Algal Based Antimicrobial Peptides: Their Proteome Scale Analysis and Bioassay

Arthrospira sp. or Spirulina was used as source for antimicrobial peptides (AMP) due to its high protein content and outdoor mass cultivation availability. The protein hydrolysate was prepared by enzymatic digestion and then several molecular weight, 100, 30, 10, 3 kDa, cut-off membranes were used in the peptide-mix preparations. Total number and sequence of peptides obtained from the preparations were analyzed by using Liquid chromatography-Tandem-mass spectrometry (LC-MS/MS), and then subjected to bioactive peptide analysis by using our bioinformatics platform, namely SmartBioPep. Antimicrobial peptides (AMP) were found in the Top-10 ranking of overall bioactivity. The antimicrobial activity was tested with 6 pathogenic bacteria including Vibrio sp. Moreover, the peptide mixtures were used as feed additives for Litopenaeus vannamei larvae from the stage of zoea-1 (Z1) to post-larvae-1 (PL1). The results showed the inhibitory effect of the peptide mixtures against the tested bacterial strains. Whereas the survival rate of shrimp larvae fed with peptide-feed supplements, 10-30 kDa, increased approximately 13-15%. Furthermore, the stage transition period of the larvae decreased about 24 hours compared to that of the control. Therefore, the bioassay data clearly supports the antimicrobial peptide analysis using SmartBioPep platform.