Hungry for algae III
After the last two articles about algae, in which we wrote about the potential of algae for human nutrition and as a source for innovative packaging materials, this article will focus on the potential of algae for animal feed, as fertilizers and and biofuels to further show how versatile and beneficial the enhanced usage of algae could be.
Algae as a source for biofuel
Since decades researchers are trying to develop efficient algae-based biofuel production systems to produce more sustainable ethanol, hydrogen and biodiesel and even sequestrate CO2 at the same time. 100 tons of microalgae, for example, can sequestrate about 180 tons of Carbon dioxide during one life-cycle in the biofuel production.1 A CO2 Balance no other biofuel source can compete with. In addition, also the yield of biofuel per hectare is reasonably higher compared to other biofuel sources, like sugar cane or rapeseed, which makes it even more interesting as a future fuel source. Unfortunately, the production systems are still too expensive in comparison to the standard bioethanol or biodiesel ones, which is why the biofuel production via microalgae haven’t reached a relevant industrial scale yet. Nevertheless, researchers are constantly trying to bring the production costs down via genetic engineering, process optimization and by opening up new ways to make use of byproducts and left-overs to gain additional returns. Two of those new ways to make the production of biofuels more profitable are algae as animal feed and fertilisers, which are getting more and more attention for some years.
Algae as fertilisers
Micro-algae (e.g. cyanobacteria), which are used in the biofuel production are often able to fix atmospheric nitrogen and can be used after the fuel processing as a good alternative to mineral nitrogen fertilizers. In addition, macroalgae like Laminaria digitata (Oarweed), Saccharina latissima (Sugar Kelp) can provide a lot of potassium, and phosphorus, which is also micronutrients often inhibiting the normal growth and could be used as a supplement to the cyanobacteria-based nitrogen fertiliser.
Furthermore, also living micro-algae can be used as biofertilizers and can strengthen and support the plant with regard to Ph-level fluctuations, salinity, and pest pressure. In addition to that, the living microalgae can also fix nitrogen and thereby support the nutrient uptake of the crop.
Algae as animal feed
As we already described in our first article, algae can have various beneficial effects on human nutrition, as they can provide some rare nutrients like Omega-3-Acids and Vitamins and are often high in protein. Also, animals could benefit from those characteristics, which is why algae should be implemented more into animal feed as a supplement. In addition, researchers found out that feeding cattle and sheep with seaweed could reduce the methane emissions of cattle by a lot, which could have a significant effect on our climate. The amount of algae, which is currently used as animal feed is still pretty low, but with increasing pressure on the farming sector to reduce carbon dioxide emissions, we believe that it will increase by a lot in the future and you don’t have to feed the animals a lot. In trials with sheep, for example, 1% of algae in the daily diet were already enough to reduce the methane emissions by the sheep by 60%. If the same would also hold true for cattle, we think it would be an easy way to cut down the agricultural greenhouse gas emissions. Just another area algae could be helpful for.
1 Chisti, Y. (2008). Biodiesel from microalgae beats bioethanol. Trends Biotechnol. 26, 126–131. doi: 10.1016/j.tibtech.2007.12.002ew