Marine microalgae commercial production improves sustainability of global fisheries and aquaculture.

A method is described for saving 30% of the world fish catch by producing fishmeal and fish oil replacement products from marine microalgae, the natural source of proteins and oils in the marine food web. To examine the commercial aspects of such a method, we adapt a model based on results of microalgae production in Hawaii and apply it to Thailand, the world's fourth largest producer of fishmeal. A model facility of 111 ha would produce 2,750 tonnes yr-1 of protein and 2,330 tonnes yr-1 of algal oil, at a capital cost of $29.3 M. Such a facility would generate $5.5 M in average annual net income over its 30-year lifetime. Deployment of 100 such facilities in Thailand would replace all domestic production of fishmeal, 10% of world production, on ~1.5% of the land now used to cultivate oil palm. Such a global industry would generate ~$6.5 billion in annual net income.

Target Cultivation and Financing Parameters for Sustainable Production of Fuel and Feed from Microalgae.

Production of economically competitive and environmentally sustainable algal biofuel faces technical challenges that are subject to high uncertainties. Here we identify target values for algal productivity and financing conditions required to achieve a biocrude selling price of $5 per gallon and beneficial environmental impacts. A modeling framework--combining process design, techno-economic analysis, life cycle assessment, and uncertainty analysis--was applied to two conversion pathways: (1) "fuel only (HTL)", using hydrothermal liquefaction to produce biocrude, heat and power, and (2) "fuel and feed", using wet extraction to produce biocrude and lipid-extracted algae, which can substitute components of animal and aqua feeds. Our results suggest that with supporting policy incentives, the "fuel and feed" scenario will likely achieve a biocrude selling price of less than $5 per gallon at a productivity of 39 g/m(2)/day, versus 47 g/m(2)/day for the "fuel only (HTL)" scenario. Furthermore, if lipid-extracted algae are used to substitute fishmeal, the process has a 50% probability of reaching $5 per gallon with a base case productivity of 23 g/m(2)/day. Scenarios with improved economics were associated with beneficial environmental impacts for climate change, ecosystem quality, and resource depletion, but not for human health.

Bioactive compounds offered in microcapsules to determine the nutritional value of copepods' natural diet.

Experiments were performed, feeding Calanus pacificus seston and a food consisting of seston and microcapsules (µ-caps), i.e., protein and lipid µ-caps to test for potential biochemical limitation. Seston was collected off Scripps Pier (La Jolla, CA, USA). Whereas protein µ-caps were too small to be efficiently ingested, lipid µ-caps rich in ω3-highly-unsaturated fatty acids (ω3-HUFA) were ingested similarly to natural seston and lipids were assimilated. However, egg production experiments exhibited that animals fed with lipid µ-caps didn't produce significantly more eggs than with seston of equal carbon concentration and egg production even declined when the diet consisted of 50% lipid µ-caps. Thus, the content of certain ω3-HUFA seemed to have been sufficiently high in seston to prevent limitation. Algal counts revealed that seston consisted mainly of plankton rich in those fatty acids, such as cryptophytes, dinoflagellates, diatoms, and ciliates in the edible size range. This might be characteristic for upwelling systems like the area off Southern California which are known for high trophic transfer efficiency.

Air-water fluxes of N2O and CH4 during microalgae (Staurosira sp.) cultivation in an open raceway pond.

The industrial-scale production of biofuels from cultivated microalgae has gained considerable interest in the last several decades. While the climate benefits of microalgae cultivation that result from the capture of atmospheric CO(2) are known, the counteracting effect from the potential emission of other greenhouse gases has not been well quantified. Here, we report the results of a study conducted at an industrial pilot facility in Hawaii to determine the air-water fluxes of N(2)O and CH(4) from open raceway ponds used to grow the marine diatom Staurosira sp. as a feedstock for biofuel. Dissolved O(2), CH(4), and N(2)O concentrations were measured over a 24 h cycle. During this time, four SF(6) tracer release experiments were conducted to quantify gas transfer velocities in the ponds, and these were then used to calculate air-water fluxes. Our results show that pond waters were consistently supersaturated with CH(4) (up to 725%) resulting in an average emission of 19.9 ± 5.6 µmol CH(4) m(-2) d(-1). Upon NO(3)(-) depletion, the pond shifted from being a source to being a sink of N(2)O, with an overall net uptake during the experimental period of 3.4 ± 3.5 µmol N(2)O m(-2) d(-1). The air-water fluxes of N(2)O and CH(4) expressed as CO(2) equivalents of global warming potential were 2 orders of magnitude smaller than the overall CO(2) uptake by the microalgae.

Haematococcus astaxanthin: applications for human health and nutrition.

The carotenoid pigment astaxanthin has important applications in the nutraceutical, cosmetics, food and feed industries. Haematococcus pluvialis is the richest source of natural astaxanthin and is now cultivated at industrial scale. Astaxanthin is a strong coloring agent and a potent antioxidant - its strong antioxidant activity points to its potential to target several health conditions. This article covers the antioxidant, UV-light protection, anti-inflammatory and other properties of astaxanthin and its possible role in many human health problems. The research reviewed supports the assumption that protecting body tissues from oxidative damage with daily ingestion of natural astaxanthin might be a practical and beneficial strategy in health management.