Application of Native Lactic Acid Bacteria (LAB) for Fermentative Recovery of Lipids and Proteins from Fish Processing Wastes: Bioactivities of Fermentation Products

Fermentation using native lactic acid bacteria (LAB) was evaluated for its effectiveness in recovering lipids and proteins simultaneously from freshwater fish visceral waste (FVW). Five different LAB isolated from fish processing waste were employed in a fermentation process that involved 10% (w/w) glucose, 2% (w/w) NaCl, and 10% (v/w) LAB. Cultures evaluated included four native isolates (Pediococcus acidilactici NCIM5368, Enterococcus faecalis NCIM5367, Pediococcus acidilactici FM37, and Pediococcus acidilactici MW2) from FVW with E. faecium NCIM5335 as the reference culture. Fermentation with native LAB resulted in recovery of > 90% oil present in the material as against no recovery in case of raw (unfermented) viscera and resulted in > 50% of degree of hydrolysis of proteins. The fatty acid profile of lipids was not affected by the fermentation process. The fermentation liquor, rich in hydrolyzed protein, exhibited antioxidant as well as antagonistic properties against several bacterial pathogens. The results clearly demonstrate the usefulness of fermentation using native isolates for simultaneous recovery of lipids and proteins from fish processing waste. It also asserts the value of fermentation as an eco-friendly method and aids in minimizing disposal/pollution problems associated with these solid wastes.