OrCaCel - OrganoCat plant and pulping combinations for the full valorization of lignocellulose from marginal land grown perennial plants

P. M. Grande* ¹, H. Klose ², T. Damm ², N.D. Jablonowski ³, B. Usadel ^2,3, U. Schurr ³, W. Leitner ^1,4

¹RWTH Aachen University, Institute for Technical and Macromolecular Chemistry ITMC, Aachen, Germany

²RWTH Aachen University, Institute of Botany and Molecular Genetics IBMG, Aachen, Germany

³Forschungszentrum Jülich, Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Jülich, Germany

⁴ Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany

*corresponding author: Grande@itmc.rwth-aachen.de

The full valorization of lignocellulose residues is a crucial step to obtain ecological and economic figures in future biorefineries. The recently developed OrganoCat technology is a promising alternative to deliver non-degraded fractions of the three main carbon components of lignocellulose. The OrCaCel project aims to combine plant science with analytics and chemical engineering to adapt the OrganoCat process for different types of plant biomass that is obtained from perennial plants growing in low-input production to minimize environmental footprint.

Within BioSC boost fund project OrCaCel different biomass fractions are produced in low input production systems and analyzed, emphasizing a further use with strong industrial application options. Data generated by characterizing the OrganoCat product streams are be correlated with those provided by the analysis and characterization of the original biomass, to create new conversion chains for biomass determined for defined chemicals and energy storage.

As one example Sida hermaphrodita (Sida), a perennial plant from the Malvaceae family, was investigated. Sida can be cultivated on marginal lands and is able to produce high amounts of biomass. Covering one year growth period a harvest time best suited for the OrganoCat processing was identified. The OrganoCat technology was adapted to Sida feedstock by knowing the composition of the main components (e.g. dominating carbohydrates, pentose-hexose ratio and ratio of three main lignocellulose components). This combination of expertize allowed for a direct comparison of different perennial plants connecting fractionation performance to cell wall composition and plant science.

Towards a Waste Stream Based Biorefinery

Dr. Wolfgang Aehle (wa@brain-biotech.de), BRAIN AG, Zwingenberg (DE)

The establishment of a bio-based economy is faced with various challenges. First, there is discussion about the use of agricultural feed-stocks for the production of industrial ingredients. Second, industrial production requires raw materials of constant quality and predictive pricing, ideally independent from seasonal fluctuations.

On the customer side, industry is faced with a reduced complexity of refinery derived chemical compounds, which makes it difficult to cope with the increasing demand for problem specific solutions. These solutions require tailor made products based on a diverse mix of chemical base materials, which is diminished by a fuel focuses chemical industry. This lack of chemical diversity in raw materials opens an opportunity for bio-based processes due to the availability of a broad range of biological raw materials.

The Innovation Alliance program ZeroCarb FP, which is supported by the German Federal Ministry of Research and Education (BMBF), is used to exemplify an approach for the realization of bio-refinery concepts. The alliance brings together a number of miscellaneous industries that seek solutions from the bio-economy for a wide variety of applications.

The presentation demonstrates that it is possible to combine the needs of diverse industries into one bio-refinery concept in order to supply industry with a diversified product portfolio based on biological waste streams converting existing infrastructure into an integrated bio-based production unit.

Integrated challenge of pretreatment and hydrolysis of biomass

Dr. Jörn Viell and Dr. Nico Anders, RWTH Aachen

Enzymatic hydrolysis of cellulose in a biorefinery process usually requires a pretreatment of the biomass. The efficiency of these two process steps is an integrated problem demanding for precise monitoring of the changes induced by pretreatment. They are addressed in literature using several parameters because the hydrolysis itself is not sufficient to differentiate between the effect of structure and inhibitors released during the pretreatment.

In this contribution, various pretreatments are characterized by several analytical techniques. Spectroscopy reveals the changes in the ultrastructure of the biomass. The mesoscale of cellulose fibrils can be very well resolved by small-angle neutron scattering and X-ray diffraction. Moreover, recent result from Raman spectroscopy are promising to obtain structural and quantitative information fast and with cheaper instruments.

In addition, HPAEC-PAD allows for the simultaneous identification and quantification of degradation products derived from all natural polymers located in the plant cell wall. The limit of detection of all compounds is in the mg/L scale allows for a quantification of hydrolysis and fermentation inhibitors simultaneously with the high sugar concentrations.

Our findings show that both methods in combination allow for an evaluation of structural changes in the biomass during the pretreatment process as well as the quantification of soluble degradation products which can inhibit the further downstream processing.

Lignin-sourced polyurethane adhesives

Dr. Stefan Friebel, Fraunhofer Institute for Wood Research, Braunschweig

Industrially produced lignins are by-products of the pulp and paper industry. Currently the kraft process is the dominating technology (80 %) followed by the sulfate process that makes 6 % of the total pulp and paper production. However, 90 % of the material application comes from the latter technology. In this presentation, possibilities of utilizing kraft lignin for adhesive applications are shown. Modification with ε-caprolactone to create hydroxyl groups, which are more available for further reactions will be discussed as well as polyurethane dispersions for adhesives made therefrom. Lignin derivatization with polyols for waterborne 2K-PU-adhesives and conventional 2K-PU-adhesives may provide additional options for value-added products. The obtained products were analyzed by size exclusion chromatography (SEC). The analytical data are presented as a function of reaction time and conclusions to crosslinking reactions were made. The practical application prospects are demonstrated by standard tests that were applied to several test samples.

Enzymes for biomass breakdown

Dr. Andreas Knapp, Heinrich-Heine University Düsseldorf

Plant biomass is regarded as the most important source of renewable raw material for the bioeconomic production of energy, fuels and chemicals. To date, the biotechnological utilization of plant biomass combines physical, chemical, and biocatalytic processes; however, substantial costs still prevent a thorough replacement of oil-based feedstocks. Here, a significant cost factor is the production of enzymes for plant biomass breakdown. Therefore, the BioBreak project aims to evaluate two well-known bacterial expression strains, namely Escherichia coli and Bacillus subtilis, for the production of biomass-degrading enzymes to establish additional expression systems besides existing fungal hosts. The biotechnological optimization of both organisms is supported by process engineering approaches.

Novel enzymes in an industrially relevant context: the tale of two xylanases and other stories.

Kirk Schnorr, Novozymes A/S

Novozymes is a world leader in bioinnovation. We believe that by using industrial biotechnology, we can potentially re-engineer thousands of everyday products to deliver enhanced and sustainable performance, while introducing energy cost savings, as well as decreased raw material costs for our customers. Our never-ending exploration of nature’s potential is evidenced by over 6,000 patents – an indication of what is possible when nature and technology join forces in biotechnology.

The definition of novelty for enzymes, to be relevant in an industrial context, is often is associated with how the enzymes are used in applications and not necessarily a novel enzyme activity. Two cases will be shown where two enzyme families, working on the same substrate, xylan, have been used to improve two separate industrial processes. The two examples, for the paper pulp industry and the baking industry illustrate how mastery of the process is vital to understanding the requirements for a successful plug in enzyme solution. Xylan is found in several forms and the cases illustrate how in depth knowledge of the decorations on the xylan can help to match an enzyme able to degrade it. Knowledge gained on substrate requirements can also be used to fine tune the enzyme to further enhance its application relevant properties, as will be shown in one of the examples. In order to establish a novel enzyme in an existing or emerging industry, some hurdles can be encountered and overcome. Two novel cellulase enzymes, identified at Novozymes will therefore be discussed.

Bioconversion of renewable feedstocks and (agri/food) residues into bio-based products

Joachim Venus, Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Max-Eyth-Allee 100, D-14469 Potsdam; e-mail: jvenus@atb-potsdam.de

Besides increasingly important issues with regard to quantity and availability of raw materials together with their properties and quality the feedstock costs are very important for the production of bulk chemicals. Especially for biotechnological processes, in which the carbon of various substrates should be converted into microbial products, there is an increasing interest in the use of cheap raw materials, biogenic residues and wastes.

Renewable feedstocks (crops, lignocellulosics, green biomass, residues etc.) are already being used as raw materials for the production of bio-based products like lactic acid. The goal is to develop a fermentation process based on the substitution of expensive nutrient supplements by cheaper materials from biomass due to their main proportion of the whole process costs.

However, these feedstocks cannot be used normally for fermentation directly because the fermentable sugars are bound in the structure especially as cellulose and hemicellulose. They have to undergo a pre-treatment to release these sugar components. Possible disturbing impurities and inhibitors (e.g. phenolic components from lignocellulosics, heavy metals in municipal waste or recycled paper), difficult to use components (e.g. pentoses) and partly fluctuating or relatively low concentrations of bio-available carbon sources in these materials should be considered.

Activation of intrinsic enzymes for degradation of plant biomass side-streams (PectiLyse)

Dr. Kerstin Schipper, Heinrich-Heine University Düsseldorf

Plant-pathogenic fungi are promising candidates for biomass valorization, because they contain a vast repertoire of hydrolytic enzymes to sustain their lifestyle. However, expression of the corresponding genes is usually tightly regulated and mostly restricted to the pathogenic phase. Here, we engineer the biotrophic smut fungus Ustilago maydis for the degradation of pectin-rich side streams from a sugar beet plant. This fungal model organism is equipped with a potent set of hydrolytic enzymes, and moreover, it naturally produces value-added substances such as organic acids and biosurfactants. To achieve the deregulated expression of relevant intrinsic enzymes during the industrially relevant yeast-like growth in axenic culture, the native promoters of the respective genes are replaced by constitutively active synthetic promoters. In parallel, the hydrolytic repertoire is extended by supplementation with potent heterologous enzymes for the degradation of pectin. This already led to an enhanced conversion of biomass components like xylan, cellobiose, polygalacturonic acid and pectin to fermentable sugars. In parallel, unique online monitoring tools were developed to follow growth on complex substrates. To enable a one-pot process, we established the constitutive production of itaconic acid independent of the strain background. Combining these strategies will enable a consolidated bioprocess in which biomass is converted into itaconic acid.