Search results for "TIMI"
showing 10 items of 4651 documents
Daphnia invest in sexual reproduction when its relative costs are reduced
2018
The timing of sex in facultatively sexual organisms is critical to fitness, due to the differing demographic consequences of sexual versus asexual reproduction. In addition to the costs of sex itself, an association of sex with the production of dormant life stages also influences the optimal use of sex, especially in environments where resting eggs are essential to survive unfavourable conditions. Here we document population dynamics and the occurrence of sexual reproduction in natural populations of Daphnia magna across their growing season. The frequency of sexually reproducing females and males increased with population density and with decreasing asexual clutch sizes. The frequency of…
Direct and correlated responses to bi-directional selection on pre-adult development time in Drosophila montana.
2019
Selection experiments offer an efficient way to study the evolvability of traits that play an important role in insects’ reproduction and/or survival and to trace correlations and trade-offs between them. We have exercised bi-directional selection on Drosophila montana flies’ pre-adult development time under constant light and temperature conditions for 10 generations and traced the indirect effects of this selection on females’ diapause induction under different day lengths, as well as on the body weight and cold tolerance of both sexes. Overall, selection was successful towards slow, but not towards fast development. However, all fast selection line replicates showed at the end of selecti…
Blattella germanica displays a large arsenal of antimicrobial peptide genes
2020
Defence systems against microbial pathogens are present in most living beings. The German cockroach Blattella germanica requires these systems to adapt to unhealthy environments with abundance of pathogenic microbes, in addition to potentially control its symbiotic systems. To handle this situation, four antimicrobial gene families (defensins, termicins, drosomycins and attacins) were expanded in its genome. Remarkably, a new gene family (blattellicins) emerged recently after duplication and fast evolution of an attacin gene, which is now encoding larger proteins with the presence of a long stretch of glutamines and glutamic acids. Phylogenetic reconstruction, within Blattellinae, suggests …
Proteomic insights into the immune response of the Colorado potato beetle larvae challenged with Bacillus thuringiensis.
2019
Bacillus thuringiensis (Bt) toxins constitute effective, environmentally safe biopesticides. Nevertheless, insects' tolerance to Bt is influenced by environmental factors affecting immunity. To understand larval immune response in the devastating coleopteran insect pest Colorado potato beetle (CPB), we undertook a proteomic analysis of hemolymph of non-treated control larvae and larvae consuming non-lethal doses of spore-crystal mixtures containing the coleopteran-active Cry3Aa toxin. Results revealed lower amount of proteins involved in insect growth and higher amount of immune response-related proteins in challenged insects, sustaining the larval weight loss observed. Additionally, we fou…
Chromatographic profiles and antimicrobial activity of the essential oils obtained from some species and cultivars of the Mentheae tribe (Lamiaceae)
2021
Abstract The present study was focused on the chemical composition and antimicrobial activity of the essential oils (EsO) obtained from five Lamiaceae representatives grown in the south of Ukraine. Among them are Salvia sclarea L., Monarda didyma (cultivar ‘Cambridge Scarlet’), Thymus pulegioides (cultivar ‘2/6-07’), Thymus vulgaris (cultivar ‘Jalos’), and Thymus serpyllum L. The component analysis of the EsO was carried out by gas chromatography method coupled with mass spectrometry (GC–MS). The antimicrobial properties of the EsO were determined using the agar diffusion test against widespread pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, St…
In vitro antifungal activity of bioactive peptides produced by Lactobacillus plantarum against Aspergillus parasiticus and Penicillium expansum
2017
Abstract Food spoilage caused by mycotoxigenic moulds represents an important problem in food security. The antimicrobial peptides are compounds of natural origin constituted by a variable number (5–100) of amino acids held together through peptide bonds. In this work, the cell free supernatants (CFSs) containing peptides obtained from four strains of LAB were lyophilized, filtered and tested to determine the antifungal activity against Aspergillus Parasiticus and Penicillium expansum . CFS obtained by Lactobacillus plantarum showed the highest inhibition activity. CFS was fractionated by size exclusion chromatography and injected into the liquid chromatography coupled to diode array detect…
Gaseous allyl isothiocyanate to inhibit the production of aflatoxins, beauvericin and enniatins by Aspergillus parasiticus and Fusarium poae in wheat…
2016
Abstract There is a growing concern about the presence of mycotoxins in foods, since up to 25% of cereals and cereal foods are contaminated with these compounds. Moreover, the general public is against the use of synthetic preservatives in foods and the use of natural antimicrobials in foods is a current trend. Allyl isothiocyanate (AITC) is a volatile antimicrobial derived from oriental and black mustard. The objective of this work was to evaluate the capacity of gaseous AITC in inhibiting the production of mycotoxins by Aspergillus parasiticus (aflatoxin producer) and Fusarium poae (beauvercin and enniatin producer) in wheat flour. Petri dish lids filled with 2 g of wheat flour were inocu…
Shelf life extension of mozzarella cheese contaminated with Penicillium spp. using the antifungal compound ɛ-polylysine.
2019
Molds are one of the most important spoilage organisms on cheese which can lead to economic loss as well as raising public health concerns due to the production of mycotoxins. This study investigates the use of ɛ-polylysine as natural antimicrobial to inhibit fungal growth. The minimal inhibitory concentrations and minimal fungicidal concentrations of ɛ-polylysine were determined against Penicillium roqueforti, Penicillium nordicum, and Penicillium solitum. Then, polylysine was tested as surface antimicrobial for the preservation of mozzarella slice cheese inoculated with these Penicillium spp. and stored in plastic trays during 25 days. The minimal inhibitory concentrations calculated for…
Immunity and other defenses in pea aphids, Acyrthosiphon pisum
2010
Background Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically distantly related to previously ch…
Micro and nano-encapsulation of vegetable and essential oils to develop functional food products with improved nutritional profiles
2020
Abstract Background A growing awareness regarding the benefits of consumption of functional foods has resulted in the development of new food products through using bioactive compounds. Vegetable-essential oils (V-EOs) are among the most popular ingredients used for the enrichment of different food products to boost their functional properties. However, these oils are sensitive to harsh conditions such as oxidation stress and high temperatures. Recently, different micro/nanoencapsulation systems have been applied to produce suitable carriers for V-EOs to be incorporated into food formulations, which can overcome the limitation of their pure application in foods. Scope and approach Controlle…