The project was funded by the Student Innovation Fund in the summer of 2008 and was carried out by Hugrún Lísa Heimisdóttir, a student who had completed her first year in biotechnology in the field of resources at the University of Akureyri. The student's project was part of a larger project, “Bætibakteríur í lúðueldi”, which was carried out in collaboration with Matís ohf., The University of Akureyri, Fiskey hf and the University of Hólar with a grant from the Technology Development Fund (2006-2008).
The aim of the project as a whole was to look for possible beneficial bacteria in the halibut farming of Fiskey hf. and which could then be added to the environment of halibut larvae for the purpose of improving the growth and performance of the larvae.
The first few weeks are the main bottleneck in halibut farming and other marine fish, but then the larvae feed on live feed animals. The forage animals carry a large number of bacteria and the larvae at this stage of development need to rely solely on a non-specific immune response. There is therefore great interest in the use of supplementary bacteria in the aim of controlling the composition of bacterial flora in the environment and gastrointestinal tract of larvae and making it more positive for the larvae.
Treatment with a mixture of three types of potential beneficial bacteria turned out to give significantly better results to halibut larvae in the early stages of rearing, and in the student's project the focus was therefore on the other side of the beneficial bacteria, ie. the aspect of the bacterial properties that can be studied and measured in the laboratory. One of the characteristics of powerful supplemental bacteria is to inhibit the growth of unwanted bacteria and the student researched this and various other properties of the bacteria. It is also important to look for cost-effective ways to produce the bacteria in large quantities and store and transport them without losing their properties. Freeze-drying is a convenient and desirable way to store and transport bacteria, and the student examined the growth of the bacteria and their growth-inhibiting effect in both fresh and freeze-dried cultures.
The main results of the project showed that the supplementary bacteria had an inhibitory effect on the growth of dominant bacteria in some samples but little or no effect on the growth of dominant bacteria in other samples. This could indicate that in some larvae the bacterial flora is rich, which has gained a good foothold there and therefore it is difficult to influence the growth of the bacteria. Therefore, it is important to treat with supplemental bacteria early in the breeding process in order for the desired bacteria to gain a foothold there. The results also indicated that the three bacterial strains grow better in the presence of each other than alone.
It can therefore be said that the student's project has shed clear light on the properties of the additive bacteria and the most suitable methods of their production for use in the early stages of halibut farming.
The project was carried out under the guidance of Rannveig Björnsdóttir, lecturer at the University of Akureyri and other experts at Matís ohf. in Akureyri. For further information, contact Rannveig at 422-5108.