Periodic Reporting for period 1 - PRODIGIO (Developing early-warning systems for improved microalgae PROduction and anaerobic DIGestIOn)
Reporting period: 2021-01-01 to 2022-06-30
Microalgae are one of nature's best examples of solar energy conversion systems, transforming carbon dioxide into biomass through photosynthesis. Microalgae biomass can be converted into methane-rich biogas through anaerobic digestion, a natural biomass degradation process carried out by bacteria and archaea in the absence of oxygen. The anaerobic digestion of microalgae biomass represents a promising biotechnological pathway leading to the establishment of a renewable fuel technology that can provide significant economic, environmental and social benefits. However, none of these bio-based production processes are yet optimized for large-scale applications, limiting their commercialization.
Bioprocess optimization depends on our ability to predict when a system becomes unstable. Ecological systems, such as microalgae photobioreactors and anaerobic reactors, are made up of tens to hundreds of microbial species that interact with each other and with the surrounding environment following non-linear dynamics. The stability of ecological systems relies on the architecture of the biological interactions network, which acts as a buffer against perturbations. As environmental conditions deteriorate and the network of interactions is disrupted, a small perturbation can lead to a sudden loss of productivity (i.e. fold-bifurcation). Catastrophe theory states that such bifurcation points tend to occur when the system approaches a tipping point. Thus, having a repertoire of early warning signals (EWS), the prelude to the system approaching a tipping point, is key to the timely implementation of corrective actions that ensure performance stability.
The main objective of PRODIGIO is to establish a base of knowledge for the development of a system failure prediction technology that boosts the sustainable production of biogas from microalgae biomass. To achieve this objective, PRODIGIO combines ‘big data’ acquisition from perturbation experiments in bioreactors and novel methods of computational ecology for the analysis of time-varying interaction networks. A Life Cycle Sustainability Assessment of PRODIGIO’s microalgae-to-biogas production chain completes the work plan. The technological solutions that will result from the project, such as a catalogue of EWS for the failure of microalgae biomass production and anaerobic digestion processes, will be of a pre-commercial nature (Technology Readiness Level 3-4). A roadmap will be compiled and updated in the course of the project that will identify priority research lines for further development and future implementation of technology. If successful, the results of PRODIGIO will pave the way for moving the entire microalgae-to-biogas production chain efficiently towards its theoretical maximum, enabling the development of a truly sustainable microalgae-derived biogas production industry.
Bioprocess optimization depends on our ability to predict when a system becomes unstable. Ecological systems, such as microalgae photobioreactors and anaerobic reactors, are made up of tens to hundreds of microbial species that interact with each other and with the surrounding environment following non-linear dynamics. The stability of ecological systems relies on the architecture of the biological interactions network, which acts as a buffer against perturbations. As environmental conditions deteriorate and the network of interactions is disrupted, a small perturbation can lead to a sudden loss of productivity (i.e. fold-bifurcation). Catastrophe theory states that such bifurcation points tend to occur when the system approaches a tipping point. Thus, having a repertoire of early warning signals (EWS), the prelude to the system approaching a tipping point, is key to the timely implementation of corrective actions that ensure performance stability.
The main objective of PRODIGIO is to establish a base of knowledge for the development of a system failure prediction technology that boosts the sustainable production of biogas from microalgae biomass. To achieve this objective, PRODIGIO combines ‘big data’ acquisition from perturbation experiments in bioreactors and novel methods of computational ecology for the analysis of time-varying interaction networks. A Life Cycle Sustainability Assessment of PRODIGIO’s microalgae-to-biogas production chain completes the work plan. The technological solutions that will result from the project, such as a catalogue of EWS for the failure of microalgae biomass production and anaerobic digestion processes, will be of a pre-commercial nature (Technology Readiness Level 3-4). A roadmap will be compiled and updated in the course of the project that will identify priority research lines for further development and future implementation of technology. If successful, the results of PRODIGIO will pave the way for moving the entire microalgae-to-biogas production chain efficiently towards its theoretical maximum, enabling the development of a truly sustainable microalgae-derived biogas production industry.
PRODIGIO consists of two lines of research, each of which focuses on the analysis of the different bio-based production systems explored in the project, microalgae photobioreactors (PBRs) for biomass production (WPs 1 and 3) and anaerobic reactors (ARs) for conversion of biomass into biogas (WPs 2 and 4). In turn, each of these lines of research is divided into two work stages: experimental (WPs 1 and 2) and analytical (WPs 3, 4 and 5). The experimental stage involves the sampling of experimental devices and the collection of data. The analytical stage is dedicated to ‘big data’ analysis using (meta)genomics and chemical fingerprinting data, and time series data analysis using empirical dynamic modeling, an emerging data-driven framework for modeling nonlinear dynamic systems (WPs 3 and 4). A Life Cycle Sustainability Assessment of PRODIGIO’s microalgae-to-biogas production chain (WP5) completes the work plan.
Experimental devices have been designed, assembled and validated to carry out the experiments planned in the project, i.e. to simulate the failure of microalgae biomass production and biomass-to-biogas conversion processes. All experimental devices, both PBRs and ARs, have been working properly since month 3 for both PBRs and ARs after the start of the project and are still in operation. During this time, the partners in charge of managing these experimental devices (UAL in charge of the PBRs and IMDEA-E in charge of the ARs) have sampled their respective bioreactors to generate high-quality time series of chemical, biochemical, metabolic and microbiological data. Samples have been collected for the analysis of genomics (metabarcodes, genomics, transcriptomics, proteomics), the fluorescence of organic matter and chemical fingerprinting. These samples are currently being analyzed at the laboratories of the corresponding partners (CSIC, NMBU, AWI).
With respect to microalgae PBRs for biomass production, 2 outdoor and 3 indoor (raceway-type) PBRs have been used to produce time series data (WP1). The outdoor PBRs, one fed with wastewater and the other fed with clean freshwater plus fertilizers, have produced each of them 9-month time series (with a sampling frequency of approximately 3 times a week) and another 9-month time series is currently underway. The other series of experiments were carried out in ARs (WP2) using the microalgae biomass generated in the external PBRs mentioned previously. With these experiments, IMDEA-E evaluated the anaerobic digestion failure of microalgae biomass against variations in the organic loading rate (OLR) and in the biochemical composition of microalgae. All samples are now being analyzed. The resulting data will feed analytical and modeling WPs 3-5 aimed at reconstructing bioreactor interactomes, identifying EWS for process failure and assessing the techno-economic, environmental and social potential of the PRODIGIO technology
Experimental devices have been designed, assembled and validated to carry out the experiments planned in the project, i.e. to simulate the failure of microalgae biomass production and biomass-to-biogas conversion processes. All experimental devices, both PBRs and ARs, have been working properly since month 3 for both PBRs and ARs after the start of the project and are still in operation. During this time, the partners in charge of managing these experimental devices (UAL in charge of the PBRs and IMDEA-E in charge of the ARs) have sampled their respective bioreactors to generate high-quality time series of chemical, biochemical, metabolic and microbiological data. Samples have been collected for the analysis of genomics (metabarcodes, genomics, transcriptomics, proteomics), the fluorescence of organic matter and chemical fingerprinting. These samples are currently being analyzed at the laboratories of the corresponding partners (CSIC, NMBU, AWI).
With respect to microalgae PBRs for biomass production, 2 outdoor and 3 indoor (raceway-type) PBRs have been used to produce time series data (WP1). The outdoor PBRs, one fed with wastewater and the other fed with clean freshwater plus fertilizers, have produced each of them 9-month time series (with a sampling frequency of approximately 3 times a week) and another 9-month time series is currently underway. The other series of experiments were carried out in ARs (WP2) using the microalgae biomass generated in the external PBRs mentioned previously. With these experiments, IMDEA-E evaluated the anaerobic digestion failure of microalgae biomass against variations in the organic loading rate (OLR) and in the biochemical composition of microalgae. All samples are now being analyzed. The resulting data will feed analytical and modeling WPs 3-5 aimed at reconstructing bioreactor interactomes, identifying EWS for process failure and assessing the techno-economic, environmental and social potential of the PRODIGIO technology
PRODIGIO is advancing our understanding of the functioning of microbial communities in bioreactors. At this point, it is too early to have results that allow us to show any progress beyond the current state of the art. We anticipate that the results of experiments performed to date will offer new insights into the ecogenomics of microalgal PBR and ARs. In particular, the consortium is reconstructing bioreactor interactomes, the set of possible ecological interactions that govern the performance of bioreactors in terms of product/s generation. The initial results have sparked interest in exploring not only early warning signals but also system recovery dynamics.
The knowledge derived from PRODIGIO will make it possible to increase the performance of bioreactors, both for the production of microalgae biomass and for the conversion of biomass into biogas. This new knowledge, translated into technological progress, will contribute to the development of a truly sustainable microalgae-based biogas production industry. In addition to providing a renewable energy source for electricity and heat generation, and for transportation, this biotechnological route has significant economic, environmental, and social benefits. For example, the use of microalgae in wastewater treatment offers a low-cost alternative to recover inorganic nutrients and use them as fertilizers, while providing a source of biomass for energy generation. PRODIGIO will contribute to reaching these goals by creating a knowledge base for the development of a system failure prediction technology that boosts the sustainable production of biogas from microalgae biomass.
The knowledge derived from PRODIGIO will make it possible to increase the performance of bioreactors, both for the production of microalgae biomass and for the conversion of biomass into biogas. This new knowledge, translated into technological progress, will contribute to the development of a truly sustainable microalgae-based biogas production industry. In addition to providing a renewable energy source for electricity and heat generation, and for transportation, this biotechnological route has significant economic, environmental, and social benefits. For example, the use of microalgae in wastewater treatment offers a low-cost alternative to recover inorganic nutrients and use them as fertilizers, while providing a source of biomass for energy generation. PRODIGIO will contribute to reaching these goals by creating a knowledge base for the development of a system failure prediction technology that boosts the sustainable production of biogas from microalgae biomass.