Identification of Antioxidative Peptides Derived from Arthrospira maxima in the Biorefinery Process after Extraction of C-Phycocyanin and Lipids

Abstract

Arthrospira maxima has been identified as a sustainable source of rich proteins with diverse functionalities and bioactivities. After extracting C-phycocyanin (C-PC) and lipids in a biorefinery process, the spent biomass still contains a large proportion of proteins with potential for biopeptide production. In this study, the residue was digested using Papain, Alcalase, Trypsin, Protamex 1.6, and Alcalase 2.4 L at different time intervals. The resulting hydrolyzed product with the highest antioxidative activity, evaluated through their scavenging capability of hydroxyl radicals, superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), was selected for further fractionation and purification to isolate and identify biopeptides. Alcalase 2.4 L was found to produce the highest antioxidative hydrolysate product after four-hour hydrolysis. Fractionating this bioactive product using ultrafiltration obtained two fractions with different molecular weights (MW) and antioxidative activity. The low-molecular-weight fraction (LMWF) with MW <3 kDa had higher DPPH scavenging activity with the IC50 value of 2.97 ± 0.33 compared to 3.76 ± 0.15 mg/mL of the high-molecular-weight fraction (HMWF) with MW >3 kDa. Two stronger antioxidative fractions (F-A and F-B) with the respective significant lower IC50 values of 0.83 ± 0.22 and 1.52 ± 0.29 mg/mL were isolated from the LMWF using gel filtration with a Sephadex G-25 column. Based on LC-MS/MS analysis of the F-A, 230 peptides derived from 108 A. maxima proteins were determined. Notably, different antioxidative peptides possessing various bioactivities, including antioxidation, were detected with high predicted scores together with in silico analyses on their stability and toxicity. This study established knowledge and technology to further value-add to the spent A. maxima biomass by optimizing hydrolysis and fraction processes to produce antioxidative peptides with Alcalase 2.4 L after two products already produced in a biorefinery. These bioactive peptides have potential applications in food and nutraceutical products.

Innovative Bioactive Products with Medicinal Value from Microalgae and Their Overall Process Optimization through the Implementation of Life Cycle Analysis—An Overview

“…The antioxidant and hepatoprotective effects were attributed mainly to the hydrophobic and cyclic amino acid residues, constituting 59.98% and 13.95% of the total amino acids, respectively. The hydrophobicity of the amino acid composites as an indication of antioxidant activity was also highlighted by Bai et al [134] after isolating 230 peptides from A. maxima biorefinery residues by an alcalase treatment, suggesting that the increased lipid solubility benefits intracellular interactions with radicals. However, it was noted that certain biopeptides are highly susceptible to degradation in the gastrointestinal tract, thus demanding stability enhancement and controlled release, attributes that could be obtained through encapsulation in proper matrices.…”

“…The peptide action is highly influenced by the amino acid sequence and composition, which is usually defined by the 3-20 contained amino acids [132,133]. Microalgae peptides can be efficiently derived from protein-rich strains (Table 2), even as a byproduct after the major accumulation of other bioactive compounds, creating an opportunity for the development of a sustainable industry based on a circular economy [134,135].…”

Simultaneous production of proteases and antioxidant biopeptides by solid-state fermentation

“…2 These biopeptides could be obtained from the hydrolysis or fermentation of proteins of vegetables such as cereals or plant wastes, 3,4 animal proteins such as whey 5 or proteins of microbial origin, such as algae. 6–8…”

“…2 These biopeptides could be obtained from the hydrolysis or fermentation of proteins of vegetables such as cereals or plant wastes, 3,4 animal proteins such as whey 5 or proteins of microbial origin, such as algae. [6][7][8] Bioactive peptides are organic molecules usually formed by 2 to 20 amino acid residues, attached by covalent bonds known as peptide bonds, 2,9 with molecular masses usually lower than 6000 Da. 10 They can be released by enzymatic hydrolysis of proteins and have several physiological activities in the body, such as antioxidant, antihypertensive, antitumor, antimicrobial, and antithrombotic activities, as well as in gastrointestinal health, among others.…”

The anti-photoaging effect of C-phycocyanin on ultraviolet B-irradiated BALB/c-nu mouse skin

“…Therefore, the development of proteins with anti-photoaging properties has a broad prospect. C-Phycocyanin (C-PC), which was discovered in cyanobacteria, red algae, and cryptophytes, is a light-trapping and pigment-binding protein and participates in photosynthesis ( Bai et al, 2023 ). C-PC consists of blue-colored phycocyanin (an open-chain linearly extended tetrapyrrole compound) bound to a carrier protein, with a thioether bond linking the carrier protein to phycocyanin ( Romay et al, 2003 ).…”