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FORNY20-FORNY2020

KVAL: Pigment producing yeast

Awarded: NOK 0.47 mill.

Project Manager:

Project Number:

333413

Project Period:

2022 - 2023

Funding received from:

Oval- or rod-shaped coral-coloured colonies-forming yeast were isolated from wild salmon captured from the enclosed area of the North Sea in Vestfjorden. We also found similar coloured colonies among the bacteria isolated from the intestine of zebrafish (AB strain). Our team was surprised to find pigment-producing yeast among the microbes isolated from the intestinal microbial community of the fishes. The discovery immediately raised a question - Can the live yeast supply astaxanthin or other pigments that may contribute to the pigmentation of flesh or skin? Can the carotenoids from the yeasts replace synthetic astaxanthin in Atlantic salmon feeds to impart better flesh pigmentation? Our team has been studying the importance of microbiota for salmon health, but the existence of pigment-producing yeast as part of the commensal microbiome was a discovery. Salmon feeds are supplemented with synthetic Ax to impart the desired red colour to the fish flesh. Among its biological functions in fish, Ax is a powerful antioxidant that prevents the oxidation of lipids in cell membranes. Supplementation of Ax, one of the most expensive ingredients in salmon feeds, has been shown to enhance the robustness of fish in terms of disease and stress tolerance. In the project, yeast strains isolated from fish intestine were cultured, and then their identity was revealed through whole genome studies. The latter study gave valuable insight into their genetic makeup, including their pigment producing capabilities. The biochemical composition of fish intestine-derived yeast was determined to reveal the content of crude fat, protein, amino acids and fatty acids. The changes in the amino acid and fatty acid composition of one of the yeast strains were governed by the wavelength of the light source. The protein content of yeast derived from Atlantic salmon was higher compared to that of the yeast from zebrafish. We are unable to report the pigments in the yeast biomass due to challenges encountered during extraction. We are continuing our efforts to generate this information even though the project period is over. When the unfinished task is completed, we intend to present the information in a peer-reviewed scientific article.

Results of microbial cultures: The techniques and protocols regarding the culture of the yeasts will be adopted by our master and PhD students to discover the full potential of other microorganisms in our culture collection. The protocols will be transferred to companies that are interested in upscaling the production of the beneficial microbes. Results of whole genome analysis: The information about all the genes in two yeasts and their functional potential reveals the capacity of the yeasts. The identification of various pathways involved in pigment production is particularly significant, as it opens new avenues for research on the biosynthesis of pigments. Further investigations into these pathways may lead to the development of new strategies to produce pigments with desirable properties for various applications. Furthermore, this knowledge is useful for other researchers investigating different species of the same genus or those of another genera. The correlation between genes and pigments will be helpful for the business community that focuses on pigments and other bioactive compounds from microbes. Results of proximate composition, amino acid, fatty acid and pigment content: The skills acquired through the activities in this Research Council of Norway-funded project, namely in microbial culturing, imaging flow cytometry-based studies and whole genome sequencing, will be transferred to other students and staff at Nord. We will continue our efforts to successfully extract the pigments from the yeast in the coming years, and such skills will also be disseminated and communicated to appropriate end users. The acquired knowledge will be used to enrich the educational experience of the students at Nord. The publication of a peer-reviewed scientific article based on the results of this project will allow the know-how to reach a wider audience. The practical information will also be transferred to small and medium-sized businesses. Furthermore, the results from this project will be disseminated to the scientific community.

Funding scheme:

FORNY20-FORNY2020