RESUMEN

Various factors may affect the antioxidative system in insects, including xenobiotics. Glycoalkaloids (GAs) are plant secondary metabolites produced mainly by the Solanaceae family (nightshades), such as the food crop tomato Solanum lycopersicum L. These compounds exhibit a wide range of biological activities and have attracted increasing interest in the context of potential insecticide properties. Therefore, the aim of the presented study was to analyze the effects of GAs (solanine, chaconine, tomatine, and extracts of tomato leaves) on lipid peroxidation; the expression levels of genes encoding manganese superoxide dismutase (MnSOD), catalase (CAT), and heat shock protein 70 (HSP70); and the enzymatic activity of SOD and CAT in Tenebrio molitor larvae. This species is amodel organism for toxicological and ecophysiological studies and is also a pest of grain storage. The reported changes depend on the GA concentration, incubation time, and type of insect tissue. We observed that the tested GAs affected MnSOD expression levels, increased SOD activity in the fat body, and reduced enzyme activity in the gut. The results showed that CAT expression was upregulated in the fat body and that the enzymatic activity of CAT in the gut was greater in the treated group than in the control group. Moreover, GAs affected HSP70 expression and malondialdehyde levels in both tested tissues. This research contributes to our knowledge about the effects of GAs on the antioxidative system of T. molitor beetles. As efficient antioxidative system functioning is necessary for survival, the tested components may be targets of potential bioinsecticides.

Asunto(s)

Antioxidantes , Catalasa , Larva , Superóxido Dismutasa , Tenebrio , Animales , Tenebrio/metabolismo , Tenebrio/efectos de los fármacos , Antioxidantes/metabolismo , Larva/efectos de los fármacos , Larva/metabolismo , Superóxido Dismutasa/metabolismo , Catalasa/metabolismo , Catalasa/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Alcaloides , Peroxidación de Lípido/efectos de los fármacos , Extractos Vegetales/farmacología , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Insecticidas/toxicidad , Solanum lycopersicum/metabolismo , Estrés Oxidativo/efectos de los fármacos , Tomatina/análogos & derivados , Tomatina/farmacología

RESUMEN

This work aimed to study the effect of defatting via the mixture of n-hexane and ethanol under different volume ratio on the changes of structural characteristics, functional properties and volatile compounds of Tenebrio molitor larvae protein (TMLP). The results showed that 1:0.6 vol ratio of n-hexane to ethanol rendered the highest defatting rate (P < 0.05), as well as led to the highest EAA/AA contents, sulfhydryl contents, surface hydrophobicity, solubility, water/oil holding capacities and emulsifying properties of TMLP (P < 0.05). However, higher volume ratio of n-hexane to ethanol led to negative impacts on functionalities of TMLP. Moreover, the contents of aldehydes and hydrocarbons which rendered off-flavour to TMLP significantly decreased with the increasing volume ratio of n-hexane to ethanol (P < 0.05), while the contents of pleasure flavour (hydrocarbons and ester compounds) were obviously enhanced. This study provides an eco-friendly defatting method on the processing of TMLP with superior quality attributes.

Asunto(s)

Etanol , Hexanos , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de Insectos , Larva , Tenebrio , Compuestos Orgánicos Volátiles , Tenebrio/química , Animales , Hexanos/química , Compuestos Orgánicos Volátiles/análisis , Etanol/química , Larva/efectos de los fármacos , Proteínas de Insectos/química , Solubilidad , Manipulación de Alimentos/métodos , Compuestos de Sulfhidrilo

RESUMEN

Plastic waste has recently become a major global environmental concern and one of the biggest challenges has been seeking for alternative management options. Several studies have revealed the potential of several coleopteran species to degrade plastics, and this is the first research paper on plastic-degradation potential by lesser mealworms from Africa. This study evaluated the whole mitogenomic profile of the lesser mealworm to further identify the insect. The ability of the mealworm to consume Polystyrene (PS) was also evaluated alongside its associated gut microbiota diversity. Our results showed a complete circular mitochondrial genome which clustered closely to the Alphitobius genus but also suggested that our insect might be a new subspecies which require further identification. During the PS feeding trials, overall survival rates of the larvae decreased when fed a sole PS diet while PS intake was observed to increase over a 30-day period. The predominant bacteria observed in larvae fed PS diets were Kluyvera, Lactococcus, Klebsiella, Enterobacter, and Enterococcus, while Stenotrophomonas dominated the control diet. These findings demonstrated that the newly identified lesser mealworm can survive on a PS diet and has a consortium of important bacteria strongly associated with PS degradation. This work provides a better understanding of bioremediation applications, paving the way for further research into the metabolic pathways of plastic-degrading microbes and bringing hope to solving plastic waste pollution while providing high-value insect protein towards a circular economy.

Asunto(s)

Microbioma Gastrointestinal , Larva , Poliestirenos , Animales , Larva/microbiología , Kenia , Bacterias/metabolismo , Bacterias/genética , Bacterias/clasificación , Biodegradación Ambiental , Tenebrio/microbiología , Tenebrio/metabolismo , Filogenia

RESUMEN

The extensive investigation into the capacity of mealworms to digest diverse food by-products, as well as plastic wastes, has been a focal point in recent years. The transition from traditional diet sources like brans to food wastes has the potential to impact the physiological properties of mealworms. This study explored the utilization of various industrial food wastes such as okara, barley spent grain (BSG), sesame oil meal (SOM), and spent coffee grounds (SCG) as feed alternatives, and reports on their survival rate, biomass variations, and nutritional composition. In additional, the shift in their gut microbiota was also assessed. Among the range of industrial food wastes, mealworms exhibited the most robust growth performance when nourished with BSG. This particular group showed a survival rate of 98.33 % and a biomass increase of 23.06 %. In contrast, mealworms fed with SCG demonstrated the lowest survival rate and experienced a significant reduction in biomass. Although the groups fed with okara and SCG displayed moderate growth performance, both exhibited protein levels comparable to those observed in the oatmeal-fed group (used as the positive control). Notably, the inclusion of BSG in the mealworm diet exhibited the potential to enrich their omega-3 fatty acid content, suggesting potential benefits for applications as animal feed or even human consumption. Furthermore, an analysis of the gut microbiome was conducted to investigate the associations between specific diets and the composition of mealworm gut microbiota. In summary, food wastes such as BSG may be repurposed as feed substrates for mealworms before converting them into an alternative source of protein.

Asunto(s)

Microbioma Gastrointestinal , Residuos Industriales , Valor Nutritivo , Tenebrio , Animales , Microbioma Gastrointestinal/fisiología , Tenebrio/microbiología , Residuos Industriales/análisis , Alimentación Animal/análisis , Biomasa

RESUMEN

Geoffroea decorticans, commonly known as Chañar, is a native Chilean plant widely used in folk medicine for its expectorant, pain relief, and antinociceptive properties. This study explored the antioxidant, cytotoxic, and protective effects of its ethanolic (EE) and aqueous (EA) seed extracts against oxidative stress induced by copper sulfate, using both in vitro and in vivo approaches. Phytochemical analyses revealed the presence of phenolic compounds and flavonoids in the extracts. High-Performance Liquid Chromatography (HPLC) coupled with Gas Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS) identified significant components such as phytol, alpha-tocopherol, vitexin, and rutin, with the EE being particularly rich in phytol and vitexin. Antioxidant assays-measuring the total antioxidant capacity (TAC), reducing power, DPPH radical scavenging, and copper and iron chelation-confirmed their potent antioxidant capabilities. Both extracts were non-cytotoxic and provided protection against CuSO4-induced oxidative stress in the 3T3 cell line. Additionally, the use of Tenebrio molitor as an invertebrate model underscored the extracts' antioxidant and protective potentials, especially that of the EE. In conclusion, this study highlights the significant antioxidant and protective properties of Chañar seed extracts, particularly the ethanolic extract, in both in vitro and in vivo models.

Asunto(s)

Antioxidantes , Estrés Oxidativo , Extractos Vegetales , Semillas , Tenebrio , Animales , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antioxidantes/farmacología , Semillas/química , Ratones , Estrés Oxidativo/efectos de los fármacos , Fenoles/análisis , Fenoles/farmacología , Flavonoides/farmacología , Flavonoides/análisis , Cromatografía Líquida de Alta Presión

RESUMEN

This work valorizes rejects from Tenebrio Molitor TM breeding through the production of chitin and chitosan. Two processes are proposed for extracting chitin from larval exuviae and adult. The first process P1 provides chitin with high contents compared to literature data but the characterization shows the presence of impurities in the exuviae chitin responsible for the shifts in the values of the physicochemical characteristics towards those presented by γ chitin. These impurities are removed by delipidation and pure α chitin is obtained. The effective delipidation of this chitin would be linked to its fibrous surface structure. The analysis of the results of P1 led us to develop a second extraction process P2 which provides pure chitin with improved yields using delipidation followed by deproteinization. The N-deacetylation of chitin according to Kurita or Broussignac process makes possible the preparation of pure, highly deacetylated chitosan samples (2 % < DA < 12 %) with high yields and controlled molar masses (Mv). A kinetic study of molecular degradation during deacetylation is carried out. A comparison with Hermetia illucens allows to extend the use of insects as a potential source of chitin and chitosan and confirms the role of the source and the processes in the determination of their characteristics.

Asunto(s)

Quitina , Quitosano , Tenebrio , Animales , Tenebrio/química , Quitina/química , Quitosano/química , Estadios del Ciclo de Vida , Cruzamiento , Larva , Acetilación

RESUMEN

Iron is an essential mineral that supports biological functions like growth, oxygen transport, cellular function, and hormone synthesis. Insufficient dietary iron can lead to anemia and cause fatigue, cognitive impairment, and poor immune function. Animal-based foods provide heme iron, which is more bioavailable to humans, while plant-based foods typically contain less bioavailable non-heme iron. Edible insects vary in their iron content and may have heme or non-heme forms, depending on their diet. Edible insects have been proposed as a protein source that could address issues of food insecurity and malnutrition in low resource contexts; therefore, it is important to understand the bioavailability of iron from insect-based foods. In this study, we used Inductively Coupled Plasma and Mass Spectrometry (IPC-MS) and Caco-2 cell culture models to compare the soluble and bioavailable iron among five different lab-produced tempeh formulations featuring Tenebrio molitor (mealworm) with their non-fermented raw ingredient combinations. Finally, we compared the iron bioavailability of a mealworm tempeh with two sources of conventional beef (ground beef and sirloin steaks) and two commercially available plant-based meat alternatives. The results show that while plant-based meat alternatives had higher amounts of soluble iron, particularly in the Beyond Burger samples, the fermented mealworm-based tempeh had greater amounts of bioavailable iron than the other samples within the set. While all the samples presented varying degrees of iron bioavailability, all products within the sample set would be considered good sources of dietary iron.

Asunto(s)

Disponibilidad Biológica , Hierro , Tenebrio , Animales , Humanos , Células CACO-2 , Hierro/metabolismo , Hierro/farmacocinética , Bovinos , Hierro de la Dieta/farmacocinética , Carne Roja/análisis , Insectos Comestibles/química , Sustitutos de la Carne

RESUMEN

The study aims to assess the impact of oven-drying and decontamination on crude protein concentration and in vitro crude protein digestibility of yellow mealworms. Two kilograms of 12-wk-old mealworm larvae were subjected to freezing prior to the drying process. Approximately 1.5 kg of mealworm larvae were divided into 3 groups and exposed to oven-drying at temperatures of 50 °C for 36 h, 60 °C, and 70 °C for 24 h each. At intervals of 2 h, sets of 3 replicates were withdrawn to record water loss. Consistent weight stabilization was observed at 36 h for 50 °C (T50), 18 h for 60 °C (T60), and 14 h for 70 °C (T70). The remaining 0.5 kg of mealworm larvae was divided and dried under treatments T50, T60, and T70. Each treatment was then split into 2 portions, with one portion subjected to 90 °C for 15 min (denoted as T50-90, T60-90, T70-90) to eliminate microbial contamination. The 6 treatments were then used to determine concentrations of dry matter, crude ash, crude protein, pre-caecal protein digestibility, and dry matter residues after neutral detergent fiber, acid detergent fiber, and acid detergent lignin treatments. No interaction was observed between drying and decontamination treatments (P > 0.17). Pre-caecal crude protein digestibility increased with decreasing temperature (T50: 58% crude protein; T60: 51% crude protein; T70: 50% crude protein). Therefore, lower temperatures for longer times preserve crude protein digestibility. These findings are crucial for understanding how drying temperature and time impact protein bioavailability.

Asunto(s)

Digestión , Larva , Tenebrio , Animales , Tenebrio/química , Tenebrio/metabolismo , Larva/crecimiento & desarrollo , Desecación , Alimentación Animal/análisis , Descontaminación/métodos , Proteínas en la Dieta/metabolismo , Proteínas en la Dieta/análisis , Proteínas de Insectos/metabolismo , Calor

RESUMEN

Agricultural mulching films are potential sources of microplastics (MPs) in soil. As an alternative to conventional non-degradable mulching films, a variety of different biodegradable mulching films are used. However, it is not yet known whether MPs from biodegradable mulching films pose a lower risk to terrestrial invertebrates compared to MPs from conventional mulching films. In this study, the effects of MPs produced from two conventional polyethylene (PE-1 and PE-2) and two biodegradable (starch-based poly(butylene adipate co-terephthalate); PBAT-BD-1, and PBAT-BD-2) fossil-based mulching films on terrestrial crustacean woodlice Porcellio scaber and mealworm Tenebrio molitor were compared. A key finding was that no clear differences in induced responses between biodegradable and conventional MPs were detected. No adverse effects on P. scaber after two weeks and on T. molitor after four weeks of exposure were observed up to 5 % (w/w dry soil) of either MP type. However, some sublethal physiological changes in metabolic rate and immune parameters were found in P. scaber after two weeks of exposure indicating a response of organisms to the presence of MP exposure in soil. In addition, it was demonstrated that both types of MPs might affect the soil water holding capacity and pH. In conclusion, we confirmed that biodegradable MPs can induce responses in organisms hence further studies testing the environmental hazard of biodegradable MPs are justified.

Asunto(s)

Microplásticos , Contaminantes del Suelo , Tenebrio , Animales , Biodegradación Ambiental , Polietileno , Poríferos/fisiología , Suelo/química

RESUMEN

This study investigated the anti-sarcopenic effect of fermented Tenebrio molitor larvae (mealworms) extract (FME) in both dexamethasone (DEX)-treated C2C12 cells and mice. FME (100 µg/mL) increased the diameter of myotubes and inhibited the gene and protein expression of atrogin-1 compared to DEX- or non-fermented mealworms extract (ME)-treated C2C12 cells. Male C57BL/6N mice were divided into five groups: Normal Control (NC), DEX (10 mg/kg, intraperitoneal), and three groups of DEX+FME (100, 200, or 500 mg FME/kg/day, oral) for two weeks. FME at doses of 200 and 500 mg/kg effectively improved grip strength when compared to the DEX group. Histological analysis of the quadriceps muscle showed a larger muscle fiber size in the DEX+FME groups compared to DEX group. FME (200 and 500 mg/kg) significantly increased cross-sectional area of the muscle fiber compared to DEX group. FME (500 mg/kg) significantly decreased the ubiquitin, atrogin-1 and MuRF-1 protein levels, and increased levels of MHC and MyoG in DEX-treated mice. The puromycin labeling assay revealed that FME increased protein synthesis in DEX-induced muscle atrophy. The FME treatment demonstrated significant upregulation in phosphorylation levels, including mTOR, FoxO3α, Akt, and PI3K compared to DEX group. In conclusion, FME inhibited the increase in proteins associated with muscle atrophy, including, atrogin-1 and MuRF-1, by regulating the PI3K-Akt-FoxO3α pathway. FME improved the PI3K-Akt-mTOR signaling pathway, which was reduced by DEX. This study suggests that FME has the potential for use in sarcopenia therapy, possibly serving as a natural agent that counteracts the negative effects of DEX on muscle tissue.

Asunto(s)

Dexametasona , Proteína Forkhead Box O3 , Larva , Atrofia Muscular , Transducción de Señal , Tenebrio , Animales , Masculino , Ratones , Línea Celular , Dexametasona/farmacología , Fermentación , Proteína Forkhead Box O3/metabolismo , Larva/efectos de los fármacos , Ratones Endogámicos C57BL , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/patología , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Atrofia Muscular/tratamiento farmacológico , Atrofia Muscular/patología , Atrofia Muscular/metabolismo , Atrofia Muscular/inducido químicamente , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Tenebrio/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo

RESUMEN

The application of novel insect proteins as future food resources in the food field has attracted more and more attention. In this study, a biodegradable antibacterial food packaging material with beneficial mechanical properties was developed using Tenebrio molitor larvae protein (TMP), chitosan (CS) and propolis ethanol extract (PEE) as raw materials. PEE was uniformly dispersed in the film matrix and the composite films showed excellent homogeneity and compatibility. There are strong intermolecular hydrogen bond interactions between CS, TMP, and PEE in the films, which exhibit the structure characteristics of amorphous materials. Compared with CS/TMP film, the addition of 3 % PEE significantly enhanced the elongation at break (34.23 %), water vapor barrier property (22.94 %), thermal stability (45.84 %), surface hydrophobicity (20.25 %), and biodegradability of the composite film. The composite film has strong antioxidant and antimicrobial properties, which were enhanced with the increase of PEE content. These biodegradable films offer an eco-friendly end-of-life option when buried in soil. Composite films can effectively delay the spoilage of strawberries and extend the shelf life of strawberries. Biodegradable active packaging film developed with insect protein and chitosan can be used as a substitute for petroleum-based packaging materials, and has broad application prospects in the field of fruits preservation.

Asunto(s)

Quitosano , Embalaje de Alimentos , Proteínas de Insectos , Larva , Própolis , Tenebrio , Quitosano/química , Quitosano/farmacología , Embalaje de Alimentos/métodos , Animales , Tenebrio/química , Própolis/química , Própolis/farmacología , Larva/efectos de los fármacos , Proteínas de Insectos/química , Antibacterianos/farmacología , Antibacterianos/química , Etanol/química , Antioxidantes/química , Antioxidantes/farmacología , Interacciones Hidrofóbicas e Hidrofílicas

RESUMEN

In this study, peptides designed using fragments of an antifreeze protein (AFP) from the freeze-tolerant insect Tenebrio molitor, TmAFP, were evaluated as inhibitors of clathrate hydrate formation. It was found that these peptides exhibit inhibitory effects by both direct and indirect mechanisms. The direct mechanism involves the displacement of methane molecules by hydrophobic methyl groups from threonine residues, preventing their diffusion to the hydrate surface. The indirect mechanism is characterized by the formation of cylindrical gas bubbles, the morphology of which reduces the pressure difference at the bubble interface, thereby slowing methane transport. The transfer of methane to the hydrate interface is primarily dominated by gas bubbles in the presence of antifreeze peptides. Spherical bubbles facilitate methane migration and potentially accelerate hydrate formation; conversely, the promotion of a cylindrical bubble morphology by two of the designed systems was found to mitigate this effect, leading to slower methane transport and reduced hydrate growth. These findings provide valuable guidance for the design of effective peptide-based inhibitors of natural-gas hydrate formation with potential applications in the energy and environmental sectors.

Asunto(s)

Proteínas Anticongelantes , Metano , Tenebrio , Agua , Proteínas Anticongelantes/química , Cinética , Metano/química , Metano/análogos & derivados , Agua/química , Tenebrio/química , Animales , Gases/química , Péptidos/química , Péptidos/farmacología

RESUMEN

The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil.

Asunto(s)

Antioxidantes , Desecación , Liofilización , Larva , Tenebrio , Animales , Larva/química , Tenebrio/química , Liofilización/métodos , Antioxidantes/química , Antioxidantes/análisis , Desecación/métodos , Polifenoles/análisis , Polifenoles/química , Aminoácidos/análisis , Aminoácidos/química

RESUMEN

Foods enriched with insects can potentially prevent several health disorders, including cardiovascular diseases, by reducing inflammation and improving antioxidant status. In this study, Tenebrio molitor and Gryllus assimilis were selected to determine the effect on the development of atherosclerosis in ApoE/LDLR-/- mice. Animals were fed AIN-93G-based diets (control) with 10% Tenebrio molitor (TM) and 10% Gryllus assimilis (GA) for 8 weeks. The nutritional value as well as antioxidant activity of selected insects were determined. The lipid profile, liver enzyme activity, and the fatty acid composition of liver and adipose tissue of model mice were evaluated. Quantitative analysis of atherosclerotic lesions in the entire aorta was performed using the en face method, and for aortic roots, the cross-section method was used. The antioxidant status of the GA cricket was significantly higher compared to the TM larvae. The results showed that the area of atherosclerosis (en face method) was not significantly different between groups. Dietary GA reduced plaque formation in the aortic root; additionally, significant differences were observed in sections at 200 and 300 µm compared to other groups. Furthermore, liver enzyme ALT activity was lower in insect-fed groups compared to the control group. The finding suggests that a diet containing edible insect GA potentially prevents atherosclerotic plaque development in the aortic root, due to its high antioxidant activity.

Asunto(s)

Apolipoproteínas E , Aterosclerosis , Receptores de LDL , Animales , Aterosclerosis/patología , Aterosclerosis/metabolismo , Ratones , Receptores de LDL/genética , Receptores de LDL/metabolismo , Apolipoproteínas E/deficiencia , Apolipoproteínas E/genética , Insectos Comestibles , Ratones Noqueados , Hígado/metabolismo , Hígado/patología , Antioxidantes/metabolismo , Masculino , Tenebrio , Dieta , Aorta/patología , Aorta/metabolismo , Modelos Animales de Enfermedad , Alimentación Animal , Placa Aterosclerótica/patología , Placa Aterosclerótica/metabolismo , Gryllidae

RESUMEN

Previous studies have shown that larvae of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae), need a source of moisture to grow and perform well. Currently, much research has been oriented towards the effect of dry feed on larval growth and performance. The effect of different wet feeds as moisture source on the performance traits of T. molitor larvae has not been thoroughly investigated yet. This study aims to investigate in laboratory trials the effect of various gelling agents (agar, carrageenans, guar gum, xanthan gum, sodium alginate, modified starch, and pectin) on the growth and performance of T. molitor larvae. A number of 50 newly emerged larvae obtained from the rearings of the LEAZ were inserted in plastic vials together with 4 g of wheat bran as dry feed. Additionally, 1 g of gelling agents was provided 3 times per week as moisture sources. Carrot slices served as control. Larval survival and weight were recorded weekly until the appearance of the first pupa. Dry feed was replenished when depleted. Our data showed that gelling agents efficiently supported the growth of T. molitor larvae, in terms of larval survival and weight, as well as feed utilization expressed as FCR. Interestingly, carrageenans seem to be the most appropriate gelling agent for T. molitor larvae rearing as it can enhance their weight and is also able to reduce their development time and their specific growth rate.

Asunto(s)

Daucus carota , Larva , Tenebrio , Animales , Larva/crecimiento & desarrollo , Tenebrio/crecimiento & desarrollo , Daucus carota/crecimiento & desarrollo , Daucus carota/química , Alimentación Animal , Gomas de Plantas/química , Geles , Carragenina/química , Galactanos/química , Mananos , Polisacáridos Bacterianos/química , Alginatos/química , Agar/química

RESUMEN

As the most numerous group of animals on Earth, insects are found in almost every ecosystem. Their useful role in the environment is priceless; however, for humans, their presence may be considered negative or even harmful. For years, people have been trying to control the number of pests by using synthetic insecticides, which eventually causes an increased level of resistance to applied compounds. The effects of synthetic insecticides have encouraged researchers to search for alternatives and thus develop safe compounds with high specificity. Using knowledge about the physiology of insects and the functionality of compounds of insect origin, a new class of bioinsecticides called peptidomimetics, which are appropriately modified insect analogues, was created. One promising compound that might be successfully modified is the thirteen amino acid peptide alloferon (HGVSGHGQHGVHG), which is obtained from the hemolymph of the blue blowfly Calliphora vicinia. Our research aimed to understand the physiological properties of alloferon and the activity of its peptidomimetics, which will provide the possibility of using alloferon or its analogues in the pharmaceutical industry, as a drug or adjuvant, or in agriculture as a bioinsecticide. We used alloferon and its three peptidomimetics, which are conjugates of the native peptide with three unsaturated fatty acids with various chain lengths: caprylic, myristic, and palmitic. We tested their effects on the morphology and activity of the reproductive system and the embryogenesis of the Tenebrio molitor beetle. We found that the tested compounds influenced the growth and maturation of ovaries and the expression level of the vitellogenin gene. The tested compounds also influenced the process of egg laying, embryogenesis, and offspring hatching, showing that alloferon might be a good peptide for the synthesis of effective bioinsecticides or biopharmaceuticals.

Asunto(s)

Reproducción , Tenebrio , Animales , Tenebrio/efectos de los fármacos , Reproducción/efectos de los fármacos , Femenino , Insecticidas/farmacología , Insecticidas/química , Masculino , Peptidomiméticos/farmacología , Peptidomiméticos/química , Hemolinfa/metabolismo , Hemolinfa/efectos de los fármacos , Péptidos/farmacología , Péptidos/química , Larva/efectos de los fármacos

RESUMEN

Cryptococcus gattii, an environmental fungus, is one of the agents of cryptococcosis. The influence of agrochemicals on fungal resistance to antifungals is widely discussed. However, the effects of benomyl (BEN) on fungal interaction with different hosts is still to be understood. Here we studied the influence of adaptation to BEN in the interaction with a plant model, phagocytes and with Tenebrio molitor. First, the strain C. gattii L24/01 non-adapted (NA), adapted (A) to BEN, and adapted with further culture on drug-free media (10p) interact with Nicotiana benthamiana, with a peak in the yeast burden on the 7th day post-inoculation. C. gattii L24/01 A and 10p provided lower fungal burden, but these strains increased cell diameter and capsular thickness after the interaction, together with decreased fungal growth. The strains NA and A showed reduced ergosterol levels, while 10p exhibited increased activity of laccase and urease. L24/01 A recovered from N. benthamiana was less engulfed by murine macrophages, with lower production of reactive oxygen species. This phenotype was accompanied by increased ability of this strain to grow inside macrophages. Otherwise, L24/01 A showed reduced virulence in the T. molitor larvae model. Here, we demonstrate that the exposure to BEN, and interaction with plants interfere in the morphophysiology and virulence of the C. gattii.

Asunto(s)

Cryptococcus gattii , Nicotiana , Cryptococcus gattii/efectos de los fármacos , Cryptococcus gattii/crecimiento & desarrollo , Cryptococcus gattii/metabolismo , Cryptococcus gattii/fisiología , Animales , Ratones , Nicotiana/microbiología , Macrófagos/microbiología , Criptococosis/microbiología , Tenebrio/microbiología , Agroquímicos/farmacología , Antifúngicos/farmacología , Enfermedades de las Plantas/microbiología

RESUMEN

Historically, males have frequently been portrayed as the manipulative and deceptive gender, while females are often seen as adopting a coy and passive role. In this context, it is proposed that males use a terminal investment strategy, misleading females about their true poor condition, while females passively opt to mate with these deceptive males. However, we hypothesize that females in suboptimal condition may also engage in a terminal investment strategy by mimicking or enhancing their attractiveness to match that of females in better conditions. We studied this hypothesis in Tenebrio molitor, by subjecting females to three varying doses of lipopolysaccharides of Escherichia coli (LPS; 0.25, 0.5, or 1 mg ml-1), or three doses of the pro-oxidant Paraquat (PQ; 20, 40 or 80 mM), and subsequently assessing their survival and attractiveness to males. The LPS treatments and 20 mM of PQ had no significant effect on the survival or attractiveness of the females. However, females treated with 40 or 80 mM PQ survived fewer days compared to the control group. Those injected with 40 mM were more attractive than their control counterparts, while those treated with 80 mM were less attractive. Since the identical doses of LPS, which induce terminal investment in males, had no effect on females, we suggest sexual dimorphism in terminal investment. Furthermore, similar to males, if the stressor reaches a sufficiently high level, the signal becomes honest. These findings highlight how the quantity of stressors influences support for the terminal investment strategy in both males and females. Notably, this study challenges prevailing notions regarding gender roles in sexual selection, indicating that females, not just males, conceal their poor condition to attract mating partners.

Asunto(s)

Lipopolisacáridos , Conducta Sexual Animal , Femenino , Masculino , Animales , Conducta Sexual Animal/efectos de los fármacos , Conducta Sexual Animal/fisiología , Lipopolisacáridos/farmacología , Tenebrio/fisiología , Tenebrio/efectos de los fármacos , Paraquat/farmacología

RESUMEN

A bacterial strain designated PU5-4T was isolated from the mealworm (the larvae of Tenebrio molitor) intestines. It was identified to be Gram-stain-negative, strictly aerobic, rod-shaped, non-motile, and non-spore-forming. Strain PU5-4T was observed to grow at 10-40 °C, at pH 7.0-10.0, and in the presence of 0-3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PU5-4T should be assigned to the genus Sphingobacterium. The 16S rRNA gene sequence similarity analysis showed that strain PU5-4T was closely related to the type strains of Sphingobacterium lactis DSM 22361T (98.49 %), Sphingobacterium endophyticum NYYP31T (98.11 %), Sphingobacterium soli NCCP 698T (97.69 %) and Sphingobacterium olei HAL-9T (95.73 %). The predominant isoprenoid quinone is MK-7. The major fatty acids were identified as iso-C15 : 0, iso-C17 : 03-OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 0 ω9c). The polar lipids are phosphatidylethanolamine, one unidentified phospholipid, and six unidentified lipids. The genomic DNA G+C content of strain PU5-4T is 40.24 mol%. The average nucleotide identity of strain PU5-4T exhibited respective values of 73.88, 73.37, 73.36 and 70.84 % comparing to the type strains of S. lactis DSM 22361T, S. soli NCCP 698T, S. endophyticum NYYP31T and S. olei HAL-9T, which are below the cut-off level (95-96 %) for species delineation. Based on the above results, strain PU5-4T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium temoinsis sp. nov. is proposed. The type strain is PU5-4T (=CGMCC 1.61908T=JCM 36663T).

Asunto(s)

Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Intestinos , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Sphingobacterium , Tenebrio , Vitamina K 2 , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , ADN Bacteriano/genética , Sphingobacterium/genética , Sphingobacterium/aislamiento & purificación , Sphingobacterium/clasificación , Animales , Intestinos/microbiología , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis , Tenebrio/microbiología , Fosfatidiletanolaminas , Larva/microbiología , Fosfolípidos/análisis

RESUMEN

Solanine (SOL) and chaconine (CHA) are glycoalkaloids (GAs) produced mainly by Solanum plants. These plant secondary metabolites affect insect metabolism; thus, they have the potential to be applied as natural plant protection products. However, it is not known which GA concentration induces physiological changes in animals. Therefore, the aim of this study was to perform a quantitative analysis of SOL and CHA in the larvae of Tenebrio molitor using LC‒MS to assess how quickly they are eliminated or metabolised. In this experiment, the beetles were injected with 2 µL of 10-5 M SOL or CHA solution, which corresponds to a dosage range of 0.12-0.14 ng/mg body mass. Then, 0.5, 1.5, 8, and 24 h after GA application, the haemolymph (H), gut (G), and the remainder of the larval body (FB) were isolated. GAs were detected in all samples tested for 24 h, with the highest percentage of the amount applied in the FB, while the highest concentration was measured in the H sample. The SOL and CHA concentrations decreased in the haemolymph over time, while they did not change in other tissues. CHA had the highest elimination rate immediately after injection, while SOL slightly later. None of the GA hydrolysis products were detected in the tested samples. One possible mechanism of the detoxification of GAs may be oxidation and/or sequestration. They may be excreted by Malpighian tubules, with faeces or with cuticles during moulting. The results presented are significant because they facilitate the interpretation of studies related to the effects of toxic substances on insect metabolism.

Asunto(s)

Hemolinfa , Larva , Tenebrio , Animales , Tenebrio/metabolismo , Larva/metabolismo , Hemolinfa/metabolismo , Hemolinfa/química , Alcaloides/metabolismo , Alcaloides/análisis , Cromatografía Liquida