Lobophorin K, a new natural product with cytotoxic activity produced by Streptomyces sp. M-207 associated with the deep-sea coral Lophelia pertusa

The present article describes the isolation of a new natural product of the lobophorin family, designated as lobophorin K (1), from cultures of the marine actinobacteria Streptomyces sp. M-207, previously isolated from the cold-water coral Lophelia pertusa collected at 1800 m depth during an expedition to the submarine Avilés Canyon. Its structure was determined using a combination of spectroscopic techniques, mainly ESI-TOF MS and 1D and 2D NMR. This new natural product displayed cytotoxic activity against two human tumor cell lines, such as pancreatic carcinoma (MiaPaca-2) and breast adenocarcinoma (MCF-7). Lobophorin K also displayed moderate and selective antibiotic activity against pathogenic Gram-positive bacteria such as Staphylococcus aureus

Esophageal cancer risk by type of alcohol drinking and smoking: a case-control study in Spain

<p>Abstract</p> <p>Background</p> <p>The effect of tobacco smoking and alcohol drinking on esophageal cancer (EC) has never been explored in Spain where black tobacco and wine consumptions are quite prevalent. We estimated the independent effect of different alcoholic beverages and type of tobacco smoking on the risk of EC and its main histological cell type (squamous cell carcinoma) in a hospital-based case-control study in a Mediterranean area of Spain.</p> <p>Methods</p> <p>We only included incident cases with histologically confirmed EC (n = 202). Controls were frequency-matched to cases by age, sex and province (n = 455). Information on risk factors was elicited by trained interviewers using structured questionnaires. Multiple logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals (CI).</p> <p>Results</p> <p>Alcohol drinking and tobacco smoking were strong and independent risk factors for esophageal cancer. Alcohol was a potent risk factor with a clear dose-response relationship, particularly for esophageal squamous-cell cancer. Compared to never-drinkers, the risk for heaviest drinkers (≥ 75 g/day of pure ethanol) was 7.65 (95%CI, 3.16–18.49); and compared with never-smokers, the risk for heaviest smokers (≥ 30 cigarettes/day) was 5.07 (95%CI, 2.06–12.47). A low consumption of only wine and/or beer (1–24 g/d) did not increase the risk whereas a strong positive trend was observed for all types of alcoholic beverages that included any combination of hard liquors with beer and/or wine (p-trend<0.00001). A significant increase in EC risk was only observed for black-tobacco smoking (2.5-fold increase), not for blond tobacco. The effects for alcohol drinking were much stronger when the analysis was limited to the esophageal squamous cell carcinoma (n = 160), whereas a lack of effect for adenocarcinoma was evidenced. Smoking cessation showed a beneficial effect within ten years whereas drinking cessation did not.</p> <p>Conclusion</p> <p>Our study shows that the risk of EC, and particularly the squamous cell type, is strongly associated with alcohol drinking. The consumption of any combination of hard liquors seems to be harmful whereas a low consumption of only wine may not. This may relates to the presence of certain antioxidant compounds found in wine but practically lacking in liquors. Tobacco smoking is also a clear risk factor, black more than blond.</p

Enzymatic characterization of the phage protein DPO7

Biofilms are communities of bacteria living inside a self-synthetized matrix that protects them from environmental conditions including antibiotics. It has been estimated that they are responsible for 65% of the infections occurring in developed countries. Staphylococci are the most common cause of biofilm-related infections, with Staphylococcus aureus and Staphylococcus epidermidis as the staphylococcal species most commonly related with them. S. epidermidis and S. aureus biofilms are an important cause of concern in medical environments and food industries, and many methods have been tried to eliminate them. This study was focused on Dpo7, a protein encoded by a S. epidermidis bacteriophage that has shown polysaccharide depolymerase activity against biofilms of S. aureus and S. epidermidis. Escherichia coli BL21 (DE3) was transformed with the pET21a-Dpo7 plasmid to induce the overexpression of a recombinant Dpo7 that was subsequently purified by affinity chromatography. Dpo7 enzymatic activity was then characterized using 4-nitrophenyl-N-acetyl-ß-D-glucosaminide, a synthetic substrate containing a glycosidic bond, whose cleavage causes the release of 4-nitrophenolate, a compound with absorbance at 405 nm. Dpo7 (in different concentrations and conditions) was added to samples containing the synthetic substrate and incubated for 1 hour at 37ºC, being the OD405 monitored during that time. The ¿OD405 obtained in each of the 8 samples containing Dpo7 was higher than the ¿OD405 of the controls (samples containing the substrate but no Dpo7), and significantly higher in 7 of the 8 cases, indicating that Dpo7 anti-biofilm activity is a glycosyl hydrolase activity. Most of the different factors tested (reduction and increase of Dpo7 concentration, use of different buffers, refrigeration and freezing of Dpo7), had a not significant effect over Dpo7 activity.Peer reviewe

Bioelectrochemical systems for ammonium removal in contaminated water

Summary Nowadays, ammonium (NH4+) is a pollutant present in all kinds of water bodies, leading to multiple environmental and health issues. The current NH4+-removing technologies are very expensive, as they require a lot of energy. Microbial electrochemical technologies (METs) are a less energy-consuming alternative to the conventional ammonium removal methods. The doctoral thesis “Bioelectrochemical systems for ammonium removal in contaminated water” by Miguel Osset Álvarez aims to contribute to the development of the two main ammonium-removing METs: bioelectrochemical nitrification and the combination of aerobic nitrification with bioelectrochemical denitrification. Bioelectrochemical nitrification is a very promising technology for NH4+ removal. However, the mechanisms behind this process have not been fully unveiled. A nitrifying bioelectrochemical system (niBES) was built, operated and studied for 550 days. A nitrifier (Achromobacter sp.) was found as the dominant microorganism in the niBES, while hydroxylamine (NH2OH) and nitrite (NO2-), two nitrification intermediates, were revealed as electroactive compounds. Overall, these results suggest that ammonium was converted into dinitrogen gas (N2) by a process combining bioelectrochemical NH4+ oxidation, denitrification and, to a lesser extent, anammox. On the other hand, a new ammonium-removing bioelectrochemical system (BES), the e-biofilter, was built by integrating bioelectrochemical denitrification into a biotrickling filter. E-biofilters were used to transform the NH4+ in synthetic aquaculture wastewater into nitrate (NO3-) and N2, enabling the reuse of this water for hydroponic culture. Moreover, the e-biofilters were capable of removing most of the ammonium, organic matter and suspended solids present in the secondary effluent of an urban wastewater treatment plant (WWTP), showing that e-biofilters can provide holistic wastewater treatmentAvui dia, l'amoni (NH4+) és un contaminant present a tot tipus d'aigües, fet que ocasiona múltiples problemes ambientals i de salut. Les tecnologies actuals d'eliminació de NH4+ són molt costoses, ja que requereixen molta energia. Les tecnologies electroquímiques microbianes (METs; sigles en anglès) suposen una alternativa amb un cost energètic més baix que els mètodes convencionals d'eliminació d'amoni. La tesi doctoral “Bioelectrochemical systems for ammonium removal in contaminated water” de Miguel Osset Álvarez té com a objectiu contribuir al desenvolupament de les dues principals METs d'eliminació d'amoni: la nitrificació bioelectroquímica i la combinació de nitrificació aeròbica amb desnitrificació bioelectroquímica. La nitrificació bioelectroquímica és una tecnologia molt prometedora per eliminar NH4+. Tot i això, els mecanismes darrere d'aquest procés no han estat completament revelats. Es va construir, operar i estudiar un sistema bioelectroquímic nitrificant (niBES; sigles en anglès) durant 550 dies. Es va descobrir que el microorganisme dominant al niBES era un nitrificant (Achromobacter sp.), i que la hidroxilamina (NH2OH) i el nitrit (NO2-), dos intermediaris de la nitrificació, són compostos electroactius. En general, aquests resultats suggereixen que l'amoni es va transformar en nitrogen gas (N2) mitjançant un procés que combina l'oxidació bioelectroquímica de NH4+, la desnitrificació i, menys, l'anammox. D'altra banda, es va construir un nou sistema bioelectroquímic (BES; sigles en anglès) d'eliminació d'amoni, l'e-biofiltre, integrant la desnitrificació bioelectroquímica en un biofiltre percolador. Es van utilitzar els e-biofiltres per transformar l'NH4+ present en aigua sintètica d'aqüicultura en nitrat (NO3-) i N2, cosa que va permetre reutilitzar aquesta aigua per a cultiu hidropònic. A més, els e-biofiltres van ser capaços d'eliminar la major part de l'amoni, la matèria orgànica i els sòlids en suspensió presents a l'efluent secundari d'una planta de tractament d'aigües residuals (EDAR) urbana, cosa que demostra que els e-biofiltres poden proporcionar un tractament holístic de les aigües residualsPrograma de Doctorat en Ciència i Tecnologia de l'Aigu

Esophageal cancer risk by type of alcohol drinking and smoking : a case-control study in Spain

Background: The effect of tobacco smoking and alcohol drinking on esophageal cancer (EC) has never been explored in Spain where black tobacco and wine consumptions are quite prevalent. We estimated the independent effect of different alcoholic beverages and type of tobacco smoking on the risk of EC and its main histological cell type (squamous cell carcinoma) in a hospital-based case-control study in a Mediterranean area of Spain. Methods: We only included incident cases with histologically confirmed EC (n = 202). Controls were frequency-matched to cases by age, sex and province (n = 455). Information on risk factors was elicited by trained interviewers using structured questionnaires. Multiple logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals (CI). Results: Alcohol drinking and tobacco smoking were strong and independent risk factors for esophageal cancer. Alcohol was a potent risk factor with a clear dose-response relationship, particularly for esophageal squamous-cell cancer. Compared to never-drinkers, the risk for heaviest drinkers (≥ 75 g/day of pure ethanol) was 7.65 (95%CI, 3.16-18.49); and compared with never-smokers, the risk for heaviest smokers (≥ 30 cigarettes/day) was 5.07 (95%CI, 2.06-12.47). A low consumption of only wine and/or beer (1-24 g/d) did not increase the risk whereas a strong positive trend was observed for all types of alcoholic beverages that included any combination of hard liquors with beer and/or wine (p-trend<0.00001). A significant increase in EC risk was only observed for black-tobacco smoking (2.5-fold increase), not for blond tobacco. The effects for alcohol drinking were much stronger when the analysis was limited to the esophageal squamous cell carcinoma (n = 160), whereas a lack of effect for adenocarcinoma was evidenced. Smoking cessation showed a beneficial effect within ten years whereas drinking cessation did not. Conclusion: Our study shows that the risk of EC, and particularly the squamous cell type, is strongly associated with alcohol drinking. The consumption of any combination of hard liquors seems to be harmful whereas a low consumption of only wine may not. This may relates to the presence of certain antioxidant compounds found in wine but practically lacking in liquors. Tobacco smoking is also a clear risk factor, black more than blond