Sustainable Bio-based Economy Research Articles

Combinatorial optimization of pathway, process and media for the production of p-coumaric acid by Saccharomyces cerevisiae.

Microbial cell factories are instrumental in transitioning towards a sustainable bio-based economy, offering alternatives to conventional chemical processes. However, fulfilling their potential requires simultaneous screening for optimal media composition, process and genetic factors, acknowledging the complex interplay between the organism's genotype and its environment. This study employs statistical design of experiments to systematically explore these relationships and optimize the production of p-coumaric acid (pCA) in Saccharomyces cerevisiae. Two rounds of fractional factorial designs were used to identify factors with a significant effect on pCA production, which resulted in a 168-fold variation in pCA titre. Moreover, a significant interaction between the culture temperature and expression of ARO4 highlighted the importance of simultaneous process and strain optimization. The presented approach leverages the strengths of experimental design and statistical analysis and could be systematically applied during strain and bioprocess design efforts to unlock the full potential of microbial cell factories.

The potential of CO2-based production cycles in biotechnology to fight the climate crisis.

Rising CO2 emissions have pushed scientists to develop new technologies for a more sustainable bio-based economy. Microbial conversion of CO2 and CO2-derived carbon substrates into valuable compounds can contribute to carbon neutrality and sustainability. Here, we discuss the potential of C1 carbon sources as raw materials to produce energy, materials, and food and feed using microbial cell factories. We provide an overview of potential microbes, natural and synthetic C1 utilization pathways, and compare their metabolic driving forces. Finally, we sketch a future in which C1 substrates replace traditional feedstocks and we evaluate the costs associated with such an endeavor.

Recycling of catering waste for sequential production of biohydrogen and biomethane; pre-treatments, batch, and continuous mode studies

Dark fermentation has emerged as a sustainable bio-based economy for bio-fuels production in accord with “carbon neutrality”. Herein, catering waste was collected, pre-treated with a series of multilevel (acidic, alkaline, Triton X100, ultrasonication, and microwave radiation) pathways, and employed as substrates to inspect their characteristics on two-stage mesophilic biohydrogen/biomethane production process through batch assays under initial pH of 6.5, and 7.5, respectively. The findings revealed that the optimized pre-treated catering waste (CW) with Triton X-100 recorded the highest biohydrogen, and biomethane production yield of 5.9 mL/g VS added (BHP of 368.5 mL), and 17.7 ± 26.8 mL/g VS (BMP 1108.5 mL), at 37 °C, respectively. Overall, the kinetic data was strongly matched with the Gompertz equation (R2 = 0.92–0.99). Afterward, the pre-treated Triton X-100-CW was introduced into a second series of continuous experiments (continuously stirred tank reactors) for sequential production of biohydrogen/ biomethane. An average yield of biohydrogen and biomethane production of 22.24 ± 2.29 mL/g VS, and 98.7 ± 10.4 mL/g VS was accomplished at hydraulic retention time (HRT), and organic loading rate (OLR) of 1.0 day, 91.5 gCOD/L.day and 10.0 days, 7.2 gCOD/L.day, respectively. Economically, the configured system displays a total energy yield of 1.634 KWh/KgVS, and the inspected 1600 kg CW produces about 2614.41 KW/day. As such, the present work broadens a salience pattern for scalable upcycling of CW organic constituent stream into biohydrogen/biomethane for potential applications in the energy sector.

Monetizing ecosystem services of perennial wild plant mixtures for bioenergy

The transition to a sustainable biobased economy promises to free the economy from its dependence on finite fossil resources by replacing them with biomass derived primarily from agricultural production. However, this often threatens the ecosystem services on which its very existence depends, such as climate regulation, erosion mitigation, and biodiversity conservation. A major challenge is that biomass provision is usually the only ecosystem service directly priced in markets. While there are several studies estimating the monetary value of a wider range of ecosystem services for common food and biomass crops, there is limited information for novel bioenergy cropping systems such as perennial wild plant mixtures (WPM). Therefore, this study assesses the monetary value of key ecosystem services of WPM, i.e. nursery services, recreational value, moderation of extreme events, climate regulation, nutrient cycling, erosion prevention, and the provision of biomass. In addition, three contrasting land use scenarios; parking lot, silage maize (Zea mays L.) cultivation for biogas production; and pristine forest; were used for comparison. While parking lot (0.15 €/ha*yr.) and pristine forest (1691.57 €/ha*yr.) yielded the minimum and maximum values, WPM cultivation (624.82 €/ha*yr.) performed surprisingly well compared to silage maize (653.61 €/ha*yr.). Thus, monetization of ecosystem services other than biomass provision made silage maize and WPM cultivation economically comparable by almost fully compensating for the lower biomass provision of WPM. Consequently, using such information to better reward farmers for more social-ecologically sound bioenergy cropping systems could help policymakers improve agricultural sustainability in the long run.

Ecomodernism and the Libidinal Economy: Towards a Critical Conception of Technology in the Bio-Based Economy

In this paper, we carry out a critical analysis of the concept of technology in the current design of the bio-based economy (BBE). Looking at the current status of the BBE, we observe a dominant focus on technological innovation as the principal solution to climatic instability. We take a critical stance towards this “ecomodernist” worldview, addressing its fundamental assumptions, and offer an underarticulated explanation as to why a successful transition toward a sustainable BBE—i.e. one that fully operates within the Earth’s carrying capacity—has not yet been reached. Bernard Stiegler has developed a philosophical perspective on the concept of economy, broadening it to include the human condition through the notion of desire. This theory can help to obtain a more profound understanding of why ecomodernist strategies are dominant today. Stiegler’s theory of the libidinal economy offers an analysis of controlled and exploited human desire as a primary driver behind modern techno-economic structures. Our hypothesis is that a critique of contemporary technofixism as a critique of libidinal economy is a necessary step to take in the discussion around the BBE as a concept, if the BBE is ever to bring about a system that can truly operate within the Earth’s carrying capacity.

Brazilian Biodiversity as a Source of Power and Sustainable Development: A Neglected Opportunity

Six terrestrial biomes and a huge coastline make Brazil one of the most biodiverse countries in the world. However, the potential of Brazilian biodiversity as a valuable and sustainable source of wealth and development is still neglected. In order to reverse this scenario, the country needs to recognize and assume the power of its biodiversity, focusing on (I) industry, science and technology, (II) biological conservation and maintenance of ecosystem services, considering reverberations on agriculture and public health, and (III) ecotourism, conservation and sustainable development of local populations. The joint action of the Brazilian population and scientific community is needed to achieve these goals, which must be translated into the election of politicians committed to sustainable development and an increase in research and technology based on Brazilian biodiversity. Additional reasons for preserving Brazilian biodiversity (e.g., intrinsic, cultural, and ethical values) are also addressed in this article. Finally, we argue that Brazil should recover its global leadership on the environmental agenda and assume its biological diversity as a source of Soft Power, as well as develop its neglected capacity in the field of the sustainable bio-based economy (bioeconomy). In brief, Brazil needs to recognize and embrace the power of its biodiversity.

Readiness for Innovation of Emerging Grass-Based Businesses

New business opportunities based on grassland and green fodder present a promising avenue to realize the transition towards a circular and sustainable bio-based economy. Yet, such potential remains largely untapped and grass-based products and businesses remain a small niche in the global economy. To understand this phenomenon, this paper introduces and operationalizes a model to assess innovation readiness built around seven focus areas: technology, manufacturing, business, IPR, customer, team, and funding readiness with their own detailed “progress scales.” We employ necessary condition analysis (NCA) to identify limiting factors and bottlenecks in actual business situations. Our results reveal that lack of consumer awareness, infant conversion technologies and paucity of long-term investments that support emerging bio-based businesses are the most limiting conditions for the growth of emerging grass-based markets. The present study advances our understanding of the factors that limit complex innovations in grassland systems. Focusing on necessary conditions in a coordinated way between practitioners and policy makers by giving priority to fostering positive awareness of bioeconomy businesses, developing conversion technologies, and improving access to capital is a recommended approach to foster emerging grass-based innovations.

Repairing What Policy Is Missing Out on: A Constructive View on Prospects and Preconditions for Sustainable Biobased Economy Options to Mitigate and Adapt to Climate Change

Biomass use for energy and materials is, on the one hand, one of the key mitigation options to reach the 1.5 °C GMT target set in the Paris Agreement, as highlighted by the IPCC and many other key analyses. On the other hand, particularly in parts of the EU, a strong negative connotation has emerged in public debate and EC policy, with a particular emphasis on the (presumed) displacement effect in markets and land use. This is a remarkable contrast because the reasons to use sustainable biomass, on the one hand, and the possibilities and synergies for supplying sustainable biomass, on the other, are underpinned with strong evidence, also providing insights on how displacement issues can be avoided. Sustainable biomass supplies can contribute 20–30% of the future global and European energy supply, leading to reduced overall mitigation costs, including realizing the net CO2 removal from the atmosphere using BECCS concepts. This paper highlights which options, pathways and preconditions are key to achieving such a substantial contribution of sustainable biomass in future (2050) energy and material supply (with a focus on the European setting). By pinpointing how “biomass can be done right” and how important synergies can be achieved via better agricultural methods, the restoration of marginal and degraded lands and the adaptation of climate change, a different policy agenda emerges in sharp contrast to how a biobased economy has been framed in recent years. It is recommended that future policy priorities, particularly at the EU level, take a more integral view on the synergy between the role of biomass in the energy transition, climate adaptation and mitigation, better agriculture and the better use of land in general. Strategies to achieve such positive results typically require an alignment between renewable energy, and agricultural, environmental, mitigation and adaptation policies, which is a largely missing nexus in different policy arenas. Resolving this lack of alignment offers a major opportunity, globally, to contribute to the European Green deal and improve energy security.

A critical review on prospects of bio-refinery products from second and third generation biomasses

Humans from the very beginning of existence utilized natural resources for various daily needs. As years have gone by and with the continuous rise in population, both the natural resources and the biodiversity of this world are at the brink of exhaustion and collapse. Circular Economy (CE) is one such method that tackles both these problems at the same time. Worldwide energy production focuses on the shift from petroleum derivatives to biomass-based biofuels for the emerging sustainable bio-based economy. However, the concept of the biomass-based bio-refinery is in the early stages of development in many parts of the world. To confront global challenges environmentally and economically, the paradigm shift from biofuel production to bio-refinery is inevitable. This review summarizes various alternative feedstocks’ availability and their chemical potential for bio-refinery, application of recent developments like Big Data, blockchain technology and Internet of Things on bio-refinery framework. Furthermore, an emphasis has been made on the strategies and challenges in the production of the broad spectrum of platform chemicals and their incomparable global market value as it is an intermediate that bridges between the biomass and the value-added bio-based products. Thus, this review is an important key resource for researchers as it is a comprehensive analysis of the vital areas in bio-refinery.

Detailed analysis of the D-galactose catabolic pathways in Aspergillus niger reveals complexity at both metabolic and regulatory level

The current impetus towards a sustainable bio-based economy has accelerated research to better understand the mechanisms through which filamentous fungi convert plant biomass, a valuable feedstock for biotechnological applications. Several transcription factors have been reported to control the polysaccharide degradation and metabolism of the resulting sugars in fungi. However, little is known about their individual contributions, interactions and crosstalk. D-galactose is a hexose sugar present mainly in hemicellulose and pectin in plant biomass. Here, we study D-galactose conversion by Aspergillus niger and describe the involvement of the arabinanolytic and xylanolytic activators AraR and XlnR, in addition to the D-galactose-responsive regulator GalX. Our results deepen the understanding of the complexity of the filamentous fungal regulatory network for plant biomass degradation and sugar catabolism, and facilitate the generation of more efficient plant biomass-degrading strains for biotechnological applications.

Lignin valorisation via enzymes: A sustainable approach

Lignin is the 3rd most abundant biopolymer surpassed by cellulose and hemicellulose and is the most abundant aromatics resource available on earth for utilization by mankind. It was considered undesirable historically which was usually burned as inefficient fuel. Lignin’s 3D recalcitrant nature caused hinderance to feasible biorefinery of holocellulosic fraction of biomass; however, with the rise of lignin biorefinery the concept has changed completely. Now modern biorefinery of biomass insists on making complete value of all the streams including lignin by valorising into variety of phenolics, biopolymers and other high value-added chemicals. Biological depolymerisation of lignin via enzymes is environmentally benign and preferred approach by virtue of low chemical requirement and disposal and energy demand; however, economic challenges are ahead. Robust enzymes are available in nature which can either modify or depolymerise lignin to add further value. Lignin modifying as well as lignin degrading auxiliary enzymes are instrumental and pave the way to a green process for lignin valorisation. This review article is focussed on various lignin degrading as well as lignin modifying enzymes produced by microorganisms especially fungi for degradation or modification of lignin, and its mechanisms, along with the strength and challenges for sustainable bio-based economy development.

Recombinant protein secretion by Bacillus subtilis and Lactococcus lactis: pathways, applications, and innovation potential

Secreted recombinant proteins are of great significance for industry, healthcare and a sustainable bio-based economy. Consequently, there is an ever-increasing need for efficient production platforms to deliver such proteins in high amounts and high quality. Gram-positive bacteria, particularly bacilli such as Bacillus subtilis, are favored for the production of secreted industrial enzymes. Nevertheless, recombinant protein production in the B. subtilis cell factory can be very challenging due to bottlenecks in the general (Sec) secretion pathway as well as this bacterium’s intrinsic capability to secrete a cocktail of highly potent proteases. This has placed another Gram-positive bacterium, Lactococcus lactis, in the focus of attention as an alternative, non-proteolytic, cell factory for secreted proteins. Here we review our current understanding of the secretion pathways exploited in B. subtilis and L. lactis to deliver proteins from their site of synthesis, the cytoplasm, into the fermentation broth. An advantage of this cell factory comparison is that it identifies opportunities for protein secretion pathway engineering to remove or bypass current production bottlenecks. Noteworthy new developments in cell factory engineering are the mini-Bacillus concept, highlighting potential advantages of massive genome minimization, and the application of thus far untapped ‘non-classical’ protein secretion routes. Altogether, it is foreseen that engineered lactococci will find future applications in the production of high-quality proteins at the relatively small pilot scale, while engineered bacilli will remain a favored choice for protein production in bulk.

Characterization and Phylogenetic Analysis of a Novel GH43 β-Xylosidase From Neocallimastix californiae.

Degradation of lignocellulosic materials to release fermentable mono- and disaccharides is a decisive step toward a sustainable bio-based economy, thereby increasing the demand of robust and highly active lignocellulolytic enzymes. Anaerobic fungi of the phylum Neocallimastigomycota are potent biomass degraders harboring a huge variety of such enzymes. Compared to cellulose, hemicellulose degradation has received much less attention; therefore, the focus of this study has been the enzymatic xylan degradation of anaerobic fungi as these organisms produce some of the most effective known hydrolytic enzymes. We report the heterologous expression of a GH43 xylosidase, Xyl43Nc, and a GH11 endoxylanase, X11Nc, from the anaerobic fungus Neocallimastix californiae in Escherichia coli. The enzymes were identified by screening of the putative proteome. Xyl43Nc was highly active against 4-Nitrophenol-xylopyranosides with a Km of 0.72 mM, a kcat of 29.28 s-1, a temperature optimum of 32°C and a pH optimum of 6. When combined, Xyl43Nc and X11Nc released xylose from beechwood xylan and arabinoxylan from wheat. Phylogenetic analysis revealed that Xyl43Nc shares common ancestry with enzymes from Spirochaetes and groups separately from Ascomycete sequences in our phylogeny, highlighting the importance of horizontal gene transfer in the evolution of the anaerobic fungi.

High yield synthesis of hexitols and ethylene glycol through one-pot hydrolytic hydrogenation of cellulose

Catalytic valorization of biomass has gained a significant global attention in recent years. Cellulose is an interesting bio-renewable feedstock, which can be utilized to replace the fossil fuel derived chemicals to attain a sustainable bio-based economy. Our research shows a one-pot conversion of cellulose through hydrolytic hydrogenation using heteropolyacid (HPA)/zirconia and Ru/C catalyst. The developed catalytic system was found to be highly active towards selective production of hexitols and ethylene glycol. A significant improvement in the catalytic performance towards cellulose conversion was observed when the cellulose was pre-treated using ball-milling (900 rpm, 8 h), as the ball-milling significantly reduced the crystallinity index of cellulose, which decreased the recalcitrance of the cellulose structure. Almost complete conversion (100%) of cellulose was observed when the reaction was performed at 220 °C for 5 h giving hexitols and ethylene glycol yields of 26.2 and 40%, respectively. Based on a series of experiments, a possible reaction pathway was proposed which suggested heteropolyacid/zirconia catalyzed hydrolysis and retro-aldol condensation reactions, accompanying by hydrogenation with Ru/C. Interestingly, HPA immobilized on the composite catalyst shows enhanced stability and recyclability, demonstrating the utilization of a heterogeneous system for tandem conversions of biomass to renewable fuels and feedstocks.

Future trends in synthetic biology in Asia.

Synthetic biology research and technology translation has garnered increasing interest from the governments and private investors in Asia, where the technology has great potential in driving a sustainable bio-based economy. This Perspective reviews the latest developments in the key enabling technologies of synthetic biology and its application in bio-manufacturing, medicine, food and agriculture in Asia. Asia-centric strengths in synthetic biology to grow the bio-based economy, such as advances in genome editing and the presence of biofoundries combined with the availability of natural resources and vast markets, are also highlighted. The potential barriers to the sustainable development of the field, including inadequate infrastructure and policies, with suggestions to overcome these by building public-private partnerships, more effective multi-lateral collaborations and well-developed governance framework, are presented. Finally, the roles of technology, education and regulation in mitigating potential biosecurity risks are examined. Through these discussions, stakeholders from different groups, including academia, industry and government, are expectantly better positioned to contribute towards the establishment of innovation and bio-economy hubs in Asia.

Flax fiber for technical textile: A life cycle inventory

Flax fiber appears as a suitable feedstock in the endeavor of deploying a sustainable biobased economy. Its environmental performance as reinforcement in composite materials has been studied in previous Life Cycle Assessments (LCAs). However, these studies only present a coarse Life cycle Inventory (LCI) and often fail to detail all processes of the supply chain or to represent the co-products. This paper aims to bridge this gap and provide data for future LCAs on flax fiber production and transformation.The study focuses on the impacts of producing a bio-based reinforcement material (a fabric product for non-aesthetic purposes) with a system expansion perspective. The functional unit is defined as the production of 2400 m2 flax-based technical textile per year, this corresponds to 1 ha of cultivated land. The geographical scope considers that the production occurs in France and that some manufacturing process are outsourced in China. A Sensitivity Analysis was carried out to assess the influence of the electricity mix in the various countries involved in the manufacturing cycle.A detailed life cycle inventory for flax fiber production and transformation was built and the environmental performance of a flax technical textile was assessed as a cradle-to-gate LCA. The fate of co-products was documented and was shown to contribute to the reduction of the generated environmental impacts.Through a cradle-to-gate LCA, a broader understanding of the environmental performance of a flax-based technical textile was presented by including the valorization of co-products and a wider set of analyzed impact categories, going therefore beyond the existing state-of-the-art. Results show agricultural activities and electricity production to be the biggest contributors to the environmental impacts of flax technical textile; contributions due to land use changes were minor in comparison. Very specifically for this case study, a sensibility analysis showed the influence of an all-French production to be more efficient from an environmental point of view.

Studying the Transition towards a Circular Bioeconomy—A Systematic Literature Review on Transition Studies and Existing Barriers

The European Commission’s strategic long-term vision for 2050, “A Clean Planet for All”, identifies the bioeconomy and the circular economy as key strategic areas for achieving a climate-neutral economy. Focus is given to the sustainability of biomass and the circularity of materials. However, in order to facilitate the transition toward a sustainable bio-based circular economy and to unlock its potential, strong accompanying measures are required. These should be designed based on a systematic understanding of transition drivers and barriers. This paper, after providing a systematic review of transition research on the circular bioeconomy, focuses on the identification and classification of transition barriers, clustering them into relevant categories. Moreover, it provides a comparison of the barriers identified by various frameworks.

Recent Developments in Low iLUC Policies and Certification in the EU Biobased Economy

The development of a sustainable biobased economy (BBE) in Europe is associated with several challenges. Amongst others, lessons learned from the development of the biofuel sector and the complex debate around land use change associated with a growing demand for biomass have to be considered when developing BBE policies. In that regard, strategies to identify and verify feedstocks with low potential risks for direct and indirect land use change (iLUC) impacts are of specific importance. Complementing existing efforts to assess iLUC with modelling activities, the European Commission (EC) has proposed a risk-based approach, aiming to differentiate high and low iLUC risk biomass. Amongst others, different additionality measures can be used to produce certified biomass with low iLUC risk. However, a comprehensive overview and analysis of these additionality measures and the challenges related to their integration in an integer verification approach is still missing. Therefore, we analyse European Union (EU) policies dealing with iLUC, iLUC risk assessment studies, certification approaches, and iLUC modelling studies to identify and develop additionality practices potentially applicable in certification and to show how the potential application of the proposed measures could be realised and verified in practice. We identified five potential practices for low iLUC risk biomass production, which are likely to be used by market actors. For each practice, we identified methods for the determination of low iLUC risk feedstock and products. Finally, our review includes recommendations for follow-up activities towards the actual implementation of additionality measures in biomass certification schemes.

Towards the Green Synthesis of Furfuryl Alcohol in A One-Pot System from Xylose: A Review

In the pursuit of establishing a sustainable biobased economy, valorization of lignocellulosic biomass is increasing its value as a feedstock. Nevertheless, to achieve the integrated biorefinery paradigm, the selective fractionation of its complex matrix to its single constituents must be complete. This review presents and examines the novel catalytic pathways to form furfuryl alcohol (FuOH) from xylose in a one-pot system. This production concept takes on chemical, thermochemical and biochemical transformations or a combination of them. Still, the bulk of the research is targeted to develop heterogeneous catalytic systems to synthesize FuOH from furfural and xylose. The present review includes an overview of the economic aspects to produce this platform chemical in an industrial manner. In the last section of this review, an outlook and summary of catalytic processes to produce FuOH are highlighted.

Solubility parameters analysis of Eucalyptus urograndis kraft lignin

Lignin has gained momentum as a renewable material because it is the largest natural source that can provide aromatic compounds in a wide range of applications. However, its heterogeneity in terms of high polydispersity molar mass distribution and variety of functional groups has limited the direct production of added-value lignin-derivatives. Among the alternatives to obtain more homogeneous lignin cuts is solvent fractionation. However, it is not well understood how different solvents influence lignin partition, and thus it is difficult to establish a rational solvent order to perform it. Thus, the purpose of this work was to understand Eucalyptus urograndis kraft lignin partition in organic solvents through the application of three solubility parameter theories: Hildebrand, Hansen (HSP), and Functional (FSP). Through the theories studied, FSP provided the best representation of lignin partition in organic solvents. In addition, the influence of solvents’ solubility parameters on lignin solubility was investigated by multiregression analyses, which revealed that only the polar solvent parameter showed statistical relevance to describe lignin solubility. The results of this work may contribute to the effective development of technical lignins’ fractionation, allowing the production of higher-value lignin derivatives, increasing the profitability of biorefineries, and establishing a sustainable bio-based economy.