EPOBIO Report
Micro- and macro-algae: Utility for industrial applications
17 September 2007

This report has been prepared by Anders S Carlsson, Jan van Beilen, Ralf Möller and David Clayton

This, the final report from EPOBIO, addresses emerging opportunities presented by phototrophic organisms of the aquatic environment. It can be downloaded from the website (click on the link below) and hard copies from October 2007. For ease, we summarise the introduction and the conclusions of the report in the following paragraphs.

Micro- and Macro-algae: Utility for Industrial Applications (2056 Kb PDF)

The purpose of EPOBIO, a Science to Support Policy Consortium funded by the European Commission, is to realise the economic potential of sustainable resources – non-food bioproducts from agricultural and forestry feedstocks. To date, our desk studies have produced eight reports addressing a range of bioproducts and feedstocks and assessing their potential for developing biorenewables with high value and utility to society. The assessment has involved a holistic analysis of the science-based projects within a wider context of environmental impact, socio economics, regulatory frameworks and attitudes of public and policy makers. This EPOBIO process has allowed costs and benefits of each application, product and process to be defined, thereby providing a robust evidence base for strategic decisions, policies and funding.

The opportunities offered by land-based agriculture, forestry and their many applications for non-food industrial products are well recognised. Most recently, the use of lignocellulose biomass for generation of transport fuels is a much debated topic in the design of future energy production systems, again illustrating the versatility of plant raw materials for both energy and non-energy products. It is in this context that the potential of marine biomass is increasingly discussed, given the size of the resource and that more than three quarters of the surface of planet earth is covered by water. These aquatic resources, comprising both marine and fresh water habitats have immense biodiversity and immense potential for providing sustainable benefits to all nations of the world. Some 80% of the world’s living organisms are found in aquatic ecosystems.

Of net primary production of biomass, it is generally accepted that 50% is terrestrial and 50% aquatic. Policies of Governments have focussed almost exclusively on the use of land plants, with little consideration so far of the non-food applications and utility of macro- and micro-algae and their products. The limitations of agricultural land and the impacts of global climate change on agricultural productivity are factors of increasing relevance in the decisions that must be taken on land use for food, feed, chemicals and energy. Clearly, this increasing competition for land is driving the current consideration of the potential of the aquatic environment for the production of biofuels and industrial feedstocks.

The technical potential of micro-algae for greenhouse gas abatement has been recognised for many years, given their ability to use carbon dioxide and the possibility of their achieving higher productivities than land-based crops. Biofuel production from these marine resources, whether use of biomass or the potential of some species to produce high levels of oil, is now an increasing discussion topic. There are multiple claims in this sector but the use of micro-algae as an energy production system is likely to have to be combined with waste water treatment and co-production of high value products for an economic process to be achieved. These current biofuel discussions illustrate two issues. First, the potential broad utility of these organisms that are capable of multiple products, ranging from energy, chemicals and materials to applications in carbon sequestration and wastewater remediation. Second, the need for a robust evidence base of factual information to validate decisions for the strategic development of algae and to counter those claims made on a solely speculative basis to support commercial investment.

The current regulatory framework under development in Europe notes that an all embracing maritime policy should aim at growth and more and better jobs, helping to develop a strong, growing, competitive and sustainable maritime economy in harmony with the marine environment. An aim is to integrate existing and future EU, regional and national policies affecting marine issues. The emphasis of the proposed framework is on use of the marine environment at a level that is sustainable where marine species and habitats are protected, human induced decline of biodiversity is prevented and diverse biological components function in balance. Whilst it is recognised that innovation may help to find solutions to issues such as energy and climate change, there is little in policy proposals that addresses the utilisation of available marine biomass.

The report explores opportunities for energy and non-energy products, encompassing both marine and fresh water macro- and micro-algae. Salt water agriculture and the use of tidal flats is not discussed nor is the harvesting of aquatic plants other than algae. The first chapters briefly introduce the range of organisms and their habitats, together with the production systems that are already in development and use for their large-scale cultivation. The later chapters summarise the diverse range of products that have arisen or could be developed in this sector, including the utility of genes.

The report concludes that the macro- and micro-algal populations of the aquatic environments provide a vast genetic resource and biodiversity. This feature alone suggests that these organisms have considerable potential for offering new chemicals, materials and bioactive compounds. The completion of the genome sequencing programmes of two micro-algae also opens up major opportunities for new applications, either using the algae themselves or through using the genes in other production systems, whether fermenter-based or fields.

The culture of micro-algae has been studied widely through their potential for greenhouse gas abatement and this information is detailed in many reviews cited in this report. There are many conflicting statements on the potential of micro-algae for high biomass production, but there is a general agreement that the current production systems are not economically viable for biomass production alone. The difficulties include high capital infrastructure costs, problems of contamination through open pond systems and costs associated with harvesting and drying. These costs adversely affect the competitiveness of aquatic biomass production systems, compared to land-based agriculture and forestry.

Thus these negative cost considerations currently preclude the widespread use of micro-algae for biofuel production or production of other forms of bioenergy. Similarly, the macro-algal seaweeds, whilst used for some specialised applications, are also expensive to farm and harvest offshore. There are few clear drivers for using these species as biomass for bioenergy, except in specific circumstances such as maritime communities with no access to productive agricultural land or alternative energy sources.

The increasing concerns of global climate change and rising levels of atmospheric carbon dioxide have led to the recognition that carbon sequestration alone can have a tangible economic value. The value placed on a tonne of carbon within current trading schemes will determine decisions on how best to cost effectively ‘manufacture’ this product. There may be conditions in the future that would support the use of aquatic and particularly marine organisms for carbon capture and income generated through this route.

Additional value products from the micro-algae, such as chemicals, can increase the cost competitiveness. Often these are manufactured by the cells following a stress shock and under low nutrient conditions. For example, there has been a study in which the production of astaxanthin has been shown to be commercially viable using a micro-algal innoculum established in photobioreactors and transferred to open ponds for three day cultivation of biomass prior to harvest of product. This system successfully avoided the problems of contamination found in open pond cultivation systems since the cycle was extremely short.

Using micro-algae for waste water treatment is not a new idea. However, combining the ability of the cells to remediate water with their use for carbon sequestration or energy production may offer an economically viable way forward for the development of multiple products.

This report does highlight the need to consider carefully the economics of using organisms of the aquatic environment for industrial production.