Diatoms synthesize sterols by inclusion of animal and fungal genes in the plant pathway

Diatoms are ubiquitous microalgae that have developed remarkable metabolic plasticity and gene diversification. Here we report the first elucidation of the complete biosynthesis of sterols in the lineage. The study has been carried out on the bloom-forming species Skeletonema marinoi and Cyclotella cryptica that synthesise an ensemble of sterols with chemotypes of animals (cholesterol and desmosterol), plants (dihydrobrassicasterol and 24-methylene cholesterol), algae (fucosterol) and marine invertebrates (clionasterol). In both species, sterols derive from mevalonate through cyclization of squalene to cycloartenol by cycloartenol synthase. The pathway anticipates synthesis of cholesterol by enzymes of the phytosterol route in plants, as recently reported in Solanaceae. Major divergences stem from reduction of Δ24(28) and Δ24(25) double bonds which, in diatoms, are apparently dependent on sterol reductases of fungi, algae and animals. Phylogenetic comparison revealed a good level of similarity between the sterol biosynthetic genes of S. marinoi and C. cryptica with those in the genomes of the other diatoms sequenced so far

CO2-Induced Transcriptional Reorganization: Molecular Basis of Capnophillic Lactic Fermentation in Thermotoga neapolitana

Capnophilic lactic fermentation (CLF) is a novel anaplerotic pathway able to convert sugars to lactic acid (LA) and hydrogen using CO2 as carbon enhancer in the hyperthermophilic bacterium Thermotoga neapolitana. In order to give further insights into CLF metabolic networks, we investigated the transcriptional modification induced by CO2 using a RNA-seq approach. Transcriptomic analysis revealed 1601 differentially expressed genes (DEGs) in an enriched CO2 atmosphere over a total of 1938 genes of the T. neapolitana genome. Transcription of PFOR and LDH genes belonging to the CLF pathway was up-regulated by CO2 together with 6-phosphogluconolactonase (6PGL) and 6-phosphogluconate dehydratase (EDD) of the Entner–Doudoroff (ED) pathway. The transcriptomic study also revealed up-regulation of genes coding for the flavin-based enzymes NADH-dependent reduced ferredoxin:NADP oxidoreductase (NFN) and NAD-ferredoxin oxidoreductase (RNF) that control supply of reduced ferredoxin and NADH and allow energy conservation-based sodium translocation through the cell membrane. These results support the hypothesis that CO2 induces rearrangement of the central carbon metabolism together with activation of mechanisms that increase availability of the reducing equivalents that are necessary to sustain CLF. In this view, this study reports a first rationale of the molecular basis of CLF in T. neapolitana and provides a list of target genes for the biotechnological implementation of this process

Enhancement of hydrogen production rate by high biomass concentrations of Thermotoga neapolitana

The objective of this study was to enhance the hydrogen production rate of dark fermentation in batch operation. For the first time, the hyperthermophilic pure culture of Thermotoga neapolitana cf. Capnolactica was applied at elevated biomass concentrations. The increase of the initial biomass concentration from 0.46 to 1.74 g cell dry weight/L led to a general acceleration of the fermentation process, reducing the fermentation time of 5 g glucose/L down to 3 h with a lag phase of 0.4 h. The volumetric hydrogen production rate increased from 323 (±11) to 654 (±30) mL/L/h with a concomitant enhancement of the biomass growth and glucose consumption rate. The hydrogen yield of 2.45 (±0.09) mol H2/mol glucose, the hydrogen concentration of 68% in the produced gas and the composition of the end products in the digestate, i.e. 62.3 (±2.5)% acetic acid, 23.5 (±2.9)% lactic acid and 2.3 (±0.1)% alanine, remained unaffected at increasing biomass concentrations

Essential requirement for sphingosine kinase activity in eNOS-dependent NO release and vasorelaxation

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that acts both as an extracellular ligand for endothelial differentiation gene receptor family and as an intracellular second messenger. Cellular levels of S1P are low and tightly regulated by sphingosine kinase (SPK). Recent studies have suggested that eNOS pathway may function as a downstream target for the biological effects of receptor-mediated S1P. Here we have studied the possible interplay between intracellular SIP generation and the eNOS activation pathway. S1P causes an endothelium-dependent vasorelaxation in rat aorta that is PTX sensitive, inhibited by L-NAME that involves eNOS phosphorylation, and mainly dependent on hsp90. When rat aorta rings were incubated with the SPK inhibitor DL-threo-dihydrosphingosine (DTD), there was a concentration-dependent reduction of Ach-induced vasorelaxation, implying a consistent contribution of sphingolipid pathway through intracellular sphingosine release and phosphorylation. Co-immunoprecipitation experiments consistently showed increased association of hsp90 with eNOS after exposure of cells to S1P as well to BK or calcium ionophore A-23187. Interestingly, as opposite to A-23187, BK and S1P effect were significantly inhibited by pretreatment with the SPK inhibitor DTD. In conclusion, our data demonstrate that an interplay exists among eNOS, hsp90, and intracellularly generated S1P where eNOS coupling to hsp90 is a major determinant for NO release as confirmed by our functional and molecular studies

Expeditious synthesis of the key unnatural aminoacid in the formal asymmetric total synthesis of (-)-Jorumycin and bioactive tetrahydroisoquinoline alkaloids

The synthesis of the enantiopure aminoacid, key intermediate in the total synthesis of (-)-Jorumycin and of various bioactive tetraidroisoquinoline alkaloids analogues, a class of compounds with antitumor and antibiotic activities, has been accomplished starting from 2,4-dimethoxy-3-methyl-benzaldehyde 1 in only 5 steps and in a very high yield. This synthesis, based on a Negishi reaction between a 5-iodo-2,4-dimethoxy-3-methylphenol and N-(tert-Butoxycarbonyl)-3-iodo-L-alanine methyl ester, permits an easy access to the intermediate, and the formal asymmetric total synthesis of (-)-Jorumycin and tetrahydroisoquinoline alkaloids of the same family, in a very shorter way with respect to the syntheses previously reported

El valor educativo de las humanidades

El presente escrito es un excursus acerca del valor de las Humanidades para el pleno desarrollo de la persona humana. Revisaremos algunos de los rasgos más significativos que constituyen una filosofía de la educación según las corrientes culturales que hemos heredado a través de los siglos. 1. La Paideia entre los antiguos griegos. 2. Las Humanidades entre los latinos. 3. Las Humanidades según el pensamiento patrístico y medieval. 4. Las Humanidades según el pensamiento cristiano. 5. Las Humanidades según la sabiduría judía, islámica y prehispánica. 6. Las Humanidades en nuestros días. En el Epilogo insistiremos sobre la urgencia del clásico imperativo “¡conócete a ti mismo!” que es el fundamento y el núcleo común de toda las corrientes educativas que hemos revisado.The current paper is an excuse about the value of humanities for the complete development of the human person. We will review some of the major features that constitute a philosophy of education according to the cultural trends we have inherited along the centuries. 1. Paideia among ancient Greeks 2. Humanities among Latin. 3. Humanities according medieval and patristic thoughts. 4. Humanities according Christian thought. 5. Humanities according to Jewish, Muslim, and Pre-Hispanic wisdom. 6. Humanities in our current days. In the Epilogue we will insist on the urgency of the classical imperative "Get to know yourself!” which is the basis and the common nucleus of all educational trends we have reviewed

Relazione tecnica sulle attività della campagna oceanografica “Evatir 2016”

La presente relazione tecnica descrive tutte le attività svolte nella Campagna oceanografica “Evatir 2017” condotta a bordo della N/O “G. Dallaporta” (dal 25 luglio al 21 agosto 2016). La Campagna “Evati 2016” è parte integrante del Progetto "Estensione della Campagna acustica Medias (Mediterranean International Acoustic Survey) nelle sub aree geografiche (GSA) 9 (Mar Ligure e Mar Tirreno settentrionale) e 10 (Mar Tirreno centrale e meridionale)", finanziato dal Ministero delle politiche agricole alimentari e forestali (Mipaaf) nell'ambito del Fondo Europeo per gli Affari Marittimi e la Pesca (FEAMP). E’ la sesta campagna rivolta alla valutazione acustica e alla distribuzione spaziale delle popolazioni di piccoli pelagici, insieme allo studio delle condizioni ambientali dell’area di studio. Le specie target del progetto sono state l’acciuga europea (Engraulis encrasicolus) e la sardina (Sardina pilchardus), specie chiave sia a livello commerciale che ecologico. La gestione di tali risorse è abbastanza complessa a causa del loro breve ciclo di vita e dall’ampia oscillazioni inter-annuali nell’abbondanza dello stock, legata al successo o al fallimento del reclutamento annuale. Insieme alle attività di acquisizione acustiche sono stati realizzati campionamenti bilogici, misurazioni, misurazioni di parametri fisico-chimici, rilevamenti di variabili oceanografiche e campionamento di acque (nei Golfi di Salerno, Napoli e Gaeta), monitoraggio della rete da pesca e campionamenti di fitoplancton, zooplancton, solidi sospesi e rilievo delle principali variabili oceanografiche (in prossimità dello stabilimento SOLVAY di Rosignano)

Relazione tecnica sulle attività della Campagna oceanografica “Ancheva 2016”

La presente relazione riporta le attività di ricerca della Campagna oceangrafica “Ancheva 2016”, svolte a bordo della N/O “G. Dallaporta” (nel periodo tra il 4 ed il 26 Luglio 2016) nello Stretto di Sicilia e nel mar Ionio occidentale (GSA 16 e 19) e nelle acque maltesi (GSA 15). Nello specifico, le attività svolte vengono sono di seguito descritte sinteticamente: - Rilevazioni acustiche degli stock di piccoli pelagici con echosounder scientifico Simrad EK60, con trasduttori split beam a scafo; - Campionamenti biologici (di piccoli pelagici) con rete pelagica (volante monobarca), dotata di sistema acustico Simrad ITI per il controllo della geometria della rete (apertura e posizione della rete nella colonna d’acqua); - Campionamenti di tessuti di pesci pelagici (gonadi, fegato e sangue); - Campionamento acqua, in specifiche stazioni, con sonda multiparametrica SEABIRD mod. 9/11 plus (per la misurazione dei parametri fisico-chimici della colonna d’acqua) dotata di bottiglie Niskin (per l’analisi di Nutrienti ed Isotopi di azoto e carbonio); - Campionamento ittioplantonico, mediante con “Bongo 40”, in specifiche stazioni, le cui bocche sono state fissate in alcool, per le analisi degli aminoacidi sulle larve di Engraulis encrasicolus

La ley natural moral según el pensamiento clásico

Este ensayo acerca de la ley natural1 moral quiere ser una colaboración en la difusión de las tesis fundamentales de la filosofía de los derechos humanos (iura humana) que hemos heredado del pensamiento clásico. Partiremos de Santo Tomás de Aquino (1225-1274), quien expuso el tema de la ley natural moral en la primera de la segunda parte de la Suma Teológica, desde la cuestión 90 hasta la cuestión 106. Para ello, Santo Tomás se apoyó en las obras de Aristóteles, Cicerón, San Agustín y la Patrística. Además, se fundamentó en el Decreto de Graciano (Corpus iuris canonici, recopilado en el año 1140 por el monje camaldulense Graciano) y en las cuatro partes del Corpus iuris civilis (Instituciones, Digesto, Código Justinianeo y Novelas posteriores a Justiniano). Asimismo, los escritos de Santo Tomás sirvieron de base para innumerables comentarios y tratados sobre la ley natural moral que influyeron profundamente en la evolución del pensamiento novo hispano, del cual somos herederos. Actualmente, después de las tragedias de la segunda guerra mundial, se recuperó la doctrina de la ley natural moral insita en la dignidad de la persona humana.2 Este nuevo humanismo es como el renacimiento de la filosofía clásica, cuyas corrientes confluyeron en la antropología tomista que sigue vigente en nuestra cultura actual, cuyo programa se puede resumir así: ”Nada humano me es ajeno” (Terencio, poeta romano de siglo II, a.C)

Relazione tecnica sulle attività della campagna oceanografica “Ancheva 2017”

La presente relazione tecnica descrive le attività svolte nella Campagna oceanografica “Ancheva 2017”, tra il 23 luglio ed il 7 agosto 2017, a bordo della N/O “G. Dallaporta”. Gli echosurvey acquisiti hanno permesso di valutare la biomassa e la distribuzione spaziale dei piccoli pelagici nella piattaforma meridionale della Sicilia, da Marsala a oltre Capo Passero, e nella piattaforma Maltese (GSA 16, FAO sub area 37.2.2). Parallelamente alle suddette attività sono state svolti il campionamento biologico (di piccoli pelagici) con rete pelagica (volante monobarca), il campionamento di tessuti di pesci pelagici (gonadi, fegato e sangue), il campionamento di acqua (per la misurazione dei parametri fisico-chimici della colonna d’acqua e per l’analisi di Nutrienti ed Isotopi di azoto e carbonio) ed, infine, il campionamento ittioplantonico (per le analisi degli aminoacidi sulle larve di Engraulis encrasicolus)