Use of organic materials to obtain valuable products through bioconversion

Bioconversion is a biological process by which organic materials are converted in products with higher biological and commercial value. During its larval stage, the Black Soldier Fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is extremely voracious and able to feed on a wide range of organic materials, ranging from fruits and vegetables to animal manure. This ethological characteristic is particularly interesting for an innovative waste management treatment. The bioconversion process is highly efficient, as the organic substance the larva feeds on is reduced up to 65%-70% and converted into larval biomass. At the end of bioconversion of the waste, the larvae are suitable for pet food as they are rich in proteins and lipids. High energy content meal, deriving from appropriately dried and ground larvae can also be used as feed for select species by the aquaculture industry, according to recent European regulation. Resulting larval frass can be used as soil conditioner for crop fertilization. Furthermore, chitin and its derivative, chitosan, are relevant for medical, pharmaceutical, agricultural fields. In order to study the effect of different substrates from the agri-food chain on several parameters such as insect growth, final larval yield, protein and lipid content, substrate reduction and bioconversion values by the BSF, 10000 larvae were reared on 7,0 kg of six substrates (watermelon, kiwi, a mix of cabbage/savoy cabbage, strawberry, tangerine, orange) and on a standard diet, used as control. The results highlight that BSF is able to successfully feed on all the tested diets, although development time, growth rate, final larval biomass and larval components (ashes, proteins and lipids) impacted by different substrates. Although the standard diet is considered balanced in all nutrients and the best diet for BSF development, strawberries turned out to be more suitable substrate, among the analysed substrates, that are by-products from the agri-food chain. Although larvae fed on a mix of cabbage/savoy cabbage achieve the worst growth and bioconversion performances, BSF consumed this substrate, still accumulating high protein content, and confirming the BSF extraordinary ability to feed and reduce different kinds of substrates. Preliminary research was carried out also on zootechnical wastes (dairy mature and fresh manure). BSF is able to correctly feed also on manure, favouring their disposal and total recovery. This research project shows that waste management through the BSF bioconversion processes can represent a new economically important resource for companies belonging to agri-food and zootechnical fields and opens new perspectives for a sustainable and environmentally friendly industrial development in which by-products and wastes from these industries could be disposed and enhanced in this unconventional way

Chemical Methods for Microbiological Control of Winemaking: An Overview of Current and Future Applications

Preservation technologies for winemaking have relied mainly on the addition of sulfur dioxide (SO2), in consequence of the large spectrum of action of this compound, linked to the control of undesirable microorganisms and the prevention of oxidative phenomena. However, its potential negative effects on consumer health have addressed the interest of the international research on alternative treatments to substitute or minimize the SO2 content in grape must and wine. This review is aimed at analyzing chemical methods, both traditional and innovative, useful for the microbiological stabilization of wine. After a preliminary description of the antimicrobial and technological properties of SO2, the additive traditionally used during wine production, the effects of the addition (in must and wine) of other compounds officially permitted in winemaking, such as sorbic acid, dimethyl dicarbonate (DMDC), lysozyme and chitosan, are discussed and evaluated. Furthermore, other substances showing antimicrobial properties, for which the use for wine microbiological stabilization is not yet permitted in EU, are investigated. Even if these treatments exhibit a good efficacy, a single compound able to completely replace SO2 is not currently available, but a combination of different procedures might be useful to reduce the sulfite content in wine. Among the strategies proposed, particular interest is directed towards the use of insect-based chitosan as a reliable alternative to SO2, mainly due to its low environmental impact. The production of wines containing low sulfite levels by using pro-environmental practices can meet both the consumers’ expectations, who are even more interested in the healthy traits of foods, and wine-producers’ needs, who are interested in the use of sustainable practices to promote the profile of their brand

Role of Ovarian Proteins Secreted by Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) in the Early Suppression of Host Immune Response

Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) is an endophagous parasitoid of the larval stages of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). During oviposition, T. nigriceps injects into the host body, along with the egg, the venom, the calyx fluid, which contains a Polydnavirus (T. nigriceps BracoVirus: TnBV), and the Ovarian Proteins (OPs). Although viral gene expression in the host reaches detectable levels after a few hours, a precocious disruption of the host metabolism and immune system is observed right after parasitization. This alteration appears to be induced by female secretions including TnBV venom and OPs. OPs, originating from the ovarian calyx cells, are involved in the induction of precocious symptoms in the host immune system alteration. It is known that OPs in braconid and ichneumonid wasps can interfere with the cellular immune response before Polydnavirus infects and expresses its genes in the host tissues. Here we show that T. nigriceps OPs induce several alterations on host haemocytes that trigger cell death. The OP injection induces an extensive oxidative stress and a disorganization of actin cytoskeleton and these alterations can explain the high-level of haemocyte mortality, the loss of haemocyte functionality, and so the reduction in encapsulation ability by the host

Hermetia illucens (L.) (Diptera: Stratiomyidae) Odorant Binding Proteins and Their Interactions with Selected Volatile Organic Compounds: An In Silico Approach

The black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae), has considerable global interest due to its outstanding capacity in bioconverting organic waste to insect biomass, which can be used for livestock, poultry, and aquaculture feed. Mass production of this insect in colonies requires the development of methods concentrating oviposition in specific collection devices, while the mass production of larvae and disposing of waste may require substrates that are more palatable and more attractive to the insects. In insects, chemoreception plays an essential role throughout their life cycle, responding to an array of chemical, biological and environmental signals to locate and select food, mates, oviposition sites and avoid predators. To interpret these signals, insects use an arsenal of molecular components, including small proteins called odorant binding proteins (OBPs). Next generation sequencing was used to identify genes involved in chemoreception during the larval and adult stage of BSF, with particular attention to OBPs. The analysis of the de novo adult and larval transcriptome led to the identification of 27 and 31 OBPs for adults and larvae, respectively. Among these OBPs, 15 were common in larval and adult transcriptomes and the tertiary structures of 8 selected OBPs were modelled. In silico docking of ligands confirms the potential interaction with VOCs of interest. Starting from the information about the growth performance of H. illucens on different organic substrates from the agri-food sector, the present work demonstrates a possible correlation between a pool of selected VOCs, emitted by those substrates that are attractive for H. illucens females when searching for oviposition sites, as well as phagostimulants for larvae. The binding affinities between OBPs and selected ligands calculated by in silico modelling may indicate a correlation among OBPs, VOCs and behavioural preferences that will be the basis for further analysis

Solanum nigrum extract and solasonine affected hemolymph metabolites and ultrastructure of the fat body and the midgut in Galleria mellonella

Glycoalkaloids, secondary metabolites abundant in plants belonging to the Solanaceae family, may affect the physiology of insect pests. This paper presents original results dealing with the influence of a crude extract obtained from Solanum nigrum unripe berries and its main constituent solasonine on the physiology of Galleria mellonella (Lepidoptera). Both extract and solasonine applied in the nourishment changed the level of hemolymph metabolites such as sugars, polyols and proline, and ultrastructure of the fat body and the midgut cells. The extract and solasonine, tested in the same concentration found in the extract, decreased the proline level, while mannitol was under the limit of detection in the hemolymph. The extract increased the erythritol level in the hemolymph compared to control, enlarged the intracellular space in fat body cells, decreased cytoplasm and lipid droplets electron density. In the midgut, vacuolized areas of cytoplasm ap-peared with vast reticulum systems. Solasonine, tested with three concentrations, caused the decrease of cytoplasm electron density in both fat body and midgut cells. Obtained results high-lighted the disturbance of the midgut and the fat body due to glycoalkaloids and the potential role of hemolymph ingredients in its detoxification

Antimicrobial Peptides: A New Hope in Biomedical and Pharmaceutical Fields

Antibiotics are essential drugs used to treat pathogenic bacteria, but their prolonged use contributes to the development and spread of drug-resistant microorganisms. Antibiotic resistance is a serious challenge and has led to the need for new alternative molecules less prone to bacterial resistance. Antimicrobial peptides (AMPs) have aroused great interest as potential next-generation antibiotics, since they are bioactive small proteins, naturally produced by all living organisms, and representing the first line of defense against fungi, viruses and bacteria. AMPs are commonly classified according to their sources, which are represented by microorganisms, plants and animals, as well as to their secondary structure, their biosynthesis and their mechanism of action. They find application in different fields such as agriculture, food industry and medicine, on which we focused our attention in this review. Particularly, we examined AMP potential applicability in wound healing, skin infections and metabolic syndrome, considering their ability to act as potential Angiotensin-Converting Enzyme I and pancreatic lipase inhibitory peptides as well as antioxidant peptides. Moreover, we argued about the pharmacokinetic and pharmacodynamic approaches to develop new antibiotics, the drug development strategies and the formulation approaches which need to be taken into account in developing clinically suitable AMP applications

An integrated transcriptomic and proteomic approach to identify the main Torymus sinensis venom components

During oviposition, ectoparasitoid wasps not only inject their eggs but also a complex mixture of proteins and peptides (venom) in order to regulate the host physiology to benefit their progeny. Although several endoparasitoid venom proteins have been identified, little is known about the components of ectoparasitoid venom. To characterize the protein composition of Torymus sinensis Kamijo (Hymenoptera: Torymidae) venom, we used an integrated transcriptomic and proteomic approach and identified 143 venom proteins. Moreover, focusing on venom gland transcriptome, we selected additional 52 transcripts encoding putative venom proteins. As in other parasitoid venoms, hydrolases, including proteases, phosphatases, esterases, and nucleases, constitute the most abundant families in T. sinensis venom, followed by protease inhibitors. These proteins are potentially involved in the complex parasitic syndrome, with different effects on the immune system, physiological processes and development of the host, and contribute to provide nutrients to the parasitoid progeny. Although additional in vivo studies are needed, initial findings offer important information about venom factors and their putative host effects, which are essential to ensure the success of parasitism

Morphological characterization of the antenna of Torymus sinensis (Hymenoptera: Torymidae) and a comparison within the superfamily Chalcidoidea

The parasitoid Torymus sinensis (Hymenoptera: Torymidae) has been successfully used in Italy since 2005 for biological control of the invasive cynipid Dryocosmus kuriphilus (Hymenoptera: Cynipidae), highly destructive for the economically relevant Castanea sativa (Fagales: Fagaceae). In order to investigate the morphological aspects related to sensorial behavior, a fine morphology study of the antennae and their sensilla was conducted by scanning electron microscopy on both sexes of T. sinensis. The antennae, composed of a scape, a pedicel and a flagellum with ten flagellomeres, had chaetic sensilla of six sub types, placoid sensilla of three subtypes, trichoid sensilla, sensilla with a roundish grooved tip, and coeloconic sensilla. The chaetic sensilla of the first three subtypes were found in the scape and in the pedicel, and those of the last three subtypes, together with trichoid, roundish grooved tip and coeloconic sensilla, were found only on flagellomeres. Sexual dimorphism was detected in the morphology of the proper pedicel and the flagellum, and in the presence and distribution of the sensilla and their subtypes. The morphological aspects of the antenna of T. sinensis and of its sensilla were compared with those found in the family Torymidae and in other families of the extremely diverse superfamily Chalcidoide

CGRP Antagonism and Ketogenic Diet in the Treatment of Migraine

The study of migraine is based on the complexity of the pathology, both at the pathophysiological and epidemiological levels. Although it affects more than a billion people worldwide, it is often underestimated and underreported by patients. Migraine must not be confused with a simple headache; it is a serious and disabling disease that causes considerable limitations in the daily life of afflicted people, including social, work, and emotional effects. Therefore, it causes a daily state of suffering and discomfort. It is important to point out that this pathology not only has a decisive impact on the quality of life of those who suffer from it but also on their families and, more generally, on society as a whole. The clinical picture of migraine is complex, with debilitating unilateral or bilateral head pain, and is often associated with characteristic symptoms such as nausea, vomiting, photophobia, and phonophobia. Hormonal, environmental, psychological, dietary, or other factors can trigger it. The present review focuses on the analysis of the physiopathological and pharmacological aspects of migraine, up to the correct dietary approach, with specific nutritional interventions aimed at modulating the symptoms. Based on the symptoms that the patient experiences, targeted and specific therapy is chosen to reduce the frequency and severity of migraine attacks. Specifically, the role of calcitonin gene-related peptide (CGRP) in the pathogenesis of migraine is analyzed, along with the drugs that effectively target the corresponding receptor. Particularly, CGRP receptor antagonists (gepants) are very effective drugs in the treatment of migraine, given their high diffusion in the brain. Moreover, following a ketogenic diet for only one or two months has been demonstrated to reduce migraine attacks. In this review, we highlight the diverse facets of migraine, from its physiopathological and pharmacological aspects to prevention and therapy