Bioplastics are gaining interest as an alternative to fossil-based plastics. In addition, biodegradable bioplastics may yield biogas after their use, giving an additional benefit. However, the biodegradability time in international norms (35 days) far exceeds processing times in anaerobic digestion facilities (21 days). As the bioplastic packaging does not indicate the actual biodegradability, it is important to understand the time required to biodegrade bioplastic if it ends up in the anaerobic digestion facility along with other organic waste. For this work, cellulose bioplastic film and polylactic acid (PLA) coffee capsules were digested anaerobically at 55 ℃ for 21 days and 35 days, which are the retention times for industrial digestors and as set by international norms, respectively. Different sizes of bioplastics were examined for this work. Bioplastic film produced more biogas than bioplastic coffee capsules. The biodegradability of bioplastic was calculated based on theoretical biogas production. With an increase in retention time, biogas production, as well as biodegradability of bioplastic, increased. The biodegradability was less than 50% at the end of 35 days for both bioplastics, suggesting that complete degradation was not achieved, and thus, the bioplastic would not be suitable for use in biogas digesters currently in use.
LINK
Rioolwaterzuiveringen zijn de belangrijkste bron van geneesmiddelen en kunstmatige zoetstoffen in oppervlaktewater. De mate waarin rwzi’s deze organische microverontreinigingen verwijderen, lijkt te variëren van locatie tot locatie en/of in de tijd. Oriënterend onderzoek bij zeven rwzi’s in Groningen en Drenthe toonde aan dat de verwijdering van de zoetstof acesulfaam erg varieerde. Om het verschil in de biologische verwijderingscapaciteit voor acesulfaam en geneesmiddelen te kunnen verklaren, bieden nieuwe DNA-technieken wellicht uitkomst. Met Next Generation Sequencing (NGS) komen verschillen tussen bacteriepopulaties aan het licht die mogelijk verschillen in verwijdering van geneesmiddelen en zoetstoffen kunnen verklaren.
MULTIFILE
The transition to a biobased economy necessitates utilizing renewable resources as a sustainable alternative to traditional fossil fuels. Bioconversion is a way to produce many green chemicals from renewables, e.g., biopolymers like PHAs. However, fermentation and bioconversion processes mostly rely on expensive, and highly refined pure substrates. The utilization of crude fractions from biorefineries, especially herbaceous lignocellulosic feedstocks, could significantly reduce costs. This presentation shows the microbial production of PHA from such a crude stream by a wild-type thermophilic bacterium Schlegelella thermodepolymerans [1]. Specifically, it uses crude xylose-rich fractions derived from a newly developed biorefinery process for grassy biomasses (the ALACEN process). This new stepwise mild flow-through biorefinery approach for grassy lignocellulosic biomass allows the production of various fractions: a fraction containing esterified aromatics, a monomeric xylose-rich stream, a glucose fraction, and a native-like lignin residue [2]. The crude xylose-rich fraction was free of fermentation-inhibiting compounds meaning that the bacterium S.thermodepolymerans could effectively use it for the production of one type of PHA, polyhydroxybutyrate. Almost 90% of the xylose in the refined wheat straw fraction was metabolized with simultaneous production of PHA, matching 90% of the PHA production per gram of sugars, comparable to PHA yields from commercially available xylose. In addition to xylose, S. thermodepolymerans converted oligosaccharides with a xylose backbone (xylans) into fermentable xylose, and subsequently utilized the xylose as a source for PHA production. Since the xylose-rich hydrolysates from the ALACEN process also contain some oligomeric xylose and minor hemicellulose-derived sugars, optimal valorization of the C5-fractions derived from the refinery process can be obtained using S. thermodepolymerans. This opens the way for further exploration of PHA production from C5-fractions out of a variety of herbaceous lignocellulosic biomasses using the ALACEN process combined with S. thermodepolymerans. Overall, the innovative utilization of renewable resources in fermentation technology, as shown herein, makes a solid contribution to the transition to a biobased economy.[1] W. Zhou, D.I. Colpa, H. Permentier, R.A. Offringa, L. Rohrbach, G.J.W. Euverink, J. Krooneman. Insight into polyhydroxyalkanoate (PHA) production from xylose and extracellular PHA degradation by a thermophilic Schlegelella thermodepolymerans. Resources, Conservation and Recycling 194 (2023) 107006, ISSN 0921-3449, https://doi.org/10.1016/j.resconrec.2023.107006. [2] S. Bertran-Llorens, W.Zhou. M.A.Palazzo, D.I.Colpa, G.J.W.Euverink, J.Krooneman, P.J.Deuss. ALACEN: a holistic herbaceous biomass fractionation process attaining a xylose-rich stream for direct microbial conversion to bioplastics. Submitted 2023.
LINK
Microbes like bacteria and fungi can grow on almost everything, including e.g. on a music CD made of aluminum and polycarbonate. How? By producing an optimal mixture of effective enzymes that degrade the material on which the microbes thrive. In this project we want to find and characterize microbes that have the ability to digest one of the most commercially successful but at the same time hard-to-degrade materials: furan-based bio-composite resin. To help the microbes to degrade this recalcitrant material, we first must open up the complex resin structure by using (mild) acidification, grinding, and/or UV light. Thus, with this project we aim to find an effective and sustainable way to safely and effectively dispose and recycle used bio-composite resins. Our findings will help to increase the circularity of bio-composite materials and as such decrease the environmental waste pressure.
It is known that several bacteria in sewage treatment plants can produce attractive quantities of biodegradable polymers within their cell walls (up to 80% of the cell weight). These polymers may consist of polyhydroxyalkanoates (PHA), a bioplastic which exhibits interesting characteristics like excellent biodegradation, low melting point and good environmental footprint. PHA bioplastics or PHBV are still quite expensive because cumbersome downstream processing steps of the PHAcontaining bacteria are needed before PHA can be applied in products. In this proposal, the consortium investigates the possibilities for eliminating these expensive and environmentally intensive purification steps, and as a result contribute to speeding up the up-take of PHA production of residual streams by the market. The objective of the project is to investigate the possibilities of direct extrusion of PHAcontaining bacteria and the application opportunities of the extruded PHA. The consortium of experienced partners (Paques Biomaterials, MAAN Group, Ecoras and CoEBBE) will investigate and test the extrusion of different types of PHA-containing biomass, and analyse the products on composition, appearance and mechanical properties. Moreover, the direct extrusion process will be evaluated and compared with conventional PHA extraction and subsequent extrusion. The expected result will be a proof of principle and provide an operational window for the application of direct extrusion with PHA-containing biomass produced using waste streams, either used as such or in blends with purified PHA. Both the opportunities of the direct extrusion process itself as well as the application opportunities of the extruded PHA will be mapped. If the new process leads to a cheaper, more environmentally friendly produced and applicable PHA, the proof of principle developed by the consortium could be the first step in a larger scale development that could help speeding up the implementation of the technology for PHA production from residual streams in the market.
Treatment of crops with insecticides remains essential because globally more than 75 billion dollars is lost through crop destruction by invasive insects. However it is accompanied by severe disadvantages including i. increasing resistance of the target insects against insecticides and ii. the undesired lethality of beneficial insects such as bees and other pollinator species. The significant reduction of insect species during the last years, at least partly caused by the presently available insecticides has also effects on insect-eating species. Last but not least the presence of residual amount of insecticides in the environment (soil and plants), because of poor (bio)degradation, is another distinct disadvantage. Therefore, the overall aim of this proposal is to design and synthesize peptide based biopesticides. This should lead to Nature inspired green alternatives for insect control because "Peptides" are the small equivalents of "proteins", that are biomolecules, which are universally present in all organisms and subject to their natural biodegradation mechanisms, as well as also chemically degraded in the soil (water, heat, UV, oxygen). Design and synthesis of these environmentally benign compounds will eventually take place in a founded company called "INNOVAPEPLINE". Evaluation of candidate peptide based biopesticides can be carried out in collaboration with a recently founded company (spin-out of the University of Glasgow) called "SOLASTA BIO" (founders professors Shireen Davies, Julian Dow and Rob Liskamp) and/or with other (third) parties such as the University of Wageningen. Upon recent identification of promising candidate compounds ("leads"), chemical optimization studies of leads will take place, followed by evaluation in field trials. In this proposal design, synthesis and chemical optimization of the biological activity of new peptides and development of methods to monitor their biodegradation rate will take place. Thereby expanding the repertoire of peptide based biopesticides. (292 words)
