Varela Villarreal et al. Biotechnol Biofuels (2020) 13:92 https://doi.org/10.1186/s13068-020-01730-y Biotechnology for Biofuels RESEARCH Open Access Acceptability of genetically engineered algae biofuels in Europe: opinions of experts and stakeholders Jessica Varela Villarreal* , Cecilia Burgués and Christine Rösch Abstract Background: The development of alternative pathways for sustainable fuel production is a crucial task for politics, industry and research, since the current use of fossil fuels contributes to resource depletion and climate change. Microalgae are a promising option, but the technology readiness level (TRL) is low and cannot compete economically with fossil fuels. Novel genetic engineering technologies are being investigated to improve productivity and reduce the cost of harvesting products extracted from or excreted by microalgae for fuel production. However, high resource efciency and low costs alone are no guarantee that algae fuels will fnd their way into the market. Technologies must be accepted by the public to become valuable for society. Despite strong eforts in algae research and development, as well as political commitments at diferent scales to promote algae biofuels for transport sectors, little is known about public acceptance of this alternative transport fuel. Despite the advantages of algae technology, genetically engineered (GE) microalgae can be controversial in Europe due to risk perception. Therefore, the aim of this study was to investigate, for the frst time, the knowledge and views of European experts and stakeholders on the conditions and requirements for acceptability of GE microalgae for next generation biofuel production. Results: The results of the survey-based study indicate that the majority of the respondents believe that GE algae biofuels could provide strong benefts compared to other fuels. The majority would choose to be fnal consumers of engineered algae biofuels, if there is clear evidence of their benefts and open communication of potential risks. They believe that closed production systems with high security standards and rigorous risk assessment should be applied to avoid unintended impacts on humans and nature. Some respondents, however, are not convinced about the need to alter natural occurring algae strains to increase productivity, arguing that there is a huge unexplored variety, and that the consequences of using genome editing are still unknown. Conclusions: This evaluation of the opinions held by European experts and stakeholders regarding GE algae biofuels provides valuable and diferentiated insights, both for future research and for the development of feasible socio-tech- nical algae systems for next generation biofuel production. The identifed conditions and requirements for achiev- ing public acceptability can support the (re-)design of this innovative technology and adaptation of the framework conditions towards the implementation of algae biofuels in Europe. Keywords: Genetically modifed organisms, Gene editing, Algae, Biofuel, Social perception, Acceptance, Risk perception, Survey Background *Correspondence: [email protected] Sustainable biofuel alternatives have been deeply inves- Institute for Technology Assessment and Systems Analysis (ITAS), tigated for decades in order to replace fossil fuels for Karlsruhe Institute of Technology (KIT), Karlstr.11, 76133 Karlsruhe, Germany future mobility [29]. Te potential of using microalgae © The Author(s) 2020. 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The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/publi cdoma in/ zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Varela Villarreal et al. Biotechnol Biofuels (2020) 13:92 Page 2 of 21 to produce biofuels continues to be investigated. Algae of 2.1 g L−1 and a maximal cumulative titer of 4.7 g L−1 technology is economically unsustainable and can only were observed in the long-term cultivation. Tese strains contribute to mitigating climate change under certain with enhanced or modifed metabolic activity show great conditions [28]. In terms of potential to reduce costs, potential for biotechnological exploitation. Since there the most important common factor is the increment of is a highly controversial general debate around agricul- average productivity (yield) [24]. Although in recent tural genetic engineering in Europe [5, 17], it cannot be years, some higher yields have been achieved by difer- ruled out that there might be similar concerns about the ent cultivation strategies using natural algal strains such impact of GE microalgae on the environment and human as Tetraselmis suecica and Nannochloropsis oculata [33, health. Whether such a debate will arise on the topic of 38], algal biofuels still cannot economically compete algae, and how this is addressed, will play a key role in with fossil fuels [3, 10]. Ketzer et al. [13] concluded in implementation and commercialization of engineered their review that a higher energy return of investment microalgae, including their application for biofuel pro- (EROI) could be achieved, from a biological point of duction [4]. view, by enhancing the efciency of photo-conversion, Te present study was conducted within the European which would lead to higher biomass and energy yields. Union (EU) H2020 project Photofuel, in order to investi- Te research focus is currently therefore to increase and gate the conditions and requirements for the implemen- modify the accumulation or release of energy products tation of a novel technology for engineered microalgae or their precursors (e.g., lipids, alcohols, hydrocarbons) biofuel production. Te objective of the work was to in photosynthetic microalgae through genetic engineer- gain insights into the opinions and attitudes of European ing. Although the application of genetic engineering to experts and stakeholders regarding their knowledge, per- improve energy production phenotypes in eukaryotic ception and views of this technology as well as on their microalgae is in its infancy, signifcant advances in the conception regarding its public acceptability. development of genetic manipulation tools have been achieved recently with microalgal model systems, and Results are being used to manipulate central carbon metabolism Te survey scored 130 valid responses from across the in these organisms [26]. It is likely that many of these EU on 16 diferent questions. advances can be extended to industrially relevant organ- isms, and that this will be a major research advance con- Descriptive statistical analysis cerning the commercialization of algae biofuels [7, 10]. 1. Sociodemographic profle Precise CRISPR/Cas9-based genome editing of indus- Te sociodemographic profle of the respondents (Fig. 1) trial algal strains such as Nannochloropsis, which accu- shows a high response rate from males (78%). Respond- mulates oil as a source of plant-like oils for biofuel ents had a high educational level; 62% had a Ph.D., and production during nitrogen deprivation, have been only 6% did not have a University degree. A high num- conducted by Wang et al. [34], opening opportunities ber of respondents had experience in the algae industry for microalgae-based biotechnological applications. (71%). Most worked in education or academia (51%), Metabolic engineering of Chlamydomonas reinhardtii followed by industry, consulting or management (33%). was presented as an option to be optimized for biofuel Te majority of respondents (73%) were between 31 production, due to the achievement of higher yields of and 61 years. Answers from 17 of the 27 EU countries terpenoids [36]. Recently, a joint study also pointed Chla- and from the former EU country United Kingdom, were mydomonas reinhardtii as the next chassis for sustainable recorded. Most of the respondents were from Germany synthetic biology [6]. Furthermore, protein engineering (26%), followed by Italy (17%), Spain (11%), France (8%), has been recently used to enhance isobutanol produc- Belgium (8%), the Netherlands (6%) and Portugal (5%). tion in the unicellular cyanobacterial strain Synechocystis A low percentage (between 3% and 1%) of respondents PCC 6803 [21, 19, 20, 37]. were from the United Kingdom, Sweden, Poland, Ire- Te use of GE microalgae strains for the release of bio- land, Greece, Finland, Czech Republic, Austria, Slovenia, fuel precursors to the culture broth for direct separation Hungary and Denmark. No response was obtained from without cell harvesting has been thoroughly investi- Bulgaria, Croatia, Cyprus, Estonia, Latvia, Lithuania, gated in the Photofuel project (http://www.photo fuel. Luxembourg, Malta, Romania and Slovakia. eu). Metabolic engineering