Shadi Rajabi - Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University,Urmia, Iran.
Amir Hessam Shakeri - Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran,Tehran, Iran.
Ramin Khorrami - Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran,Tehran, Iran.
Reyhaneh Sadat Radnia - Faculty of Veterinary Medicine, Islamic Azad University, Tehran, Iran

We need to get various nutrients to have a healthy body, among these important nutrients, fatty acids can bementioned. Fatty acids exist in two forms, saturated and unsaturated and unsaturated fatty acids are dividedinto two types: monounsaturated fat and polyunsaturated fat. Essential fatty acids cannot be produced by thehuman body and therefore must be obtained from food. Omega-۳ and omega-۶ fatty acids are both necessaryfatty acids. The three most important omega-۳ fatty acids are alpha- linolenic acid (ALA), eicosapentaenoicacid (EPA), and docosahexaenoic acid (DHA). Today, fish oil is the most common source of omega-۳. Plantssuch as soy, rapeseed, flaxseed, some marine organisms (microalgae) consumed by fish are good source offatty acids. However, the fatty acids in these sources are mostly (ALA), which must be converted into EPAor DHA in the body. In the comparison between fatty acid producing organisms and plant sources, it can bepointed out the rapid growth and low cost of lipid production by microorganisms.

omega-۳, essential fatty acids, microbial resources, fish oil