Microalgal Aquafeeds As Part of a Circular Bioeconomy

Photosynthetic microalgae are unicellular plants, many of which are rich in pro-tein, lipids, and bioactives and form an important part of the base of the natural aquatic food chain. Population growth, demand for high-quality protein, and depletion of wildfish stocks are forecast to increase aquacultural fish demand by 37% between 2016 and 2030. This review highlights the role of microalgae andrecent advances that can support a sustainable‘circular’aquaculture industry. Microalgae-based feed supplements and recombinant therapeutic production offer significant opportunities to improve animal health, disease resistance,and yields. Critically, microalgae in biofloc, ‘green water’, nutrient remediation,and integrated multitrophic aquaculture technologies offer innovative solutions for economic and environmentally sustainable development in line with key UN Sustainability Goals

Chapter 19 Uncertainty

This handbook brings together leading international academic experts to provide a comprehensive and authoritative survey of Global Environmental Politics. Fully revised, updated and expanded to 45 chapters, the book: • Describes the history of global environmental politics as a discipline and explains the various theories and perspectives used by scholars and students to understand it. • Examines the key actors and institutions in global environmental politics, explaining the roles of states, international organizations, regimes, international law, foreign policy institutions, domestic politics, corporations and transnational actors. • Addresses the ideas and themes shaping the practice and study of global environmental politics, including sustainability, consumption, expertise, uncertainty, security, diplomacy, North-South relations, globalization, justice, ethics, public participation and citizenship. • Assesses the key issues and policies within global environmental politics, including energy, climate change, ozone depletion, air pollution, acid rain, transport, persistent organic pollutants, hazardous wastes, rivers, wetlands, oceans, fisheries, marine mammals, biodiversity, migratory species, natural heritage, forests, desertification, food and agriculture. This second edition includes new chapters on plastics, climate change, energy, earth system governance and the Anthropocene. It is an invaluable resource for students, scholars, researchers and practitioners of environmental politics, environmental studies, environmental science, geography, globalization, international relations and political science

Chapter 19 Uncertainty

This handbook brings together leading international academic experts to provide a comprehensive and authoritative survey of Global Environmental Politics. Fully revised, updated and expanded to 45 chapters, the book: • Describes the history of global environmental politics as a discipline and explains the various theories and perspectives used by scholars and students to understand it. • Examines the key actors and institutions in global environmental politics, explaining the roles of states, international organizations, regimes, international law, foreign policy institutions, domestic politics, corporations and transnational actors. • Addresses the ideas and themes shaping the practice and study of global environmental politics, including sustainability, consumption, expertise, uncertainty, security, diplomacy, North-South relations, globalization, justice, ethics, public participation and citizenship. • Assesses the key issues and policies within global environmental politics, including energy, climate change, ozone depletion, air pollution, acid rain, transport, persistent organic pollutants, hazardous wastes, rivers, wetlands, oceans, fisheries, marine mammals, biodiversity, migratory species, natural heritage, forests, desertification, food and agriculture. This second edition includes new chapters on plastics, climate change, energy, earth system governance and the Anthropocene. It is an invaluable resource for students, scholars, researchers and practitioners of environmental politics, environmental studies, environmental science, geography, globalization, international relations and political science

Design scenarios of outdoor arrayed cylindrical photobioreactors for microalgae cultivation considering solar radiation and temperature

Advancing microalgae biotechnologies requires the design of high efficiency, large scale outdoor photobioreactor systems. Here we present a predictive biomass productivity model to define system design parameters yielding high biomass productivities for a facility encompassing arrays of cylindrical photobioreactors (PBRs) in a sub-tropical location (Brisbane, Australia). The model analyses the temperature and the light distributed through the culture medium as a function of PBR height, diameter, spacing distance between reactors, biomass concentration and cultivation regime (continuous vs. batch; fixed vs. capped temperature control). Temporal changes in light and temperature were used to predict volumetric and areal productivities (Pvol and Pareal respectively) for three Chlorella strains (C. vulgaris, C. sp. 11_H5 and C. pyrenoidosa). A simple empirical relationship was derived to rapidly predict Pvol in PBR arrays based on the ratio of spacing distance and reactor height (L/H) if the Pvol of a single, unshaded PBR was known. For C. vulgaris under a continuous operation and variable temperature (within its maximum growth threshold), the highest Pvol in the range analysed was obtained at the smallest diameter (0.1 m), highest biomass concentration (1.5 g L−1) and largest L/H, (Pvol ~0.3 g L−1 d−1). In contrast, the highest Pareal (~50 t ha−1 yr−1) was found at higher diameters (0.15 and 0.3 m), a lower biomass concentration (0.3 g L−1) and low L/H (0.2–0.4); this was attributed to a higher overall culture volume per PBR and per area. Our predictions, based on light and temperature effects on productivity, suggest that attaining a high Pvol could reduce costs, energy and materials associated with water usage, harvest loads and PBRs; whereas attaining a Pareal toward its maxima could reduce costs associated with land. The model supports effective PBR array design and process optimisation to help minimise production cost

High-throughput optimisation of light-driven microalgae biotechnologies

Microalgae biotechnologies are rapidly developing into new commercial settings. Several high value products already exist on the market, and systems development is focused on cost reduction to open up future economic opportunities for food, fuel and freshwater production. Light is a key environmental driver for photosynthesis and optimising light capture is therefore critical for low cost, high efficiency systems. Here a novel high-throughput screen that simulates fluctuating light regimes in mass cultures is presented. The data was used to model photosynthetic efficiency (PE, mol photon m) and chlorophyll fluorescence of two green algae, Chlamydomonas reinhardtii and Chlorella sp. Response surface methodology defined the effect of three key variables: density factor (D, 'culture density'), cycle time (t, 'mixing rate'), and maximum incident irradiance (I). Both species exhibited a large rise in PE with decreasing I and a minimal effect of t (between 3-20 s). However, the optimal D of 0.4 for Chlamydomonas and 0.8 for Chlorella suggested strong preferences for dilute and dense cultures respectively. Chlorella had a two-fold higher optimised PE than Chlamydomonas, despite its higher light sensitivity. These results demonstrate species-specific light preferences within the green algae clade. Our high-throughput screen enables rapid strain selection and process optimisation

From ‘mad cow’ crisis to synthetic biology: challenges to EU regulation of GMOs beyond the European context

This paper provides a historical and legal perspective of EU regulation on genetically modified organisms (GMOs)—through its initial development to its current position—in view of major advancements of modern molecular biotechnologies used for agriculture. We argue that the emergence and development of EU regulation of GMOs were shaped by antecedent events, notably bovine spongiform encephalopathy (BSE) or ‘mad cow disease’ and the public fears that ensued around food safety. These regulatory emergencies were a key factor prompting national governments and EU institutions to work out the framework for the application of the precautionary principle to agricultural biotechnology. Moreover, while modern biotechnology techniques eliminate many of the perceived health and safety risks of earlier predecessors, the EU regulatory framework has been slow to keep up, lacking the proper regulatory tools that allow for a balanced policy approach towards the techniques underlying genome editing and synthetic biology. Difference in approaches to the regulation of GMOs between the EU and US, to a large extent, precipitated the transatlantic conflict over agricultural biotechnology. Specifically, a significant incompatibility between the application of the precautionary principle in the EU and the substantial equivalence in the US to assess GM food and feed risk was the main reason for the international trade dispute. The ruling of the Court of Justice of the European Union that genome editing techniques will not be warranted exemption from authorisation process suggests that EU policy on agricultural biotechnology is likely to remain stringent. This may complicate the progress of synthetic biology and render the EU vulnerable to future food security and economic contingencies

Carbon farming and nature repair markets: Benefits, opportunities and risks for Queensland

There are growing opportunities for Queensland land managers and farmers to receive payments for carbon abatement, biodiversity conservation, reef water quality improvements and other environmental services through sustainable land management practices under market-based schemes. This brief provides an overview and update on recent developments to environmental markets in Australia and Queensland, and what the potential risks and unique opportunities are for Queensland

Photoacclimation and productivity of Chlamydomonas reinhardtii grown in fluctuating light regimes which simulate outdoor algal culture conditions

Outdoor microalgae systems are a promising platform for fuels and chemicals, but are currently limited by relatively low productivities. This study investigated the effects of photoacclimation on the productivity of Chlamydomonas reinhardtii grown under fluctuating light regimes which simulate well-mixed cultures in outdoor reactors. Simulations represented cells cycling between high light and dark zones in high-density (HDFluc, light fraction (LF)= 0.5) and low-density (LDFluc, LF= 0.9) cultures. Each fluctuating treatment was controlled by cultures grown under non-fluctuating light of the same hourly average irradiance (HDAvg and LDAvg) to differentiate between light dosage and regime. The large dark fraction of HDFluc resulted in a low-light acclimated phenotype displaying up-regulation of light harvesting pigments and low NPQ caused by reduced levels of the dissipative protein LHCSR3. All other treatments led to high-light acclimation phenotypes. HDFluc showed an estimated three-fold lower biomass yield relative to light absorbed and significant reductions in the quantum yield of PSII compared to HDAvg. This suggests that during high lightp eriods of fluctuating cycles, higher absorption and an inability to safely dissipate excess light, resulted in greater photodamage and respiration required for repair. A framework for including these findings in predictive modelling of mass cultures is presented. (C) 2015 Elsevier B.V. All rights reserved

Techno-economic evaluation of microalgae high-density liquid fuel production at 12 international locations

Abstract Background Microalgae-based high-density fuels offer an efficient and environmental pathway towards decarbonization of the transport sector and could be produced as part of a globally distributed network without competing with food systems for arable land. Variations in climatic and economic conditions significantly impact the economic feasibility and productivity of such fuel systems, requiring harmonized technoeconomic assessments to identify important conditions required for commercial scale up. Methods Here, our previously validated Techno-economic and Lifecycle Analysis (TELCA) platform was extended to provide a direct performance comparison of microalgae diesel production at 12 international locations with variable climatic and economic settings. For each location, historical weather data, and jurisdiction-specific policy and economic inputs were used to simulate algal productivity, evaporation rates, harvest regime, CapEx and OpEx, interest and tax under location-specific operational parameters optimized for Minimum Diesel Selling Price (MDSP, US$L−1). The economic feasibility, production capacity and CO2-eq emissions of a defined 500 ha algae-based diesel production facility is reported for each. Results Under a for-profit business model, 10 of the 12 locations achieved a minimum diesel selling price (MDSP) under US$ 1.85 L−1 / US$6.99 gal−1. At a fixed theoretical MDSP of US$ 2 L−1 (US$7.57 gal−1) these locations could achieve a profitable Internal Rate of Return (IRR) of 9.5–22.1$ 1.24 L−1 (US$ 4.69 gal−1). The CO2-eq emissions of microalgae diesel were about one-third of fossil-based diesel. Conclusions The public utility approach could reduce the fuel price toward cost-competitiveness, providing a key step on the path to a profitable fully commercial renewable fuel industry by attracting the investment needed to advance technology and commercial biorefinery co-production options. Governments’ adoption of such an approach could accelerate decarbonization, improve fuel security, and help support a local COVID-19 economic recovery. This study highlights the benefits and limitations of different factors at each location (e.g., climate, labour costs, policy, C-credits) in terms of the development of the technology—providing insights on how governments, investors and industry can drive the technology forward. Graphic abstrac