Pontiella desulfatans gen. nov., sp. nov., and Pontiella sulfatireligans sp. nov., two marine anaerobes of the Pontiellaceae fam. nov. producing sulfated glycosaminoglycan-like exopolymers

Recently, we isolated two marine strains, F1T and F21T, which together with Kiritimatiella glycovorans L21-Fru-ABT are the only pure cultures of the class Kiritimatiellae within the phylum Verrucomicrobiota. Here, we present an in-depth genome-guided characterization of both isolates with emphasis on their exopolysaccharide synthesis. The strains only grew fermentatively on simple carbohydrates and sulfated polysaccharides. Strains F1T, F21T and K. glycovorans reduced elemental sulfur, ferric citrate and anthraquinone-2,6-disulfonate during anaerobic growth on sugars. Both strains produced exopolysaccharides during stationary phase, probably with intracellularly stored glycogen as energy and carbon source. Exopolysaccharides included N-sulfated polysaccharides probably containing hexosamines and thus resembling glycosaminoglycans. This implies that the isolates can both degrade and produce sulfated polysaccharides. Both strains encoded an unprecedently high number of glycoside hydrolase genes (422 and 388, respectively), including prevalent alpha-L-fucosidase genes, which may be necessary for degrading complex sulfated polysaccharides such as fucoidan. Strain F21T encoded three putative glycosaminoglycan sulfotransferases and a putative sulfate glycosaminoglycan biosynthesis gene cluster. Based on phylogenetic and chemotaxonomic analyses, we propose the taxa Pontiella desulfatans F1T gen. nov., sp. nov. and Pontiella sulfatireligans F21T sp. nov. as representatives of the Pontiellaceae fam. nov. within the class Kiritimatiellae.ERC -European Research Council(024.002.002)info:eu-repo/semantics/publishedVersio

Novel sulfate- and sulfur-reducing bacteria from the Black Sea: metagenomics, enrichment and isolation

[Excerpt] Background: Anoxic and euxinic marine waters are of importance to the biogeochemistry of modernday ocean as well as the ancient Proterozoic ocean. In these environments, sulfate- and sulfurreducing bacteria (SRB) play a key role through the reduction of oxidized sulfur compounds such as sulfate, thiosulfate and elemental sulfur to sulfide. In previous studies, these marine SRB were found to be comprised of both canonical deltaproteobacterial and non-canonical, mostly uncultured lineages. Objectives: We aimed to test these findings, and to assess the diversity of SRB in the Black Sea, the largest euxinic basin on the planet and a well-studied model ecosystem. [...]info:eu-repo/semantics/publishedVersio

Surgical quality in organ procurement during day and night: an analysis of quality forms

OBJECTIVES: To analyse a potential association between surgical quality and time of day. DESIGN: A retrospective analysis of complete sets of quality forms filled out by the procuring and accepting surgeon on organs from deceased donors. SETTING: Procurement procedures in the Netherlands are organised per region. All procedures are performed by an independent, dedicated procurement team that is associated with an academic medical centre in the region. PARTICIPANTS: In 18 months' time, 771 organs were accepted and procured in The Netherlands. Of these, 17 organs were declined before transport and therefore excluded. For the remaining 754 organs, 591 (78%) sets of forms were completed (procurement and transplantation). Baseline characteristics were comparable in both daytime and evening/night-time with the exception of height (p=0.003). PRIMARY OUTCOME MEASURE: All complete sets of quality forms were retrospectively analysed for the primary outcome, procurement-related surgical injury. Organs were categorised based on the starting time of the procurement in either daytime (8:00-17:00) or evening/night-time (17:00-8:00). RESULTS: Out of 591 procured organs, 129 organs (22%) were procured during daytime and 462 organs (78%) during evening/night-time. The incidence of surgical injury was significantly lower during daytime; 22 organs (17%) compared with 126 organs (27%) procured during evening/night-time (p=0.016). This association persists when adjusted for confounders. CONCLUSIONS: This study shows an increased incidence of procurement-related surgical injury in evening/night-time procedures as compared with daytime. Time of day might (in)directly influence surgical performance and should be considered a potential risk factor for injury in organ procurement procedures

Exploration of sulfur-cycling microorganisms from anoxic Black Sea waters and sediment

All forms of life, from bacteria to humans, require sulfur as essential nutrient. Furthermore, many bacteria and archaea interact with sulfur compounds to obtain the energy they need for growth. Some of these sulfur microbes – for instance sulfate-reducing microorganisms – produce sulfide (H2S), which has the smell of rotten eggs and can create ‘dead zones’ in the ocean because of its toxicity. However, other sulfur microbes do the opposite and consume H2S, using it as electron donor for energy. Sulfur microbes thus have a big impact on the marine environment, and even on the global climate. As microbiologists, we want to find out who are these sulfur microbes, and what else do they do?To answer these questions, we focused on the Black Sea, the world’s largest anoxic basin. It is home to many different sulfur microbes which cannot tolerate oxygen and are yet to be studied. As tools, we used metagenomics and anaerobic cultivation. Metagenome-assembled-genomes (MAGs) were obtained from a cross-assembly of 15 metagenomes sampled at different water column depths. MAGs were then taxonomically classified, screened for functional marker genes to hypothesize their energy metabolism, and their relative abundance was profiled over depth to refine these hypotheses. We obtained medium-to-high-quality MAGs of various putative sulfur-oxidizing and sulfate-reducing bacteria, including known ones and novel ones. Specifically sulfate-reducing bacteria were surprisingly diverse and novel, meaning much is still to be learned about their role in the Black Sea and other marine waters with low oxygen levels.With anaerobic cultivation, we have brought new and exciting sulfur microbes from Black Sea samples into pure culture, allowing us to study their metabolism in detail. For instance, we isolated two strains of a novel bacterial family which cleave sulfate ester groups from polysaccharides to digest their food. Their genomes contain more genes for sulfate-cleaving enzymes (sulfatases) than any other known organism. We narrowed down the complete enzymatic pathway used for degrading sulfated polysaccharides using transcriptomics, and along the way we found evidence for a novel pathway for degradation of the sugar molecule L-fucose. What's also exciting is that we observed other interesting features - these bacteria produce slimy extracellular biopolymers, part of which is structurally similar to specific polysaccharides found only in animals

Microbial catabolism-based grouping enables read-across of non-persistency for all constituents of hexyl glucoside and 2-ethylhexyl glucoside

Alkyl polyglucosides are nonionic surfactants consisting of a hydrophobic alkyl chain and a hydrophilic (oligo)saccharide moiety linked through a glucosidic bond. Ready biodegradability of hexyl glucoside (multi-constituent) and 2-ethylhexyl glucoside (multi-constituent) was demonstrated in Closed Bottle tests (OECD 301D) inoculated with river water. Read-across was used to assess the non-persistency for all constituents of the multi-constituent surfactants. To enable catabolism-based grouping bacteria were isolated from river water using hexyl glucoside (multi-constituent), 2-ethylhexyl glucoside (multi-constituent), hexyl-β-maltoside, glucose, and maltose as sole source of carbon and energy. The first step in the biodegradation of all constituents of hexyl glucoside and 2-ethylhexyl glucoside was cleavage of the glucosidic bond resulting in stoichiometric formation of hexanol and 2-ethylhexanol, respectively. Hydrolysis products formed were mineralized by the isolates or excreted and subsequently metabolized by other microorganisms. Complete degradation of alkyl polyglucosides was achieved by a consortium of microorganisms. Read-across of ready biodegradability and herewith non-persistency for all constituents of hexyl glucoside (multi-constituent) and 2-ethylhexyl glucoside (multi-constituent) is justified based on: the broad substrate specificity of glucosidases in the first biodegradation step resulting in stoichiometric formation of alcohols and the subsequent rapid mineralization of the formed hydrolysis products.</p

Microbial Diversity and Organic Acid Production of Guinea Pig Faecal Samples

The guinea pig (Cavia porcellus) or cavy is a grass-eating rodent. Its main diet consists of grass or hay, which comprises cellulose, hemicellulose, lignin and their derivatives. Here, the microbial diversity of faecal samples of two guinea pigs and microbial enrichments made with substrates, including starch waste and dried grass, were investigated along with organic acid production profiles. The microbial communities of the faecal samples were dominated by the phyla Bacteroidetes (40%) and Firmicutes (36%). Bacteroidales S24-7 (11% in Cavy 1 and 21% in Cavy 2) was the most abundant order. At genus level, many microorganisms remained unclassified. Different carbon sources were used for organic acid production in faecal enrichments. The dominant bacterial groups in the secondary enrichments with dried grass, starch waste and xylose were closely related to Prevotella and Blautia. Acetate was the predominant organic acid from all enrichments. The organic acid production profiles corresponded to a mixed acid fermentation but differed depending on the substrate. Eight phylogenetically different isolates were obtained, including a novel Streptococcus species, strain Cavy grass 6. This strain had a low abundance (1%) in one of the faecal samples but was enriched in the dried grass enrichment (3%). Cavy grass 6, a fast-growing heterolactic bacterium, ferments cellobiose to lactate, acetate, formate and ethanol. Our results show that cavy faecal samples can be applied as microbial source for organic acid production from complex organic substrates. The cavy gut contains many as-yet-uncultivated bacteria which may be appropriate targets for future studies.</p

Long Lasting Antibodies From Convalescent Pertussis Patients Induce ROS Production and Bacterial Killing by Human Neutrophils.

Pertussis is a respiratory infection caused by the Gram-negative bacterium Bordetella pertussis. Despite high vaccination coverage this disease remains a public health concern worldwide. A better understanding of the protective immune responses to B. pertussis is required for the development of improved vaccines. The aim of this study was to determine the production of reactive oxygen species (ROS) by human neutrophils in response to B. pertussis and to determine the contribution of opsonizing antibodies from convalescent pertussis patients in this response. The serum samples from convalescent patients were taken at <3, 9, 18 and 36 months after diagnosis of pertussis. Also included were sera from healthy age-matched controls. We show that neutrophils produced high levels of ROS in response to opsonized, compared to non-opsonized, B. pertussis and that this effect was independent of the time the convalescent serum samples were taken. This indicates the presence of functional opsonizing antibodies up to 3 years after B. pertussis infection. While opsonization of B. pertussis with serum samples from uninfected controls also induced ROS production, sera from infected individuals induced significantly higher ROS levels. Spearman correlations analysis showed that IgG antibodies targeting fimbriae3 followed by pertactin, and BrkA correlate with ROS production. Additionally, we observed that neutrophils killed opsonized B. pertussis in a ROS-dependent manner. Searching for other antigen-specific antibodies from convalescent pertussis patients involved in ROS production by neutrophils may assist in the identification of novel antigens to improve the current pertussis vaccines

The bacterial sulfur cycle in expanding dysoxic and euxinic marine waters

Dysoxic marine waters (DMW, < 1 μM oxygen) are currently expanding in volume in the oceans, which has biogeochemical, ecological and societal consequences on a global scale. In these environments, distinct bacteria drive an active sulfur cycle, which has only recently been recognized for open-ocean DMW. This review summarizes the current knowledge on these sulfur-cycling bacteria. Critical bottlenecks and questions for future research are specifically addressed. Sulfate-reducing bacteria (SRB) are core members of DMW. However, their roles are not entirely clear, and they remain largely uncultured. We found support for their remarkable diversity and taxonomic novelty by mining metagenome-assembled genomes from the Black Sea as model ecosystem. We highlight recent insights into the metabolism of key sulfur-oxidizing SUP05 and Sulfurimonas bacteria, and discuss the probable involvement of uncultivated SAR324 and BS-GSO2 bacteria in sulfur oxidation. Uncultivated Marinimicrobia bacteria with a presumed organoheterotrophic metabolism are abundant in DMW. Like SRB, they may use specific molybdoenzymes to conserve energy from the oxidation, reduction or disproportionation of sulfur cycle intermediates such as S0 and thiosulfate, produced from the oxidation of sulfide. We expect that tailored sampling methods and a renewed focus on cultivation will yield deeper insight into sulfur-cycling bacteria in DMW

Integrale analyse van kwetsbaarheid voor klimaatveranderingen en aanpassingsmogelijkheden aan klimaatveranderingen in Nederland

Abstract niet beschikbaarIn recent decades, it has become increasingly clear that the global climate is becoming warmer and that regional climates are changing. This report summarizes the results of an integrated assessment of vulnerability to climate change and adaptation options in the Netherlands carried out between July 2000 and July 2001 within the framework of the Dutch National Research Program on Global Air Pollution and Climate Change (NRP-2). The project's main aims were: - to provide an overview of scientific insights, expert judgements and stakeholders' perceptions of current and future impacts (positive and negative) of climate change for several economic sectors, human health, and natural systems in the Netherlands, considering various cross-sectoral interactions, - to develop a set of adaptation options for these sectors through a participatory process with the main stakeholders, - to perform an integrated assessment of cross-sectoral interactions of climate change impacts and adaptation options. Climate change impacts and adaptation options have been investigated for several important economic sectors (including agriculture, forestry, fisheries, industry, energy, transport, insurance and recreation & tourism), human health and natural systems (including soils, water and biodiversity issues).The results of this study are based on literature survey, a dialogue with experts and stakeholders. We are convinced that the report represents the most essential and relevant aspects of the impacts and adaptation options for climate change in the Netherlands, given the scenario setting of this study, the state of the art of current scientific knowledge, and today's expert and stakeholders' perceptions of the issues at stake.SG-NO