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Project description

What are the objectives of the project?

The ultimate objective of OLEOFERM is the Sustainable OLEOchemicals bioproduction from carboxylates via oleaginous FERMentation. OLEOFERM is designed to develop a new oleochemicals supply chain. Accordingly, the specific objectives are:

1

Attaining a suitable conversion of organic wastes into SCFAs by means of AF

2

Development of an economic, energy efficient, and effective separation

3

Identification of the metabolic routes involved in lipid production from SCFAs in yeast

4

Optimization of fermentation to favor lipids accumulation in yeasts

5

Quantification of the potential environmental, economic and social impacts of the new microbial lipids, compared to current technologies

Attaining maximum suitable conversion of organic wastes into SCFAs by means of anaerobic fermentation

Anaerobic digestion is a biological process driven by bacteria and consisting in the breakdown of the macromolecular organic components contained in the substrate. The first steps of the process, hydrolysis and acidogenesis, convert proteins, lipids and carbohydrates of biomass into SCFAs, among other by-products. By inhibiting methanogenesis, anaerobic digestion would not produce biogas but organic matter will be converted to SCFAs. In this sense, the recovery of carbon contained in the substrate (wastes) can be maximized in the form of SCFAs. The optimization of the conversion of organic wastes into SCFAs can be achieved by appropriately tuning operational parameters in the fermentation system. Next generation sequencing will be used to identify both archaeal and bacterial communities in the anaerobic reactor and the anaerobic microbiome in digesters will be linked with the SCFAs profile and production.

Development of an economic, energy efficient, and effective separation process for the separation and concentration of SCFAs in an appropriate stream for yeast fermentation

After anaerobic fermentation, the produced SCFAs are in a diluted suspension. This suspension also contains residues of anaerobic microorganisms and non-organic components (unfermented waste). To separate the SCFAs from the fermentation broth, a mild and energy efficient membrane separation process coupled to the bioreactor will be developed through an external submerged membrane bioreactor technology.

Identification of the metabolic routes involved in lipid production from SCFAs in oleaginous yeast

Efficient metabolic engineering to increase lipid production capacity in oleaginous yeasts requires sufficient knowledge of the lipid metabolic pathways. However, the lipid production routes from SCFAs are still not completely understood. Improving lipid biosynthesis capacity will require identification of metabolic pathways and their regulation in the selected oleaginous yeasts. Genomes of the selected strains after screening will be sequenced. A model of the molecular mechanism leading to microbial oil production will be produced by means of -omics analysis, i.e. through genome sequencing and annotation as well as transcriptome analysis at different conditions.

Optimization of the fermentation process to produce high amount of lipids by oleaginous yeasts

When using SCFAs as carbon source, the C/N ratio may affect not only carbon flow within yeast cells but also substrate utilization. A suitable C/N ratio during fermentation should be determined to optimize the lipid accumulation in yeast. Agitation, temperature, pH and nutrients or oxygen concentrations are other culture conditions that can strongly influence microbial lipid accumulation. The operation of the upstream processes (anaerobic fermentation and membrane separation) will be tailored for ensuring the production of yeast biomass with a high content of oil, i.e. lipids. In this manner, yeast biomass containing a large percentage of lipids will be generated using SCFAs-rich permeates.

Quantification of the potential environmental, economic and social impacts of the new microbial lipids, compared to current technologies

Different metrics will be applied for the quantification of the life-cycle sustainability impacts of the new oleochemicals produced from microbial oils, compared to current technologies. The life-cycle approach will also address key issues such as social materiality of the new value chain and social and customer´s acceptance.

What technologies are involved in the project?

Biotechnology is a key pillar of OLEOFERM in which two bioprocesses including anaerobic fermentation of organic wastes for SCFAs production and oleaginous fermentation for microbial oils are interconnected.

The use of bioinformatics tools, biotechnology and systems biology are key disciplines to unravel the full potential of OLEOFERM technologies.

 

Bioinformatics tools

Biotechnology

Systems biology

Expected Benefits

Social, economic and environmental benefits:

  • OLEOFERM aims at expanding the available sources of Oleochemicals and attempts to replace at some extent fossil-based chemicals
  • OLEOFERM uses SCFAs as carbon source for yeast fermentation. SCFAs are produced from organic-waste streams. In this way,
  • OLEOFERM does not only decrease the environmental burden by valorizing organic waste but also contributes to the transition from linear to circular economy
    • OLEOFERM proposes a sustainable option for waste management, thereby reducing GHG emissions and feedstock cost for oleochemicals

Scientific and Technological benefits:

  • OLEOFERM focuses on manipulating the anaerobic microbiome to accumulate SCFAs and unraveling which metabolic pathway is used by yeast for SCFAs uptake and utilization
  • OLEOFERM targets at developing key enabling technologies (anaerobic fermentation with open microbiomes and oleoaginous fermentation by using yeasts) for the sustainable production of oleochemicals

At present, the cost of microbial oil production is higher than those of vegetable and animal oils. Finding alternatives to improve the process economics of microbial oil production processes holds significant potential and great promise for further societal development. Drawbacks such as the limitation of the feedstock to be employed should be overcome. In this sense, OLEOFERM will facilitate the replacement of fossil fuels-based chemicals by sustainably produced oleochemicals from carboxylates via oleaginous fermentation.

OLEOFERM proposes the use of microbial oils that can be produced by using SCFAs as carbon source. These SCFAs can be produced from a wide range of organic substrates via anaerobic fermentation and thus, unlocking feedstock limitation.

Within this research approach, OLEOFERM proposes an innovative biotechnologically-sound strategy in which system biology and bioinformatics tools will aid to unravel how carboxylates produced from organic wastes can be utilized by oleaginous yeast in an efficient way to accumulate high levels of microbial oils to be subsequently converted in oleochemicals.

OLEOFERM relies on innovative feedstocks (organic waste streams) that are ubiquitous and inherent to mankind. With the rapid growth and development of the human population, the selected feedstocks (municipal solid waste and food waste) are largely produced. Therefore, valorization of organic wastes does not only help to solve environmental pollution but could also contribute to the transition from a linear to a renewable circular economy.

Obtaining an economic feedstock supply remains crucial to achieve competitiveness in most of the bio-based products. For this purpose, waste streams constitute an innovative cost-effective raw material from which SCFAs can be obtained through anaerobic fermentation and further fed to oleaginous yeast for microbial lipids production and ultimately oleochemicals synthesis. Great knowledge exists when it comes to sugar-based feedstock for microbial oils production while the use of alternative carbon sources, such as the case of SCFAs, remains limited.

OLEOFERM can contribute to reducing the cost of the feedstock but also GHG emissions. The production of microbial oils is expected to offer lower environmental impacts than the use of vegetable oils due to the lower GHG emissions during their production and processing, which will be quantitatively checked throughout the project by following a life-cycle sustainability perspective.

OLEOFERM is expected to advance the knowledge and scientific proofs of the technological feasibility of the proposed concept including the environmental, social and economic benefits. The technological feasibility of all single reactions proposed in OLEOFERM has been confirmed at low TRL. Nevertheless, OLEOFERM is designed to combine them all and further advance in their knowledge and hence increase their TRLs.

Overall, the research proposed in OLEOFERM can have a positive impact in the production of microbial oils for the oleochemical industry. The development of robust and reliable microbial systems will pave the way to produce microbial oils even with complex fermentation media such as SCFAs-rich digestates. Transition towards feedstock based on wastes can be challenging, but also an opportunity for producing economically competitive bio-based chemicals.

Work Packages

To accomplish OLEOFERM´s objective, the work plan has been divided in 6 WPs to be developed in 3 years.

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