Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Biofuel burning and human respiration bias on satellite estimates of fossil fuel CO2emissions
    Ciais, P. ; Wang, Y. ; Andrew, R. ; Bréon, F.M. ; Chevallier, F. ; Broquet, G. ; Nabuurs, G.J. ; Peters, G. ; Mcgrath, M. ; Meng, W. ; Zheng, B. ; Tao, S. - \ 2020
    Environmental Research Letters 15 (2020)7. - ISSN 1748-9318
    biofuels - fossil fuel emissions - satellites

    The satellites that have been designed to support the monitoring of fossil fuel CO2 emissions aim to systematically measure atmospheric CO2 plumes generated by intense emissions from large cities, power plants and industrial sites. These data can be assimilated into atmospheric transport models in order to estimate the corresponding emissions. However, plumes emitted by cities and powerplants contain not only fossil fuel CO2 but also significant amounts of CO2 released by human respiration and by the burning of biofuels. We show that these amounts represent a significant proportion of the fossil fuel CO2 emissions, up to 40% for instance in cities of Nordic countries, and will thus leave some ambiguity in the retrieval of fossil fuel CO2 emissions from satellite concentration observations. Auxiliary information such as biofuel use statistics and radiocarbon measurement could help reduce the ambiguity and improve the framework of monitoring fossil fuel CO2 emissions from space.

    Progress and barriers in understanding and preventing indirect land-use change
    Daioglou, Vassilis ; Woltjer, Geert ; Strengers, Bart ; Elbersen, Berien ; Barberena Ibañez, Goizeder ; Sánchez Gonzalez, David ; Gil Barno, Javier ; Vuuren, Detlef P. van - \ 2020
    Biofuels Bioproducts and Biorefining 14 (2020)5. - ISSN 1932-104X - p. 924 - 934.
    agriculture - bioenergy - biofuels - climate change mitigation - indirect land-use change - modeling

    Climate change mitigation pathways have highlighted both the critical role of land-use emissions, and the potential use of biofuels as a low-emission energy carrier. This has led to concerns about the emission mitigation potential of biofuels, particularly related to indirect land-use change (ILUC). This arises when the production of biofuels displaces the production of land-based products elsewhere, either directly or via changes in crop prices, leading to indirect greenhouse gas (GHG) emissions. We review a large body of literature that has emerged on ILUC assessment and quantification, highlighting the methodologies employed, the resultant emission factors, modeled dynamics driving ILUC, and the uncertainty therein. Our review reveals that improvements in ILUC assessment methods have failed to reduce uncertainty and increase confidence in ILUC factors, instead making marginal improvements to economic models. Thus, while assessments have highlighted measures that could reduce ILUC, it is impossible to control or determine the actual ILUC resulting from biofuel production. This makes ILUC a poor guiding principle for land-use and climate policy, and does not help with the determination of the GHG performance of biofuels. Instead climate and land-use policy should focus on more integrated protection of terrestrial resources, covering all land-use-related products.

    The contribution of biorefineries to rural development: the case of employment in Hungary
    Heijman, W.J.M. ; Szabo, Zoltan ; Veldhuizen, Esther - \ 2019
    Studies in Agricultural Economics 121 (2019). - ISSN 1418-2106 - 12 p.
    biofuels - biofuel policies - ethanol - rural development - input-output analysis - employment
    Most recent research concerning biofuels focuses on their potential for mitigating climate change, while their rural development dimension is given less prominence. Ongoing policy debates, including EU and US biofuel policies, pay little attention to this feature of the industry. This paper explores the impact of biorefineries on rural development, and employment in particular. It shows that biorefineries can have a considerable economic impact on the regions in which they are located. Embedded in the local social and economic fabric, the paper demonstrates their influence on regional and national labour markets. The case of a bioethanol plant in Hungary and its effect on the rural labour market in two counties of the country is studied by way of an input-output model. The research has found that the operation of a biorefinery stimulates the creation and maintenance of jobs in both farming and service industries. Results suggest that biorefineries are an important driver of rural development and that this aspect of the industry should be given greater weight in formulating biofuel policies.
    A different way to approach the biorefinery process | WURcast
    Nikiforidis, K. - \ 2019
    Wageningen : WURcast
    biomass - biorefinery - biobased economy - biofuels - plant residues
    How can we make the best use of biomass while having only a small to zero impact on our environment? Can we utilize all functional fractions available in the biomass via biorefinery? This video answers these questions and more about the biorefinery process.
    De keerzijde van houtstook in open haarden en kachels
    Hein, L.G. - \ 2018
    Milieu (2018)9. - ISSN 0920-2234 - p. 41 - 45.
    biomass - biobased economy - wood - stoves - heat - bioenergy - biofuels
    Het toenemende gebruik van conventionele open haarden en houtkachels levert geen bijdrage aan de
    vermindering van de opwarming van de aarde. Voor het klimaat is het beter het huis te ver warmen
    met de cv-ketel. Daarentegen leveren pelletkachels wel klimaatwinst ten opzichte van de cv-ketel.
    Verder worden voor alle vormen van houtstook de gezondheidseffecten van fi jnstof uit deze bronnen,
    zeker ook voor de stoker zelf, sterk onderschat. Een eerste, voorlopige inschatting is dat het stoken
    van hout jaarlijks leidt tot 900 à 2700 voortijdige sterfgevallen in Nederland. Tenslotte lijken de emis-
    sies van houtstook in de Nederlandse emissieregistratie sterk onderschat te worden. Aanvullende
    maatregelen voor het tegengaan van het stoken van hout zijn wenselijk vanuit zowel gezondheids- als
    klimaatperspectief.
    Toward Sustainable Biofuels in the European Union? Lessons from a Decade of Hybrid Biofuel Governance
    Stattman, S.L. ; Gupta, A. ; Partzsch, Lena ; Oosterveer, P.J.M. - \ 2018
    Sustainability 10 (2018)11. - ISSN 2071-1050
    biofuels - European Union - Renewable Energy Directive (RED) - hybrid governance - sustainability - certification - multi-stakeholder initiatives
    The European Union (EU) stands at a crossroads regarding its biofuel policies. For more than a decade, the EU sought to create a market for and govern sustainable biofuels for the transport sector, even as debates over sustainability escalated. It did so by devising novel hybrid (public and private) governance arrangements. We took stock of the nature and outcomes of this experiment in hybrid biofuel governance. We relied on qualitative methods of analysis, whereby we reviewed and synthesized the evolution of EU biofuel governance arrangements over time, through detailed document analysis of secondary and primary literature, including EU and related policy documents and private certification scheme websites. Our analysis reveals that, instead of yielding an increasingly stringent sustainability framework, the hybrid EU governance arrangements resulted
    in a proliferation of relatively lax, industry-driven, sustainability standards, even as the notion of “sustainable biofuels” remained contested in public and political debate. These findings contribute to an ongoing debate about the merits of hybrid (public–private) governance arrangements, and whether a hybrid approach helps strengthen or weaken sustainability objectives. We conclude that a more stringent EU meta-standard on sustainability needs to be developed, to underpin future governance arrangements.
    Factsheets SYSTEMIC Demonstration Plant
    Schoumans, O.F. ; Regelink, I.C. ; Ehlert, P.A.I. - \ 2018
    Wageningen : Wageningen University & Research - 25 p.
    EU H2020
    SYSTEMIC Newsletter, issue 1
    Schoumans, O.F. ; Regelink, I.C. ; Ehlert, P.A.I. - \ 2018
    Wageningen : Wageningen University & Research - 3 p.
    EU H2020
    ‘We’ve still got a way to go’
    Thoden van Velzen, E.U. ; Molenveld, K. - \ 2018
    recycling - biobased economy - polymers - residual streams - organic wastes - biofuels - bioenergy - renewable energy
    Er is nog veel te winnen
    Thoden van Velzen, E.U. ; Molenveld, K. ; Hugenholtz, J. - \ 2018
    biobased economy - recycling - biobased materials - biomass - residual streams - agricultural wastes - biofuels - bioenergy

    Willen we ons huishoudelijk afval optimaal benutten, dan moeten we de grondstoffen erin efficiënter scheiden en terugwinnen. 'We zijn nog ver verwijderd van het ideale, circulaire beeld.'

    De toekomst van hout in de biobased economy
    Annevelink, E. ; Harmsen, P.F.H. ; Spijker, J.H. - \ 2018
    Vakblad Natuur Bos Landschap 15 (2018)141. - ISSN 1572-7610 - p. 7 - 11.
    biobased economy - hout - biobrandstoffen - biomassa - hernieuwbare energie - materialen uit biologische grondstoffen - cellulose - lignine - vezels - biobased economy - wood - biofuels - biomass - renewable energy - biobased materials - cellulose - lignin - fibres
    De laatste jaren is de biobased economy sterk gegroeid door allerlei activiteiten, variërend van fundamenteel onderzoek naar nieuwe biobased toepassingen, tot het op commerciële schaal vervaardigen van biobased producten. Welke kansen biedt dit voor hout en houtige biomassa en wat zijn de verwachte effecten op de houtmarkt?
    Plant power : environmental technologist set up a business
    Strik, D.P.B.T.B. - \ 2017
    bioenergy - biofuels - residual streams - agricultural wastes
    Why plants are little solar panels
    Schipper, R. - \ 2017
    Wageningen : WURcast
    biobased economy - plants - miscanthus - bioenergy - fibres - biofuels - breeding methods
    What are plants contributing to a biobased society?
    Overheidsmaatregelen biokerosine : mogelijkheden om de vraag naar biokerosine te stimuleren en de effecten op de luchtvaart en de economie
    Faber, Jasper ; Smeets, E.M.W. - \ 2017
    Delft : CE Delft - 112
    biobrandstoffen - biobased economy - kerosine - overheidsbeleid - stimulatie - subsidies - emissiereductie - luchttransport - biofuels - biobased economy - kerosene - government policy - stimulation - subsidies - emission reduction - air transport
    De maatregel met het grootste potentieel om CO2-emissies van de luchtvaart te verminderen is het gebruik van brandstoffen met lage emissies over de levenscyclus, zoals bijvoorbeeld geavanceerde biobrandstoffen gemaakt van residuen uit de bos- en landbouw. Om de luchtvaart te laten bijdragen aan de afname van de wereldwijde emissies is het dus wenselijk een groter aandeel alternatieve duurzame brandstoffen in de luchtvaart in te zetten. Vanwege het prijsverschil tussen fossiele kerosine en biokerosine is hier overheidsbeleid voor nodig. Het doel van deze studie is het beantwoorden van de volgende twee centrale onderzoeksvragen: 1. Met welke beleidsmaatregelen kan de Nederlandse Rijksoverheid de vraag naar en productie van biokerosine laten toenemen? 2. Wat zijn de directe en indirecte effecten van de beleidsmaatregelen?
    Final report: Environmental assessment of algae-based PUFA production
    Keller, H. ; Reinhardt, G. ; Rettenmaier, N. ; Schorb, A. ; Dittrich, M. ; Wolf, P.L. de; Voort, M.P.J. van der; Spruijt, J. ; Potters, J.I. ; Elissen, H.J.H. - \ 2017
    Heidelberg : PUFAChain - 94
    algae - biofuels - bioenergy - biobased economy - biomass - omega-3 fatty acids - plant oils - biobased chemistry - fermentation
    Socio-economic assessment of Algae-based PUFA production : The value chain from microalgae to PUFA ('PUFACHAIN')
    Voort, M.P.J. van der; Spruijt, J. ; Potters, J.I. ; Elissen, H.J.H. - \ 2017
    Göttingen : PUFAChain - 84
    biobased economy - biomass - bioenergy - biofuels - algae - plant oils - omega-3 fatty acids - economic analysis
    Socio-economic assessment of Algae-based PUFA production
    Voort, Marcel van der; Spruijt, Joanneke ; Potters, Jorieke ; Wolf, Pieter de; Elissen, Hellen - \ 2017
    Göttingen : PUFAChain - 84
    bioenergy - biobased economy - biofuels - biomass - algae - fatty acids - bio-energie - biobased economy - biobrandstoffen - biomassa - algen - vetzuren
    Biobased materialen, circulaire economie en natuurlijk kapitaal
    Overbeek, M.M.M. ; Smeets, E.M.W. ; Verhoog, A.D. - \ 2017
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 109) - 37
    biomassa - biobased economy - materialen uit biologische grondstoffen - bioplastics - hernieuwbare energie - duurzaamheid (sustainability) - biobrandstoffen - recycling - chemie op basis van biologische grondstoffen - biomass - biobased economy - biobased materials - bioplastics - renewable energy - sustainability - biofuels - recycling - biobased chemistry
    This preliminary study investigates the amount of biomass that would be needed in the Netherlands to replace the fossil raw materials used in the manufacture of plastics and how this transition to biobased plastics can be achieved. It is based on desk research and calculations of the area of agricultural land that would be needed to produce sufficient biobased material to meet Dutch demand for biobased plastics. In addition, interviews were held with experts on the institutional obstacles to such a transition. Far too little agricultural land is available in the Netherlands to produce the required amount of biomass needed to replace fossil plastics. Research with the aim of increasing the contribution made by biobased materials to the circular economy should focus on assessing the options for producing sustainable raw materials and on a comprehensive assessment of the sustainable use of biomass in various applications.
    Circular food chains and cascading of biomass in metropolitan regions : Vision on metropolitan biorefinery concepts in relation to resource-efficient cities
    Annevelink, E. ; Gogh, J.B. ; Groot, J.J. - \ 2017
    Wageningen : Wageningen Food & Biobased Research (Wageningen Food & Biobased Research report 1790) - ISBN 9789463437424 - 18
    biomass - bioenergy - residual streams - refining - biofuels - biobased economy - biogas - biomassa - bio-energie - reststromen - raffineren - biobrandstoffen - biobased economy - biogas
    Expectations are that 80 percent of the global population will reside in urban areas by the year 2050. As urbanisation levels increase so do ecological footprint sizes in these areas, as it is in the cities that income levels are higher, and where higher levels of disposable incomes exist. Whereas the circular economy is gaining ground as a concept for increasing sustainability by the efficient use of available materials and resources, urban areas are often recognised as attractive starting points for making the transition towards a circular economy. The paper “Circular food chains and cascading of biomass in metropolitan regions” contains the description of a vision on how biorefinery concepts in current and future metropoles may contribute to the increased efficiency in the use of resources for biomass production. As such this vision forms the interpretation of the principles of the circular economy within the context of biomass value chains and within the geographic boundaries of a metropolitan region. This is also referred to as the circular metropolitan system. With this paper researchers from Wageningen Food & Biobased Research intend to contribute to a scientific basis for increasing resource use efficiency in metropolitan regions through developing appropriate and sustainable biorefinery concepts.
    Innovatieve technologie in beheer en oogst van houtige biomassa : eindrapportage
    Raa, Rik te; Pfau, S. ; Clerkx, A.P.P.M. ; Massop, Hans ; Hissink, H.J. - \ 2017
    BTG Biomass Technology Group - 57
    bio-energie - biobased economy - biobrandstoffen - hout - biomassa productie - bosbeheer - bioenergy - biobased economy - biofuels - wood - biomass production - forest administration
    Opiniestuk sustainable development goals : transities realiseren met duurzaam bodem - en landgebruik
    Mol, G. ; Cleen, M. de; Molenaar, Co ; Keesstra, S. ; Visser, S. ; Okx, J. - \ 2017
    Wageningen : Wageningen University and Research - 7
    duurzame energie - biobased economy - biobrandstoffen - biogas - overheidsbeleid - klimaat - bio-energie - reststromen - hernieuwbare energie - energiebeleid - sustainable energy - biobased economy - biofuels - biogas - government policy - climate - bioenergy - residual streams - renewable energy - energy policy
    In 2015 hebben de Verenigde Naties de Duurzame Ontwikkelingsdoelen – beter bekend als de Sustainable Development Goals of kortweg SDGs – aangenomen als de weg waarlangs ze de meest urgente problemen op het gebied van armoede, honger, maar ook onderwijs, economie, en milieu en klimaat wil aanpakken. De ambities, geformuleerd in de 17 SDGs, zijn verstrekkend en hoog. In verschillende Nederlandse beleidsdocumenten1234567 wordt daarom aangegeven dat hiervoor serieuze maatschappelijke transities nodig zijn zoals op het gebied van energie en klimaat, voedselvoorziening en circulaire economie, mobiliteit en leefbare steden. Voor veel van deze transities is duurzaam gebruik en beheer van bodem, water en land een essentieel onderdeel. Dit opiniestuk heeft als doel de rol van duurzaam bodem- en landgebruik te benadrukken en de urgentie ervan agenderen voor de maatschappelijke transities waar Nederland voor staat. En laten zien dat de maatschappelijke opgaven te complex zijn voor een sectorale aanpak. Integrale benadering en goede samenwerking tussen alle stakeholders zijn nodig om te komen tot duurzame oplossingen. Het is raadzaam hier voortvarend werk van te maken; de bodem is een traag systeem, dus 2030 – het jaar waarin de SDGs moeten zijn gerealiseerd – is al morgen.
    Fermentatie is hot: nieuwe toepassingen van een oeroude techniek
    Smid, E.J. ; Hugenholtz, J. - \ 2017
    biofuels - biobased economy - bioenergy - chemical industry - nutrition - fermentation - cellulose - bacteria - biomass
    Biodigestion at the Neighbourhood Level : from community participation to waste separation
    Hiemstra, J. ; Lie, R. ; Rietveld, M. - \ 2017
    Urban Agriculture Magazine (2017)32. - ISSN 1571-6244 - p. 49 - 51.
    bio-energie - biobrandstoffen - biobased economy - reststromen - projecten - co-vergisting - digestaat - hernieuwbare energie - energiebronnen - organisch afval - recycling - bioenergy - biofuels - residual streams - projects - co-fermentation - digestate - renewable energy - energy sources - organic wastes
    Urban Agriculture magazine • number 32 • September 2017 49 www.ruaf.org High energy bills and litter on the streets caused a group of residents of the Wildeman neighbourhood in the district of Osdorp in Amsterdam to act. Expecting no solution from the municipality, they decided to take care of it themselves and tackled these two problems with one solution: using the technology of biodigestion to produce energy from municipal food waste - a perfect example of the urban food-waste-energy nexus.
    Groene Cirkels : Resultaatrapportage
    Steingröver, E.G. ; Vos, C.C. - \ 2017
    Wageningen : Groene Cirkels - 15
    bio-energie - biobrandstoffen - biobased economy - duurzame energie - indicatoren - biomassa - bioenergy - biofuels - biobased economy - sustainable energy - indicators - biomass
    Met de resultaatmeting wil Groene Cirkels inzichtelijk maken wat er bereikt is ten aanzien van het bereiken van onze doelen en ambities. Met deze informatie wil Groene Cirkels effectief sturen op het behalen van de ambities en inzicht geven in de bijdragen en resultaten van de diverse thema-activiteiten en Groene Cirkels
    The SEEA EEA carbon account for the Netherlands
    Lof, Marjolein ; Schenau, Sjoerd ; Jong, Rixt de; Remme, Roy ; Graveland, Cor ; Hein, Lars - \ 2017
    The Hague : Statistics Netherlands - 64
    carbon dioxide - netherlands - carbon - economics - environment - biofuels - bioenergy - biogas - emission - kooldioxide - nederland - koolstof - economie - milieu - biobrandstoffen - bio-energie - biogas - emissie
    The carbon account provides a comprehensive overview of all relevant carbon stocks and flows. The carbon account for the Netherlands was developed within the scope of the ‘System of Environmental Economic Accounts – Experimen tal Ecosystem Accounting’ (SEEA EEA) project for the Netherlands (Natuurlijk Kapitaalrekeningen Nederland: NKR_NL), which is currently c arried out jointly by Statistics Netherlands and Wageningen University. Funding and support was provided by the Ministries of Economic Affairs and Infrastructure and the Environment. Within the NKR_NL project, a number of accounts are currently under devel opment. The carbon account is described in detail in this report.
    Sustainable woodfuel for food security : A smart choice: green, renewable and affordable
    Sooyeon, Laura Jln ; Schure, J.M. ; Ingram, V.J. ; Yoo, Byoung Il ; Reeb, Dominique ; Xia, Zuzhang ; Perlis, Andrea ; Nordberg, Mats ; Campbell, Jeffrey ; Muller, Eva - \ 2017
    FAO - ISBN 9789251099629 - 35
    biobased economy - biofuels - bioenergy - wood - biomass - heat - biobased economy - biobrandstoffen - bio-energie - hout - biomassa - warmte
    With food insecurity, climate change and deforestation and forest degradation remaining key global issues, this paper highlights the role of sustainable woodfuel in improving food security. Food insecurity and a high dependence on woodfuel as a primary cooking fuel are characteristics common to vulnerable groups of people in developing regions of the world.With adequate policy and legal frameworks in place, woodfuel production and harvesting can be sustainable and a main source of green energy. Moreover, the widespread availability of woodfuel, and the enormous market for it, presents opportunities for employment and for sustainable value chains, providing further rationale for promoting this source of energy. This paper explains how sustainable woodfuel is closely linked to food security and provides insights in how the linkages could be strengthened at all stages of woodfuel production, trade and use.
    Measurements of transcripts, proteome and metabolite profiles
    Peters, Sander - \ 2017
    Fuel4Me - 7
    biobased economy - biobrandstoffen - algen - algenteelt - oliën - biobased economy - biofuels - algae - algae culture - oils
    The work described for this deliverable was carried out by DLO-PRI, in collaboration with WU, and aim ed to understanding lipid production in Phaeodactylum tricornutum . By means of transcriptome, proteome and metabolome analyses we aimed to provide insight into the one step lipid production performed by partner WU. Cultivation conditions were chosen to steer lipid profile towards most suitable composition for biofuel production.
    Photosynthetic efficiency in microalgal lipid production
    Remmers, Ilse M. - \ 2017
    Wageningen University. Promotor(en): R.H. Wijffels, co-promotor(en): P.P. Lamers. - Wageningen : Wageningen University - ISBN 9789463434607 - 200
    algae - biofuels - light - triacylglycerols - lipids - metabolism - algae culture - cultural methods - algen - biobrandstoffen - licht - triacylglycerolen - lipiden - metabolisme - algenteelt - cultuurmethoden

    Microalgae can contain large amounts of lipids which make them a promising feedstock for sustainable production of food, feed, fuels and chemicals. Various studies, including pilot-scale, have been performed and the knowledge on microalgal processes has advanced quickly. Unfortunately, current production costs for cultivation are still too high for bulk lipid production from microalgae.

    One of the major causes for the high costs of bulk lipid production is the reduced solar-to-lipid conversion efficiency. Current research, however, does not provide sufficient insight to identify optimization targets. Therefore, in this thesis we have studied the lipid production in microalgae in depth.

    Different TAG-accumulation strategies were investigated from a process engineering and metabolic point of view. The combination of all findings were used in the general discussion to thoroughly evaluate the microalgal lipid accumulation strategies. Current phototrophic microalgal lipid yields are still 10 times lower than the theoretical maximum. There is, however, still an enormous potential for further improvements. Future research should focus on (genetically) improved strains and advanced cultivation strategies, including adaptation to fluctuating outdoor weather conditions.

    This thesis was performed within the EU FP7 FUEL4ME project under grand agreement No 308938. Objective of this program is to develop a sustainable and scalable process for biofuels from microalgae and to valorize the by-products.

    Exploring opportunities for rural livelihoods and food security in Central Mozambique
    Leonardo, Wilson José - \ 2017
    Wageningen University. Promotor(en): K.E. Giller, co-promotor(en): G.W.J. van de Ven; H.M.J. Udo. - Wageningen : Wageningen University - ISBN 9789463431651 - 183
    agricultural production systems - food security - crop production - livelihoods - small farms - biofuels - farming systems - models - intensification - mozambique - agrarische productiesystemen - voedselzekerheid - gewasproductie - middelen van bestaan - kleine landbouwbedrijven - biobrandstoffen - bedrijfssystemen - modellen - intensivering - mozambique

    Growing awareness of widespread hunger and poverty in many countries in the SSA is spurring a focus on productivity increase in smallholder farming systems. The rationale is that with current production systems many SSA countries are not keeping pace with population growth and changing of peoples’ lifestyles. To respond to this challenge the Government of Mozambique developed its Strategic Plan for Agricultural Development (PEDSA) aiming to improve agricultural productivity of the majority of smallholder farmers who depend on agriculture for their livelihoods. Smallholder farmers are diverse in terms of resources and aspirations. The main objectives of this study are first to understand the diversity among maize-based smallholder farms and their current constraints in improving agricultural productivity in the Manica Plateau, Central Mozambique, and second, building on that understanding to explore options for biomass production either for food, cash or biofuel at farm level and contributions to maize availability in the region. The study was conducted in the Dombe and Zembe Administrative Posts. Farmers in the two posts cultivate both food and cash crops using the same resources, however, distances to the urban market differ, with Zembe close and Dombe far away from the markets. In addition, the agroecological conditions for crop production are more favourable in Dombe compared with Zembe. Using farm surveys, direct observations and on-farm measurements, followed by Principal Components Analysis (PCA) I identified land and labour as the variables that can best explain the variability found among smallholder farms (Chapter 2). Based on these variables I categorised farms into four Farm Types (FT): FT1. Large farms (4.4 ha in Dombe and 2.2 ha in Zembe), hiring in labour; FT2. Intermediate sized farms (1.9-1.2 ha), hiring in and out labour; FT3a. Small farms (1.1-0.9 ha), sharing labour; and FT3b. Small farms (1.0-0.7 ha), hiring out labour. The maize yield and maize labour productivities were higher on large farms (2.3 t ha-1 in Dombe and 2.0 t ha-1 in Zembe; 2.5×10-3 t h-1 in Dombe and 2.6 ×10-3 t h-1 in Zembe) compared with small farms (1.5 t ha-1 in Dombe and 1.1 t ha-1 in Zembe; 1.4×10-3 t h-1 in Dombe and 0.9×10-3 t h-1 in Zembe). The hiring in labour from small farms allowed large farms to timely weed their fields. Small farms were resource constrained and hired out labour (mutrakita) for cash or food to the detriment of weeding their own fields, resulting in poor crop yields. Excessive alcohol consumption by small farms also raised concerns on labour quality. Chapter 3 explored options aiming at addressing farmers’ objectives of being maize self-sufficient and increased gross margin and the contribution to national objective of producing food. A bio-economic farm model was used to investigate two pathways to increase agricultural production: (i) extensification, expanding the current cultivated area; and (ii) intensification, increasing input use and output per unit of land.

    In the extensification pathway I considered the use of animal traction, herbicides and cultivators to save labour, whereas in the intensification pathway I explored the use improved varieties of maize, sesame, sunflower, pigeonpea and fertilizers. I focused on the large farms and the small farms hiring out labour as they represent both sides of the spectrum. The simulated results showed that combining labour and labour saving technologies substantially increased both gross margin and maize yields of large and small farms in both posts. Minor trade-offs is observed on large farms between the two goals whereas for small farms we see synergies between the goals. We concluded that prospects for increasing gross margin and food production are much better for large farms in Dombe compared with other farms. In Dombe, the maximum gross margin of large farms was 7530 $ y-1 per farm and maximum maize sales of 30.4 t y-1 per farm. In Zembe, the maximum gross margin of large farms (2410 $ y-1 per farm) and maximum maize sales (9.5 t y-1 per farm) were comparable to small farms in Dombe. I further assessed the impact of two biofuel investments (jatropha plantation and sunflower outgrower schemes) on farm level food security (food availability, access to food, stability of food, utilization of food). The results showed positive impact on small farms from employment on a jatropha plantation by increasing access to food and no impacts on intermediate and large farms. Impacts on food security from the sunflower outgrower scheme were minor which may be explained by the poor yields.

    The need to link smallholder farmers to markets has been increasingly recognized as important strategy to promote rural development and poverty reduction. I developed an analytical framework, the Windmill Approach that looked at decision making at farm level to grow certain crops and at transaction strategies (Chapter 5). Through this framework I showed that a farmer decision to participate in a particular (new) value chain is determined by (a) the suitability of the new crop in the farm system (including the adaptability of the current farm system), and (b) the farmer’s experience with selling in various value chains. This has major policy implications as it highlights that to support smallholder farmers access to markets a holistic approach is needed that combines farming systems analysis and transaction cost theory.

    In order to explore the opportunities for smallholder development there is need to understand the diversity of farms and farmers’ social and economic context. For large farms, in Central Mozambique farms with on average 2-4 ha of land, opportunities to improve their livelihoods through crop production can follow two pathways: intensification and extensification. Smallholders continue to produce staple food crops even when working on a plantation or participating in outgrower schemes. For small farms, off-farm opportunities such as those in a biofuel plantation are the best options to improve their livelihoods.

    Groot TKI-BBE overleg
    Lopez Contreras, Ana - \ 2017
    biofuels - biobased economy - airplanes - residual streams - potato factory effluent - sustainability
    Biojet fuel : innovative value chain from potato waste streams to aviation fuel / Presentation
    Safely combining wind turbines and seaweed farms: research project on multipurpose sea
    Castel, Fanny ; Stuiver, M. - \ 2016
    biobased economy - bioenergy - seaweeds - renewable energy - biofuels
    Simulating plants: Research on photosynthesis will bear fruit
    Klein Lankhorst, R.M. ; Aarts, M.G.M. - \ 2016
    biobased economy - biofuels - photosynthesis - renewable energy - biomass - bioenergy - plants
    Assessing the case for sequential cropping to produce low ILUC risk biomethane : final report
    Peters, Daan ; Zabeti, Masoud ; Kühner, Ann-Kathri ; Spöttle, Matthias ; Werf, Wopke van der; Stomph, Jan - \ 2016
    Utrecht : ECOFYS Netherlands - 39
    methane - biofuels - sequential cropping - farmers' associations - biogas - ancillary enterprises - farm management - agricultural energy production - transport - biobased economy - fuel crops - biomass production - methaan - biobrandstoffen - estafetteteelt - boerenorganisaties - biogas - nevenactiviteiten - agrarische bedrijfsvoering - energieproductie in de landbouw - transport - biobased economy - brandstofgewassen - biomassa productie
    In recent years and especially since the COP - 21 climate agreement reached in Paris last year, efforts to mitigate climate change accelerate. All sectors need to contribute in order to achieve the well below 2 degree climate target. The agricultural sector is relevant for climate change in various ways. Like the agricultural sector, the transport sector is also responsible for significant greenhouse gas emissions. Advanced biofuels and biogas produced from wastes and residues can play an increasingly important role in the transport mix. In Italy, 600 Italian farmers are organised in the Italian Biogas Council (Consorzio Italiano Biogas e Gassificazione, CIB). Some years ago, CIB members developed a concept that they coined Biogasdoneright. In collaboration with various research institutes they seeked for a way to combine biogas feedstock production with crop production for food and feed as a way to generate additional income in a sustainable manner. The core of the Biogasdoneright concept is that farmers apply sequential cropping by growing a winter cover crop on land that was previously fallow during winter time, while maintaining the main crop production during summer time as previously. Multiple claims can be made about Biogasdoneright, for example related to the large potential role for biogas in our future energy system. This project focussed on the most relevant claims related to the use of biomethane in transport, with a focus on sustainability aspects.
    Planten nabootsen : onderzoek naar fotosynthese gaat vruchten afwerpen
    Klein Lankhorst, Rene ; Aarts, Mark ; Amerongen, Herbert van - \ 2016
    biobased economy - biobased chemistry - biofuels - photosynthesis - biotechnology - biobased chemicals - energy sources - solar energy - renewable energy - techniques

    Planten zijn meesters in het gebruik van zonlicht. Daarmee zetten ze water en kooldioxide om in suikers en zuurstof. Wageningse onderzoekers kunnen dit proces nabootsen en verbeteren. Zo willen ze biobrandstoffen maken en beter groeiende gewassen

    Methodologies identification and certification of Low ILUC risk biofuels : final report
    Peters, Daan ; Spöttle, ; Hähl, Thomas ; Kühner, Ann-Kathrin ; Cuijpers, Maarten ; Stomph, Tjeerd Jan ; Werf, Wopke van der; Grass, Martin - \ 2016
    Utrecht : ECOFYS Netherlands - 58
    biofuels - greenhouse gases - land use - biomass - biomass production - biobased economy - indirect land use change - biobrandstoffen - broeikasgassen - landgebruik - biomassa - biomassa productie - biobased economy - indirecte veranderingen van landgebruik
    Biofuels can be an important instrument to decarbonise the transport sector. However, the greenhouse gas performance of biofuels can be negatively impacted by Indirect land use change (ILUC) effects. In this report, Ecofys proposes two methodologies to identify and demonstrate low ILUC risk biofuel feedstock production through the application of yield increase (see Chapter 3) or unused land (see ILUC mitigation methodology for unused land).
    Microbial electrosynthesis of biochemicals : innovations on biocatalysts, electrodes and ion-exchange for CO2 supply, chemicals production and separation
    Bajracharya, S. - \ 2016
    Wageningen University. Promotor(en): Cees Buisman; David Strik; Deepak Pant. - Wageningen : Wageningen University - ISBN 9789462578531 - 181
    carbon dioxide - biofuels - chemicals - biocatalysis - ion exchange - electrodes - kooldioxide - biobrandstoffen - chemicaliën - biokatalyse - ionenuitwisseling - elektrodes

    Microbial electrosynthesis (MES) is an electricity-driven production of chemicals from low-value waste using microorganisms as biocatalysts. MES from CO2 comprises conversion of CO2 to multi-carbon compounds employing microbes at the cathode which use electricity as an energy source. This thesis presents innovations on MES from CO2 using anaerobic mixed-cultures, circumventing the methane generation. Acetate was the primary product but other products including ethanol, butyrate were also produced. Establishment of active biocathode at the graphite felt cathode was achieved under long-term operation which led to the acetate accumulation up to 7-10 g L-1 at -1 V/Ag/AgCl cathode potential. CO2 reduction in MES requires continuous availability of CO2 and low cathode potential to ensure the supply of reducing equivalents/hydrogen. Use of gas diffusion biocathode doubled the CO2 mass-transfer rate which enhanced the production rates, reaching. Furthermore, a sustainable technology for manufacturing biochemicals/biofuels was demonstrated in this thesis by integrating the product separation in MES. The electricity-driven production of chemicals/biofuels from CO2/waste products and subsequent product recovery studies prospect an integration of microbial electrosynthesis with biorefineries for the up-scaling of both technologies.

    Targets and tools for optimizing lignocellulosic biomass quality of miscanthus
    Weijde, R.T. van der - \ 2016
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Luisa Trindade; Oene Dolstra. - Wageningen : Wageningen University - ISBN 9789462578388 - 231
    miscanthus - bioethanol - biomass - biofuels - lignocellulose - fuel crops - plant breeding - cell walls - cell wall components - genetic diversity - genetic variation - biomass conversion - biobased economy - miscanthus - bioethanol - biomassa - biobrandstoffen - lignocellulose - brandstofgewassen - plantenveredeling - celwanden - celwandstoffen - genetische diversiteit - genetische variatie - biomassaconversie - biobased economy

    Miscanthus is a perennial energy grass characterized by a high productivity and resource-use efficiency, making it an ideal biomass feedstock for the production of cellulosic biofuels and a wide range of other biobased value-chains. However, the large-scale commercialization of converting biomass into cellulosic biofuel is hindered by our inability to efficiently deconstruct the plant cell wall. The plant cell wall is a complex and dynamic structure and its components are extensively cross-linked into an unyielding matrix. The production of biofuel depends on the extraction, hydrolysis and fermentation of cell wall polysaccharides, which currently requires energetically and chemically intensive processing operations that negatively affect the economic viability and sustainability of the industry. To address this challenge it is envisioned that the bioenergy feedstocks can be compositionally tailored to increase the accessibility and extractability of cell wall polysaccharides, which would allow a more efficient conversion of biomass into biofuel under milder processing conditions.

    Extensive phenotypic and genetic diversity in cell wall composition and conversion efficiency was observed in different miscanthus species, including M. sinensis, M. sacchariflorus and interspecific hybrids between these two species. In multiple experiments a twofold increase in the release of fermentable sugars was observed in ‘high quality’ accessions compared to ‘low quality’ accessions. The exhaustive characterization of eight highly diverse M. sinensis genotypes revealed novel and distinct breeding targets for different bioenergy conversion routes. The key traits that contributed favourably to the conversion efficiency of biomass into biofuel were a high content of hemicellulosic polysaccharides, extensive cross-linking of hemicellulosic polysaccharides (revealed by a high content of trans-ferulic acids and a high ratio of arabinose-to-xylose), a low lignin content and extensive incorporation of para-coumaric acid into the lignin polymer.

    Lignin is widely recognized as one of the key factors conveying recalcitrance against enzymatic deconstruction of the cell wall. The incorporation of para-coumaric acid into the lignin polymer is hypothesized to make lignin more easily degradable during alkaline pretreatment, one of the most widely applied processing methods that is used to pretreat biomass prior to enzymatic hydrolysis. Previous studies have shown that reducing lignin content is often implicated in reduced resistance of plants to lodging. We hypothesize that extensively cross-linked hemicellulosic polysaccharides may fulfil a similar function in supporting cell wall structural rigidity and increasing the content of hemicellulosic polysaccharides may be a way to reduce lignin content without adversely affecting cell wall rigidity. This strategy can be used to improve biomass quality for biobased applications, as hemicellulosic polysaccharides are more easily degradable during industrial processing than lignin. Furthermore, hemicellulosic polysaccharides adhere to cellulose, which negatively affects the level of cellulose crystallinity. Crystalline cellulose is harder to degrade than its more amorphous form. Therefore the reduction of cellulose crystallinity is another mechanism through which increasing the content of hemicellulosic polysaccharides positively contributes to cell wall degradability. These results provided new insights into the traits that may be targeted to improve the quality of lignocellulose feedstocks.

    However, evaluation of complex biochemical traits for selection purposes is hindered by the fact that their accurate quantification is a costly, lengthy and laborious procedure. To overcome these limitations an accurate and high-throughput method was developed based on near-infrared spectroscopy. Through extensive calibration we developed accurate prediction models for a wide range of biomass quality characteristics, which may be readily implemented as a phenotyping tool for selection purposes.

    Additionally, progress through breeding may substantially be improved by marker-assisted selection, which will reduce the need for the evaluation of genotype performance in multi-year field trials. To this end, a biparental M. sinensis mapping population of 186 individuals was developed and genotyped using a genotyping-by-sequencing approach. A total of 564 short-sequence markers were used to construct a new M. sinensis genetic map. Cell wall composition and conversion efficiency were observed to be highly heritable and quantitatively inherited properties. This is the first genetic study in miscanthus to map quantitative trait loci (QTLs) for biomass quality properties and is a first step towards the application of marker-assisted selection for biomass quality properties.

    Through the evaluation of a diverse set of miscanthus genotypes in multiple locations we demonstrated that in addition to genotypic variation, growing conditions may have a substantial influence on cell wall composition and conversion efficiency. While further research is needed to identify which specific environmental parameters are responsible for the observed effects, these results clearly indicate that the environmental influence on biomass quality needs to be taken into account in order to match genotype, location and end-use of miscanthus as a lignocellulose feedstock. Moreover, significant genotype-by-environment interaction effects were observed for cell wall composition and conversion efficiency, indicating variation in environmental sensitivity across genotypes. Although the magnitude of the genotypic differences was small in comparison to genotype and environmental main effects, this affected the ranking of accession across environments. Stability analysis indicated some stable accessions performed relatively across diverse locations.

    In addition to trialing miscanthus in diverse locations, we also evaluated miscanthus biomass quality under drought conditions for a number of reasons: 1) drought stress is linked to a differential expression of cell wall biosynthesis genes, 2) incidence of drought events is increasing due to climate change, 3) irrigation is likely to be uneconomical during the cultivation of miscanthus and 4) miscanthus has many characteristics that make it a crop with a good potential for cultivation on marginal soils, where abiotic stresses such as drought may prevail. Drought stress was shown to result in a large reduction in cell wall and cellulose content and a substantial increase in hemicellulosic polysaccharides and cellulose conversion rates. We hypothesized that the reduction in cellulose content was due to an increase in the production of osmolytes, which are well-known for their role in plant protection against drought. The results indicated that drought stress had a positive effect on the cell wall degradability of miscanthus biomass.

    Overall the compendium of knowledge generated within the framework of this thesis provided insights into the variation in biomass quality properties in miscanthus, increased our understanding of the molecular, genetic and environmental factors influencing its conversion efficiency into biofuel and provided tools to exploit these factors to expand the use of miscanthus as a lignocellulose feedstock.

    Zambia kan biodiesel uit soja produceren
    Drabik, Dusan - \ 2016
    biodiesel - soyabeans - biofuels - government policy - zambia - developing countries - biobased economy
    The effect of ethanol policies on the vertical price transmission in corn and food markets
    Drabik, D. ; Ciaian, P. ; Pokrivcak, J. - \ 2016
    Energy Economics 55 (2016). - ISSN 0140-9883 - p. 189 - 199.
    price transmission - food supply chain - biofuels - policies - mandate - tax credit - prices
    This paper analyzes the impact of ethanol policies on price transmission along the food supply chain. We consider the US corn sector and its vertical links with food and ethanol (energy) markets. We find that ethanol is a source of imperfect price transmission in the food supply chain. Ethanol, however, alters price transmission only under a binding blender's tax credit and only from food to corn (not vice versa). Our results indicate that ethanol weakens the response of corn and food prices in terms of their level changes to shocks occurring in agricultural (corn and food) markets. The results are robust to different assumptions on the model parameters. Although market power has previously been identified as a source of imperfect price transmission in the food supply chain, our findings show that in the presence of ethanol, the imperfect price transmission may occur even if markets are perfectly competitive. This warrants careful evaluation of markets before any policy intervention.
    Biofuel production in Vietnam : Greenhouse gas emissions and socioeconomic impacts
    Thanh, L. le - \ 2016
    Wageningen University. Promotor(en): Ekko van Ierland; Xueqin Zhu. - Wageningen : Wageningen University - ISBN 9789462576186 - 197
    biofuels - greenhouse gases - environmental economics - emission - socioeconomics - fuels - natural resources - vietnam - biobrandstoffen - broeikasgassen - milieueconomie - emissie - sociale economie - brandstoffen - natuurlijke hulpbronnen - vietnam
    The overall objective of this thesis is to study the energy efficiency, GHG emission savings, and the economic viability of biofuels as energy for transportation and to examine the impacts of biofuel policies on food production, welfare, and emission in Vietnam.
    An economic model for offshore cultivation of macroalgae
    Dijk, Wim van; Schoot, Jan Rinze van der; Edwards, Maeve ; Queguineur, Benoit ; Champenois, Jennifer ; Mooney, Karen ; Barrento, Sara - \ 2015
    Swansea : Swansea University - 21
    biobased economy - biomass - biofuels - algae - algae culture - oils - seaweeds - seaweed culture - biobased economy - biomassa - biobrandstoffen - algen - algenteelt - oliën - zeewieren - zeewierenteelt
    Algae biomass is considered as a potential non-fossil source of raw materials to produce fuel, feed, chemicals and materials. For this purpose microalgae as well as macroalgae can be used, and in this report we focus on the latter. More than 99% of the world production of aquatic plants is produced in Asia (FAO 2012, Table 1). From the remaining 1% about 4% is cultivated in Europe. Important European countries with commercial seaweed cultivation are Denmark, Ireland and France. Depending on their pigmentation seaweed species are commonly grouped in brown, red and green seaweeds.
    Biorefinery : recovery of valuable biomolecules
    Eppink, M.H.M. - \ 2015
    Wageningen : Wageningen University - ISBN 9789462573789 - 28
    biorefinery - recovery - biomass - biofuels - separation technology - biomass conversion - biomass cascading - biobased economy - bioraffinage - terugwinning - biomassa - biobrandstoffen - scheidingstechnologie - biomassaconversie - biomassa cascadering - biobased economy
    Inaugural speech Wageningen University, 23 April 2015
    The feasibility of direct processing of sugar beets in Slovenia: a quick scan
    Jongeneel, R.A. ; Smit, A.L. ; Bakker, Tom ; Jager, J.H. - \ 2015
    LEI Wageningen UR (Report / LEI Wageningen UR 2015-149) - ISBN 9789086157280 - 25
    sugarbeet - processing - arable farming - ethanol production - biofuels - economic viability - slovenia - cap - european union - biobased economy - suikerbieten - verwerking - akkerbouw - ethanolproductie - biobrandstoffen - economische haalbaarheid - slovenië - gemeenschappelijk landbouwbeleid - europese unie - biobased economy
    This study presents a quick scan of the economic feasibility of direct processing of sugar beet for ethanol production in Slovenia, using the Betaprocess technology. The outcome is that given the prices for sugar, sugar beets, ethanol and other relevant arable crops that are expected to prevail after the liberalisation of the EU’s sugar policy in 2017, direct processing of sugar beets is a profitable activity. This result is conditional on a number of requirements.
    Duurzaamheid, communicatie en veiligheid : verslag van de landelijke bijeenkomst 'Kenniskringen Visserij en duurzaamheid'
    Zaalmink, W. ; Smith, S.R. ; Steenbergen, J. ; Trapman, B.K. ; Valk, O.M.C. van der - \ 2015
    LEI Wageningen UR (Rapport / LEI Wageningen UR 2015-160) - 25
    visserij - duurzaamheid (sustainability) - biobrandstoffen - communicatie - familiebedrijven, landbouw - veiligheid - coöperaties - nederland - fisheries - sustainability - biofuels - communication - family farms - safety - cooperatives - netherlands
    Op 6 juni 2015 vond op Fort IJmuiden een landelijke bijeenkomst plaats van het project Kenniskringen Visserij. Het doel van deze dag was te komen tot een uitwisseling van kennisvragen over verschillende visserij gerelateerde thema’s. Het programma bestond uit een plenaire bijeenkomst en uit een aantal zogenoemde cafébijeenkomsten. Bij elke cafébijeenkomst was een relevante expert aanwezig, die de bijeenkomst inleidde. Hierna konden de aanwezigen vragen aan de expert en aan elkaar stellen. Dit verslag is een samenvatting van de uitspraken die door de deelnemers en experts op deze dag gedaan zijn rond de thema’s: 1. Duurzaamheid en de visser als onderzoeker (expert: Bas Haring, volksfilosoof) 2. Communicatie (expert: Marissa Tanis, GoMaris) 3. Fuel of the future (expert: Dirk Kronemeijer) 4. Veiligheid aan boord (expert: Cor Blonk) 5. Coöperaties (expert: Thomas Højrup)
    Illusions, hunger and vices: smallholders, environmentalism and the green agrarian question in Chiapas' biofuel rush
    Castellanos-Navarrete, A. - \ 2015
    Wageningen University. Promotor(en): Cees Leeuwis. - Wageningen : Wageningen University - ISBN 9789462576094 - 221
    biofuels - fuel crops - food vs fuel - mexico - peasant farming - oil palms - biobased economy - biobrandstoffen - brandstofgewassen - voedsel versus brandstof - mexico - landbouw bedrijven in het klein - oliepalmen - biobased economy
    Isolation, characterization and engineering of Bacillus smithii : a novel thermophilic platform organism for green chemical production
    Bosma, E.F. - \ 2015
    Wageningen University. Promotor(en): Willem de Vos; John van der Oost, co-promotor(en): Richard van Kranenburg. - Wageningen : Wageningen University - ISBN 9789462575073 - 220
    bacillus smithii - bacillus (bacteria) - biobrandstoffen - chemicaliën uit biologische grondstoffen - thermofielen - metabolische profilering - genoomanalyse - mutaties - isolatie - bioengineering - karakterisering - bacillus smithii - bacillus (bacteria) - biofuels - biobased chemicals - thermophiles - metabolic profiling - genome analysis - mutations - isolation - bioengineering - characterization

    Due to the globally increasing demand for chemicals and fuels and the high environmental impact and limited amount of fossil resources, there is a growing interest in green chemicals and fuels derived from renewable resources. As described in Chapter 1, one of the most feasible alternatives on the short term is microbial conversion of the sugars in biomass to fuels and chemicals in a biorefinery. To be economically and ethically feasible, non-food biomass should be used as a resource, which is often difficult with currently used production organisms. Also, to be economically feasible, the costs of green chemicals and fuels need to be further reduced to be below the costs of products based on fossil resources. To do so, other organisms than the currently most-used platform organisms such as Escherichia coli and Saccharomyces cerevisiae should be used. Ideally, this alternative organism is genetically accessible, has high productivity, titre and yield, is flexible in carbon source, robust, moderately thermophilic, acidophilic, facultatively anaerobic and has little nutritional requirements. The organisms that come closest to these criteria are thermophilic bacilli, which form a diverse class of organisms in the family of Bacillaceae. This thesis describes the isolation, characterization and metabolic engineering of Bacillus smithii, a novel potential thermophilic platform organism.

    Chapter 2 provides more detail on the use of thermophilic microorganisms as platform organisms for green chemical production in a biorefinery concept. As commercially available enzyme mixtures used in the simultaneous saccharification and fermentation (SSF) of biomass have their optimum temperature around 50-60°C, using a moderately thermophilic organism would reduce the costs of the SSF process compared to when using mesophiles by reducing the amount of required enzyme. Also, thermophilic processes are less prone to contaminations, and substrate and product solubility are increased. Several successful examples of the application of facultatively anaerobic thermophiles for green chemical production from lignocellulose in an SSF setting are for example Bacillus coagulans for lactic acid production and Bacillus licheniformis for 2,3-butanediol production. However, whereas strongly developed genetic toolboxes are available for current mesophilic production organisms, these tools are still in their infancy for thermophilic organisms. Such tools are required to optimize production and to study metabolism. Thermophilic organisms show a wide variety in metabolism and in many cases the metabolism of these organisms is still poorly understood, hampering full optimization. Chapter 2 furthermore provides an overview of transformation, integration and counter-selection methods currently used for thermophiles. Although several deletion mutants have been constructed using these methods, not all of them are entirely markerless and most are not suited as high-throughput engineering tools, stressing the need for further research in this area.

    Despite several facultatively anaerobic thermophiles being described as genetically accessible, this feature is still one the major bottlenecks in developing these organisms into platform organisms. Therefore, in Chapter 3, we set out to isolate a facultatively anaerobic, moderately thermophilic bacterium that was genetically accessible and produced high titers of organic acids. A total of 267 strains of different thermophilic bacilli species were isolated from compost and screened for C5 and C6 sugar utilization and acid production. The 44 best strains were screened for genetic accessibility via electroporation. Only 3 strains tested positive for this, namely Geobacillus thermodenitrificans strains ET 144-2 and ET 251 and B. smithii strain ET 138. In subsequent evaluations in lab-scale bioreactors at 55°C and pH 6.5 on glucose, the two G. thermodenitrificans strains performed poorly whereas B. smithii performed well with high titers, yields and productivity of mainly lactate. In similar lab-scale reactors, this strain also performed well on xylose and at pH 5.5 and was still able to perform for 48 at pH 4.5. The electroporation protocol for this strain was optimized, resulting in a maximum efficiency of 5x103 colonies per µg plasmid pNW33n. Two other B. smithii strains, among which the type strain DSM 4216T, were also shown to be transformable with pNW33n. This is the first time that genetic accessibility is described for B. smithii and it is the first step towards developing it into a platform organism, for which it appears to be suitable based on its efficient C5 and C6 sugar utilization and acid production profile.

    In order to become a platform organism and to study its atypical metabolism, a genetic toolbox needs to be established for B. smithii. Chapter 5 describes the development of a markerless gene deletion method for B. smithii. For strains ET 138 and DSM 4216T, the ldhL gene was markerlessly removed via double homologous recombination using plasmid pNW33n. Despite the replicative nature of this plasmid at 55°C, mixtures of single and double crossovers were readily obtained. A pure double crossover deletion mutant was obtained after several transfers on a more defined medium containing acetate or lactate and PCR-based screenings. To eliminate the possibility of mixed genotypes, we subsequently developed a lacZ-counter-selection system, which is based on the toxicity of high X-gal concentrations in the presence of the plasmid-encoded lacZ gene. Using this method, the sporulation-specific sigma factor sigF and pyruvate dehydrogenase complex E1-α pdhA were consecutively removed from the B. smithii ET 138 genome in a markerless way. An initial evaluation of the growth and production profiles of the mutant strains in tubes showed that removal of the ldhL gene eliminates l-lactate production and causes a severe decrease in anaerobic growth and production capacities. B. smithii mutants lacking the sigF gene were unable to sporulate and removal of the pdhA gene eliminated acetate production and rendered the strains auxotrophic for acetate.

    Biobrandstof met het gemak van benzine
    Klein Lankhorst, R.M. - \ 2015
    Akker magazine 11 (2015)6. - ISSN 1875-9688 - p. 34 - 34.
    brandstoffen - biobrandstoffen - waterstof - zonne-energie - fotosynthese - energiebronnen - projecten - biobased economy - fuels - biofuels - hydrogen - solar energy - photosynthesis - energy sources - projects - biobased economy
    Onderzoekers in Wageningen werken aan brandstoffen voor voertuigen die hernieuwbaar zijn en tegelijk hetzelfde gemak kennen als benzine en diesel. In het BioSolar Cellsconsortium werken ze met technieken die geïnspireerd zijn op fotosynthese in planten. Van water wordt met zonlicht waterstof gemaakt. Met koolzuurgas en enzymen wordt dit gas omgezet in een vloeibare brandstof. Dat is makkelijker te transporteren dan waterstofgas. In plaats van benzine kan de automobilist dan straks klimaatneutrale zonnebrandstof tanken.
    Macro-economics of algae products : Output WP2A7.02
    Voort, M.P.J. van der; Vulsteke, E. ; Visser, C.L.M. de - \ 2015
    EnAlgae Swansea University - 47
    marktonderzoek - algen - macro-economische analyse - markten - materialen uit biologische grondstoffen - chemie op basis van biologische grondstoffen - biobased economy - biobrandstoffen - market research - algae - macroeconomic analysis - markets - biobased materials - biobased chemistry - biobased economy - biofuels
    This report is part of the EnAlgae Workpackage 2, Action 7, directed at the economics of algae production. The goal of this report is to highlight potential markets for algae. Per type of algae market the market size, product alternatives, constraints and prices are highlighted. Based on these market characteristics a conclusion is drawn on the market potential for algae products. Per market desk research is done and literature is consulted to create a reliable market outlook.
    AlgaeEconomics: bio-economic production models of micro-algae and downstream processing to produce bio energy carriers
    Spruijt, J. ; Schipperus, R. ; Kootstra, A.M.J. ; Visser, C.L.M. de - \ 2015
    EnAlgae Swansea University - 67
    algenteelt - teeltsystemen - productiekosten - biomassa productie - economische modellen - groeimodellen - biobrandstoffen - biobased economy - bioraffinage - algae culture - cropping systems - production costs - biomass production - economic models - growth models - biofuels - biobased economy - biorefinery
    This report describes results of work carried out within the EnAlgae project to describe production costs and identify the variables that have most effect in determining future cost prices so that R&D can be focussed on these issues. This has been done by making use of pilots within the EnAlgae consortium and by describing the process in Excel models that have been spread among and discussed with stakeholders active in the field of commercial algae production. The expectation is that this transparency and interaction will lead to an increase of the learning curve to make algae production cheaper and thus supplying more markets.
    Inventory of North-West European algae initiatives
    Spruijt, J. - \ 2015
    EnAlgae Swansea University (Report WP2A7.01 )
    projecten - algen - algenteelt - biobrandstoffen - biobased economy - europa - projects - algae - algae culture - biofuels - biobased economy - europe
    In 2012 an inventory of North-West European (NWE) algae initiatives was carried out to get an impression of the market and research activities on algae production and refinery, especially for bioenergy purposes. A questionnaire was developed that would provide the EnAlgae project with information on the value chains in which algae production was positioned within these initiatives. The questionnaire was used by EnAlgae project partners to collect information in Great Britain, Ireland, Germany, Belgium, France, Switzerland, Luxemburg and the Netherlands. Information about algae initiatives originated from networks and from internet searches. Additional information was collected by bilateral contact with contact persons of several initiatives. The analysis of the results is reported here.
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