Overcoming Technical and Market Barriers to Enable Sustainable Large-Scale Production and Consumption of Insect Proteins in Europe: A SUSINCHAIN Perspective.

The expected global population growth to 9.7 billion people in 2050 and the significant change in global dietary patterns require an increase in global food production by about 60%. The protein supply for feed and food is most critical and requires an extension in protein sources. Edible insects can upgrade low-grade side streams of food production into high-quality protein, amino acids and vitamins in a very efficient way. Insects are considered to be the "missing link" in the food chain of a circular and sustainable economy. Insects and insect-derived products have entered the European market since first being acknowledged as a valuable protein source for feed and food production in around 2010. However, today, scaling up the insect value chain in Europe is progressing at a relatively slow pace. The mission of SUSINCHAIN (SUStainable INsect CHAIN)-a four-year project which has received funding from the European Commission-is to contribute to novel protein provision for feed and food in Europe by overcoming the remaining barriers for increasing the economic viability of the insect value chain and opening markets by combining forces in a comprehensive multi-actor consortium. The overall project objective is to test, pilot and demonstrate recently developed technologies, products and processes, to realize a shift up to Technology Readiness Level 6 or higher. In addition to these crucial activities, the project engages with stakeholders in the insect protein supply chain for feed and food by living labs and workshops. These actions provide the necessary knowledge and data for actors in the insect value chain to decrease the cost price of insect products, process insects more efficiently and market insect protein applications in animal feed and regular human diets that are safe and sustainable. This paves the way for further upscaling and commercialization of the European insect sector.

Valorisation Potential of Using Organic Side Streams as Feed for Tenebrio molitor, Acheta domesticus and Locusta migratoria.

Due to increasing welfare and population, the demand for alternative protein sources, obtained with minimal use of natural resources, is rising in today's society. Insects have the potential to be used as an alternative protein source since they are considered to be able to convert low-value biomass into high-value components, resulting in opportunities for valorisation of organic side streams. Moreover, insects are suggested to be a sustainable protein source, referring to the efficient "feed to body" mass conversion potential. The aim of this review was to explore the potential to rear the yellow mealworm (Tenebrio molitor), the house cricket (Acheta domesticus) and the migratory locust (Locusta migratoria) on low or not yet valorised organic side streams within the food supply chain. This was performed by collecting research information focusing on the rearing of the insects in scope on organic biomass. In addition, the nutritional composition of the produced insects as well as their dietary requirements will be reviewed. Finally, the availability of side streams in the EU will be discussed as well as their potential to be used as insects feed.

Mixture toxicity in the marine environment: Model development and evidence for synergism at environmental concentrations.

Little is known about the effect of metal mixtures on marine organisms, especially after exposure to environmentally realistic concentrations. This information is, however, required to evaluate the need to include mixtures in future environmental risk assessment procedures. We assessed the effect of copper (Cu)-Nickel (Ni) binary mixtures on Mytilus edulis larval development using a full factorial design that included environmentally relevant metal concentrations and ratios. The reproducibility of the results was assessed by repeating this experiment 5 times. The observed mixture effects were compared with the effects predicted with the concentration addition model. Deviations from the concentration addition model were estimated using a Markov chain Monte-Carlo algorithm. This enabled the accurate estimation of the deviations and their uncertainty. The results demonstrated reproducibly that the type of interaction-synergism or antagonism-mainly depended on the Ni concentration. Antagonism was observed at high Ni concentrations, whereas synergism occurred at Ni concentrations as low as 4.9 µg Ni/L. This low (and realistic) Ni concentration was 1% of the median effective concentration (EC50) of Ni or 57% of the Ni predicted-no-effect concentration (PNEC) in the European Union environmental risk assessment. It is concluded that results from mixture studies should not be extrapolated to concentrations or ratios other than those investigated and that significant mixture interactions can occur at environmentally realistic concentrations. This should be accounted for in (marine) environmental risk assessment of metals. Environ Toxicol Chem 2017;36:3471-3479. © 2017 SETAC.

Salinity, dissolved organic carbon, and interpopulation variability hardly influence the accumulation and effect of copper in Mytilus edulis.

To improve the ecological relevance of environmental risk assessment, an improved understanding is needed of 1) the influence of environmental conditions on the toxicity of pollutants, and 2) the effect of these factors in combination with possible interpopulation variability. The influences of salinity and dissolved organic carbon (DOC) on the accumulation and effect of copper (Cu) to settled mussels were investigated with mussels from a North Sea and a Baltic Sea population. We found that both populations were equally Cu-sensitive, even though the Baltic Sea population lives in suboptimal conditions. Baltic Sea mussels, however, accumulated more Cu. This suggests that these populations may have different ways of coping with excess Cu. The influence of salinity on Cu toxicity to settled mussels was limited for both populations. An increase in DOC did not decrease the Cu accumulation or effect in either population. This suggests that DOC-Cu complexes are bioavailable for settled mussels. These findings are in contrast with previous research which indicated that DOC decreased the toxicity and accumulation of Cu in the D-larvae life stage. As a consequence, the mussel larval stage is not the most Cu-sensitive life stage at high DOC concentrations. Furthermore, a DOC correction factor for Cu toxicity cannot be used for settled mussels. This should be accounted for in future marine Cu environmental risk assessment. Environ Toxicol Chem 2017;36:2074-2082. © 2017 SETAC.

Effect of temperature on chronic toxicity of copper, zinc, and nickel to Daphnia magna.

Few studies have considered the effect of temperature on the chronic sensitivity of Daphnia magna to other stressors. The present study investigated the effect of temperature on chronic metal toxicity and whether this effect differed among 4 different D. magna clones. Life table experiments were performed with copper, zinc, and nickel at 15 °C, 20 °C, and 25 °C. General linear modeling indicated that chronic Cu, Zn, and Ni toxicity to D. magna were all significantly affected by temperature. When averaged across clones, our results suggest that chronic metal toxicity to D. magna was higher at 15 °C than at 20 °C, which is the temperature used in standard toxicity tests. At 15 °C, the 21-d median effect concentrations (EC50s) of Cu, Zn, and Ni were 1.4 times, 1.1 times, and 1.3 times lower than at 20 °C, respectively. At 25 °C, chronic Cu and Zn toxicity did not change in comparison with 20 °C, but chronic Ni toxicity was lower (21-d EC50 of nickel at 25 °C was 1.6 times higher than at 20 °C). The same trends were observed for Cu and Ni when the 21-d 10% and 20% effect concentrations were considered as the effect estimator, but not for Zn, which warns against extrapolating temperature effects on chemical toxicity across effect sizes. Overall, however, chronic metal toxicity was generally highest at the lowest temperature investigated (15 °C), which is in contrast with the usually observed higher acute metal toxicity at higher temperatures. Furthermore, the effect of temperature on chronic Ni toxicity depended significantly on the clone. This warns against extrapolating results about effect of temperature on chemical toxicity from single clone studies to the population level. Environ Toxicol Chem 2017;36:1909-1916. © 2016 SETAC.

Methodological challenges of optical tweezers-based X-ray fluorescence imaging of biological model organisms at synchrotron facilities.

Recently, a radically new synchrotron radiation-based elemental imaging approach for the analysis of biological model organisms and single cells in their natural in vivo state was introduced. The methodology combines optical tweezers (OT) technology for non-contact laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time at ESRF-ID13. The optical manipulation possibilities and limitations of biological model organisms, the OT setup developments for XRF imaging and the confocal XRF-related challenges are reported. In general, the applicability of the OT-based setup is extended with the aim of introducing the OT XRF methodology in all research fields where highly sensitive in vivo multi-elemental analysis is of relevance at the (sub)micrometre spatial resolution level.

Salinity and dissolved organic carbon both affect copper toxicity in mussel larvae: Copper speciation or competition cannot explain everything.

Predicting copper (Cu) toxicity in marine and estuarine environments is challenging because of the influence of anions on Cu speciation, competition between Cu(2+) and other cations at the biotic ligand and the effect of salinity on the physiology of the organism. In the present study the combined effect of salinity and dissolved organic carbon (DOC) on Cu toxicity to larvae of Mytilus galloprovincialis was assessed. Two statistical models were developed and used to elucidate the relationship between Cu toxicity, salinity, and DOC. All models based on dissolved Cu indicate a decrease in Cu toxicity with increasing DOC concentrations, which can partly be explained by complexation of Cu(2+) ions with DOC. These models also indicate an increase in Cu toxicity (modeled with dissolved Cu or Cu(2+) activity) with increasing salinity, suggesting a salinity-induced alteration in the physiology of the mussel larvae. When based on Cu body burdens, neither of the models indicates an effect of salinity or DOC. This shows that the Cu body burden is a more constant predictor of Cu toxicity, regardless of the water chemistry influencing Cu speciation or competition and possible physiological alterations or changes in Cu speciation or competition.

In vivo X-ray elemental imaging of single cell model organisms manipulated by laser-based optical tweezers.

We report on a radically new elemental imaging approach for the analysis of biological model organisms and single cells in their natural, in vivo state. The methodology combines optical tweezers (OT) technology for non-contact, laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time. The main objective of this work is to establish a new method for in vivo elemental imaging in a two-dimensional (2D) projection mode in free-standing biological microorganisms or single cells, present in their aqueous environment. Using the model organism Scrippsiella trochoidea, a first proof of principle experiment at beamline ID13 of the European Synchrotron Radiation Facility (ESRF) demonstrates the feasibility of the OT XRF methodology, which is applied to study mixture toxicity of Cu-Ni and Cu-Zn as a result of elevated exposure. We expect that the new OT XRF methodology will significantly contribute to the new trend of investigating microorganisms at the cellular level with added in vivo capability.

The combined effect of dissolved organic carbon and salinity on the bioaccumulation of copper in marine mussel larvae.

Larvae of Mytilus spp. are among the most Cu sensitive marine species. In this study we assessed the combined effect of salinity and dissolved organic carbon (DOC) on Cu accumulation on mussel larvae. Larvae were exposed for 48 h to three Cu concentrations in each of nine salinity/DOC treatments. Synchrotron radiation X-ray fluorescence was used to determine the Cu concentration in 36 individual larvae with a spatial resolution of 10 × 10 µm. Cu body burden concentrations varied between 1.1 and 27.6 µg/g DW larvae across all treatments and Cu was homogeneously distributed at this spatial resolution level. Our results indicate decreasing Cu accumulation with increasing DOC concentrations which can be explained by an increase in Cu complexation. In contrast, salinity had a nonlinear effect on Cu. This cannot be explained by copper speciation or competition processes and suggests a salinity-induced alteration in physiology.