Potential Application of Omega-3 Fatty Acids Gene Cluster in Probiotics

Mitra Amiri-jami* and Mansel W. Griffiths

Department of Food Science, University of Guelph, Guelph, ON, Canada

*Corresponding author: amiri@uoguelph.ca

 

Introduction: It is becoming increasingly evident that both probiotics and omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have beneficial effects on human health. Marine bacteria such as Shewanella and Colwellia are the only omega-3-producting bacteria. Probiotics, which are members of the lactic acid-producing bacteria such as Lactobacillus acidophilus and bifidobacteria strains are unable to produce omega-3 fatty acids. The aim of our work was to isolate omega-3 fatty acids genes from Shewanella in order to produce recombinant EPA/DHA by other microorganisms such as lactic acid bacteria and bifidobacteria some of which are probiotics.

 

Methods: To isolate EPA and DHA gene cluster a fosmid library was prepared from the genomic DNA of Shewanella. The fosmid clones were screened for EPA and DHA genes by colony hybridization. Analysis of total fatty acids isolated from one transgenic E. coli positive for EPA/DHA genes by gas chromatography and gas chromatography-mass spectrometry indicated recombinant production of both EPA and DHA.

 

Results: In this study, we successfully isolated 16 genes from Shewanella of which five were responsible for both EPA and DHA production. Those genes were transferred to E. coli strains which resulted in the recombinant production of EPA and DHA. Interestingly, transgenic E. coli was able to produce 5 times more EPA compared to the marine bacterium.

 

Conclusion: Our findings have implications for any future use of transferring EPA and DHA gene cluster to lactic acid bacteria and bifidobacteria strains in order to generate omega-3-producing probiotics.