Reduction of alternative electron acceptors drives biofilm formation in Shewanella algae

Shewanella spp. possess a broad respiratory versatility, which contributes to the occupation of hypoxic and anoxic environmental or host-associated niches. Here, we observe a strain-specific induction of biofilm formation in response to supplementation with the anaerobic electron acceptors dimethyl sulfoxide (DMSO) and nitrate in a panel of Shewanella algae isolates. The respiration-driven biofilm response is not observed in DMSO and nitrate reductase deletion mutants of the type strain S. algae CECT 5071, and can be restored upon complementation with the corresponding reductase operon(s) but not by an operon containing a catalytically inactive nitrate reductase. The distinct transcriptional changes, proportional to the effect of these compounds on biofilm formation, include cyclic di-GMP (c-di-GMP) turnover genes. In support, ectopic expression of the c-di-GMP phosphodiesterase YhjH of Salmonella Typhimurium but not its catalytically inactive variant decreased biofilm formation. The respiration-dependent biofilm response of S. algae may permit differential colonization of environmental or host niches.We thank Prof. Lone Gram (DTU, Denmark), Dr. Margarita Bolaños (Hospital Unversitario Insular de Gran Canaria), and Dr. Fernando Artiles-Campelo (Hospital Dr. Negrín de Gran Canaria) for provision of Shewanella algae strains, and Prof. Didier Mazel (Institut Pasteur, Paris) for the kind gift of E. coli MFDpir. AJM-R acknowledges funding from FEMS (RG2015-0084), the Karolinska Institutet Research Foundation (FS2018:0007), the Hans Dahlbergs Foundation, the Lars Hiertas Minne Foundation (FO2018-0196), and the Längmanska Kulturfonden (BA19-1128). J.M.G. acknowledges funding from the Spanish Ministry of Economy and Competitiveness (CTM201680095-C2-2-R). Work at the EEZ was supported by grants to TK from the Spanish Ministry of Economy and Competitiveness (BIO2013-42297 and BIO2016-76779-P). U.R. was supported by the Swedish Research Council for Natural Sciences and Engineering (project numbers 621-2013-4809 and 2017-04465) and Karolinska Institutet. The GC-MS experiments were conducted by Dr. Rafael Núñez Gómez from the Scientific Instrumentation Service of the Estación Experimental del Zaidín (Granada, Spain). RNA sequencing was performed at the Science for Life Laboratory (SciLife Lab), Uppsala, Sweden. The authors are grateful to Dr. K. Thorell (University of Gothenburg) for bioinformatics support and to Dr. M. A. Matilla (EEZ-CSIC), funded by the Spanish Ministry for Science, Innovation and Universities (PID2019-103972GAI00), for experimental assistance during the revision of this work.Peer reviewe

La pesca recreativa en Tenerife y su regulación

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Chemical evaluation of white wines elaborated with a recombinant Saccharomyces cerevisiae strain overproducing mannoproteins

In this study, a recombinant Saccharomyces cerevisiae strain EKD13 overproducing mannoproteins has been used to obtain Albariño white wines. The inoculated strain prevailed and produced complete fermentation of the must, as also occurred in the case of spontaneous (non-inoculated) fermentation and in the must inoculated with the S. cerevisiae EC1118 strain. The analytical study of the wines obtained showed that the most important chemical differences among the wines produced with EKD-13, corresponded to the high concentration of mannoproteins, 2-phenyl ethanol and tyrosol. These differences were attributed to the expression, during must fermentation, of genes modified in the recombinant EKD-13 strain. The results obtained imply that this strain could be potentially useful to produce wines rich in mannoproteins that have distinctive characteristics compared to other similar wines, modifying the sensorial and technological parameters of the wines obtained. © 2013 Elsevier Ltd. All rights reserved.This work was funded through Projects Bodega Terras Gauda LTD. Xunta de Galicia (PGIDIT04TAL035E), 2004-7-OE-242, AGL2006-02558, A36108900, ALIBIRD-CM-S-0505/AGR-0153, and CONSOLIDER INGENIO 2010 (CSD2007-00063FUN-C-FOOD).Peer Reviewe

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding