Cyanobacterial Polyhydroxyalkanoates: A Sustainable Alternative in Circular Economy

Diana Gomes Gradíssimo; Luciana Pereira Xavier; Agenor Valadares Santos

doi:10.3390/molecules25184331

Cyanobacterial Polyhydroxyalkanoates: A Sustainable Alternative in Circular Economy

Molecules ◽

10.3390/molecules25184331 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4331 ◽

Cited By ~ 1

Author(s):

Diana Gomes Gradíssimo ◽

Luciana Pereira Xavier ◽

Agenor Valadares Santos

Keyword(s):

Circular Economy ◽

Durable Goods ◽

Carbon Sources ◽

Terrestrial Ecosystems ◽

Production Costs ◽

Biotechnological Production ◽

Minimum Requirement ◽

Photosynthetic Organisms ◽

Low Costs ◽

By Products

Conventional petrochemical plastics have become a serious environmental problem. Its unbridled use, especially in non-durable goods, has generated an accumulation of waste that is difficult to measure, threatening aquatic and terrestrial ecosystems. The replacement of these plastics with cleaner alternatives, such as polyhydroxyalkanoates (PHA), can only be achieved by cost reductions in the production of microbial bioplastics, in order to compete with the very low costs of fossil fuel plastics. The biggest costs are carbon sources and nutrients, which can be appeased with the use of photosynthetic organisms, such as cyanobacteria, that have a minimum requirement for nutrients, and also using agro-industrial waste, such as the livestock industry, which in turn benefits from the by-products of PHA biotechnological production, for example pigments and nutrients. Circular economy can help solve the current problems in the search for a sustainable production of bioplastic: reducing production costs, reusing waste, mitigating CO2, promoting bioremediation and making better use of cyanobacteria metabolites in different industries.

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Low-quality animal by-product streams for the production of PHA-biopolymers: fats, fat/protein-emulsions and materials with high ash content as low-cost feedstocks

Biotechnology Letters ◽

10.1007/s10529-020-03065-y ◽

2020 ◽

Author(s):

Victoria Saad ◽

Björn Gutschmann ◽

Thomas Grimm ◽

Torsten Widmer ◽

Peter Neubauer ◽

...

Keyword(s):

Ralstonia Eutropha ◽

Low Cost ◽

Carbon Sources ◽

Dry Weight ◽

Ash Content ◽

Production Costs ◽

Medium Chain Length ◽

Current Production ◽

Copolymer Poly ◽

By Products

Abstract Objective The rapid accumulation of crude-oil based plastics in the environment is posing a fundamental threat to the future of mankind. The biodegradable and bio-based polyhydroxyalkanoates (PHAs) can replace conventional plastics, however, their current production costs are not competitive and therefore prohibiting PHAs from fulfilling their potential. Results Different low-quality animal by-products, which were separated by thermal hydrolysis into a fat-, fat/protein-emulsion- and mineral-fat-mixture- (material with high ash content) phase, were successfully screened as carbon sources for the production of PHA. Thereby, Ralstonia eutropha Re2058/pCB113 accumulated the short- and medium-chain-length copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)]. Up to 90 wt% PHA per cell dry weight with HHx-contents of 12–26 mol% were produced in shake flask cultivations. Conclusion In future, the PHA production cost could be lowered by using the described animal by-product streams as feedstock. Graphical abstract

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Reuse and Recycling of By-Products in the Steel Sector: Recent Achievements Paving the Way to Circular Economy and Industrial Symbiosis in Europe

Metals ◽

10.3390/met10030345 ◽

2020 ◽

Vol 10 (3) ◽

pp. 345 ◽

Cited By ~ 8

Author(s):

Teresa Annunziata Branca ◽

Valentina Colla ◽

David Algermissen ◽

Hanna Granbom ◽

Umberto Martini ◽

...

Keyword(s):

Environmental Sustainability ◽

Circular Economy ◽

Steel Industry ◽

Carbon Sources ◽

Steel Production ◽

Production Cycle ◽

Comprehensive Overview ◽

Sustainable Solutions ◽

Industrial Sectors ◽

By Products

Over the last few decades, the European steel industry has focused its efforts on the improvement of by-product recovery and quality, based not only on existing technologies, but also on the development of innovative sustainable solutions. These activities have led the steel industry to save natural resources and to reduce its environmental impact, resulting in being closer to its “zero-waste” goal. In addition, the concept of Circular Economy has been recently strongly emphasised at a European level. The opportunity is perceived of improving the environmental sustainability of the steel production by saving primary raw materials and costs related to by-products and waste landfilling. The aim of this review paper was to analyse the most recent results on the reuse and recycling of by-products of the steelmaking cycles as well as on the exploitation of by-products from other activities outside the steel production cycle, such as alternative carbon sources (e.g., biomasses and plastics). The most relevant results are identified and a global vision of the state-of-the-art is extracted, in order to provide a comprehensive overview of the main outcomes achieved by the European steel industry and of the ongoing or potential synergies with other industrial sectors.

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Leasing, Modularity, and the Circular Economy

Management Science ◽

10.1287/mnsc.2020.3829 ◽

2021 ◽

Author(s):

Vishal Agrawal ◽

Atalay Atasu ◽

Sezer Ülkü

Keyword(s):

Environmental Impact ◽

Operations Management ◽

Circular Economy ◽

Durable Goods ◽

Production Costs ◽

Product Architecture ◽

Model Choice ◽

Modular Architecture ◽

Environmental Implications ◽

Modular Product

We investigate the economic and environmental implications of jointly implementing leasing and modularity, two prominent circular economy strategies, and their interaction. We develop a durable goods model to obtain insights for firms considering the use of these strategies. We first analyze the effect of adopting leasing on a firm’s product architecture choice. We find that a modular product architecture is more attractive under leasing only if off-lease products depreciate to a greater extent. We next analyze the effect of adopting a modular product architecture on the firm’s business model choice. We find that adopting a modular architecture can cause a leasing firm to switch to selling but will not lead a selling firm to switch to leasing. Building on these results, we show that leasing a modular product is preferred by the firm only under limited conditions (i.e., when production costs are low, off-lease products are in relatively better condition, and when there is a large difference between depreciation levels of different modules). Finally, we show that jointly implementing leasing and modularity can also lead to higher environmental impact than only adopting leasing or modularity in isolation. This paper was accepted by Vishal Gaur, operations management.

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Monomers, Materials and Energy from Coffee By-Products: A Review

Sustainability ◽

10.3390/su13126921 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6921

Author(s):

Laura Sisti ◽

Annamaria Celli ◽

Grazia Totaro ◽

Patrizia Cinelli ◽

Francesca Signori ◽

...

Keyword(s):

Circular Economy ◽

Food Industry ◽

Food Packaging ◽

Low Cost ◽

Biofuel Production ◽

Material Technology ◽

Coffee Production ◽

Coffee Pulp ◽

Coffee Waste ◽

By Products

In recent years, the circular economy and sustainability have gained attention in the food industry aimed at recycling food industrial waste and residues. For example, several plant-based materials are nowadays used in packaging and biofuel production. Among them, by-products and waste from coffee processing constitute a largely available, low cost, good quality resource. Coffee production includes many steps, in which by-products are generated including coffee pulp, coffee husks, silver skin and spent coffee. This review aims to analyze the reasons why coffee waste can be considered as a valuable source in recycling strategies for the sustainable production of bio-based chemicals, materials and fuels. It addresses the most recent advances in monomer, polymer and plastic filler productions and applications based on the development of viable biorefinery technologies. The exploration of strategies to unlock the potential of this biomass for fuel productions is also revised. Coffee by-products valorization is a clear example of waste biorefinery. Future applications in areas such as biomedicine, food packaging and material technology should be taken into consideration. However, further efforts in techno-economic analysis and the assessment of the feasibility of valorization processes on an industrial scale are needed.

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Valorization of Kiwi by-Products for the Recovery of Bioactive Compounds: Circular Economy Model

Proceedings ◽

10.3390/foods_2020-07647 ◽

2020 ◽

Vol 70 (1) ◽

pp. 9

Author(s):

Franklin Chamorro ◽

María Carpena ◽

Bernabé Nuñez-Estevez ◽

Miguel A. Prieto ◽

Jesus Simal-Gandara

Keyword(s):

Bioactive Compounds ◽

Circular Economy ◽

Agricultural Production ◽

Organic Waste ◽

Antimicrobial Activities ◽

Added Value ◽

Economic Returns ◽

Industrial Processing ◽

Pharmaceutical Industries ◽

By Products

Currently, agricultural production generates large amounts of organic waste, both from the maintenance of farms and crops, and from the industrialization of the product. Generally, these wastes are accumulated in landfills or burned, sometimes causing environmental problems. However, many scientific studies suggest that these residues are rich in bioactive compounds, so these matrices could be revalued for their use in food, cosmetic, or pharmaceutical industries. In this way, the circular and sustainable economy is favored, while obtaining products with high added value. In this case, this approach is applied to the residues generated from kiwi production, since numerous studies have shown the high content of kiwi in bioactive compounds of interest, such as phenolic compounds, vitamins, and carotenoids. These compounds have been reported for their antioxidant, anti-inflammatory, and antimicrobial activities, among other beneficial properties for health such as its use as prebiotic. Therefore, this article reviews the potential of residues derived from industrial processing and agricultural maintenance of kiwi as promising matrices for the development of new nutraceutical, cosmetic, or pharmacological products, obtaining, at the same time, economic returns and a reduction of the environmental impact of this industry, attaching it to the perspective of the circular economy.

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Sustainability: Recovery and Reuse of Brewing-Derived By-Products

Sustainability ◽

10.3390/su13042355 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2355

Author(s):

Tiziana Amoriello ◽

Roberto Ciccoritti

Keyword(s):

Circular Economy ◽

Inclusive Growth ◽

Global Challenge ◽

Use Of Resources ◽

By Products ◽

Recovery And Reuse

The great global challenge in order to achieve sustainable and inclusive growth over the coming decades is the promotion of the efficient use of resources, favoring a transition to a cleaner and circular economy [...]

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Sporulation in solventogenic and acetogenic clostridia

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11289-9 ◽

2021 ◽

Author(s):

Mamou Diallo ◽

Servé W. M. Kengen ◽

Ana M. López-Contreras

Keyword(s):

Current Knowledge ◽

Carbon Sources ◽

Cost Effective ◽

Biotechnological Production ◽

Key Points ◽

Wide Range ◽

Potential Applications ◽

A Cell ◽

Sporulation Initiation ◽

Solventogenic Clostridia

AbstractThe Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.

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Sustainable Agri-Food Processes and Circular Economy Pathways in a Life Cycle Perspective: State of the Art of Applicative Research

Sustainability ◽

10.3390/su13052472 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2472

Author(s):

Teodora Stillitano ◽

Emanuele Spada ◽

Nathalie Iofrida ◽

Giacomo Falcone ◽

Anna Irene De Luca

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Circular Economy ◽

Social Life ◽

Food Systems ◽

State Of The Art ◽

Terrestrial Ecosystems ◽

Point Of View ◽

Social Life Cycle Assessment ◽

Qualitative Synthesis

This study aims at providing a systematic and critical review on the state of the art of life cycle applications from the circular economy point of view. In particular, the main objective is to understand how researchers adopt life cycle approaches for the measurement of the empirical circular pathways of agri-food systems along with the overall lifespan. To perform the literature review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was considered to conduct a review by qualitative synthesis. Specifically, an evaluation matrix has been set up to gather and synthesize research evidence, by classifying papers according to several integrated criteria. The literature search was carried out employing scientific databases. The findings highlight that 52 case studies out of 84 (62% of the total) use stand-alone life cycle assessment (LCA) to evaluate the benefits/impacts of circular economy (CE) strategies. In contrast, only eight studies (9.5%) deal with the life cycle costing (LCC) approach combined with other analyses while no paper deals with the social life cycle assessment (S-LCA) methodology. Global warming potential, eutrophication (for marine, freshwater, and terrestrial ecosystems), human toxicity, and ecotoxicity results are the most common LCA indicators applied. Only a few articles deal with the CE assessment through specific indicators. We argue that experts in life cycle methodologies must strive to adopt some key elements to ensure that the results obtained fit perfectly with the measurements of circularity and that these can even be largely based on a common basis.

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