| 1. |
- Aleknavičius, D., et al.
(författare)
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Can crickets recognise bacterially contaminated feed? Gryllus assimilis odour perception of Escherichia coli
- 2023
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Ingår i: Journal of Insects as Food and Feed. - 2352-4588. ; 9:7, s. 947-954
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Tidskriftsartikel (refereegranskat)abstract
- Edible crickets Acheta domesticus and Gryllus assimilis are worldwide mass-reared insects. They are recognised as a sustainable source of protein in the food and feed industries and, in relation to this, must comply with food safety requirements. In this study, we assessed the self-protective ability of crickets to recognise potentially hazardous bacteria-contaminated feed. A two-choice test was carried out to estimate the crickets’ preference between the bacteria-contaminated and control feed. Three bacterial species were tested as potential contaminants: Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. A. domesticus did not recognise feed contaminated with any of the bacterial species tested. G. assimilis avoided E. coli-contaminated feed, while the other two bacteria did not cause differences in feeding behaviour. The study of gas chromatography-electroantennogram detection showed that E. coli released a volatile compound, which was olfactory perceived by both males and females of G. assimilis. The compound was identified as indole. In a behavioural test, crickets spent less time feeding on indole-contaminated feed compared to control feed. Hence, indole induced an avoidance response in G. assimilis. It can be concluded that G. assimilis perceives and recognises some bacteria contaminants and thereby avoids spoiled feed.
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| 2. |
- Church, Tamara L., et al.
(författare)
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Functional Wood-Foam Composites for Controlled Uptake and Release
- 2021
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:46, s. 15571-15581
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Tidskriftsartikel (refereegranskat)abstract
- Wood-foam hierarchical composites were produced via the shear-forced infiltration of shear-thinning nanocellulose-based foams or gels into the tracheids of Picea abies. Shear processing viscoelastic and shear-thinning aqueous foams composed of cellulose nanocrystals, methylcellulose, and tannic acid (total solids content: 2 wt %) resulted in foam-filled wood composites containing 15-20 wt % foam, with open foam structures and compression strengths similar to those of unmodified P. abies. An amino-functionalized nanocellulose-containing foam confined in wood reversibly adsorbed CO2, retaining 15% of its theoretical uptake capacity over 50 cycles in the thermogravimetric analyzer, and a citronellol-loaded foam released this mosquito-repellent compound over four days, as evaluated using solid-phase microextraction. Shear-forced infiltration of functional foams into wood is an operationally simple route to hierarchically porous composites based on renewable materials.
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| 3. |
- Enge, Swantje, et al.
(författare)
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A supergene in seaweed flies modulates male traits and female perception
- 2023
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Ingår i: Proceedings of the Royal Society B: Biological Sciences. - 0962-8452 .- 1471-2954. ; 290:2008
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Tidskriftsartikel (refereegranskat)abstract
- Supergenes, tightly linked sets of alleles, offer some of the most spectacular examples of polymorphism persisting under long-term balancing selection. However, we still do not understand their evolution and persistence, especially in the face of accumulation of deleterious elements. Here, we show that an overdominant supergene in seaweed flies, Coelopa frigida, modulates male traits, potentially facilitating disassortative mating and promoting intraspecific polymorphism. Across two continents, the Cf-Inv(1) supergene strongly affected the composition of male cuticular hydrocarbons (CHCs) but only weakly affected CHC composition in females. Using gas chromatography-electroantennographic detection, we show that females can sense male CHCs and that there may be differential perception between genotypes. Combining our phenotypic results with RNA-seq data, we show that candidate genes for CHC biosynthesis primarily show differential expression for Cf-Inv(1) in males but not females. Conversely, candidate genes for odorant detection were differentially expressed in both sexes but showed high levels of divergence between supergene haplotypes. We suggest that the reduced recombination between supergene haplotypes may have led to rapid divergence in mate preferences as well as increasing linkage between male traits, and overdominant loci. Together this probably helped to maintain the polymorphism despite deleterious effects in homozygotes.
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| 4. |
- Iqbal, Sajid, et al.
(författare)
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Essential oils of four wild plants inhibit the blood seeking behaviour of female Aedes aegytpi
- 2023
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Ingår i: Experimental parasitology. - : Elsevier BV. - 0014-4894 .- 1090-2449. ; 244
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Tidskriftsartikel (refereegranskat)abstract
- Aedes aegypti (Diptera: Culicidae) mosquito is an important vector of many disease-causing pathogens. An effective way to escape from these mosquito-borne diseases is to prevent mosquito bites. In the current study, essential oils of Lepidium pinnatifidum, Mentha longifolia, Origanum vulgare, and Agrimonia eupatoria were evaluated for their repellent potential against Ae. aegypti females. Essential oils were extracted using steam distillation from freshly collected aerial parts of the plants and tested against 4–5 day old females of Ae. aegypti through the human bait technique for repellency and repellent longevity assays. The chemical composition of extracted essential oils was explored by gas chromatography coupled with mass spectrometry (GC-MS). The essential oils of L. pinnatifidum, M. longifolia, O. vulgare, and A. eupatoria at a dose of 33 μg/cm2 showed 100%, 94%, 87%, and 83% mosquito repellent activity, respectively. Furthermore, M. longifolia and O. vulgare essential oils exhibited 100% repellency at a dose of 165 μg/cm2, whereas A. eupatoria essential oil showed 100% repellency only at 330 μg/cm2. In the time-span bioassay, M. longifolia and O. vulgare essential oils showed protection against Ae. aegypti bites for 90 and 75 min, respectively whereas both A. eupatoria and L. pinnatifidum were found active for 45 min. Phenylacetonitrile (94%), piperitone oxide (34%), carvacrol (20%) and α-pinene (62%) were the most abundant compounds in L. pinnatifidum, M. longifolia, O. vulgare and A. eupatoria essential oils, respectively. The current study demonstrates that M. longifolia and O. vulgare essential oils possess the potential to be used as an alternative to synthetic chemicals to protect humans from mosquito bites.
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| 5. |
- Kumar, Sunjeet, et al.
(författare)
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Chemical Composition of Fresh Leaves Headspace Aroma and Essential Oils of Four Coriander Cultivars
- 2022
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Aroma is one of the key food characteristics determining consumers' perception and acceptability of products. Coriandrum sativum L. is an aromatic herb commonly used as a food additive and taste enhancer. Besides the culinary applications, coriander is also used in traditional medicine, cosmetics, and the food industry. In this study, we aimed to determine aroma composition of fresh chopped leaves and essential oils extracted from the leaves of four coriander cultivars. The essential oils were extracted from the fresh leaves using steam distillation and volatile aroma components were collected from the headspace by solid phase micro extraction technique. Analyses were carried out by gas chromatography-mass spectrometry. Free radical scavenging activity of essential oils was determined by using 2,2-diphenyl-1-picrylhydrazyl assay. The essential oils were also investigated for their anti-microbial potential. The aroma of freshly chopped coriander leaves was characterized by thirteen compounds, including six aldehydes, four alcohols, one ester and one hydrocarbon. The essential oils were comprised of twenty-seven compounds, where (E)-2-decenal, decanal, (E)-2-dodecenal and (E)-2-tetradecenal were the main components in all cultivars. Free radical scavenging activity of the essential oil samples was in the range of 6-15%. The essential oils of Desi and Hybrid cultivars exhibited least minimum inhibitory concentration (MIC) against all tested bacterial strains. Fresh green leaves of the Desi and Peshawari cultivars were found to be the richest in six carbon chain length alcohols and acetates, which are important constituents of the aroma giving a characteristic odor referred to as the "green note." The Hybrid cultivar showed the highest free radical scavenging activity, bearing the highest amount of antioxidants. The study revealed that the fresh leaves HS aroma of Desi and Hybrid cultivars were different, however, their essential oils possessed almost similar chemistry and anti-bacterial activity.
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| 6. |
- Rafiei, Vahideh, et al.
(författare)
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A Verticillium longisporum pleiotropic drug transporter determines tolerance to the plant host β-pinene monoterpene
- 2022
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Ingår i: Molecular plant pathology. - : Wiley. - 1464-6722 .- 1364-3703. ; 23:2, s. 291-303
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Tidskriftsartikel (refereegranskat)abstract
- Terpenes constitute a major part of secondary metabolites secreted by plants in the rhizosphere. However, their specific functions in fungal–plant interactions have not been investigated thoroughly. In this study we investigated the role of monoterpenes in interactions between oilseed rape (Brassica napus) and the soilborne pathogen Verticillium longisporum. We identified seven monoterpenes produced by B. napus, and production of α-pinene, β-pinene, 3-carene, and camphene was significantly increased upon fungal infection. Among them, β-pinene was chosen for further analysis. Transcriptome analysis of V. longisporum on exposure to β-pinene resulted in identification of two highly expressed pleotropic drug transporters paralog genes named VlAbcG1a and VlAbcG1b. Overexpression of VlAbcG1a in Saccharomyces cerevisiae increased tolerance to β-pinene, while deletion of the VlAbcG1a homologous gene in Verticillium dahliae resulted in mutants with increased sensitivity to certain monoterpenes. Furthermore, the VlAbcG1a overexpression strain displayed an increased tolerance to β-pinene and increased virulence in tomato plants. Data from this study give new insights into the roles of terpenes in plant–fungal pathogen interactions and the mechanisms fungi deploy to cope with the toxicity of these secondary metabolites.
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