<b>Antimicrobial activity of mustard against Mackerel fish pathogens</b> Fish is a nutritionally rich food which is more prone to spoilage. It harbours variety of pathogens. Mustard is medicinally important spice. Isolation of Mackerel fish pathogens was done using selective and differential media. Nutritional characterization of mustard was carried out with respect to carbohydrate, protein and fat content. Antimicrobial activity of mustard against fish pathogen was studied using mustard paste and various mustard extracts. The optimum concentration of the extracts to be used for fish preservation was determined by agar cup diffusion method. Mustard crude oil extract prepared using chloroform and methanol mixture showed prominent antimicrobial activity. Marination effect of mustard paste, mustard crude oil extract and mustard oil revealed the preservative effect of mustard. Thus, the present study promotes the use of mustard as a natural preservative agent for seafood industry. Mackerel fish, Mustard, Antimicrobial activity, Preservative 888-891 Issue-2 Volume-2 Khushali Chandulal Ahire | Ranjana Ganesh Khade