• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.560-563
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• 2003

During our previous studies on the relationship between nutrient requirements of S. hygroscopicus C9 and rapamycin biosynthesis, we developed chemically-defined media containing among other nutrients, aspartic acid, arginine, histidine, or ammonium sulfate. However, these media (“Cheng et al. medium” and “Lee et al. medium”) showed very slow growth characterized by a very long lag phase of growth. In an attempt to develop a chemically-defined or semi-defined medium to support more rapid growth and increased cell production, we have carried out studies to shorten the lag phase. Of the various additives tested, vitamin-free casein acid hydrolysate was the most significant by shortening the lag phase by 2-3 days. Mixtures of amino acids failed to replace casein acid hydrolysate. The active principle passed through an ultrafilter with a molecular weight cutoff of 1,000 and thus may be a peptide. The present work has yielded a semi-defined medium which should be useful for further growth studies on S. hygroscopicus C9.

• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.507-514
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• 2013

In this study, oxalic acid pretreatment of empty fruit bunch (EFB) was performed at different pretreatment temperatures. Also, we evaluated oxalic acid recovery from hydrolysate by electrodialysis. The fermentable sugar concentration in hydrolysate was high at more than $20g/{\ell}$, when pretreatment was carried out at $150^{\circ}C$. At the same time, ethanol production was $3.78g/{\ell}$ after 72 h which correspond to the ethanol yield of 0.21 g/g. On the other hydrolysate (160, $170^{\circ}C$), fermentable sugar was not consumed by Pichia stipitis during fermentation. Most of the oxalic acid was recovered and some of the fermentation inhibitors were removed by electrodialysis. For the electrodialysis treated hydrolysate, ethanol production was increased compared to the original hydrolysate. The highest ethanol production was $5.38g/{\ell}$ after 24 h which correspond to the yield of 0.33 g/g. The ethanol production by simultaneous saccharification and fermentation (SSF) under all pretreatment conditions was more than $15g/{\ell}$ after 96 h. The highest ethanol production was $20.54g/{\ell}$, when pretreatment was performed at $170^{\circ}C$. In particular, ethanol production was increased, when electrodialysis treated hydrolysate was used for SSF.

• Fisheries and Aquatic Sciences
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• v.22 no.10
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• pp.22.1-22.7
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• 2019

The functional peptides from protein hydrolysates of various fishery sources have been identified such as antioxidant activity. The main intention of this study was purification and characterization of antioxidative peptide from black eelpout muscle. The antioxidative peptides were purified from black eelpout (Lycodes diapterus) muscle using different proteases. Antioxidant activity of black eelpout hydrolysates was evaluated using DPPH radical scavenging activity. Among six hydrolysates, the pepsin hydrolysate had the highest antioxidant activity compared to the other hydrolysates. Therefore, it was further purified and a peptide with seven amino acid residues of DLVKVEA (784 Da) was identified by amino acid sequence analysis. The EC₅₀ value for scavenging DPPH radicals by purified peptide was 688.77 μM. Additionally, the purified peptide exhibited protective effect against DNA damage induces by oxidation in mouse macrophages (RAW 264.7 cells). The results of this study suggest that black eelpout muscle protein hydrolysate could potentially contribute to development of bioactive peptides in basic research.

• Korean Journal of Pharmacognosy
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• v.33 no.1 s.128
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• pp.21-28
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• 2002

Antidiabetic effects of the acid hydrolysate of silk fibroin were investigated by oral administration to animal models for diabetes mellitus, Fibroin protein was extracted from cocoon and digested to peptides of low-molecular weight range (mainly below 3,000) and amino acids by acid hydrolysis, Feeding of the fibroin hydrolysate resulted in a significant recovering effect on reduction of body weight gain and a lowering effect on blood glucose gain in streptozotocin-induced diabetic Sprague Dawley rats (STZ rats) which were used as an insulin-dependent diabetic animal model. But the body weight and blood glucose level in C57BL/KsJ-db/db mice (db/db mice), an non-insulin-dependent diabetic animal model, were not changed significantly by the feeding, On the other hand, plasma leptin levels increased according to increased feeding amount of the hydrolysate in STZ rats and db/db mice in common, It was concluded from the results that the fibroin hydrolysate might stimulate the insulin secretion by recovering or activating pancreatic ${\beta}$ cells and result in the increased plasma leptin level. It was also deduced that the antidiabetic improvements in body weight and blood glucose gain in STZ were thought to be due to the increased insulin secretion, but in db/db mice of which the diabetic symptoms were caused by insulin resistance, the stimulated secretion of insulin was unlikely to be able to change body weight and blood glucose level significantly.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.259-262
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• 2003

In this study, batch production of lactic acid from cheap law material such as barley, wheat, and corn, was tried to lower the total production cost of lactic acid. Although no nutrients were supplemented, lactic acid productivities were achieved up to 0.88 $g/(L{\cdot}hr)$ from barley, wheat and com enzymatic hydrolysate. By adding corn steep liquor to com and wheat hydrolysate media, realtively high lactic acid $productivities(4.14\;g/(L{\cdot}hr))$ were obtained.

• BMB Reports
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• v.34 no.3
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• pp.219-224
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• 2001

To identify the antioxidative peptides in the gelatin hydrolysate of bovine skin, the gelatin was hydrolyzed with serial digestions in the order of Alcalase, pronase E, and collagenase using a three-step recycling membrane reactor. The second enzymatic hydrolysate (hydrolyzed with pronase E) was composed of peptides ranging from 1.5 to 4.5 kDa, and showed the highest antioxidative activity, as determined by the thiobarbituric acid method. Three different peptides were purified from the second hydrolysate using consecutive chromatographic methods. This included gel filtration on a Sephadex G-25 column, ion-exchange chromatography on a SP-Sephadex C-25 column, and high-performance liquid chromatography on an octadecylsilane chloride column. The isolated peptides were composed of 9 or 10 amino acid residues. They are: Gly-Glu-Hyp-Gly-Pro-Hyp-Gly-Ala-Hyp (PI), Gly-ProHyp-Gly-Pro-Hyp-Gly-Pro-Hyp-Gly (PII), and Gly-ProHyp-Gly-Pro-Hyp-Gly-Pro-Hyp (PIII), as characterized by Edman degradation and fast-atom bombardment mass spectrometry. The antioxidative activities of the purified peptides were measured using the thiobarbituric acid method, and the cell viability with a methylthiazol tetrazolium assay The results showed that PII had potent antioxidative activity on peroxidation of linoleic acid. Moreover, the cell viability of cultured liver cells was significantly enhanced by the addition of the peptide. These results suggest that the purified peptide, PII, from the gelatin hydrolysate of bovine skin is a natural antioxidant, which has potent antioxidative activity.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.807-818
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• 2016

The effect of addition commercial fish collagen hydrolysate and encapsulated fish collagen hydrolysate on the quality characteristics of sucuk (a traditional Turkish dry-fermented sausage) was investigated. Fish collagen hydrolysates were encapsulated with maltodextrin (MD) which has two different dextrose equivalent (12DE and 19 DE), with two different types of core/coating material ratios (10% peptide : 90% MD, 20% peptide : 80% MD). Than six group of sucuk dough (control, peptide, MD1210, MD1220, MD1910, MD1920) prepared and naturally fermented. The effects of the ripening period (28 d), treatment (peptide and encapsulated peptide addition) 'ripening period ${\times}$ treatment' interaction on sucuk's pH, lactic acid contents, $a_w$ values and moisture contents were statistically significant (p<0.01). The pH, moisture and $a_w$ decrease and lactic acid concentration increses during ripening period. The highest pH was observed with peptide added group (5.41), and encapsulated peptide added groups (4.76-4.77) were lower than the control group (5.26). Lactic acid concentration was affected from treatment and all treatment groups lactic acid concentration (0.185-0.190%) were higher than the control group (0.164%). Antioxidant and Angiotensin converting enzyme inhibition activities of water soluble protein extracts were significantly (p<0.01) increased during ripening time. Antioxidant activity reached the highest level at $28^{th}$ d. There was no significant increase observed after fermentation for both activities. Antioxidant activity of encapsulated peptide added (%39.56-40.48) groups were higher than control (34.28%) and peptide added (33.99%) groups except MD1920 (38.30%). The effect of the ripening period of the sucuk samples on TBA values was found to be statistically significant (p<0.01) while treatment and 'ripening period ${\times}$ treatment' interaction were not to be significant (p<0.05). The value of hardness was the highest in the encapsulated peptide added groups (29.27, 35.83 N), and it was 20.40 N and 15.41 N in the peptide added group and the control group respectively.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.26-35
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• 2017

The hydrolysis of proteins constitutes an invaluable tool, granting access to a variety of peptide fragments with potentially interesting biological properties. Therefore, a hemoglobin (Hb) hydrolysate of Crocodylus siamensis was generated by digestion under acidic conditions. The antibacterial and antioxidant activities of the Hb hydrolysate were assessed in comparison with intact Hb. A disc diffusion assay revealed that the Hb hydrolysate exhibited antibacterial activity against eight strains of gram-positive bacteria and showed a higher efficacy than intact Hb. Moreover, the antioxidant activity of intact Hb and its hydrolysate was evaluated using ABTS and DPPH radical scavenging assays. The Hb hydrolysate exhibited free radical scavenging rates of 6-32%, whereas intact Hb showed a slightly higher activity. In addition, non-toxicity to human erythrocytes was observed after treatment with quantities of Hb hydrolysate up to $10{\mu}g$. Moreover, active fragmented Hb (P3) was obtained after purifying the Hb hydrolysate by reversed-phase HPLC. Scanning electron microscopy demonstrated the induction of bacterial cell membrane abnormalities after exposure to P3. Antibacterial and antioxidant activities play crucial roles for supporting the wound healing activity. Consequently, an in vivo mice excisional skin wound healing assay was carried out to investigate the effects of intact Hb treatment on wound healing in more detail. The results clearly demonstrate that intact Hb is capable of promoting 75% wound closure within 6 days. These findings imply that intact Hb of C. siamensis and its acid hydrolysate may serve as valuable precursors for food supplementary products benefitting human health.

• KSBB Journal
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• v.6 no.4
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• pp.327-336
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• 1991

A study on the optimum hydrolysis conditions of fish skin through the aid of enzymes and the development of a natural seasoning using the hydrolysate has been carried out for the effective utilization of fish skin. Using the "pH-drop" techniques the collagenase and pronase were identified as most suitable for this purpose. The $K_m$ and $V_{max}$ values of pronase were 1.82 mgN/ml and 0.06 mgN/mL/min, respectively. The hydrolysis conditions of the cod skin for the pronase were as follows: reaction temperature, $50^{\circ}C$; reaction time, 3hrs; pH 6; enzyme concentration, 0.03%. The degree of hydrolysis at these conditions was 76.8%. But after hydrolyzing cod skin with collagenase for 1hr, when the pronase was treated, the degree of hydrolysis was 83.13%. The molecular weight of the hydrolysate was 8,000 daltons. Among the amino acids in the hydrolysate, glycine(27.95%), glutamic acid(10.94%), proline(7.39%), aspartic acid(9.47%) and serine(7.39%) were responsible for 64.23% of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only 13.05%. From the results of the sensory evaluation, the imitation sauce which was made of 20% fermented soy sauce prepared from the hydrolysate was at least similar to the traditional soybean sauce in product quality. The complex seasoning containing 31.7% of the hydrolysate was nearly equal to complex seasonings on the market, too.

• Journal of Life Science
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• v.10 no.2
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• pp.140-149
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• 2000

In order to utilize marine processing waste which would normally be discarded, cod liver protein was hydrolysed by ${\alpha}$-chymotrysin, and the hydrolysate was investigated for the new angiotensin I converting enzyme (ACE) inhibitor. Thy hydrolysate was separated into three major types, with molecular weight cut-off (MWCO) values less than 10 kDa, 5 kDa and 1 kDa of ultrafiltration membranes, respectively. ACE inhibitory peptides were isolated from the fractions passed through MWCO 1 kDa membrane, and purified by using ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, and HPLC on an ODS column. The purity was identified with capillary electrophoresis. The amino acid sequences of two peptides were Met-Ile-Pro-Pro-Tyr-Tyr (IC50=10.9 ${\mu}$M) and Gly-Leu-Arg-Asn-Gly-Ile (IC50=35.0 ${\mu}$M)