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A continuación se muestran las últimas novedades sobre investigaciones, eventos, actividades y descubrimientos que se llevan a cabo en el Instituto de Productos Naturales y Agrobiología.

Publicaciones recientes

A validated workflow for rapid taxonomic assignment and monitoring of a national fauna of bees

A validated workflow for rapid taxonomic assignment and monitoring of a national fauna of bees (Apiformes) using high throughput DNA barcoding

Improved taxonomic methods are needed to quantify declining populations of insect pollinators. This study devises a high-throughput DNA barcoding protocol for a regional fauna (United Kingdom) of bees (Apiformes), consisting of reference library construction, a proof-of-concept monitoring scheme, and the deep barcoding of individuals to assess potential artefacts and organismal associations. A reference database of cytochrome oxidase c subunit 1 (cox1) sequences including 92.4% of 278 bee species known from the UK showed high congruence with morphological taxon concepts, but molecular species delimitations resulted in numerous split and (fewer) lumped entities within the Linnaean species. Double tagging permitted deep Illumina sequencing of 762 separate individuals of bees from a UK-wide survey. Extracting the target barcode from the amplicon mix required a new protocol employing read abundance and phylogenetic position, which revealed 180 molecular entities of Apiformes identifiable to species. An additional 72 entities were ascribed to nuclear pseudogenes based on patterns of read abundance and phylogenetic relatedness to the reference set. Clustering of reads revealed a range of secondary operational taxonomic units (OTUs) in almost all samples, resulting from traces of insect species caught in the same traps, organisms associated with the insects including a known mite parasite of bees, and the common detection of human DNA, besides evidence for low-level cross-contamination in pan traps and laboratory procedures. Custom scripts were generated to conduct critical steps of the bioinformatics protocol. The resources built here will greatly aid DNA-based monitoring to inform management and conservation policies for the protection of pollinators.

Creedy, Thomas J.; Norman, Hannah; Tang, Cuong Q.; Qing Chin, Kai; Andujar, Carmelo; Arribas, Paula; O'Connor, Rory S.; Carvell, Claire; Notton, David G.; Vogler, Alfred P.

Molecular Ecology Resources 20(1): 40-53 (2020)
Niosomes encapsulated in biohydrogels

Niosomes encapsulated in biohydrogels for tunable delivery of phytoalexin resveratrol

A series of biohydrogels based on mixtures of kappa-carrageenan (κ-carrageenan, κ-C) and gelatin were evaluated as potential soft delivery vehicles for the encapsulation and subsequent release of non-ionic surfactant vesicles (niosomes) loaded with resveratrol (RSV). The niosomes were prepared using a mixture of amphiphilic lipids Tween 80 and Span 80 in water. The results showed that RSV-niosomes did not significantly affect the hydrogelation properties of the biopolymer mixture. Moreover, in vitro drug release experiments from biohydrogels containing RSV-niosomes were successfully carried out under simulated gastrointestinal conditions. The RSV-niosomal liberation profiles from hydrogels were fitted using first order kinetics, Higuchi, Korsmeyer-Peppas and Weibull drug release models, showing the prevalence of diffusion mechanisms in each case. In addition, the RSV release was easily tuned by adjusting the total concentration of κ-C : gelatin. Interestingly, the niosomal-hydrogel system was also found to prevent the trans-to-cis photoisomerization of RSV.

Machado, Noelia D.; Fernández, Mariana A.; Häring, Marleen; Saldías, César; Díaz Díaz, David

RSC Advances 9: 7601-7609 (2019)
Rigor mortis in guinea pigs

First report of postmortem pH evolution and rigor mortis in guinea pigs

In the Andean region, Philippines, and central Africa most guinea pigs are raised for meat production. Guinea pig meat is of increasing interest to researchers. One of the critical questions in meat production is to know when muscles convert to meat. The objective of this study was to describe the pH evolution in guinea pig muscles and to determine the establishment and resolution time of rigor mortis. Forty-eight guinea pig carcasses were divided into four groups: 12 male and 12 female of 3 month-old fattened animals, and 12 male and 12 female of 12 month-old reproductive animals. The pH was measured using a penetration probe in Longissimus thoracis, Quadriceps femoris, Triceps brachii and Psoas major muscles for 24 h, and rigor mortis was monitored during this time. The initial and final pH ranged between 6.56–7.00 and 5.97–6.27, respectively. Rigor mortis was established at ∼5 h and resolved at ∼15 h postmortem. The Psoas major was the muscle with lower initial pH and higher final pH, while no differences were found between the other muscles. Initial, evolution and final pH were not affected by the sex. No differences were found in the productive-reproductive status between males, whereas the older female guinea pigs presented higher pH in three muscles. In conclusion, in our test conditions final pH in guinea pigs remains high enough to permit microbial growth, which could affect the shelf-life of Guinea pig meat. Moreover, it is recommended to keep guinea pig carcasses in refrigeration until 15 h postmortem, when rigor mortis is resolved, and muscle-to-meat conversion finished. Management of these carcasses should be different depending if the animals belong to a productive or reproductive animal system. It is therefore necessary to chill guinea pig carcasses at least 15 h, to achieve a correct muscle-to-meat conversion.

Sánchez-Macías, David; Cevallos-Velastegui, Lesllie; Nuñez-Valle, Diego; Morales-delaNuez, Antonio 

Livestock Science 229: 22-27 (2019)


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