A group of researchers at the University of Bergen (UiB) and Uni Research (Norway) – engaged in research and development in the fields of marine biology, the environment, climate, petroleum, culture and the social sciences – have found that a certain type of tunicate – ascidiacea – can be used as a renewable source of biofuel and fish food. This is particularly good news for the growing aquaculture industry, which for years has struggled to find enough quality feed for its fish. There also is the prospect of reducing emissions from traffic.
It is the cellulose, the protein, and the Omega-3 fatty acids in the ascidiacea that is the cause for its many uses. Its mantle consists of cellulose, which is a collection of sugars. When cellulose is cleaved, one can obtain ethanol. And ethanol can be used for biofuel in cars. The animal’s body consists of large amounts of protein and Omega-3. This can be used for fish feed, says professor Eric Thompson at UiB’s Department of Biology.
Thompson and his colleagues have spent years looking into the many possible uses of the ascidiacea. Why are tunicates particularly suited for use as biofuel? “The bioethanol used today is unsustainable as it comes from foods already used for human consumption. That is why there has been a move towards using cellulose from the timber industry to produce bioethanol”, says Christofer Troedsson of Uni Research’s Molecular Ecology Group and head of the research at UiB’s Marine Development Biology and the tunicate research project.
However, it is quite complicated to break down the cellulose in trees and convert it into ethanol. This is because the wood contains a substance called lignin, which is hard to separate from the cellulose. Tunicates contain no lignin. Their cellulose is also low in crystals and is more efficiently converted into ethanol.
Troedsson also points out that using ascidiacea rather than trees is more environmentally friendly, because this does not occupy large tracts of land which could otherwise be used for other purposes, such as growing food. On the ocean floor, under the pier, and on ship ropes – that’s where the tunicates live. They are marine filter feeders that serve as bacteria eaters and as a foodstuff in Korea and Japan. But in the future they may become more prevalent.
Another important point is that the ascidiacea are not in the food chain, probably because of their protective mantle. So there are no creatures dependent on the ascidiacea to survive. They also grow very quickly. Four-six months after birth they are ready for harvesting. Tunicates are also found in all oceans, with an enormous growth potential that exceeds most land-based feedstock.
Source: University of Bergen