The team of scientists of University of Almeria. (Photo: Universidad de Almería)
Marine microalgae biomass production boosted for aquaculture feed
Tuesday, July 16, 2013, 04:20 (GMT + 9)
A team of scientists from the Group of Marine Microalgae Biotechnology of the University of Almería (UA) developed a process to obtain microalgae that increased biomass production that is rich in polyunsaturated fat for aquaculture species.
According to the researchers involved in the study, published in the journal Bioresource Technology and entitled Medium recycling for Nannochloropsis gaditana cultures for aquaculture, the process is cheaper and environmentally friendly.
The scientists selected the alga Nannochloropsis gaditana because it is a good producer of valuable fatty acids and proteins for aquaculture
According to Maria del Carmen Ceron, responsible for the research, this alga contains "omega 3 and omega 6 acids, EPA and DHA, two beneficial fatty acids that are incorporated to the fish fat and, in turn, become part of the human diet."
As part of this initiative bioreactors incorporating improvements to optimize the biomass production process were developed by incorporating fertilizers and the reuse of the farming medium, stated the expert to Fundación Descubre.
After the addition of fertilizers, the scientists incorporated essential nutrients -- nitrogen and phosphorus -- and micro-nutrients to the water where the microalgae need them to grow.
This formula lowers the cost and keeps the same composition of nutrients needed by the microorganisms.
Furthermore, in order to reduce costs and avoid contamination, UA researchers reuse this water by previously sterilizing it in order to avoid the accumulation of unwanted microorganisms.
The expert panel found that the most effective technique is the ozonation, that is to say, the addition of ozone.
"This method reduces the bacterial load to values that are 1,000 times smaller than they are with other techniques such as initial filtering, chlorination, the addition of hydrogen peroxide or heating," explained Cerón.
"Our technologies favour the production of microorganisms so that all cells of microalgae grow in the most effective way and the quality of the biomass that is intended to aquaculture is boosted," the scientist added.
Finally, UA researchers also participated in the study Process for the biodiesel production involving the Chlorella protothecoides heterotrophic fermentation with glycerol as carbon source, in order to obtain biodiesel.
The novelty of this research is the use of glycerol as an organic substrate.
Ceron stressed that "there has been very high biomass yields and biodiesel productivities equivalent to those reported for the same species but using glucose as carbon source."
By Analia Murias