Synthetic enzyme supercomplexes: Co-immobilization of enzyme cascades

A sustainable alternative to traditional chemical synthesis is the use of enzymes as biocatalysts. Using enzymes, different advantages such as mild reaction conditions and high turnover rates are combined. However, the approach of using soluble enzymes suffers from the fact that enzymes have to be separated from the product post-synthesis and can be inactivated by this process. Therefore, enzymes are often immobilized to solid carriers to enable easy separation from the product as well as stabilization of the enzyme structure. In order to mimic the metabolic pathways of living cells and thus to create more complex bioproducts in a cell-free manner, a series of consecutive reactions can be realized by applying whole enzyme cascades. As enzymes from different host organisms can be combined, this offers enormous opportunities for creating advanced metabolic pathways that do not occur in nature. When immobilizing this enzyme cascades in a co-localized pattern a further advantage emerges: as the product of the previous enzyme is directly transferred to its co-immobilized subsequent catalyst, the overall performance of the cascade can be enhanced. Furthermore when enzymes are in close proximity to each other, the generation of by-products is reduced and obstructive effects like product inhibition and unfavorable kinetics can be disabled. This review gives an overview of the current state of the art in the application of enzyme cascades in immobilized forms. Furthermore it focuses on different immobilization techniques for structured immobilizates and the use of enzyme cascade in specially designed (microfluidic) reactor devices

Optimization of enzyme immobilization on magnetic microparticles using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a crosslinking agent

Enzyme immobilization is a versatile tool in biotransformation processes to enhance enzyme activity and to secure an easy separation of catalysts and products and the reusability of enzymes. A simple and commonly used method for crosslinking enzymes to a solid support is the zero-length crosslinking agent 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). This work shows the optimization of the EDC-crosslinking protocol for two enzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), to functionalized magnetic microparticles. For GOx the optimization of the immobilization parameters pH-value and the enzyme to particle ratio results in activity yields of up to 36%, which is in the usual range for undirected enzyme immobilisations. In contrast, for HRP the activity yield does not exceed 6% even after optimization of the protocols. The main reasons for this unusually low activity yield are the presence of multiple HRP isoforms in the enzyme solution used for immobilisation and the observed tendency of HRP to be inactive even in the case of simple physisorption to the particle surface. © 2015 The Royal Society of Chemistry

Factors Affecting European Farmers’Participation in Biodiversity Policies

This article reports the major findings from an interdisciplinary research project that synthesises key insights into farmers’ willingness and ability to co-operate with biodiversity policies. The results of the study are based on an assessment of about 160 publications and research reports from six EU member states and from international comparative research.We developed a conceptual framework to systematically review the existent literature relevant for our purposes. This framework provides a common structure for analysing farmers’ perspectives regarding the introduction into farming practices of measures relevant to biodiversity. The analysis is coupled and contrasted with a survey of experts. The results presented above suggest that it is important to view support for practices oriented towards biodiversity protection not in a static sense – as a situation determined by one or several influencing factors – but rather as a process marked by interaction. Financial compensation and incentives function as a necessary, though clearly not sufficient condition in this process

Downscaling of agricultural market impacts under bioeconomy development to the regional and the farm level—An example of Baden‐Wuerttemberg

The expansion of the bioeconomy sector will increase the competition for agricultural land regarding biomass production. Furthermore, the particular path of the expansion of the bioeconomy is associated with great uncertainty due to the early stage of technology development and its dependency on political framework conditions. Economic models are suitable tools to identify trade-offs in agricultural production and address the high uncertainty of the bioeconomy expansion. We present results from the farm model Economic Farm Emission Model of four bioeconomy scenarios in order to evaluate impacts and trade-offs of different potential bioeconomy developments and the corresponding uncertainty at regional and farm level in Baden-Wuerttemberg, Germany. The demand-side effects of the bioeconomy scenarios are based on downscaling European Union level results of a separate model linkage between an agricultural sector and an energy sector model. The general model results show that the expanded use of agricultural land for the bioeconomy sector, especially for the cultivation of perennial biomass crops (PBC), reduces biomass production for established value chains, especially for food and feed. The results also show differences between regions and farm types in Baden-Wuerttemberg. Fertile arable regions and arable farms profit more from the expanded use of biomass in the bioeconomy than farms that focus on cattle farming. Latter farms use the arable land to produce feed for the cattle, whereas arable farms can expand feedstock production for new value chains. Additionally, less intensive production systems like extensive grassland suffer from economic losses, whereas the competition in fertile regions further increases. Hence, if the extensive production systems are to be preserved, appropriate subsidies must be provided. This emphasizes the relevance of downscaling aggregated model results to higher spatial resolution, even as far as to the decision maker (farm), to identify possible contradicting effects of the bioeconomy as well as policy implications.Ministerium für Wissenschaft, Forschung und Kunst Baden‐Württemberg http://dx.doi.org/10.13039/501100003542Peer Reviewe

The blood vasculature instructs lymphatic patterning in a SOX7-dependent manner

Despite a growing catalog of secreted factors critical for lymphatic network assembly, little is known about the mechanisms that modulate the expression level of these molecular cues in blood vascular endothelial cells (BECs). Here, we show that a BECspecific transcription factor, SOX7, plays a crucial role in a noncell-autonomous manner by modulating the transcription of angiocrine signals to pattern lymphatic vessels. While SOX7 is not expressed in lymphatic endothelial cells (LECs), the conditional loss of SOX7 function in mouse embryos causes a dysmorphic dermal lymphatic phenotype. We identify novel distant regulatory regions in mice and humans that contribute to directly repressing the transcription of a major lymphangiogenic growth factor (Vegfc) in a SOX7-dependent manner. Further, we show that SOX7 directly binds HEY1, a canonical repressor of the Notch pathway, suggesting that transcriptional repression may also be modulated by the recruitment of this protein partner at Vegfc genomic regulatory regions. Our work unveils a role for SOX7 in modulating downstream signaling events crucial for lymphatic patterning, at least in part via the transcriptional repression of VEGFC levels in the blood vascular endothelium.Ivy K N Chiang ... Natasha L Harvey ... et al

Agri-environmental Instruments for an Integrated Rural Policy: An Economic Analysis

The new Rural Development Regulation of the EU reflects the shift of attention within rural areas from agricultural production towards rural development and embraces both farmers and non-farm residents. While agricultural production is required to comply with environmental standards, rural areas also have to fulfil the growing demand for landscape, outdoor recreation and wildlife conservation. This paper develops a model of a rural area where farmers and non-farm residents live together. A central government uses a combination of two-policy instruments - direct compensation payments and public services - aimed at encouraging farmers to adopt environmentally beneficial practices and at the same time to increase the provision of countryside amenities and the sustained vitality of the rural area. The optimal mix of the policy instruments is evaluated under various governmental objectives. The analysis suggests that a combination of direct payments to farmers with the supply of local public services is a promising tool for policy development initiatives in the EU