Lactobacillus plantarum and Bacillus subtilis, known for their versatility in fermentation studies, were used to ferment tuna processing waste, leveraging their ability to hydrolyse protein sequences and generate bioactive peptides. Following optimization of the fermentation process, peptides were filtered using a 10 kDa size cutoff and analysed by nanolC-MS/MS using a Thermo Exploris 480 mass spectrometer. Analysis of the raw data via MSFragger 21.1 employing a non-specific search identified reproducible peptides observed in three biological replicate experiments.

This resulted in the identification of 74 peptides from L. plantarum fermentation and 31 peptides from B. subtilis fermentation, none of which were found in the control (unfermented) experiments. In silico analysis revealed that out of the 74 peptides produced by L. plantarum, only 4 exhibited a bioactive probability exceeding 0.7, while 14 out of 31 peptides produced by B. subtilis surpassed this threshold. Peptides identified in the control group did not exhibit a bioactive probability greater than 0.7. Interestingly, most of the highly bioactive peptides identified in the fermentation experiments were found to originate from collagen.

Keywords: Tuna waste, Protein, Bioactive peptides, Mass spectrometry, Fermentation