Polyunsaturated Aldehydes Profile in the Diatom Cyclotella cryptica Is Sensitive to Changes in Its Phycosphere Bacterial Assemblages

Diatoms are responsible for the fixation of ca. 20% of the global CO2 and live associated with bacteria that utilize the organic substances produced by them. Current research trends in marine microbial ecology show which diatom and bacteria interact mediated through the production and exchange of infochemicals. Polyunsaturated aldehydes (PUA) are organic molecules released by diatoms that are considered to have infochemical properties. In this work, we investigated the possible role of PUA as a mediator in diatom-bacteria interactions. To this end, we compare the PUA profile of a newly isolated oceanic PUA producer diatom, Cyclotella cryptica, co-cultured with and without associated bacteria at two phosphate availability conditions. We found that the PUA profile of C. cryptica cultured axenically was different than its profile when it was co-cultured with autochthonous (naturally associated) and non-autochthonous bacteria (unnaturally inoculated). We also observed that bacterial presence significantly enhanced diatom growth and that C. cryptica modulated the percentage of released PUA in response to the presence of bacteria, also depending on the consortium type. Based on our results, we propose that this diatom could use released PUA as a specific organic matter sign to attract beneficial bacteria for constructing its own phycosphere, for more beneficial growth.

Novel terephthalamide diol monomers synthesis from PET waste to Poly(Urethane acrylates)

Due to its excellent properties, poly(ethylene terephthalate) (PET) is one of the most produced and consumed polymers. Among plastics, it represents the main contributor to environmental pollution. Following the circular economy model, the chemical upcycling of PET reduces the amount of waste generated and transforms it into high-value products. The depolymerization of poly(ethylene terephthalate) into oligomers or monomers leads to forming a library of reactive molecules involved in different polymerization processes to obtain compounds with improved properties. Herein, several β-hydroxy amines were synthesized and used for the chemical recycling of water bottle waste by an environmental benefit aminolysis process to get very useful new terephthalamide diol monomers. The recycled diol monomers were subsequently exploited to synthesize poly(urethane acrylates) (PUAs) UV-curable coatings, and their chemical, thermal and mechanical characterizations were performed. The results show the great potential of the developed synthesis protocols to obtain PUAs with final properties that can be modulated to meet the requirements of different applications.

Novel insights into the evolution and structural characterization of dyskerin using comprehensive bioinformatics analysis

Dyskerin is a conserved nucleolar protein. Several related genetic diseases are caused by defects in dyskerin. We hypothesized that having a comprehensive bioinformatic analysis of dyskerin will help to develop new drugs for this diseases. We predicted protein domains and compared sequences and structures to detect the universe of dyskerin-like proteins. We identified conserved features of shared domains in the three superkingdoms. We analyzed the phylogenetic diversity, confirming that there is a strong structural conservation. Also, we studied the relationship of dyskerin-like proteins with other proteins through an integrative protein-protein interaction approach. Most of them are conserved among homologous eukaryotic and archaeal proteins. Our results highlighted the preservation of proteins interacting with dyskerin. We identified conserved dyskerin interactor proteins between the different eukaryotes organisms. Furthermore, we studied the existence of dyskerin-like proteins in different species. Also, we compared and analyzed the secondary structure with the hydrophobic profile, confirming that all have hydrophilic properties highly conserved among proteins. The greatest difference was observed in the NTE and CTE regions. Another aspect studied was the comparison and analysis of tertiary structures. In our knowledge, this is the first time that these analyses were performed in such a comprehensive manner.

DNA repair mechanisms in dividing and non-dividing cells

DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease.