Project description:Antimicrobial peptides (AMPs) play a key role in the innate immunity, the first line of defense against bacteria, fungi, and viruses. AMPs are small molecules, ranging from 10 to 100 amino acid residues produced by all living organisms. Because of their wide biodiversity, insects are among the richest and most innovative sources for AMPs. In particular, the insect Hermetia illucens (Diptera: Stratiomyidae) shows an extraordinary ability to live in hostile environments, as it feeds on decaying substrates, which are rich in microbial colonies, and is one of the most promising sources for AMPs. The larvae and the combined adult male and female H. illucens transcriptomes were examined, and all the sequences, putatively encoding AMPs, were analysed with different machine learning-algorithms, such as the Support Vector Machine, the Discriminant Analysis, the Artificial Neural Network, and the Random Forest available on the CAMP database, in order to predict their antimicrobial activity. Moreover, the iACP tool, the AVPpred, and the Antifp servers were used to predict the anticancer, the antiviral, and the antifungal activities, respectively. The related physicochemical properties were evaluated with the Antimicrobial Peptide Database Calculator and Predictor. These analyses allowed to identify 57 putatively active peptides suitable for subsequent experimental validation studies.
Project description:There can be substantial negative consequences for insects colonizing a resource in the presence of competitors. We hypothesized that bacteria, associated with an oviposition resource and the insect eggs deposited on that resource, serve as a mechanism regulating subsequent insect attraction, colonization, and potentially succession of insect species. We isolated and identified bacterial species associated with insects associated with vertebrate carrion and used these bacteria to measure their influence on the oviposition preference of adult black soldier flies which utilizes animal carcasses and is an important species in waste management and forensics. We also ascertained that utilizing a mixture of bacteria, rather than a single species, differentially influenced behavioral responses of the flies, as did bacterial concentration and the species of fly from which the bacteria originated. These studies provide insight into interkingdom interactions commonly occurring during decomposition, but not commonly studied.
Project description:Structural changes and growth of animal production systems have resulted in greater volumes of manure. Current manure storage methods pose a potential environmental threat. Lessening these issues is a key concern for the animal production industry. The primary aim of this research was to evaluate black soldier fly (BSF) performance when fed poultry, swine, or dairy manure at different rates (18 or 27 g/2 d until 40% prepupation). The results indicated that larvae fed with the control diet (Gainesville diet) were the heaviest (+31-70%); however, for other life-history traits, those fed the higher feed rate of poultry manure produced comparable results to the control. Larvae fed more resource, regardless of manure type, weighed more as larvae (+3-9%), pupae (+22-48%), and adults (+18-42%), developed faster (up to 3-4 d), had a higher percentage reach the prepupal stage (+2-16%), lived longer as adults (+1 d), and converted more resource to biomass (up to 1% more) than those fed at the lower rate. Yet, no difference was detected in dry matter (DM) reduction across feed rate for a given manure type. Based on these results, all three manure types can be digested by black soldier fly larvae, thus demonstrating their potential for waste management.
Project description:BackgroundIn recent years, there has been a rapidly growing demand for readily accessible substrates for mass production of Black Soldier Fly, Hermetia illucens Linnaeus. Beer production results in various by-products that typically end up in uncontrolled dumpsites constituting pollution problems, which merits urgent attention. The present study investigated whether the 12 formulated diets composed of brewers' spent grains (BSGs), brewers' yeast and cane molasses can serve as substrate for H. illucens production.MethodsFour different BSGs were selected and formulated into 12 diets, aiming at varying protein and net energy levels. The diets were offered to newly hatched (∼1 h old) H. illucens larvae and the influence on developmental duration, survival, wet weight, pre-oviposition time, fecundity, and longevity were compared.ResultsDevelopmental duration of the larvae (16-21 days) and pre-pupae (8-11 days) differed significantly across the different diets. The developmental duration of the pupae (8.7-9.1 days) was not affected by diet. The larval (86-99.2%), pre-pupal (71-95%), and pupal (65-91%) survival rates varied significantly between flies reared on the different diets. The pre-oviposition time was similar for flies provided with water (7-11 days) and 10% sugar solution (8-14 days) or across the different diets. The mean fecundity per female ranged from 324-787 eggs and did not differ between females provided with water or sugar solution. However, the number of eggs laid per female varied significantly across the different diets when provided with water. The longevity of starved H. illucens adults was significantly lower (5 days) compared to those provided with water (11-14 days) or sugar solution (14-15 days).DiscussionThe implications of these findings as part of a quality control procedure for commercial production of high-quality H. illucens larvae as an alternative protein ingredient in livestock and aquaculture feed are discussed.
Project description:The growing global demand for food, particularly animal protein, is intensifying challenges related to food security and environmental sustainability. The increase in organic waste generation, coupled with inefficient waste management, is further deteriorating living conditions by negatively impacting the environment and public health, especially in developing nations. This study investigated the potential of black soldier fly larvae (BSFL) to recycle major daily organic waste fractions in Nepal. BSFL were exposed to seven different biowaste-based substrates locally sourced from fruit and vegetable markets, farms, and food industries. Additionally, the study evaluated rapeseed cake as a supplement to enhance BSFL growth and nutritional content. BSFL survival rates exceeded 80 % on food industry waste but dropped to 63 % on high-moisture substrates like vegetable waste. Mixed vegetable waste (14.7 mg/day) and bakery waste (11.5 mg/day) supported higher average daily weight gain, likely due to their better nutrient values (soluble carbohydrates and proteins). Although rapeseed cake alone hindered larval growth, its supplementation to biowastes improved growth, survival, and bioconversion rates, increased larval protein content up to 32 %, and reduced fat by 36 %. These findings indicate BSFL can effectively recycle diverse, locally available organic wastes in developing countries like Nepal, providing a sustainable source of domestic protein and contributing to feed security. As this is the first BSFL study in Nepal, further research is needed to elucidate the chemical and microbial safety of BSFL reared on biowastes and to develop technical solutions for commercial BSFL production in countries with a low-income economy.
Project description:BackgroundSpent coffee grounds (SCG), an increasingly abundant waste product with environmental disposal problems, has been used as a dietary supplement for many animals and have the potential to be used as a dietary supplement for black soldier fly (BSF) larvae; however, its effective use is still under scrutiny. To date, no studies have considered the use of SCG after microbial fermentation (fSCG) and its effects on BSF life history.MethodsA mixture of fruit and vegetable pulp residue supplemented with one of six different fSCG percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) were provided as a diet substrate in order to evaluate the effect of the fSCG quantity on BSF growth, yield, and conversion ability.ResultsThe addition of fSCG to the pulp diet prolonged larval development times, while 100% fSCG affected the larval survival rate and resulted in a male-biased adult sex ratio. The 20-40% fSCG and 40-60% fSCG treatments supported the largest prepupal and mature larval sizes, respectively. The highest waste reduction efficiency and feed conversion rate by BSF larvae was found with 20% fSCG, similar to the control (0% fSCG).DiscussionFrom the short rearing time, high yield, and high bioconversion efficiency, a 20% fSCG supplementation of the mixed pulp was recommended for rearing BSF larvae. These data are valuable for coffee by-product waste management in urban areas.
Project description:Black soldier fly larvae (BSFL) are considered a commercially viable solution for global organic waste problems. The objective of this study was to assess the feasibility of rearing BSFL on a wide range of low-value waste streams and its potential to transform them into high-quality animal feed and fertilizer. Six waste streams of different origins were selected and each tested in triplicate. Several parameters were analysed: growth performance, waste reduction index (WRI), conversion efficiency (ECI) and larval composition. Frass composition was also analysed. Larvae reared on fast food waste (FFW) had the highest ECI and WRI and the lowest values when reared on pig manure slurry mixed with silage grass (PMLSG) and slaughter waste (SW). The highest protein content was found for larvae reared on mushroom stems (MS) although this substrate had the lowest protein content. Moreover, the frass nutritional profile was proportionally related to the substrate's nutritional profile: the protein-rich substrate (SW) resulted in protein-rich frass and the low-protein substrate (MS) resulted in protein-poor frass. The same was true for the lipid content. In conclusion, this study showed that BSFL can be successfully reared on a wide range of waste streams that can affect the larval and frass chemical compositions.
Project description:The black soldier fly (BSF), Hermetia illucens (L., 1758) (Diptera: Stratiomyidae), is an endemic fly species from the tropical, subtropical and warm temperate zones of America. This saprophagous species relies on its environment where it finds the decomposing matter for the larvae to grow. The polyphagous diet and the macronutrient quality (mainly lipids and proteins) of these larvae make them excellent candidates for various applications such as waste and organic material management, incorporation in animal feed or alternative energy source. Although rearing development in temperate regions requires artificial processes to continuously produce high quality eggs and larvae, few studies have been conducted on the mating and oviposition processes governing H. illucens reproduction. Research conducted in semi-artificial rearing conditions showed that the number of mating varied according to the season. It has been speculated that this behavior could be due to differences in the intensity of sunlight caused by the change of seasons. This study aims at evaluating the influence of sex-ratio, density and nycthemeral cycle on H. illucens reproduction. In order to tackle this issue, an artificial set up for oviposition to collect eggs has been developed. This egg collection system aims at centralize oviposition and simplify eggs collection. Two populations with opposite sex-ratio (male-dominant and female-dominant) were selected. Their respective eggs productions have been evaluated for five breeding densities. Eggs weights varied significantly among the densities for each opposite sex-ratio population and female dominant population produced most eggs weight from 6500 individuals /m3. Finally, four nycthemeral cycles (2, 6, 12 and 18h of daily light) were simulated to evaluate the impact of light duration on reproduction. Early oviposition pic associated with a decrease of the oviposition period are shown when H. illucens are exposed to increasing light duration. These experiments enable improvement of the understanding on artificial reproduction of H. illucens.
Project description:The black soldier fly, Hermetia illucens (L. 1758), is an omnivorous saprophagous insect with a high potential for valorizing organic by-products rich in carbohydrates. Among carbohydrates, H. illucens relies on soluble sugars for the growth and storage lipid synthesis. This study aimed to assess the impact of common soluble sugars on the development, survival, and fatty acid composition of H. illucens. Monosaccharides and disaccharides were individually incorporated into a chicken feed diet. Cellulose was used as a control. Larvae fed glucose, fructose, sucrose, and maltose grew faster than control larvae. In contrast, lactose exhibited anti-nutritional effects on larvae, slowing down growth and reducing final individual weight. However, all soluble sugars produced larvae fatter than the control diet. Notably, the tested sugars shaped the fatty acid profile. Maltose and sucrose increased saturated fatty acid content compared to cellulose. Conversely, lactose increased the bioaccumulation of dietary unsaturated fatty acids. This study is the first to demonstrate the effect of soluble sugars on the fatty acid profile of H. illucens larvae. Our findings highlight that the tested carbohydrates have significant effects on black soldier fly fatty acid composition and can thus determine their final applications.
Project description:Hermetia illucens, one kind of necrophagous insects, belongs to the family Stratiomyidae (Diptera). In this study, the complete mitochondrial genome of H. illucens was investigated. The total number of nucleic acids were 15,698 bp. The genome contains 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a non-coding control region. The phylogenetic relationship of H. illucens and its 12 related species was reconstructed to confirm the taxonomic status of our sample.