• Journal of Marine Bioscience and Biotechnology
• /
• v.16 no.1
• /
• pp.55-62
• /
• 2024

Various antimicrobial peptides (AMPs) from microalgae have shown antibacterial, antiviral, antifungal, anticancer, and antioxidant effects, and play crucial roles in medical applications, aquaculture-related disease management, and the food industry. Magainin 2 (MAG2), an AMP, exhibits high antibacterial and antitumor activity, necessitating an efficient recombinant expression system for low-cost, large-scale production. To enhance MAG2 secretion efficiency in Chlorella, we constructed the SS:MAG2:His vector using the known Chlamydomonas reinhardtii CA1 signal sequence (SS) and obtained a stable transformant via an Agrobacterium-mediated transformation method and RT-qPCR. ELISA results revealed that the MAG2 content secreted into the medium by the SS:MAG2:His transformants increased proportionally with mRNA expression. These findings offer a strategy for high MAG2 secretion in the Chlorella vulgaris platform, potentially minimizing downstream processing costs.

• Korean Journal of Food Science and Technology
• /
• v.51 no.5
• /
• pp.473-479
• /
• 2019

Gryllus bimaculatus (GB) has recently been registered as a food variety in Korea. In the present study, we prepared protein hydrolysates from GB and evaluated their antioxidant capacity. Protein hydrolysates were prepared from dried GB using enzymatic hydrolysis using five different proteases, and protein hydrolysates showing high hydrolysis value (alcalase, flavourzyme, and neutrase) were separated further into fractions ${\leq}3kDa$ and then lyophilized. Based on $RC_{50}$ values of hydrolysates (${\leq}3kDa$) obtained from four different antioxidant analyses, the flavourzyme hydrolysates showed relatively high levels of antioxidant capacity among the three hydrolysates, and in particular, it showed considerably strong antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The flavourzyme hydrolysate also significantly inhibited peroxidation of linoleic acid. These results suggest that protein hydrolysates from GB represent potential sources of natural antioxidants. Our current studies are focused on identification of active peptides from the flavourzyme hydrolysate.

• Food Science of Animal Resources
• /
• v.41 no.6
• /
• pp.967-982
• /
• 2021

Probiotics are living microorganisms that, when administered in adequate amounts, provide a health benefit to the host and are considered safe. Most probiotic strains that are beneficial to human health are included in the "Lactic acid bacteria" (LAB) group. The positive effects of probiotic bacteria on the host's health are species-specific and even strain-specific. Therefore, evaluating the probiotic potential of both wild and novel strains is essential. In this study, the probiotic characteristics of Lactobacillus brevis KT38-3 were determined. The strain identification was achieved by 16S rRNA sequencing. API-ZYM test kits were used to determine the enzymatic capacity of the strain. L. brevis KT38-3 was able to survive in conditions with a broad pH range (pH 2-7), range of bile salts (0.3%-1%) and conditions that simulated gastric juice and intestinal juice. The percentage of autoaggregation (59.4%), coaggregation with E. coli O157:H7 (37.4%) and hydrophobicity were determined to be 51.1%, 47.4%, and 52.7%, respectively. L. brevis KT38-3 produced β-galactosidase enzymes and was able ferment lactose. In addition, this strain was capable of producing antimicrobial peptides against the bacteria tested, including methicillin and/or vancomycin-resistant bacteria. The cell-free supernatants of the strain had high antioxidant activities (DPPH: 54.9% and ABTS: 48.7%). Therefore, considering these many essential in vitro probiotic properties, L. brevis KT38-3 has the potential to be used as a probiotic supplement. Supporting these findings with in vivo experiments to evaluate the potential health benefits will be the subject of our future work.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.2
• /
• pp.293-303
• /
• 2016

Protein hydrolysate that shows physiological function such as antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was performed to optimize the hydrolysis of the wing's meat of Yosan-Ogae by a commercial protease. The ranges of processes were the reaction temperature of 40 to $60^{\circ}C$, pH 6 to 8, and enzyme concentration 1 to 3%(w/v). As a result, the optimization of process was determined at temperature of $48-50^{\circ}C$, pH of 7.0-7.2, and enzyme concentration of 3%(w/v), and degree of hydrolysis was 68 to 69% at above conditions. The molecular weight of hydrolysate was distributed to 500-1,200 Da and showed typical peptides. The amino acids of peptides showing presumably antioxidant activity such as histidine, proline, methionine, cystein, tyrosine, tryptophan, phenylalanine comprised about 43.07%. The glutamic acid was 13.6%. Therefore, we expect that those products are useful as functional food ingredients.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1892-1903
• /
• 2022

Objective: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. Methods: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBM_B), or Lactobacillus spp. (as commercial control) (FSBM_L). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBM_B+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBM_B+L, FSBM_B, and FSBM_L). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. Results: Compared to SBM, FSBM_B+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBM_B+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBM_B group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBM_B+L increased CAT mRNA level to 5 times of the control (p<0.05). Conclusion: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.

• Korean journal of food and cookery science
• /
• v.24 no.3
• /
• pp.349-357
• /
• 2008

In an effort to augment extractability of carnosine and anserine at the levels of pro-oxidants such as iron and protein in Tuna boiled extracts(Skipjack, Yellowfin and Bigeye), we assessed the effects of heated and ion exchange chromatography(IEC) and ultrafiltration(UF) using a MW 500 cut-off(500 MWCO). We also evaluated the antioxidant activity of these extracts processed as free radical scavengers and reducing agents. Tuna boiled extracts of dark and ordinary muscle protein and total iron were reduced, whereas carnosine and anserine concentrations and antioxidant activity were increased. The carnosine and anserine concentrations of the ion exchange and permeate UF(IEC-UF) extracts were higher than those observed in the heated and permeate UF(heat-UF), whereas the protein and total iron contents were lower than that observed in the heat-UF. The quantity of carnosine and anserine in ordinary muscle was higher than that detected in dark muscle. HPLC analysis and SDS-PAGE were shown to removes the effect of UF on high molecular weight impurities in the tuna boiled extracts. The major free amino acids(FFAs) from Skipjack, Yellowfin and Bigeye tuna IEC-UF extracts were anserine, histidine and carnosine. These three peptides constituted more than 80～85%. of the detected amino acid. The IEC-UF treated ordinary muscle extracts evidenced the highest levels of DPPH radical scavenging activity and the highest levels of reducing power among the various extracts. The IEC-UF extracts evidenced a DPPH radical scavenging effect equal to that of 1mM ascorbic acid.

• Food Science of Animal Resources
• /
• v.34 no.6
• /
• pp.844-851
• /
• 2014

This study focused on the anti-oxidative and collagenase- and elastase inhibition effects of low molecular weight peptides (LMP) from commercial Jeju horse leg bone hydrolysates (JHLB) on pancreatin, via enzymatic hydrolysis. Cell viability of dermal fibroblasts exposed to UVB radiation upon treatment with LMP from JHLB was evaluated. Determination of the antioxidant activity of various concentrations of LMP from JHLB were carried out by assessing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethybenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC). The DPPH radical scavenging activity of LMP from JHLB (20 mg/mL) was 92.21% and ABTS radical scavenging activity (15 mg/mL) was 99.50%. FRAP activity (30 mg/mL) was $364.72{\mu}M/TE$ and ORAC activity (1 mg/mL) was $101.85{\mu}M/TE$. The anti-wrinkle potential was assessed by evaluating the elastase- and collagenase inhibition potential of these LMP. We found that 200 mg/mL of LMP from JHLB inhibited elastase activity by 41.32%, and 100 mg/mL of LMP from JHLB inhibited collagenase activity by 91.32%. The cell viability of untreated HS68 human dermal fibroblasts was 45% when exposed to a UVB radiation dose of $100mJ/cm^2$. After 24 h of incubation with $500{\mu}g/mL$ LMP from JHLB, the cell viability increased to 60%. These results indicate that LMP from JHLB has potential utility as an anti-oxidant and anti-wrinkle agent in the food and cosmetic industry. Additional in vivo tests should be carried out to further characterize these potential benefits.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.46-60
• /
• 2023

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55℃/3 h) and thermolysin (pH 7.5/37℃/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.8
• /
• pp.5452-5457
• /
• 2015

Conjugating a phytochemical, a strong antioxidant, with a functional peptide not only compensates for its stability, but also improves its solubility and anti-wrinkle effects, thereby contributing to the possibility of becoming an excellent cosmetic ingredient. Thus, in this study we examined the potential cosmetic use of a phytochemical-peptide derivative using gallic acid, a phytochemical with antioxidant, anti-inflammatory, and anti-cancer effects. To evaluate the antioxidant and wrinkle-improving efficacy of 5 synthesized gallic acids conjugated with LVH, IVH, KTTKS, YGGFM, and YGGFLRKYP respectively, we observed the expression of genes related to wrinkle improvement using DPPH radical scavenging activity and real-time PCR. As a result, all 5 derivatives had excellent free radical scavenging effects. The expression level of genes involved collagen synthesis also increased, and the secreted peptides during collagen production contributed to their antioxidant and wrinkle improving effects. These results mark the potential use of gallic acid peptide derivatives as a cosmetic ingredient for anti-oxidation and wrinkle improvement.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.30 no.1
• /
• pp.33-39
• /
• 2016

Alzheimer's disease(AD), one of the most common forms of dementia, is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of β-amyloid(Aβ) peptides of 40-42 residues. Aβ has been believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. Only a few acetylcholinesterase(AChE) inhibitors have been developed for treatment of AD, although the numbers of patients are rapidly increasing within aging society. Here, we show that ethanol extract of Rosae Rugosae Flos(RR) or its butanol fraction reduce the enzyme activity of AChE and BACE1(β-site APP cleaving enzyme 1). Furthermore, We found that RR inhibits Aβ aggregation and removes Aβ aggregates by Transmission electron microscopy(TEM). In addition, RR reduces the free radical of 2, 2-diphenyl-1-picrylhydrazyl(DPPH). We suggest that Rosae Rugosae Flos may be useful as a herbal medicine to treat AD.