.39%) at phylum level, Bacilli (71.61%) at class level and Pseudogracilibacillus (11.08%) at genus level. Antibiotic resistance genes (ARGs) were used to assess the harmlessness of BSFL residue. After BSFL treatment, 36.2% decrease in ARGs was observed. Taking nutrients quality into consideration, dissolved organic carbon, dissolved nitrogen, available phosphorous, and available potassium significantly increased in the co-digestion system. These results demonstrated that co-digestion of chicken manure and excess sludge in BSFL bioconversion system could improve the nutrients quality of residues. However, removal of ARGs in the bioconversion process should be further explored to eliminate environmental concerns associated with application of BSFL residue as biofertilizers. [ABSTRACT FROM AUTHOR]

The accumulation of cull potato piles is a concern because they take up space and harbor potato-associated pathogens. Black soldier fly, Hermetia illucens, larvae are an increasingly popular agent for converting organic wastes into ingredients for animal feeds. In this investigation, their ability to process cull potato waste was assessed. Potato tubers were suitable for larval development, but only following their disintegration through thermal or mechanical means. Optimal bioconversion was observed when potato substrate was provided at a rate of 1 g per larva. The presence of ground turkey meat and sawdust was generally beneficial to larval development and biomass accumulation. The presence of potato foliage in diet showed no negative effects on larval development and there was no glycoalkaloid bioaccumulation in larval tissues. Evidence from this investigation suggests that culled potato waste may be recycled using black soldier fly larvae. [ABSTRACT FROM AUTHOR]

Chitin from crustaceans is used in food, pharmaceutical, medical, agricultural and environmental sectors. Edible insects' chitin is an untapped resource since edible insects have a high biodiversity and considerable amounts of chitin. Therefore, this study aimed at characterizing the functional properties and microstructure of chitin extracted from House cricket (Acheta domesticus), field cricket (Gryllus bimaculatus) and black soldier fly cocoons (Hermetica illucens) and compared with shrimp chitin (commercial). Chitin was chemically extracted and the functional groups were determined by Fourier Transform Infrared Spectroscopy (FTIR). Solubility, emulsion capacity, Water Holding Capacity, Fat Binding Capacity, degree of deacetylation and purity of the extracted chitin were also determined. Based on the FTIR spectra the extracted chitin showed the characteristic functional groups i.e. O–H stretch, C=O stretch, N–H bend, CH2 ending and CH3 deformation, C–N stretch and C–O–C stretch. Chitin extracted from Gryllus bimaculatus recorded the highest values in fat absorption capacity (780.14%), emulsion capacity (65.67%) and emulsion stability (65.67%). Chitin extracted from, Acheta domesticus was more soluble in water as compared to the commercial chitin. The highest level of deacetylation was reported in Hermetia illucens chitin (66.2%) while Acheta domesticus chitin had the least value (47.1%). The commercial chitin and Gryllus bimaculatus had the highest values for purity followed by Hermetia illucens. The microstructure images showed presence of pores and fibers in all the chitin samples. In conclusion, the insect chitin had characteristics similar to commercial chitin and are thus a suitable alternative in industrial application. [ABSTRACT FROM AUTHOR]

Aquaculture solid waste (ASW) is a nutrient rich material that can pose a significant environment challenge if not properly managed. This study investigated the potential of black soldier fly (BSF) larvae in converting this waste into biomass. Five substrates comprising chicken feed supplemented with varying proportions of fresh ASW (0%, 25%, 50%, 75%, 100%) were formulated and evaluated for larval growth and waste bioconversion efficiency. High nutrients retention (N: 23.25 ± 1.40%; C: 21.94 ± 0.99%; S: 12.20 ± 1.33%) and feed conversion ratio (1.78 ± 0.08) were detected on substrate 100ASW, although the limited feeding rate (114.54 ± 5.38 mg dry substrate/larvae) and the high amount of indigestible fibres (ADF = 15.87 ± 0.24%; ADL = 6.36 ± 0.17%) were translated to low larval growth (final larval average weight: 66.17 ± 1.81 mg). Decreasing ASW content resulted in reduced fibres and ash, increase in non-fibrous carbohydrates and C/N ratio, and improved larval growth and substrate utilization. However, high larval metabolic activity suggested higher nutrients loss to the environment. Substrate 75ASW demonstrated the best performances in terms of larval production (final larval average weight: 176.30 ± 12.12 mg), waste reduction (substrate reduction corrected by percentage of ASW: 26.76 ± 0.86%) and nutrients assimilation (N: 22.14 ± 1.14%; C: 15.29 ± 0.82%; S: 15.40 ± 0.99%). This substrate closely aligned with optimal BSF rearing substrates reported in literature. Overall, this study highlights the potential of BSF larvae in managing fresh ASW, offering a dual benefit of waste reduction and insect biomass production. [ABSTRACT FROM AUTHOR]

In this present study, different life-history attributes of Black Soldier fly (BSF) such as mating, oviposition activity, larval and adult weights, survival, etc. were investigated under the effect of two different light sources (Sunlight and Halogen light). The light exposure was for 9 h per day in both the experimental conditions. It was observed that sunlight exposure enhanced the mating and oviposition activity in adult females over halogen light. The total development time and days to first prepupa and adult fly emergence were also significantly different (p < 0.05). The egg hatchability also varied differently in halogen light (67%) and sunlight (92%) however, there was not any significant difference in the weights of larva (0.17 g), prepupa (0.14 g), pupa (0.12 g) and adult flies (0.05 g) in both the experimental conditions. The larval (87% and 89%) and prepupal (74% and 75%) survival rate also did not vary in both the treatments. Moreover, the overall physiological significance of the entire study has been dealt in detail in the full paper. [ABSTRACT FROM AUTHOR]

Background: Fruit and vegetables are highly perishable. In an era where reducing food waste is absolutely essential, packaging is important for maintaining the postharvest quality of these fresh products. Research is working to reduce the use of synthetic materials, not safe for the environment and human health. In this perspective, chitosan emerges as a viable solution for this purpose, as it is biodegradable, biocompatible and also safe for food application. The growing interest in using insects as a source of chitin has allowed for increased exploitation of insect-based waste products to recover valuable materials, such as biopolymers. The black soldier fly (Hermetia illucens L.) is the most widely reared species in Europe for feed production and waste management. Results: In this work, fresh mature apricots (Prunus armeniaca L.), nectarines (Prunus persica vulgaris Mill.) and yellow peaches (Prunus persica var. laevis Gray) were coated with 0.5% and 1% chitosan from the pupal exuviae of Hermetia illucens, applied by spraying and stored at room temperature or 4 °C until they decay. Then, to validate the effectiveness of chitosan as a polymer for fruit preservation, several parameters including pH, TSS and weight loss were evaluated. Conclusions: The results showed that chitosan derived from the black soldier fly is as effective as or better than the commercially available crustacean chitosan in maintaining more stable some storage parameters in fresh apricots, nectarines and peaches. Thus, insects, especially Hermetia illucens, are confirmed as a viable alternative source of the polymer. [ABSTRACT FROM AUTHOR]

Food waste (FW) treatment has attracted increasing attention since waste classification occurred in China. Analyzing the environmental and economic impacts of different FW treatment technologies is required. In this study, four FW treatments, i.e., anaerobic digestion, black soldier fly (BSF) bioconversion, composting, and landfill, were evaluated using life cycle assessment (LCA) and life cycle cost (LCC). LCA results show that anaerobic digestion outperforms the other technologies, while LCC results indicate anaerobic digestion has the lowest economic benefits ($5.16) and landfill has the highest ($14.22). Bioconversion has the highest product revenue ($37.98). FW anaerobic digestion followed by treating digestate and waste crude oil was employed to investigate the environmental differences between waste classification and mixed incineration. Digestate gasification and conversion of waste crude oil to biodiesel are found to be environmentally friendly, and waste classification outperforms mixed incineration. Furthermore, we explored national-level environmental emission reduction with anaerobic digestion as the dominant technology via increasing resource utilization rate and applying household FW disposers. Results display that a 60% resource utilization rate decreases the overall environmental impact by 36.68% compared with current situation, and treating household FW separately at the source can further lead to emission reduction. This study provides a reference for selecting FW technologies for countries worldwide from environmental and economic perspectives, as well as a direction of resource utilization for how to reduce environmental emissions from treating the total FW produced by all humanity. [ABSTRACT FROM AUTHOR]

The best diet for Artemia culture is phytoplankton; yet it is expensive and laborious work. Thus, cheaper and easily prepared feed such as formulated diet is required. The present study aimed to investigate the effect of different protein sources in formulated diets on growth performance, feed utilization, survival rate, fecundity, and nauplius production of Artemia franciscana. A total of 6,000 Artemia nauplii were randomly distributed equally into 20 rearing tanks (5 treatment groups with 4 replicates): Artemia fed with Tetraselmis chuii as control (T1), Artemia fed with a formulated diet with fish meal inclusion (T2), Artemia fed with the formulated diet with sergestid shrimp meal inclusion (T3), Artemia was fed with the formulated diet with soybean meal inclusion (T4), and formulated diet with Black Soldier Fly meal inclusion (T5). The results showed that protein sources in formulated diets had a significant effect on growth performances, feed utilization, survival rate, fecundity, and nauplius production of A. fransciscana (p < 0.05). The best result, in general, was obtained from the soybean meal-fed group (T4): specific growth rate in length (17.78% BL.d−1), the specific growth rate in body weight (35.95% BW.d−1), feed conversion ratio (1.37), feed efficiency (74.00 %), protein retention (64.07%), fat retention (55.93%), fecundity (44 eggs.broodstock−1), and nauplius production (35 nauplii.broodstock−1). While the highest energy retention was obtained from the control group (60.90%). These results suggest that soybean meal can be used as the protein source in formulated diets to replace phytoplankton usage in Artemia culture. [ABSTRACT FROM AUTHOR]

The digestive capacity of organic compounds by the black soldier fly (BSF, Hermetia illucens, Diptera: Stratiomyidae, Linnaeus, 1758) is known to rely on complex larva-microbiota interactions. Although insect development is known to be a driver of changes of bacterial communities, the fluctuations along BSF life cycle in terms of composition and diversity of bacterial communities are still unknown. In this work, we used a metabarcoding approach to explore the differences in bacterial diversity along all four BSF developmental stages: eggs, larvae, pupae, and adult. We detected not only significant differences in bacterial community composition and species richness along the development of BSF, but also nine prevalent amplicon single variants (ASVs) forming the core microbiota. Out of the 2010 ASVs identified, 160 were significantly more abundant in one of the life stages. Moreover, using PICRUSt2, we inferred 27 potential metabolic pathways differentially used among the BSF life cycle. This distribution of metabolic pathways was congruent with the bacterial taxonomic distribution among life stages, demonstrating that the functional requirements of each phase of development are drivers of bacterial composition and diversity. This study provides a better understanding of the different metabolic processes occurring during BSF development and their links to changes in bacterial taxa. This information has important implications for improving bio-waste processing in such an economically important insect species. [ABSTRACT FROM AUTHOR]

The physicochemical and sorption characteristics of the pupal cuticle of the black soldier fly have been studied. The qualitative and granulometric compositions of chitin material were determined, and the surface microrelief of chitin particles was studied by scanning microscopy. The sorption properties of the material were studied using methylene blue dye. It was found that the sorption capacity of the material is 0.118 mmol/g, or about 38 mg/g. Mathematical processing of the sorption isotherm using the Langmuir, Freindlich, and Dubinin–Radushkevich models showed that the process is best described by the Dubinin–Radushkevich model (R2 = 0.8031), and the sorption process has a physical nature (E = 5.534 kJ/mol). [ABSTRACT FROM AUTHOR]

Black Soldier Fly Larvae (BSFL) is a potential for future feed source that can be grown in Palm Kernel Meal (PKM). To fortify the substrate of BSFL, fish feed and fructose can be added to induce BSFL metabolize polyunsaturated fatty acids which makes them more valuable. Their nutritive value and its growth performance reared in PKM supplemented with Fish Feed Pellet (FFP) and fructose has never been investigated. Present study aimed to evaluate the proximate, mineral, and fatty acid concentration, material reduction (MR), biomass conversion rate (BCR), and survival of BSFL grown on PKM, FFP, PKM:FFP (1:1), and fructose at various concentration (2.5, 5, 7.5, and 10%) in PKM:FFP. After 12 days of rearing, a high protein was observed in BSFL fed FFP (55.68 ± 2.30%), while moisture (2.74 ± 0.05%) and crude fat (7.69 ± 0.04%) were found on the BSFL grown in PKM:FFP. The fructose (2.5–7.5%) in PKM:FFP increased carbohydrate content of BSFL. The highest relative concentration of fatty acids was found in the BSFL fed PKM:FFP with 10% fructose. The addition of fructose in either PKM, FFP or its combination significantly affected (P < 0.05) on the fatty acid composition and some mineral accumulation, such as phosphorus (1.16 ± 0.04%), sodium (1.17 ± 0.01%), and iron (77.00 ± 1.00%) of the BSFL. However, the BSFL length, MR, and BCR were not significantly (P > 0.05) affected by the addition of fructose. The survival did not differ significantly (P > 0.05) among the BSFL grown in the various substrates. It is suggested that fructose is added to substrat of the BSFL to optimize fatty acid composition, mineral accumulation, proximate analysis without affected the growth and the survival of the BSFL. [ABSTRACT FROM AUTHOR]

Edible insects are increasingly gaining popularity as research reveals multiple benefits. However, the rediscovery of natural products from insects as medicinal agents has received limited attention. This study aimed at evaluating the diversity of sterols in extracts of nine edible insects and potential antibacterial activities. Dichloromethane extracts of these insects were analyzed using gas chromatography–mass spectrometry to identify important sterols, followed by evaluation of their anti-bacterial activities. Nineteen sterols were identified with the highest recorded in African fruit beetle [Pachnoda sinuata (47.37%)], crickets [Gryllus bimaculatus (36.84%) and Scapsipedus icipe (31.58%)]. Cholesterol was the most prevalent, except in black soldier fly (Hermetia illucens). Bioactivity revealed S. icipe as the most potent extract against Escherichia coli and Bacillus subtilis whereas G. bimaculatus was highest against Methicillin-susceptible Staphylococcus aureus 25923. These findings unravels the diversity of sterols in edible insects and their possible application in food, pharmaceutical and cosmetic industries. [ABSTRACT FROM AUTHOR]

Black soldier fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is predominantly reared on organic wastes and other unused complementary substrates. However, BSF may have a buildup of undesired substances in their body. The contamination of undesired substance, e.g., heavy metals, mycotoxins, and pesticides, in BSF mainly occurred during the feeding process in the larval stage. Yet, the pattern of accumulated contaminants in the bodies of BSF larvae (BSFL) is varied distinctively depending on the diets as well as the contaminant types and concentrations. Heavy metals, including cadmium, copper, arsenic, and lead, were reported to have accumulated in BSFL. In most cases, the cadmium, arsenic, and lead concentration in BSFL exceeded the recommended standard for heavy metals occurring in feed and food. Following the results concerning the accumulation of the undesired substance in BSFL's body, they did not affect the biological parameters of BSFL, unless the amounts of heavy metals in their diets are highly exceeding their thresholds. Meanwhile, a study on the fate of pesticides and mycotoxins in BSFL indicates that no bioaccumulation was detected for any of the target substances. In addition, dioxins, PCBs, PAHs, and pharmaceuticals did not accumulate in BSFL in the few existing studies. However, future studies are needed to assess the long-term effects of the aforementioned undesired substances on the demographic traits of BSF and to develop appropriate waste management technology. Since the end products of BSFL that are contaminated pose a threat to both human and animal health, their nutrition and production process must be well managed to create end products with a low contamination level to achieve a closed food cycle of BSF as animal feed. [ABSTRACT FROM AUTHOR]

Black Soldier Fly (BSF) is a novel option to convert organic waste into high economic products such as protein, lipid, and chitin. Due to the drawbacks of petrochemical-based plastic, the biodegradable film has attracted much attention; among these, chitin-based packaging film is a promising material. This study extracted the chitin from BSF using a co-solvent of glycerol and hydrochloric acid (HCl). The chitin nanofiber has a dimension of 34 nm in width and 494 in length following Transmission Electron Microscopy analysis (TEM). Besides, the obtained chitin was also added to the gelatin-based film for packaging application. The chitin/gelation packaging was evaluated for its suitability in food application by testing its antioxidant activity, thickness, grammage, opacity, moisture, and water solubility. The film developed with more than 0.5 wt.% chitin and nanochitin showed high antioxidant activity, while adding chitin does not significantly change the thermal stability of the gelatin films. The chemical structure of chitin and bio-packaging was determined by Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), and Thermogravimetric Analysis (TGA). This study provides a green and facile approach for chitin production from BSF by using co-solvent and reveals the potential of insect chitin in creating active bio-packaging. [ABSTRACT FROM AUTHOR]

Using the method of scanning electron microscopy, a comparative study of the morphology of the particle surface and the elemental composition of the cuticle of Hermetia illucens pupa before and after the application of a liquid culture (LC) of the probiotic strain Lactobacillus acidophilus B 2707 was carried out. At the same time, under the influence of the LC, destruction of relatively large particles of the powder of the chitin–protein complex of the cuticle (average particle diameter D 845.3 ± 109.1 μm) and the formation of small fragments (average D 63.4 ± 13.9 μm) occurred, including nanoparticles (average D 54 ± 18 nm). A biofilm of lactobacilli enriched with calcium, magnesium, and phosphorus was obtained on a sorbent consisting of microparticles of the cuticle of insect pupae and including nanoparticles, which provided the probiotic preparation with high biological efficiency. [ABSTRACT FROM AUTHOR]

Insect chitin was isolated from different life stages of the black soldier fly Hermetia illucens, such as instar stages, prepupae and pupae, reared separately on fruit and vegetable waste substrates after removal of fat, protein and minerals. Chitin yield was high in prepupae fed with vegetable waste (11.78 ± 0.13%) followed by fruit waste (6.82 ± 0.36%). The extracted chitin was compared with a commercial chitin from shrimp by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The results revealed that both chitins from commercial shrimp source and the H. illucens had similar chemical structures and physicochemical properties indicating the H. illucens chitin samples to be of α- chitin orientation type. With regards to the H. illucens samples, small physiochemical changes were noticed. Furthermore, the polymers derived from BSF are equivalent to commercial polymers in terms of purity and structural morphology, indicating their utility for industrial and medical applications. Thus, H. illucens prepupae is a promising alternative source of chitin. [ABSTRACT FROM AUTHOR]

The immunological effects according to the difference in the degree of deacetylation (DD) and molecular weight (MW) of chitosan purified from Hermetia illucens larvae were investigated. The DD of purified high molecular weight chitosan (Hi-CTSN) from H. illucens larvae was found to be 87.2%. According to the substrate specificity of the enzyme, Hi-CTSN was treated with chitosanase and chitinase to prepare chitooligosaccharides (CTS) named CTS2 and CTS3, respectively. For comparison of relative activity, CTS1 obtained by treating crab shell-derived HMWC1 with chitosanase was used as a control. Matrix-assisted laser desorption/ionization (MALDI-TOF) mass spectrometry was subjected to determine the sugar components constituting CTS1, CTS2, and CTS3, respectively. By examining the biological activity of CTS and the immuno-stimulatory activity of CTS according to MW and DD, the expression of many inflammatory cytokines related to the peripheral immune system in macrophage RAW 264.7 cells was confirmed. As a result, all CTS showed similar effects on the expression of tumor necrosis factor-α (TNF-α) in all concentration ranges used. Among them, CTS1 was verified to have a significant effect on the secretion of inflammatory cytokines, such as interleukin-6 (IL-6) and interleukin-1β (IL-1β), at a high concentration of 250–500 μg/mL. However, CTS3 showed significantly higher expression than CTS1 and CTS2 at low concentrations ranging from 50 to 100 μg/mL. However, there was no significant difference in antioxidant activity against FRAP, ABTS, and DPPH in all CTS. Our results suggest that the presence or absence of the acetyl group of CTS in response to immune stimulation showed a very significant difference, but had a less substantial association with antioxidant activity. Therefore, our data suggested that the difference in DD had a more substantial effect on the immuno-stimulatory activity than the MW of CTS. [ABSTRACT FROM AUTHOR]

The breeding of insects generates waste in the form of insect excrement and feed residues. In addition, a specific chitinous waste in the form of insect larvae and pupae exuvia is also left. Recent research tries to manage it, e.g., by producing chitin and chitosan, which are value-added products. The circular economy approach requires testing new, non-standard management methods that can develop products with unique properties. To date, the possibility of biochar production from chitinous waste derived from insects has not been evaluated. Here we show that the puparia of Hermetia illucens are suitable for biochar production, which in turn exhibits original characteristics. We found that the biochars have a high nitrogen level, which is rarely achievable in materials of natural origin without artificial doping. This study presents a detailed chemical and physical characterization of the biochars. Moreover, ecotoxicological analysis has revealed the biochars' stimulation effect on plant root growth and the reproduction of the soil invertebrate Folsomia candida, as well as the lack of a toxic effect on its mortality. This predisposes these novel materials with already built-in stimulating properties to be used in agronomy, for example as a carriers for fertilizers or beneficial bacteria. [ABSTRACT FROM AUTHOR]

Chitosan was produced from Hermetia illucens pupal exuviae by heterogeneous and homogeneous deacetylation. Tomato fruits (Solanum lycopersicum), that are one of the most grown and consumed food throughout the world, were coated with 0.5 and 1% chitosan, applied by dipping or spraying, and stored at room temperature or 4 °C, for a storage period of 30 days. Statistical analysis give different results depending on the analysed parameters: heterogeneous chitosan, indeed, had a better effect than the homogenous one in maintaining more stable physico-chemical parameters, while the homogenous chitosan improved the total phenols, flavonoids and antioxidant activity. Chitosan coatings applied by spraying were more effective in all the analyses. Chitosan derived from H. illucens always performed similarly to the commercial chitosan. However, a general better performance of insect-derived chitosan on the concentration of phenolics and flavonoids, and the antioxidant activity was observed as compared to the commercial one. Chitosan coating has already been successfully used for preservation of fresh fruits, as alternative to synthetic polymers, but this is the first investigation of chitosan produced from an insect for this application. These preliminary results are encouraging regarding the validation of the insect H. illucens as a source of chitosan. [ABSTRACT FROM AUTHOR]

Black soldier fly (BSF) larvae (Hermetia illucens) are voracious feeders that can be reared on food waste streams originating from the food industry and retailers. Because these food waste streams are automatically being unpacked in substantial amounts, they can contain microplastics, potentially jeopardising the larvae's chemical safety when applied as compound feed ingredients. During this study, the dynamics of ingestion and excretion of microplastics by BSF larvae reared on substrates containing different contents (wMP = 0.00, 0.01, 0.10, 0.50, 1.00, 3.00%) of fluorescent blue-labelled microplastics (median size, Dv(50) = 61.5 µm) were monitored. To correlate the particle size with their uptake, larval mouth opening dimensions were measured during the rearing process. In conclusion, it appeared that ingestion of microplastics by BSF larvae depends on initial particle load, mouth size, and consequently also age. The larvae took up between 131 (wMP = 0.01%) and 4866 (wMP = 3.00%) particles leading to bioaccumulation factors (BAF) between 0.12 (wMP = 3.00%) and 1.07 (wMP = 0.01%). Larvae also appeared to excrete the microplastics, lowering the BAFs to values between 0.01 (wMP = 3.00%) and 0.54 (wMP = 0.01%). [ABSTRACT FROM AUTHOR]

The black soldier fly (BSF; Hermetia illucens) is used in sustainable processing of many types of organic waste. However, organic waste being decomposed by BSF produces strong odors, hindering more widespread application. The odor components and how they are produced have yet to be characterized. We found that digestion of food waste by BSF significantly alters the microbial flora, based on metagenomic analyses, and the odor components generated, as shown by thermal desorption gas chromatography mass spectrometry analysis. Inoculation with BSF significantly decreased production of volatile organic sulfur compounds (dimethyl disulfide and dimethyl trisulfide), which are known to be released during methionine and cysteine metabolism by Lactobacillus and Enterococcus bacteria. BSF inoculation significantly changed the abundance of Lactobacillus and Enterococcus and decreased microbial diversity overall. These findings may help in optimizing use of BSF for deodorization of composting food waste. [ABSTRACT FROM AUTHOR]

Bioconversion of meat and bone meal (MBM), a kind of organic waste, by black soldier fly larvae (BSFL) is promising. Knowledge on the dissolved organic matter (DOM) features in larval frass is important for the further application of insect frass fertilizers. However, information about DOM characteristics in BSFL frass is limited. In this study, BSFL were fed with chicken or fish MBM containing 0% (CK), 1% (T1), 2% (T2) and 3% (T3) of rice straw, and DOM features in BSFL frass were characterized by UV–Vis and fluorescence spectroscopy. DOM concentrations in fish MBM group (37.06–40.82 mg/g) were higher than those in chicken MBM group (28.25–31.72 mg/g). Straw addition into two types of MBM had different effects on spectroscopic features of DOM. UV–Vis spectral results showed that small addition of straw (T1 and T2) into chicken MBM stimulated the humification and aromatization degree of BSFL frass. For fish MBM, CK sample had better humification and aromatization degree, whereas adding more straw (i.e., T3) caused a negative effect. DOM in chicken MBM group was likely to be dominated by fulvic-like substances, while those in fish MBM group were humic acid-like substances. Moreover, fluorescence spectra results showed the humification degree of BSFL frass from fish MBM (61–63%) was greater than that from chicken MBM (51–55%). Over than 50% of humification degree revealed potentials of BSFL frass as promising organic fertilizers after MBM digestion. However, low germination index values of some frass samples implied a further composting might be necessary to stabilize frass fertilizers. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSF, Hermetia illucens) have gained much attention for their industrial use as biowaste recyclers and as a new source of animal proteins. The functional effect that microbiota has on insect health and growth performance remains largely unknown. This study clarifies the role of microbiota in BSF ontogeny by investigating the differential genomic expression of BSF larvae in axenic conditions (i.e., germfree) relative to non-axenic (conventional) conditions. We used RNA-seq to measure differentially expressed transcripts between axenic and conventional condition using DESeq2 at day 4, 12 and 20 post-hatching. Gene expression was significantly up or down-regulated for 2476 transcripts mapped in gene ontology functions, and axenic larvae exhibited higher rate of down-regulated functions. Up-regulated microbiota-dependant transcriptional gene modules included the immune system, the lipid metabolism, and the nervous system. Expression profile showed a shift in late larvae (day 12 and 20), exposing a significant temporal effect on gene expression. These results provide the first evidence of host functional genes regulated by microbiota in the BSF larva, further demonstrating the importance of host-microbiota interactions on host ontology and health. These results open the door to optimization of zootechnical properties in alternative animal protein production, biowaste revalorization and recycling. [ABSTRACT FROM AUTHOR]

Agro-industrial waste is considered as an agro-industrial by-product that can produce another valuable product and, at the same time, lessen the waste disposal problem. Here, we suggest the usage of black soldier fly larvae (BSFL) as an organism to convert the agro-industrial wastes, particularly the desiccated coconut residue (DCr) and soybean curd residue (SCr), into highly valuable biomass. In this experiment, we observed the bioconversion of BSFL using fermented DCr and SCr at different ratios (DCr:SCr), namely T1 (4:0), T2 (3:1), and T3 (2:2), T4 (1:3), and T5 (0:4). The amount of food given to BSFL was standardized for every treatment during the rearing duration of 20 days. Waste reduction (WR), bioconversion rates, growth rate, feed conversion ratio (FCR), and nutrient content of the BSFL fed with different treatments were analyzed. The larvae fed with T5 shows significant higher growth rate and waste reduction, which was 15.78 g day−1 and 80.05%, followed by T4 (15.05 g day−1 and 77.36%), T2 (14.98 g day−1 and 69.95%), T3 (14.88 g day−1 and 62.65%), and T1 (13.37 g day−1 and 57.76%) respectively. In addition, larvae fed with T5 also show higher protein content (46.37%) and lower lipid content (46.37%). In all treatments, the higher macronutrient content indicates BSFL frass content's potential as a novel organic fertilizer in agriculture. [ABSTRACT FROM AUTHOR]

The use of black soldier fly larvae (BSFL) in livestock farming and aquaculture as an alternative protein source sheds light on sustainable development of agriculture. The aims of this scientific note were to address the recent progress and the challenges specifically in the research of BSFL rearing using locally available organic waste as feedstock. It has been found that the pre-treatment of feedstock with blending and fermentation methods increases nutrient content and palatability. Studies examining bioconversion of feedstock, growth performance and protein production of BSFL are highlighted. Moving towards Industry 4.0, the Internet of Things (IoT) and automated smart farming systems have been proposed and implemented recently to establish a sustainable agriculture system in BSFL rearing industry. Notwithstanding, much work is still required on the post-harvest processing techniques and the application of advanced technologies to standardize BSFL protein quality. The resolution of industrialization challenges will comprehend the sustainable production and the potential applications of BSFL protein. [ABSTRACT FROM AUTHOR]

Treatment of biodegradable waste using the black soldier fly larvae (BSFL) is an emerging waste treatment technology attracting entrepreneurial activities around the globe, mainly because the larvae grown on the waste have the potential to become starting material for several commercial products such as animal feed, biodiesel, chitin as a biopolymer, and soil fertilizer. Insect-based waste treatment technology offers a financially viable solution for the solid waste problem mitigation, which otherwise has been an arduous task for many parts of the globe, especially for the developing nations. Although considered a better alternative than other well-established technologies such as composting or anaerobic digestion, the technology is still in its infancy. The researchers and entrepreneurs who wish to gain an insight into and develop the BSFL-based waste processing technology further, require to have a holistic understanding of the various ways in which the performance of BSFL technology can be enhanced and its scaling-up can be formulated to solve the waste management problems in community- and city-level. This review article is a collection of state-of-the-art knowledge on various aspects related to the technology development for full-scale utilization for commercialization purposes, such as the artificial rearing techniques of BSF, waste stabilization performances of the BSFL at different environmental conditions, and the effects of micronutrients and associated microorganism communities. [ABSTRACT FROM AUTHOR]

In the present work, a statistical optimization of a sustainable coating for core–shell NPK (Nitrogen–Phosphorus–Potassium) fertilizers was investigated. The environmental green coating was enriched in nitrogen using a biomass and renewable source, namely the nitrogen rich fraction of black soldier fly larvae (BSFL) (Hermetia Illucens, Diptera: Stratiomyidae) reared on vegetable waste. A rational approach was proposed with the aim of calculating the best formulation of the coating, considering both its manufacturing behavior, such as adhesion to the core, and its physical properties, such as homogeneity or plasticity. From a circular economy perspective, together with the nitrogen-rich fraction from BSFL (from 51 to 90 wt.%), water and glycerol were considered for the coating formulation in different proportion: from 10 to 32 wt.% and from 0 to 17 wt.% respectively. The Design of Experiments technique was implemented to limit the total number of tests for the coating formulation (18 tests). ANOVA was employed, with the aim of obtaining mathematical models to derive a better precise and objective formulation. The results show that the use of glycerol can be avoided, as well as only a limited amount of water (11 wt.%) is necessary to obtain an optimized coating formulation, thereafter, satisfying the more relevant technological and physical properties for the coating manufacturing. [ABSTRACT FROM AUTHOR]

Growing antimicrobial resistance has prompted researchers to identify new natural molecules with antimicrobial potential. In this perspective, attention has been focused on biopolymers that could also be functional in the medical field. Chitin is the second most abundant biopolymer on Earth and with its deacetylated derivative, chitosan, has several applications in biomedical and pharmaceutical fields. Currently, the main source of chitin is the crustacean exoskeleton, but the growing demand for these polymers on the market has led to search for alternative sources. Among these, insects, and in particular the bioconverter Hermetia illucens, is one of the most bred. Chitin can be extracted from larvae, pupal exuviae and dead adults of H. illucens, by applying chemical methods, and converted into chitosan. Fourier-transformed infrared spectroscopy confirmed the identity of the chitosan produced from H. illucens and its structural similarity to commercial polymer. Recently, studies showed that chitosan has intrinsic antimicrobial activity. This is the first research that investigated the antibacterial activity of chitosan produced from the three developmental stages of H. illucens through qualitative and quantitative analysis, agar diffusion tests and microdilution assays, respectively. Our results showed the antimicrobial capacity of chitosan of H. illucens, opening new perspectives for its use in the biological area. [ABSTRACT FROM AUTHOR]

Globally, there is growing interest to recycle organic waste using insect larvae into high-quality frass fertilizer through circular economy approach. This paper presents the first comparative report on the nutrient concentrations, fertilizing indices, nutrient supply potentials and compost maturity of nine edible insect frass fertilizers. Our results revealed that frass fertilizers from all the insect species had adequate concentrations and contents of macronutrients [nitrogen (N), phosphorus (P), potassium (K)], secondary nutrients (calcium, magnesium, and sulphur) and micro-nutrients (manganese, copper, iron, zinc, boron, and sodium). The fertilizing indices of the frass fertilizers were above 3. However, black soldier fly (BSF) frass fertilizer had significantly higher N (20–130%) and K (17–193%) concentrations compared to others. The P concentration of Gryllus bimaculatus frass fertilizer was 3–800% higher compared to those of frass fertilizers from other insect species. The potential N and K supply capacities of BSF frass fertilizer was 19–78% and 16–190% higher, respectively. The P supply capacity of cricket frass fertilizer was 17–802% higher compared to others. The highest seed gemination rate (> 90%) and germination index (267%) were observed in seeds treated with BSF frass fertilizer. Frass fertilizer obtained from the other eight insect species showed medium to high phytotoxicity. These findings demonstrate that insect frass fertilizers are promising alternatives to existing commercial fertilizers (i.e., mineral, and organic) for improved soil health and crop yield. [ABSTRACT FROM AUTHOR]

The growth and sustainability of freshwater aquaculture are highly dependent on economic feed which is the major running cost. Fish feed industries depend on the high-priced fish meal (FM) as protein source in feed formulations. In this context, a nutrient-rich, and palatable insect meal–based fish feed was developed incorporating the black soldier fly (BSF) (Hermetia illucens) prepupae meal (BSFPM) reared on organic waste imparting additional benefit of waste bioremediation to make cost-effective feed. Feeding trial was conducted to evaluate growth performance on monosex Nile tilapia (Oreochromis niloticus). The different treatments were (1) dried BSF prepupae, (2) BSF prepupae and BSFPM-based feed in 1:1 proportion, (3) BSFPM feed, and (4) control feed with FM. The survival, growth, feed efficiency, and haematological parameters were not significantly different between BSFPM and control feed. Fish fed with control feed and BSFPM feed showed significantly higher (P ≤ 0.05) weight gain, specific growth rate, and percentage weight gain. Lowest food conversion ratio (P ≤ 0.05) was recorded for fish fed control feed with a significantly higher feed efficiency ratio (0.65d ± 0.034) and protein efficiency ratio (2.11a ± 0.063). The mean corpuscular volume of blood in fish fed BSF prepupae (128.5a ± 3.2) is significantly higher. The good growth of fish fed BSFPM feed may be attributed to the essential amino acids which are not limiting in feed. Absence of microbes and safe level heavy metals in BSFPM feed ensures safety of the ingredient. Hence, it can be used as a suitable protein source in feed formulations. [ABSTRACT FROM AUTHOR]