Bioactive peptides from Chlamydomonas reinhardtii protein hydrolysate: Identification, antimicrobial activity, and mechanism of action.

Algal-derived peptides are gaining attention as potential natural bio-preservatives. This study aimed to identify antimicrobial peptides from Chlamydomonas reinhardtii protein hydrolysates against Salmonella. Protein hydrolysates were prepared, fractionated, and screened for antimicrobial activity, and the optimal fraction TC3-10 was selected for mechanisms elucidation, peptides identification and in silico analysis. Results showed that TC3-10 displayed the continuously strong inhibitory effect at the concentraction at 0.25-1 mg/mL of 40.24 ± 6.94 %-46.36 ± 3.86 %, primarily through membrane disruption, leakage of intracellular components, and Na(+)/K(+)-ATPase activity reduced. After in silico screening, peptide EWRPF showed high affinity potential against LuxS of -132.4 with six hydrogen bonds and two π-stacking, and GyraseA C-terminal domain of -133.6 with two hydrogen bonds and three π-stacking. This work provided the first evidence of antimicrobial peptides from C. reinhardtii hydrolysates, combining experimental validation with in silico prediction to highlight their potential as novel bio-preservatives.