Search Results (173)

The extensive use of veterinary antibiotics in livestock production is a growing concern, particularly in terms of environmental sustainability and health security. This review presents the case of veterinary antibiotic use and regulations in Canada before exploring a potential novel avenue for agricultural antibiotics waste up-cycling. The impact of the widespread use of antibiotics in animal husbandry is reviewed, and the dissemination routes of antibiotic residues and antibiotic-resistant bacteria from farms to the environment are explored to identify potential weaknesses in the management of veterinary antibiotics. The presence of antibiotic residues in livestock products and manure poses significant challenges, as these residues contribute to the development of antibiotic-resistant bacteria, which poses a threat to both the environment and health. The review examines the fate of animal waste contaminated with antibiotics in the environment, exploring the impact of management practices on antibiotic degradation and their persistence in soil and water systems. Additionally, the potential risks to human and animal health are addressed, emphasizing the links between antibiotic residues in the environment and the rising threat of antimicrobial resistance. The last part of this review focuses on exploring how up-cycling veterinary antibiotic residues in insects for feed and fertilizers could contribute to mitigating these risks. Overall, this review calls for more integrated solutions that balance the need for antibiotics in animal agriculture with the prevention of environmental contamination and the antibiotic resistance threat, while meeting the rising demand for animal proteins, highlighting the need for more region-specific surveillance programs. Full article

The rapid expansion of the global population has intensified the demand for protein-rich food sources, positioning aquaculture as a crucial sector in the endeavor to alleviate global hunger through the provision of high-quality aquatic protein. Traditional protein sources such as fishmeal have historically served as the foundation of aquafeeds; however, their elevated costs and limited availability have catalyzed the search for sustainable alternatives. These alternatives encompass plant-based proteins, insect meals, and, more recently, single-cell proteins (SCPs), which are derived from microorganisms including bacteria, yeast, fungi, and microalgae. Nonetheless, SCP remains in its nascent stages and currently accounts for only a minor fraction of aquafeed formulations relative to other established alternatives. The production of SCP utilizes low-cost substrates, such as agricultural and dairy wastes, thereby supporting waste mitigation and principles of the circular economy. This review elucidates the nutritional value of SCPs, their potential for biofortification, and their emerging roles as functional feeds with immunomodulatory and nutrigenomic effects. Additionally, the review underscores the potential of endophytes as a novel SCP source, highlighting their underutilized capacity to foster sustainable innovations in aquafeeds. Full article

The growing demand for nutraceuticals has driven interest in upcycling low-value proteins from processed animal by-products and insect larvae into functional protein hydrolysates. This study evaluated five such hydrolysates in comparison to a high-value commercial reference (CPSP90), assessing the proximate composition, amino acid profile, molecular weight distribution, antioxidant activity, and bacterial growth dynamics. Results revealed a wide variability in the composition and bioactivity, driven by the raw material and processing conditions. All hydrolysates displayed a medium to high crude protein content (55.1–89.5% DM), with SHARK being the most protein-rich. SHARK and SWINE hydrolysates were particularly rich in collagenic amino acids, while FISH and CPSP90 contained higher levels of essential amino acids. FISH and INSECT demonstrated the strongest antioxidant activity, with INSECT also showing the highest protein solubility. INSECT and SWINE further displayed mild, selective antibacterial effects, indicating a potential for disease mitigation. Conversely, SHARK and FISH supported opportunistic bacteria growth, suggesting a potential use as nitrogen sources in microbial media. These findings highlight the nutritional and functional versatility of animal-derived protein hydrolysates and support their integration into sustainable feed strategies within a circular bioeconomy. Full article

Laccase, a member of the blue multicopper oxidase family, is widely distributed across diverse taxonomic groups, including fungi, bacteria, plants, and insects. This enzyme drives biocatalytic processes through the oxidation of phenolic compounds, aromatic amines, and lignin derivatives, underpinning its significant potential in the food industry, cosmetics, and environmental remediation. However, wild-type laccases face critical limitations, such as low catalytic efficiency, insufficient expression yields, and poor stability. To address these bottlenecks, this review systematically examines optimization strategies for heterologous laccase expression by fungal and bacterial systems. Additionally, we discuss protein engineering for laccase modification, with a focus on the structural basis and active-site redesign. The comprehensive analysis presented herein provides strategic suggestions for advancing laccase engineering, ultimately establishing a theoretical framework for developing high-efficiency, low-cost engineered variants for large-scale biomanufacturing and green chemistry applications. Full article

The northern region of Brazil is endemic for American Tegumentary Leishmaniasis (ATL) primarily caused by Leishmania guyanensis and transmitted by the sand fly Nyssomyia umbratilis. The disease occurs at different rates in the municipalities of Manacapuru (MAN) and Rio Preto da Eva (RPE), located in the state of Amazonas. Despite their geographic proximity and separation by the Rio Negro, MAN has a low incidence, whereas RPE reports a significantly higher number of cases. Since the vector is present in both locations, potential biological differences in N. umbratilis may influence transmission. Previous studies suggested genotypic and phenotypic differences in N. umbratilis from both localities. To investigate the molecular factors underlying their potentially differential vectorial capacities, we performed a comparative proteomic analysis of dissected insect intestines from both localities. Our results revealed that sand flies from MAN showed a higher abundance of proteins related to gene transcription, protein translation, amino acid and proton transport, innate immune response and intestinal motility. Since the importance of microbiota has previously been shown in parasite–vector interactions, we also identified bacteria from both vector populations. We detected bacteria specific to each population and, exclusively in MAN, some species described in the literature as having parasiticidal properties. These findings highlight molecular and microbial peculiarities that could contribute to the observed difference in ATL prevalence in the two areas. Full article

Leucaena leucocephala (Lam.) de Wit is listed in the world’s 100 worst alien invasive species because of the risks it poses to native plant communities. Life history traits, such as high growth and reproductive rates, and a high capacity to adapt to different environmental conditions may contribute to its invasive properties. Biotic stressors, such as herbivores, pathogens, and competing plant species are known to exert significant selective pressure on the plant’s survival, distribution, and abundance. L. leucocephala has been reported to contain several compounds involved in the defense functions against these biotic stressors. A large amount of L-mimosine, a non-protein amino acid, was found in all plant parts of L. leucocephala, including its flowers. L-Mimosine is toxic to herbivorous mammals and insects, parasitic nematodes, pathogenic fungi, and neighboring competing plant species by inactivating various essential enzymes and blocking DNA replication, and/or inducing oxidative stress conditions. Several flavonoids, polyphenolic compounds, and/or derivatives of benzoic and cinnamic acids are toxic to parasitic nematodes, pathogenic fungi and bacteria, and competing plant species by disrupting plasma membrane structures and functions, and various metabolic processes. These compounds may represent the invasive traits of L. leucocephala that have undergone natural selection during the evolution of the species. They may contribute to the defense functions against the biotic stressors, and increase its survival, distribution, and abundance in the introduced ranges. This is the first review to focus on the compounds involved in the defense functions against biotic stressors. Full article

The insect olfactory system is vital for survival, enabling the recognition and discrimination of a wide range of odorants present in the environment. This process is mediated by odorant receptors (Ors) and the highly conserved co-receptor Orco. Insect Ors are structurally distinct from mammalian olfactory receptors, a divergence that presents unique advantages for developing insect-specific pest control strategies. In this study, we explored the molecular-level interactions between insect Ors and volatile organic compounds. Specifically, we investigated the response of Ors/Orco to phenethyl acetate (PA), a volatile compound found in the culture media of acetic acid bacteria. PA elicited activation in a concentration-dependent, reversible, and voltage-independent manner in Or1a, Or24a, and Or35a when combined with Orco, as well as in Orco homomers. Through molecular docking studies, we determined that the PA-binding site is localized to the Orco subunit, a highly conserved protein across diverse insect taxa. To further elucidate the role of key residues in the Orco homotetramer receptor, we performed site-directed mutagenesis. A mutational analysis identified W146 and E153 as critical residues for PA binding and activation. A double-mutant Orco receptor (W146A + E153A) exhibited a significant reduction in PA-induced activation compared to the wild-type receptor. These findings indicate that PA functions as an agonist for the Drosophila melanogaster Orco receptor and highlight its potential applications in chemosensory research and insect pest management strategies. Full article

Maize (Zea mays) is a critical staple crop whose post-harvest losses, predominantly due to infestations by the maize weevil, Sitophilus zeamais, threaten food security. This study explores the possibility of utilizing S. zeamais, traditionally known as a pest, as an alternative protein source by assessing its nutritional profile and food safety attributes. Cultured under controlled conditions, S. zeamais specimens were processed into flour, which was subsequently analyzed for microbiological safety, protein content, and amino acid composition. Microbiological assays confirmed that the flour met established food safety standards, with aerobic mesophilic bacteria, fungi, and yeast present at negligible levels and no detection of coliforms, Salmonella spp., or Escherichia coli. Protein quantification revealed a high total protein content (48.1 ± 0.3%), although the salt-soluble fraction constituted only 13.7% of the total. The amino acid profile exhibited elevated levels of isoleucine, valine, and threonine, while deficiencies in leucine, lysine, sulfur amino acids, and tryptophan were noted. These findings suggest that, despite certain limitations, S. zeamais flour represents a viable protein source. Integrating targeted insect harvesting for protein into pest management strategies could help reduce post-harvest losses and contribute to improved food security and nutritional availability. Full article

Trehalose, a disaccharide consisting of two D-glucose molecules, is present in a variety of organisms, including bacteria, yeast, fungi, insects, and plants. In plants, it functions as a source of energy and carbon, and in yeast and plants, it serves as a signaling molecule, influencing metabolic pathways and growth regulation. Additionally, it plays a role in protecting proteins and cell membranes from stress-induced damage. This study aims to assess the optimal level of trehalose supplementation in the diets of layer hens aged 34 to 49 weeks, addressing the limited existing literature on its effects on productivity. Experimental diets, designed in accordance with nutritional recommendations, were formulated to contain six different levels of trehalose (0, 0.05, 0.10, 0.30, 0.60, and 1.00%). The study was conducted over five 21-day periods, during which various performance parameters were evaluated. The results indicated that trehalose supplementation at levels of 0.05%, 0.10%, and 0.30% led to increased feed intake (FI) compared to the 1.00% level (p < 0.05). Furthermore, the highest trehalose level (1.00%) significantly reduced the feed conversion ratio by egg mass (FCRem) compared to both the control group and the other supplementation levels; however, the feed conversion ratio by dry matter (FCRDz) remained consistent across all treatments. The levels of 0.05%, 0.10%, and 0.30% exhibited superior FCREm and FCRDz compared to the 1.00% level. Egg weight (EW) was higher in the trehalose-supplemented groups compared to the control group. Additionally, the 1.00% trehalose treatment was found to be the most effective in terms of relative weights of shells (RWS), and egg mass (EM) was higher at all trehalose levels compared to the control group. The antioxidant status, as measured by malondialdehyde (MDA) levels, indicated that supplementation with 0.30% and 0.60% trehalose had a protective effect against oxidative stress, although the 1.00% level resulted in increased MDA levels. Total weight (TW) was highest in the 0.30% treatment group, and bone strength (BS) improved in the groups supplemented with 0.10% and 1.00% trehalose. Other parameters, including lipid content (L), dry matter (DM), phosphorus (P), and calcium (Ca), did not show any significant differences among the treatment groups. In conclusion, supplementation with 1.00% trehalose enhances feed efficiency, egg weight, and quality, with minimal impact on lipid peroxidation, while potentially providing benefits for gut health and egg quality. Full article

Interactions between species give rise to chemical pathways of communication that regulate the interactions of transboundary species. The communication between nematodes and other species primarily occurs through the regulation of chemicals, with key species including plants, insects, bacteria, and nematode-trapping fungi that are closely associated with nematodes. G protein-coupled receptors (GPCRs) play a crucial role in interspecies communication. Certain flp genes, which function as GPCRs, exert varying degrees of influence on how nematodes interact with other species. These receptors facilitate the transmission of corresponding signals, thereby completing the interactions between species. This paper introduces the interactions between nematodes and other species and discusses the role of GPCRs in these organisms, contributing to a deeper understanding of the impact and significance of GPCRs in cross-border regulation between nematodes and other species. Furthermore, it is essential to leverage GPCRs in efforts to control pests. Full article

Aphids (Hemiptera: Aphididae) are cosmopolitan generalist pests of many agricultural crops. Their ability to reproduce rapidly through parthenogenesis allows them to quickly reach population sizes that are difficult to control. Their damage potential is further exacerbated when they act as vectors for plant pathogens, causing diseases in plants. Aphids are typically managed through the widespread use of insecticides, increasing the likelihood of short-term insecticide resistance. However, for the past few decades, entomopathogenic bacteria have been used as an alternative management strategy. Entomopathogenic bacteria have demonstrated their effectiveness for biologically suppressing insect pests, including aphids. In addition to identifying bacterial species that are pathogenic to aphids, research has been conducted on toxins such as Cry, Cyt, Vip, recombinant proteins, and other secondary metabolites with insecticidal activity. Most studies on aphids have been conducted in vitro, exposing them to an artificial diet contaminated with entomopathogenic bacteria or bacterial metabolites for periods ranging from 24 to 96 h. The discovery of new bacterial species with insecticidal potential, as well as the possibility of biotechnological applications through the genetic improvement of crops, will provide more alternatives for managing these agricultural pests in the future. This will also help address challenges related to field application. Full article

The increasing demand for sustainable and nutritionally rich protein sources has led to a growing interest in edible insects as a viable alternative to traditional meat. This study evaluates the potential of mealworm (Tenebrio molitor) flour as a partial meat replacer in the formulation of dry fermented sausages (salchichón). Four formulations were prepared, replacing 0%, 5%, 10%, and 15% of pork meat with mealworm flour, and their microbiological, physicochemical, rheological, technological, and sensory properties were analyzed. Results showed that the incorporation of mealworm flour did not compromise the growth of lactic acid bacteria or Gram-positive catalase-positive cocci, both essential for fermentation and curing. The inclusion of mealworm flour significantly increased the protein, fiber, and polyunsaturated fatty acid (PUFA) content of the sausages, improving their nutritional profile. Notably, despite the higher PUFA content, lipid oxidation was reduced, as evidenced by lower concentrations of oxidation-derived volatile compounds. Significant changes were also observed in color, particularly at higher replacement levels, which resulted in a noticeable darkening of the sausages. Sensory evaluation indicated that replacing up to 5% of pork meat maintained product acceptability, whereas higher levels caused significant changes. The partial replacement of pork by mealworm flour shows interesting possibilities to produce more sustainable and functional dry fermented meats. Full article

Insect metabolites are known for their preservative potential, but the time-consuming and unsustainable extraction process compromises their transferability. This study aimed to identify user-friendly solutions based on the use of insect meals that could improve microbiological safety as well as consumer acceptability. In this regard, the antimicrobial activity of Alphitobius diaperinus and Tenebrio molitor meals against surrogate strains of Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) pathogenic bacteria and mycotoxin-producing fungi (Penicillium expansum) was evaluated. Minimum inhibitory concentration values of between 3.12 mg/mL vs. Listeria innocua and 12.50 mg/mL vs. Escherichia coli were found. Based on this finding, a model food was developed also considering consumer acceptance. Statistical analysis of food preferences showed that nutritional and sustainability claims were the independent variables of greatest interest. Therefore, waste or by-products from other food chains were selected as co-ingredients for sustainability, nutritional, and sensory claims. Analysis of the chemical composition showed that the insect bar-style snack qualifies as a “high-protein” food, as protein provides more than 20% of the energy value. Based on the moisture (30%) and water activity (0.77) values, the bar could be classified as an intermediate-moisture food. The challenge test showed that the insect meal prevented the proliferation of intentionally added undesirable microorganisms. Conclusively, the findings complement the knowledge on the antimicrobial activities of insect meals, offering new possibilities for their use as natural preservative ingredients with nutritionally relevant properties. Full article

Heat shock proteins (HSPs), particularly HSP90, play a vital role in insect responses to environmental and biotic stresses by maintaining protein stability and supporting immune defenses. This study explores HSP90 regulation in Galleria mellonella larvae following exposure to the nematode Steinernema carpocapsae and its symbiotic bacterium Xenorhabdus nematophila. Exposure to live nematodes caused slight changes in HSP90 expression, while non-viable nematodes had no effect, suggesting that nematode secretions or symbiotic bacteria do not directly influence HSP90 levels. However, nematodes with altered surface properties significantly increased HSP90 expression. X. nematophila also moderately elevated HSP90 levels but this effect disappeared when weakly bound surface proteins were removed. Interestingly, under thermal stress, live nematodes reduced heat-induced HSP90 expression, whereas surface-treated nematodes enhanced it. These findings suggest that HSP90 modulation is influenced by biological control agents, highlighting a potential link between HSP90 and immune detection of invaders. This interaction may be crucial in adapting biological control strategies in response to climate change. Further research is needed to clarify HSP activation pathways, host immune interactions, and mechanisms of entomopathogen immune evasion, particularly under varying environmental temperatures, to enhance bioinsecticide efficacy. Full article

Protease inhibitors are biomolecules with growing biotechnological and biomedical relevance, including those derived from plants. This study investigated strong trypsin inhibitors in quinoa, amaranth, and lupine seeds, plant grains traditionally used in Andean South America. Amaranth seeds displayed the highest trypsin inhibitory activity, despite having the lowest content of aqueous soluble and thermostable protein material. This activity, directly identified by enzymatic assay, HPLC, intensity-fading mass spectrometry (IF-MS), and MS/MS, was attributed to a single protein of 7889.1 Da, identified as identical in Amaranthus caudatus and A. hybridus, with a K_i of 1.2 nM for the canonical bovine trypsin. This form of the inhibitor, which is highly homogeneous and scalable, was selected, purified, and structurally–functionally characterized due to the high nutritional quality of amaranth seeds as well as its promising agriculture–biotech–biomed applicability. The protein was crystallized in complex with bovine trypsin, and its 3D crystal structure resolved at 2.85 Å, revealing a substrate-like transition state interaction. This verified its classification within the potato I inhibitor family. It also evidenced that the single disulfide bond of the inhibitor constrains its binding loop, which is a key feature. Cell culture assays showed that the inhibitor did not affect the growth of distinct plant microbial pathogen models, including diverse bacteria, fungi, and parasite models, such as Mycoplasma genitalium and Plasmodium falciparum. These findings disfavour the notion that the inhibitor plays an antimicrobial role, favouring its potential as an agricultural insect deterrent and prompting a redirection of its functional research. Full article