University scientists are currently evaluating the merits of the Shewanella bacterium. (Photo: FIS/Stock File)
Probiotic feed cultivated for farmed fish
Wednesday, January 27, 2010, 01:50 (GMT + 9)
Researchers from the universities of Almeria and Malaga have collaborated on a method of feed production with probiotics intended for marine fish farmed in captivity.
Scientists kicked off the study in 2006 in an effort to look for a solution to disease transmission and contagion control in aquaculture, especially of Senegal sole.
In fish-farming, a probiotic microorganism is a live organism that exerts a beneficial effect on the fish by means of the modification of its microbial community, that is, it improves its immunological system and/or increases the nutritious advantage of feed, Andalucia Investiga reports.
The research, funded by the Ministry of Innovation and Science, concluded with the creation of the first system of encapsulation of said microorganisms for employment as nutritional complements.
According to Francisco Javier Alarcon Lopez, lead researcher and member of the group Nutrition and Animal Feeding of the University of Almeria, “the problem with the use of probiotics in marine species farming is in its administration, since these can be diluted or not be ingested by the fish within the aquatic medium.”
The Department of Microbiology at the University of Malaga selected a bacterium of marine origin, of the Shewanella genus, as the most suitable to reach the proposed objective. The encapsulation method was designed by the team led by Alarcon Lopez.
“We have chosen sodium alginate to create the spheres because it is a substance of a non-toxic nature, quite economical and easy to produce,” the researcher said on the matter.
The scientists assured that a pair of doses covers the daily amount of recommended probiotic and that they are visible to fish when dealing with macrospheres of two millimetres in diameter, which facilitates consumption.
Also, the experts took it upon themselves to make them more appetising, incorporating natural scents and specific colorants for each aquaculture species.
The Standing Committee on the Food Chain and Animal Health (SCFCAH) of the European Union (EU) has already authorised the use of a probiotic in aquaculture. One is the lactic-acid bacterium registered under the name Bactocell®, intended for the feed of salmonids and crustaceans.
The researchers of the Department of Applied Biology at the University of Almeria are developing a second project to design and assess specific feed for flat fish.
This study is funded by the National Institute of Agrarian and Alimentary Research and Technology (INIA) and coordinated by the Andalusian Agricultural and Fisheries Research and Training Institute (IFAPA) of Agua del Pino, in Huelva.
By Analia Murias