Extremofiele micro-organismen: some like it hot

Een duik nemen in de Noordzee op nieuwjaarsdag vinden we behoorlijk stoer. De Russen doen er een schepje bovenop door het begin van de winter te vieren met een duik in ijswater van nul graden. Dat valt best wel mee, zeker wanneer je dit afwisselt met een bezoek aan de sauna met een luchttemperatuur van 90 graden. Hiermee hebben we de extremen die we als mens kunnen trotseren echter wel gehad. Wat te denken van een duik in kokend water, zwemmen in een zwembad gevuld met azijn of ammonia, of kokend zwavelzuur? Wat voor ons onmogelijk is, is voor veel micro-organismen de normaalste zaak van de werel

Divergent roles of CprK paralogues from Desulfitobacterium hafniense in activating gene expression

Gene duplication and horizontal gene transfer play an important role in the evolution of prokaryotic genomes. We have investigated the role of three CprK paralogues from the cAMP receptor protein-fumarate and nitrate reduction regulator (CRP-FNR) family of transcriptional regulators that are encoded in the genome of Desulfitobacterium hafniense DCB-2 and possibly regulate expression of genes involved in the energy-conserving terminal reduction of organohalides (halorespiration). The results from in vivo and in vitro promoter probe assays show that two regulators (CprK1 and CprK2) have an at least partially overlapping effector specificity, with preference for ortho-chlorophenols, while meta-chlorophenols proved to be effectors for CprK4. The presence of a potential transposase-encoding gene in the vicinity of the cprK genes indicates that their redundancy is probably caused by mobile genetic elements. The CprK paralogues activated transcription from promoters containing a 14 bp inverted repeat (dehalobox) that closely resembles the FNR-box. We found a strong negative correlation between the rate of transcriptional activation and the number of nuclecitide changes from the optimal dehalobox sequence (TTAAT-N-4-ATTAA). Transcription was initiated by CprK4 from a promoter that is situated upstream of a gene encoding a methyl-accepting chemotaxis protein. This might be the first indication of taxis of an anaerobic bacterium to halogenated aromatic compounds

Structural Features of a Hyperthermostable Endo-β-1,3-glucanase in Solution and Adsorbed on “Invisible” Particles

AbstractConformational characteristics and the adsorption behavior of endo-β-1,3-glucanase from the hyperthermophilic microorganism Pyrococcus furiosus were studied by circular dichroism, steady-state and time-resolved fluorescence spectroscopy, and calorimetry in solution and in the adsorbed state. The adsorption isotherms were determined on two types of surfaces: hydrophobic Teflon and hydrophilic silica particles were specially designed so that they do not interact with light and therefore do not interfere with spectroscopic measurements. We present the most straightforward method to study structural features of adsorbed macromolecules in situ using common spectroscopic techniques. The enzyme was irreversibly adsorbed and immobilized in the adsorbed state even at high temperatures. Adsorption offered further stabilization to the heat-stable enzyme and in the case of adsorption on Teflon its denaturation temperature was measured at 133°C, i.e., the highest experimentally determined for a protein. The maintenance of the active conformation and biological function particularly at high temperatures is important for applications in biocatalysis and biotechnology. With this study we also suggest that nature may employ adsorption as a complementary mode to maintain structural integrity of essential biomolecules at extreme conditions of temperature

Hot Transcriptomics

DNA microarray technology allows for a quick and easy comparison of complete transcriptomes, resulting in improved molecular insight in fluctuations of gene expression. After emergence of the microarray technology about a decade ago, the technique has now matured and has become routine in many molecular biology laboratories. Numerous studies have been performed that have provided global transcription patterns of many organisms under a wide range of conditions. Initially, implementation of this high-throughput technology has lead to high expectations for ground breaking discoveries. Here an evaluation is performed of the insight that transcriptome analysis has brought about in the field of hyperthermophilic archaea. The examples that will be discussed have been selected on the basis of their impact, in terms of either biological insight or technological progress

Innovation Dynamics of Socio-Technical Alignment in Community Energy Storage:The Cases of DrTen and Ecovat

With energy transition gaining momentum, energy storage technologies are increasingly spotlighted as they can effectively handle mismatches in supply and demand. The decreasing cost of distributed energy generation technologies and energy storage technologies as well as increasing demand for local flexibility is opening up new possibilities for the deployment of energy storage technologies in local energy communities. In this context, community energy storage has potential to better integrate energy supply and demand at the local level and can contribute towards accommodating the needs and expectations of citizens and local communities as well as future ecological needs. However, there are techno-economical and socio-institutional challenges of integrating energy storage technologies in the largely centralized present energy system, which demand socio-technical innovation. To gain insight into these challenges, this article studies the technical, demand and political articulations of new innovative local energy storage technologies based on an embedded case study approach. The innovation dynamics of two local energy storage innovations, the seasalt battery of DrTen® and the seasonal thermal storage Ecovat®, are analysed. We adopt a co-shaping perspective for understanding innovation dynamics as a result of the socio-institutional dynamics of alignment of various actors, their articulations and the evolving network interactions. Community energy storage necessitates thus not only technical innovation but, simultaneously, social innovation for its successful adoption. We will assess these dynamics also from the responsible innovation framework that articulates various forms of social, environmental and public values. The socio-technical alignment of various actors, human as well as material, is central in building new socio-technical configurations in which the new storage technology, the community and embedded values are being developed

Geography in The Netherlands

Geographical thought in Dutch society In May 1999, after years of preparation, the EU Council of Ministers approved the European Spatial Development Perspective (ESDP), a non-binding framework for spatial and regional policies at a European scale. The Netherlands had been one of the pioneers of this project. The ESDP had been given a substantial stimulus at the June 1997 conference of EU Ministers in the Dutch seaside resort of Noordwijk, a meeting about the (un)desirability and feasibility o..

Being a Better Neighbor:A Value-Based Perspective on Negotiating Acceptability of Locally-Owned Wind Projects

We pose that instead of problematizing negative attitudes of local stakeholders, such as citizens and NGOs, wind energy implementers should be more focused on scrutinizing the acceptability of their projects. The emphasis in this study is on the potential for representation of local stakeholders’ values in the project design, including amongst others business model and placement. Informed by value sensitive design literature, we analyzed two contrasting, locally-owned wind projects in the Dutch province of Groningen: the implementation of mini-turbines in a national landscape and a large-scale multi MW wind project in an industrialized area close to a World Heritage nature reserve. The study analyses how the respective farmer-developers and other local stakeholders attempted to resolve or ameliorate inter-and intra-value conflicts regarding livability, economy, landscape, and nature. The value conflicts turned out to be fruitful to identifying key issues and creating more widely shared value conceptualizations and design priorities. Hence, from this study it can be concluded that value conflict can be productive if carefully unpacked and managed. Uneven power distribution among stakeholders in the planning process, overcoming incommensurability of perspectives, and creating intersubjectivity remain challenges

Fortuitous structure determination of ‘as-isolated’ Escherichia coli bacterioferritin in a novel crystal form

E. coli bacterioferritin was crystallized in a novel crystal form from different conditions and the structure was solved. The crystals belonged to space group P213 and diffracted to a resolution of 2.5 Å