Browsing by Issue Date, starting with "2023-09-06"
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- The impact of HPP-assisted biocontrol approach on the bacterial communities’ dynamics and quality parameters of a fermented meat sausage modelPublication . Komora, Norton; Maciel, Cláudia; Isidro, Joana; Pinto, Carlos A.; Fortunato, Gianuario; Saraiva, Jorge M. A.; Teixeira, PaulaTraditional foods are increasingly valued by consumers, whose attention and purchase willingness are highly influenced by other claims such as ‘natural’, ‘sustainable’, and ‘clean label’. The purpose of the present study was to evaluate the impact of a novel non-thermal food processing method (i.e., HPP-assisted biocontrol combining mild high hydrostatic pressure, listeriophage Listex, and pediocin PA-1 producing Pediococcus acidilactici) on the succession of bacterial communities and quality of a fermented sausage model. A comparative analysis of instrumental color, texture, and lipid peroxidation revealed no significant differences (p > 0.05) in these quality parameters between non- and minimally processed fermented sausages throughout 60-day refrigerated storage (4 °C). The microbiota dynamics of biotreated and untreated fermented sausages were assessed by 16S rRNA next-generation sequencing, and the alpha and beta diversity analyses revealed no dissimilarity in the structure and composition of the bacterial communities over the analyzed period. The innovative multi-hurdle technology proposed herein holds valuable potential for the manufacture of traditional fermented sausages while preserving their unique intrinsic characteristics.
- On the molecular selection of exopolysaccharide-producing lactic acid bacteria from indigenous fermented plant-based foods and further fine chemical characterizationPublication . Angelov, Angel; Georgieva, Aneliya; Petkova, Mariana; Bartkiene, Elena; Rocha, João Miguel; Ognyanov, Manol; Gotcheva, VelitchkaExopolysaccharides (EPSs) produced by lactic acid bacteria present a particular interest for the food industry since they can be incorporated in foods via in situ production by selected starter cultures or applied as natural additives to improve the quality of various food products. In the present study, 43 strains were isolated from different plant-based fermented foods and identified by molecular methods. The species found were distinctively specific according to the food source. Only six Lactiplantibacillus plantarum strains, all isolated from sauerkraut, showed the ability to produce exopolysaccharide (EPS). The utilization of glucose, fructose and sucrose was explored with regard to EPS and biomass accumulation by the tested strains. Sucrose was clearly the best carbon source for EPS production by most of the strains, yielding up to 211.53 mg/L by strain Lactiplantibacillus plantarum ZE2, while biomass accumulation reached the highest levels in the glucose-based culture medium. Most strains produced similar levels of EPS with glucose and fructose, while fructose was utilized more poorly for biomass production, yielding about 50% of biomass compared to glucose for most strains. Composition analysis of the EPSs produced by strain Lactiplantibacillus plantarum ZE2 from glucose (EPS-1) and fructose (EPS-2) revealed that glucose (80–83 mol%) and protein (41% w/w) predominated in both analyzed EPSs. However, the yield of EPS-1 was twice higher than that of EPS-2, and differences in the levels of all detected sugars were found, which shows that even for the same strain, EPS yield and composition vary depending on the carbon source. These results may be the basis for the development of tailored EPS-producing starter cultures for food fermentations, as well as technologies for the production of EPS for various applications.
- Exploring bioactivities and peptide content of body mucus from the lusitanian toadfish Halobatrachus didactylusPublication . Cunha, Marta Fernandez; Coscueta, Ezequiel R.; Brassesco, María Emilia; Marques, Rita; Neto, José; Almada, Frederico; Gonçalves, David; Pintado, ManuelaIdentifying bioactive molecules from marine organisms is still vastly understudied. Fish remain an untapped source of bioactive molecules, even when considering species whose toxicity to other fish species has been noticed before. We assessed potential applications of crude body mucus of the Lusitanian toadfish (Halobratachus didactylus) and characterized its peptide fraction composition. Mucus samples from three individuals (two wild and one captive) revealed potential antioxidant, antihypertensive, and antimicrobial activities. For antioxidant activity, the best results of 2371 ± 97 µmol Trolox Equivalent/g protein for ORAC and 154 ± 6 µmol Trolox Equivalent/g protein for ABTS were obtained. For antihypertensive activity, the relevant inhibitory activity of ACE resulted in IC50 of 60 ± 7 µg protein/mL. Antimicrobial activity was also identified against the pathogenic bacteria Escherichia coli and Listeria monocytogenes. The peptide profile of the crude body mucus was obtained through size exclusion chromatography, with a conspicuous peak at ca. 800 Da. LC-MS/MS allowed the detection of the most probable peptide sequences of this dominant peptide. This is the first study where the bioactive potential of mucus from the Lusitanian toadfish is demonstrated. Peptides with such properties can be applied in the food and pharmaceutical industries.
- A dual-function SNF2 protein drives chromatid resolution and nascent transcripts removal in mitosisPublication . Carmo, Catarina; Coelho, João; Silva, Rui D.; Tavares, Alexandra; Boavida, Ana; Gaetani, Paola; Guilgur, Leonardo G.; Martinho, Rui Gonçalo; Oliveira, Raquel A.Mitotic chromatin is largely assumed incompatible with transcription due to changes in the transcription machinery and chromosome architecture. However, the mechanisms of mitotic transcriptional inactivation and their interplay with chromosome assembly remain largely unknown. By monitoring ongoing transcription in Drosophila early embryos, we reveal that eviction of nascent mRNAs from mitotic chromatin occurs after substantial chromosome compaction and is not promoted by condensin I. Instead, we show that the timely removal of transcripts from mitotic chromatin is driven by the SNF2 helicase-like protein Lodestar (Lds), identified here as a modulator of sister chromatid cohesion defects. In addition to the eviction of nascent transcripts, we uncover that Lds cooperates with Topoisomerase 2 to ensure efficient sister chromatid resolution and mitotic fidelity. We conclude that the removal of nascent transcripts upon mitotic entry is not a passive consequence of cell cycle progression and/or chromosome compaction but occurs via dedicated mechanisms with functional parallelisms to sister chromatid resolution.
- O Espírito Santo faça de nós uma oferenda permanente : estudo sobre a Oração Eucarística IIIPublication . Souza, Fabrício Lima; Eleutério, João José MarquesA ação anamnética é tipicamente divina, porque Deus não se esquece do seu povo. A origem da Eucaristia cristã está na Última Ceia, na qual Jesus, por meio do pão e do vinho, e de gestos e palavras, institui o memorial da sua Paixão, dizendo no fim da Ceia: «fazei isto em memória de mim». O memorial celebrado é bem evidenciado na Oração Eucarística III. Este memorial, mais do que ativar a dimensão psicológica do sujeito celebrante, requer a sua configuração com Cristo, pela ação do Espírito Santo, que faz de cada membro da assembleia celebrante uma oferenda permanente a Deus Pai. Celebrar a Eucaristia significa atualizar os benefícios da ação salvífica do Senhor. As dimensões da comensalidade e do sacrifício, presentes na Oração Eucarística III, têm a sua origem remota na liturgia judaica da ceia festiva e do sacrifício no Templo em Jerusalém, e, mais proximamente, na liturgia antioquena.