Specific conversion of amino acids as a means for their separation Yinglai Teng Thesis committee Promotor Prof. Dr J.P.M. (Johan) Sanders Emeritus professor of Valorization of Plant Production Chains Wageningen University Co-promotor Dr E.L. (Elinor) Scott Assistant professor, Biobased Commodity Chemicals Wageningen University Other members Prof. Dr A.A. (Ton) Broekhuis, University of Groningen, the Netherlands Prof. Dr D.C. (Kitty) Nijmeijer, University of Twente, Enschede, the Netherlands Dr R.H. (Robert) Carr, Huntsman Corporation, Everberg, Belgium Prof. Dr H. (Harry) Gruppen, Wageningen University This research was conducted under the auspices of the Graduate School VLAG (Advanced studies in Food Technology, Agrobiotechnology, Nutrition and Health Sciences). Specific conversion of amino acids as a means for their separation Yinglai Teng Thesis submitted in fulfillment of the requirements for the degree of doctor at Wageningen University by the authority of the Rector Magnificus Prof. Dr M.J. Kropff, in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Wednesday 10 September 2014 at 4 p.m. in the Aula. Yinglai Teng Specific conversion of amino acids as a means for their separation, 205 pages. PhD thesis, Wageningen University, Wageningen, NL (2014) With references, with summaries in Dutch and English ISBN 978-94-6257-065-8 Table of Contents List of abbreviations 7 Chapter 1 11 General introduction Chapter 2 47 The use of L-lysine decarboxylase as a means to separate amino acids by electrodialysis Chapter 3 67 Separation of L-aspartic acid and L-glutamic acid for making bio-based chemicals Chapter 4 91 The selective conversion of glutamic acid in amino acid mixtures using glutamic acid decarboxylase – a means of separating amino acids for synthesizing Biobased chemicals Chapter 5 115 Simultaneous decarboxylation of L-serine and deamination of L-phenylalanine as a means to separate neutral amino acids Chapter 6 135 General discussion Appendix A 175 Supplementary material to Chapter 3 Appendix B 183 Supplementary material to Chapter 4 Summary 187 Samenvatting 191 Acknowledgements 195 Curriculum vitae 199 List of publications 201 Overview of completed training activities 203 List of abbreviations Amino acids AA Amino acid Ala L-Alanine Arg L-Arginine Arg·HCl L-Arginine monohydrochloride Arg·2HCl L-Arginine dihydrochloride Asn L-Asparagine Asp L-Aspartic acid Cys L-Cysteine GABA γ-Aminobutyric acid Gln L-Glutamine Glu L-Glutamic acid Gly L-Glycine His L-Histidine Ile L-Isoleucine Leu L-Leucine Lys L-Lysine Lys·HCl L-Lysine monohydrochloride Lys·2HCl L-Lysine dihydrochloride Met L-Methionine pGlu L-Pyroglutamic acid Phe L-Phenylalanine Pro L-Proline Ser L-Serine Thr L-Threonine Trp L-Tryptophan Tyr L-Tyrosine 7 Val L-Valine Chemicals and materials BDA 1,4-Butanediamine DDGS Dried distillers grains and solubles FUM Fumaric acid MAE Maleic acid PDA 1,5-Pentanediamine PLP Pyridoxal 5'-phosphate PLP·H2O Pyridoxal 5'-phosphate monohydrate Enzymes ADC L-Aspartate α-decarboxylase GAD L-Glutamate α-decarboxylase IGAD Immobilized GAD (by entrapment in calcium alginate beads) ILDC Immobilized L-lysine decarboxylase (by entrapment in calcium alginate beads) LDC L-Lysine decarboxylase ODC L-Ornithine decarboxylase PAL L-Phenylalanine ammonia-lyase PDC L-Phenylalanine decarboxylase SDC L-Serine decarboxylase TDC L-Tyrosine decarboxylase VDC L-Valine decarboxylase Others terms AEM Anion exchange membranes BtU British thermal unit CEM Cation exchange membranes 8 ED Electrodialysis EIA The U.S. Energy Information Administration E stream Electrode stream EU European Union GHG Greenhouse gases IEA International Energy Agency IFPRI International Food Policy Research Institute IP Isoelectric point ISPR in-situ product formation and removal MMM Mixed matrix membrane OECD Organization for Economic Co-operation and Development SMB Simulated moving bed chromatography U-HPLC Ultra high pressure liquid chromatography EDAA Electrodialysis separation of amino acids 9 10 Chapter 1 General Introduction 11 1.1 Introduction The current dependency of our society for chemicals and fuels on fossil based resources (oil, gas, coal) causes great uncertainties for the future. The fossil sources are diminishing, unequally distributed, prices are fluctuating – but overall increasing, concern about their (negative) environmental impacts and geopolitical issues have arisen. This required development of replacements for fossil feedstocks to achieve more carbon neutral and sustainable production approaches.1 Biomass and thus biorefinery technology is one of the potential solutions to secure future supply of chemicals and fuels and is therefore receiving more and more attention.2 This chapter will provide background information about replacing fossil fuels with biomass, the concept of biorefinery, the application of biomass in the production of chemicals, and the possibility of using amino acids (AAs) as a feedstock for chemical industry. 1.2 Drawbacks of fossil fuels Currently, fossil fuels gas, coal and especially oil (petroleum) are dominantly used to meet our societies need for energy carriers (fuels) and chemicals as feedstock for making materials.3 For example, according to BP,4 in 2010 the production of oil, coal and gas in 2010 was approximately 3900, 3700 and 2900 million tons of oil equivalent respectively. However, the use of fossil resources has many drawbacks as briefly addressed in the previous paragraph. Here I will focus in some detail on 1) depletion of resource, 2) insecure supply and 3) CO2 emission. 1.2.1 Depletion of limited reserves Fossil fuels are formed from fossilized plants and animals over millions of years.5 Due to that long time scale fossil fuels are regarded as non-sustainable. Therefore their use will lead to an inevitable depletion. The peak oil theory developed by M. K. Hubbert is often used to discuss the timeframe of depletion.5,6 Hubbert showed that the extraction rate of a finite resources will first exponentially increase and after passing through a maximum (Hubbert peak) decrease with time (Fig. 1.1A).3,6 As a result after passing the maximum reserves would run out if the need is not 12 decreased or the supply increased.5 As predicted by Hubbert, the peak oil of U.S. would be reached around 1970 as compared to 2000 for the world production.5 The US prediction has been proven, and nowadays the peak oil theory is the most widely useful model for the oil depletion.7 Hubbert estimated that the peak of world oil production would occur around 2000 (Fig. 1.1 A).5 However, according to the International Energy Agency (IEA), the peak of world oil production was delayed to 2006.8 This could be due to several reasons related to both changes in production and consumption rates which will be discussed now. Firstly, more oil fields have been found in the recent years thus increasing the reserves. For example, the proven oil reserves in 1990, 2000 and 2010 were about 1000, 1100 and 1400 thousand million barrels respectively,4 while oil production in those years was 24, 28 and 31 thousand million barrels respectively.9 Secondly, more advanced technologies were used in the oil extraction process thus increasing the production. For example, after 2010 deep water drilling gained more attention to meet the oil demand.10 Finally, more alternatives for oil have been developed thus decreasing the oil use. These include unconventional oil (e.g. oil shale, extra heavy oil and bitumen11) and hydrocarbons produced from natural gas (e.g. via Fischer Tropsch synthesis) the so called natural gas liquids.8 The latter is estimated to reach a globe output of 11 million barrels in 2030.10 Recently, the extraction of shale gas in U.S. resulted in an oversupply of natural gas, leading to a decline of the U.S. gas prices and related oil prices (shale gas revolution).12 The production of shale gas is considered to delay the depletion of oil and is therefore in competition with other options to decrease fossil resource use e.g., the use of biomass.12,13 Based on these developments, IEA have estimated that from 2009 to 2035, the world total oil production could even increase at a slow rate (Fig. 1.1 B).8 13 A B Fig. 1.1 A. Prediction of world crude-oil production originally in Hubbert’s paper.5 B. World oil production by type as presented by IEA in the World Energy Outlook 2010 – presentation to the press.8 The depletion of oil is also related to the demand of energy i.e. the rate of consumption of fossil sources. The U.S. Energy Information Administration (EIA) estimated that from 2008 to 2035 the world energy consumption would increase by 1.6% per year, and oil based liquid fuels would remain the largest product group in that respect but the oil share is expected to slightly reduce due to the possible increase in oil price.14 The expected changes in energy use vary geographically. The energy consumption of non-OECD (Organization for Economic Co- operation and Development) countries already exceed that of OECD countries in 2008 (ca. 260 vs. 240 quadrillion Btu, or ca. 270 vs. 250 exajoule), and the difference is expected to further 14 increase.14 The projected energy consumption of non-OECD countries in Asia, especially China and India, will be the largest contributors due to the expected growth of population and economy.14 This is a trend also predicted by many other international organizations and energy companies, such as IEA,8,15 ExxonMobil,10 BP,16 and Shell.17 Though exact timescales are difficult to establish, at which rate fossil source will deplete, as discussed above, it is clear that the reserves will diminish with time. Therefore, to meet the need of energy and materials in the future, it is necessary to shift from fossil fuel to other resources.