Long-term farming systems comparisons in the tropics Participatory technology development

Posterpresentation - Overview - Approaches and Results - Methodological Questions - Discussio

Impact of different alginate lyases on combined cellulase–lyase saccharification of brown seaweed

Alginate attack characteristics and impact on cellulase–lyase catalyzed saccharification of brown seaweed were compared for three microbial PL7 alginate lyases (EC 4.2.2.-) two of them heterologously expressed in Escherichia coli as part of the work.</p

Design of Trypanosoma rangeli sialidase mutants with improved trans-sialidase activity

A sialidase (EC 3.2.1.18) from the non-pathogenic Trypanosoma rangeli, TrSA, has been shown to exert trans-sialidase activity after mutation of five specific amino acids in the active site (M96V, A98P, S120Y, G249Y, Q284P) to form the so-called TrSA5mut enzyme. By computational and hypothesis driven approaches additional mutations enhancing the trans-sialidase activity have been suggested. In the present work, we made a systematic combination of these mutations leading to seven new variants of the T. rangeli sialidase, having 6-16 targeted amino acid mutations. The resulting enzyme variants were analyzed via kinetics for their ability to carry out trans-sialidase reaction using CGMP and D-lactose as substrates. The sialidase variants with 15 and 16 mutations, respectively, exhibited significantly improved trans-sialidase activity for D-lactose sialylation. Our results corroborate, that computational studies of trans-glycosylation can be a valuable input in the design of novel trans-glycosidases, but also highlight the importance of experimental validation in order to assess the performance. In conclusion, two of the seven mutants displayed a dramatic switch in specificity from hydrolysis towards trans-sialylation and constitute the most potent trans-sialidase mutants of TrSA described in literature to date

Metabolic engineering of Saccharomyces cerevisiae to harness natures valuable compounds

Nature contains a treasure trove of small molecule ingredients that can improve health, wellness and nutrition. However, most of these ingredients have “issues”: the organism that makes the compound of interest is too rare, too hard to grow or does not make enough of it. Hence, the ingredient is not available at the right quality, the right price nor the necessary amount. These issues need to be solved in order to allow a larger society having access to these valuable ingredients in a sustainable manner at low costs. Evolva is leader in metabolic engineering of yeast for the production by fermentation of a diverse array of small molecule ingredients. The small molecule ingredients introduced to the market by Evolva include Resveratrol, Nootkatone, Valencene and Vanillin. Evolva and its commercial partner will launch the next-generation stevia sweetener EverSweetTM in 2018. All of these molecules are produced in a sustainable, reliable, cost-effective production at consistent quality by fermentation of engineered yeast strains, using abundant, inexpensive raw materials. Of particular interest to Evolva are the terpenes, which are known to work in a wide range of high value applications including sweeteners, flavors and fragrances, personal care, as well as human and animal health products. In spite of proven efficacy, there has been relatively little commercial development of terpene-based ingredients, mostly due to their high production cost. Here, we will present a number of terpene-based Evolva ingredient projects such as e.g. the stevia pathway, which use Evolva’s technology platforms, allowing us to produce these ingredients in an efficient and sustainable way. Please click Additional Files below to see the full abstract

It All Starts with a Sandwich: Identification of Sialidases with Trans-Glycosylation Activity

Sialidases (3.2.1.18) may exhibit trans-sialidase activity to catalyze sialylation of lactose if the active site topology is congruent with that of the Trypanosoma cruzi trans-sialidase (EC 2.4.1.-). The present work was undertaken to test the hypothesis that a particular aromatic sandwich structure of two amino acids proximal to the active site of the T. cruzi trans-sialidase infers trans-sialidase activity. On this basis, four enzymes with putative trans-sialidase activity were identified through an iterative alignment from 2909 native sialidases available in GenBank, which were cloned and expressed in Escherichia coli. Of these, one enzyme, SialH, derived from Haemophilus parasuis had an aromatic sandwich structure on the protein surface facing the end of the catalytic site (Phe168; Trp366), and was indeed found to exhibit trans-sialidase activity. SialH catalyzed production of the human milk oligosaccharide 3'-sialyllactose as well as the novel trans-sialylation product 3-sialyllactose using casein glycomacropeptide as sialyl donor and lactose as acceptor. The findings corroborated that Tyr119 and Trp312 in the T. cruzi trans-sialidase are part of an aromatic sandwich structure that confers trans-sialylation activity for lactose sialylation. The in silico identification of trans-glycosidase activity by rational active site topology alignment thus proved to be a quick tool for selecting putative trans-sialidases amongst a large group of glycosyl hydrolases. The approach moreover provided data that help understand structure-function relations of trans-sialidases

Identifying PLM themes and clusters from a decade of research literature

Product lifecycle management (PLM) encompasses a wide array of expertise, from designing green products to knowledge representation techniques. This paper characterises PLM as a research domain through the themes and clusters of a decade of scientific literature. Authors’ keywords from 1,390 research papers published from 2005 to 2015 are analysed. The co-occurrence of these 2,947 normalised authors’ keywords, connected in pairs via 11,289 edges, indicates how PLM research themes relate to each other to form communities – or clusters. These communities are revealed by filtering the network according to the weights of the network’s edges. The PLM core cluster, the PLM global cluster and the PLM overall cluster are distinguished based on the level of filtering, thus unveiling increasing levels of detail. The four major communities composing the PLM global cluster are ‘interoperability’, ‘ontology’, ‘product data management’ and ‘lifecycle assessment’. The PLM overall cluster also reveals the ‘intelligent product’ community, which relates to the Industry 4.0 phenomenon. The BIM community is revealed as well, but remains isolated from the PLM overall cluster