Spongiibacter marinus gen. nov., sp. nov., a halophilic marine bacterium isolated from the boreal sponge Haliclona sp. 1

Strain HAL40bT was isolated from the marine sponge Haliclona sp. 1 collected at the Sula Ridge off the Norwegian coast and characterized by physiological, biochemical and phylogenetic analyses. The isolate was a small rod with a polar flagellum. It was aerobic, Gram-negative and oxidase- and catalase-positive. Optimal growth was observed at 20–30 °C, pH 7–9 and in 3 % NaCl. Substrate utilization tests were positive for arabinose, Tween 40 and Tween 80. Enzyme tests were positive for alkaline phosphatase, esterase lipase (C8), leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and N-acetyl-β-glucosaminidase. The predominant cellular fatty acid was C17 : 1 ω8, followed by C17 : 0 and C18 : 1 ω7. Analysis by matrix-assisted laser desorption/ionization time-of-flight MS was used to characterize the strain, producing a characteristic low-molecular-mass protein pattern that could be used as a fingerprint for identification of members of this species. The DNA G+C content was 69.1 mol%. Phylogenetic analysis supported by 16S rRNA gene sequence comparison classified the strain as a member of the class Gammaproteobacteria. Strain HAL40bT was only distantly related to other marine bacteria including Neptunomonas naphthovorans and Marinobacter daepoensis (type strain sequence similarity >90 %). Based on its phenotypic, physiological and phylogenetic characteristics, it is proposed that the strain should be placed into a new genus as a representative of a novel species, Spongiibacter marinus gen. nov., sp. nov.; the type strain of Spongiibacter marinus is HAL40bT (=DSM 17750T =CCUG 54896T)

The deep-subsurface sulfate reducer Desulfotomaculum kuznetsovii employs two methanol-degrading pathways

Methanol is generally metabolized through a pathway initiated by a cobalamine-containing methanol methyltransferase by anaerobic methylotrophs (such as methanogens and acetogens), or through oxidation to formaldehyde using a methanol dehydrogenase by aerobes. Methanol is an important substrate in deep-subsurface environments, where thermophilic sulfate-reducing bacteria of the genus Desulfotomaculum have key roles. Here, we study the methanol metabolism of Desulfotomaculum kuznetsovii strain 17T, isolated from a 3000-m deep geothermal water reservoir. We use proteomics to analyze cells grown with methanol and sulfate in the presence and absence of cobalt and vitamin B12. The results indicate the presence of two methanol-degrading pathways in D. kuznetsovii, a cobalt-dependent methanol methyltransferase and a cobalt-independent methanol dehydrogenase, which is further confirmed by stable isotope fractionation. This is the first report of a microorganism utilizing two distinct methanol conversion pathways. We hypothesize that this gives D. kuznetsovii a competitive advantage in its natural environment.Research was funded by grants of the Division of Chemical Sciences (CW-TOP 700.55.343) and Earth and Life Sciences (ALW 819.02.014) of The Netherlands Organisation for Scientific Research (NWO), the European Research Council (ERC grant 323009), and the Gravitation grant (024.002.002) of the Netherlands Ministry of Education, Culture and Scienceinfo:eu-repo/semantics/publishedVersio

Limits of Life and the Habitability of Mars: The ESA Space Experiment BIOMEX on the ISS

BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports—among others—the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit

Studies on the electrochemical disinfection of water containing Escherichia coli using a Dimensionally Stable Anode

The aim of this work was to investigate the disinfectant effect of electrolysis on chlorine-free water, artificially contaminated with Escherichia coli (CCT-1457) and to evaluate the bactericidal activity of electrolysis and kinetic behavior of a single-cell reactor, with a DSA (Dimensionally Stable Anode) electrode to develop a scaled-up system. A high-density E. coli suspension (10(6) CFU mL-1) was electrolyzed in this reactor at 25, 50 and 75 mA cm-2 for up to 60 min, at flow rates of 200 and 500 L h-1. Bacterial survival fell by 98.9% without addition of chlorinated compounds and a power consumption rate not more than 5.60 kWh m-3 at flow rate of 200 L h-1 and 75 mA cm-2. The process produced a germicidal effect that reached this inactivation rate within a relatively short contact time. Also, a solution of electrolyzed 0.08 M Na2SO4 added to the inoculum showed residual bactericidal effect. The efficiency of disinfection was regulated by both the contact time and current density applied, and a kinetic function for the survival rate was developed for the purpose of scaling up.Água contaminada é uma das maiores origens de doenças em seres humanos. Em todo o mundo, a cloração é o método mais utilizado para promover desinfecção em águas de abastecimento devido ao seu efeito residual, quando adequadamente calculado. Contudo, se a água apresentar matéria orgânica, pode haver a geração de organoclorados, os quais são genotóxicos e carcinogênicos. Sob esta óptica, investigamos o efeito bactericida da aplicação da eletrólise em água sem cloro contaminada com Escherichia coli (CCT-1457). O objetivo deste estudo foi avaliar o poder de desinfecção e o comportamento cinético da eletrólise realizada em reator de compartimento único e usando eletrodos ADE (Anodo Dimensionalmente Estável), visando ampliação de escala. Uma suspensão contendo elevada concentração de E. coli (10(6) UFC mL-1) foi submetida ao tratamento no reator em 25, 50 e 75 mA cm-2 durante 60 min, em vazões de 200 e 50 Lh-1. A taxa de inativação foi aproximadamente 99% para a solução isenta de compostos clorados, com consumo de energia elétrica menor que 5,60 kWh m-3 em 200 L h-1 e 75 mA cm-2. Uma solução de Na2SO4 0,08M eletrolisada e adicionada posteriormente ao inoculo apresentou efeito residual bactericida. A eficiência da desinfecção foi regida pelo tempo de contato e pela densidade de corrente aplicada, e foi realizado um estudo cinético que permite a ampliação de escala

Microbial analysis of in situ biofilm formation in drinking water distribution systems: implications for monitoring and control of drinking water quality.

Biofilm formation in drinking water distribution systems (DWDS) is influenced by the source water, the supply infrastructure and the operation of the system. A holistic approach was used to advance knowledge on the development of mixed species biofilms in situ, by using biofilm sampling devices installed in chlorinated networks. Key physico-chemical parameters and conventional microbial indicators for drinking water quality were analysed. Biofilm coverage on pipes was evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The microbial community structure, bacteria and fungi, of water and biofilms was assessed using pyrosequencing. Conventional wisdom leads to an expectation for less microbial diversity in groundwater supplied systems. However, the analysis of bulk water showed higher microbial diversity in groundwater site samples compared with the surface water site. Conversely, higher diversity and richness were detected in biofilms from the surface water site. The average biofilm coverage was similar among sites. Disinfection residual and other key variables were similar between the two sites, other than nitrates, alkalinity and the hydraulic conditions which were extremely low at the groundwater site. Thus, the unexpected result of an exceptionally low diversity with few dominant genera (Pseudomonas and Basidiobolus) in groundwater biofilm samples, despite the more diverse community in the bulk water, is attributed to the low-flow hydraulic conditions. This finding evidences that the local environmental conditions are shaping biofilm formation, composition and amount, and hence managing these is critical for the best operation of DWDS to safeguard water quality

Degradation of haloaromatic compounds

An ever increasing number of halogenated organic compounds has been produced by industry in the last few decades. These compounds are employed as biocides, for synthetic polymers, as solvents, and as synthetic intermediates. Production figures are often incomplete, and total production has frequently to be extrapolated from estimates for individual countries. Compounds of this type as a rule are highly persistent against biodegradation and belong, as "recalcitrant" chemicals, to the class of so-called xenobiotics. This term is used to characterise chemical substances which have no or limited structural analogy to natural compounds for which degradation pathways have evolved over billions of years. Xenobiotics frequently have some common features. e.g. high octanol/water partitioning coefficients and low water solubility which makes for a high accumulation ratio in the biosphere (bioaccumulation potential). Recalcitrant compounds therefore are found accumulated in mammals, especially in fat tissue, animal milk supplies and also in human milk. Highly sophisticated analytical techniques have been developed for the detection of organochlorines at the trace and ultratrace level

Growth and survival of Serratia marcescens under aerobic and anaerobic conditions in the presence of materials from blood bags

Several patients receiving blood transfusions during the summer of 1991 developed bacteremia after the transfusion. In all cases, the infection was caused by Serratia marcescens. The same strain of Serratia marcescens was isolated from the patients and from the outer surface of unfilled blood bags. The transport containers for the blood bags were made anoxic by using a catalyst in order to prevent microbial growth. The survival and growth of S. marcescens K202, which was isolated from the blood bags, was studied at different oxygen concentrations in deionized water containing materials derived from the blood bags. The rate of survival and growth of S. marcescens was highest under anaerobic conditions, in which growth occurred with all materials and even in deionized water alone. In contrast, S. marcescens did not survive in control cultures under semi-anaerobic and aerobic conditions. Growth was observed, however, under both aerobic and semi-anaerobic conditions in the presence of each of the tested blood bag materials. These findings indicate that the conditions in the transport containers for the blood bags were favorable for the survival and growth of S. marcescens.</jats:p