• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.11-18
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• 2005

Angiotensin Ⅰ converting enzyme(ACE) inhibitory activities of laver(Porphyra tenera) protein hydrolysates were investigated by enzymes used for hydrolysis, molecular fractions and drying methods. For the enzymatic hydrolysis, crude laver protein, separated by filtration of water extract of dried laver extracted with 20 times(w/v) water for 3 hours at boiling temperature, were hydrolyzed with three commercial protease, Pepsin, alcalase and maxazyme NNP at optimal conditions. The yield of hydrolysis and ACE inhibitory activities of which were high in order of pepsin, alcalase and maxazyme NNP. ACE inhibitory activities of laver hydrolysates by molecular levels were high in order of 3 kDa > 10 kDa > 3∼10 kDa, and the IC/sub 50/ ACE inhibitory activities by molecular lebels were 4 mg/mL(3 kDa), 5 mg/mL(total hydrolysate), and 20 mg/mL(10 kDa), respectively. The storage stability of dried laver hydrolysates at 20℃ were strongly affected by drying methods, hot air dried of which were much stabler than freeze-dried one.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.197-202
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• 1997

To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.401-408
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• 2018

The waste seaweed from Gwangalli beach, Busan, Korea was utilized as biomass for ethanol production. Sagassum fulvellum (brown seaweed, Mojaban in Korean name) comprised 72% of the biomass. The optimal hyper thermal acid hydrolysis conditions were obtained as 8% slurry contents, 138 mM sulfuric acid, and $160^{\circ}C$ of treatment temperature for 10 min with a low content of inhibitory compounds. To obtain more monosaccharides, enzymatic saccharification was carried out with Viscozyme L for 48 h. After pretreatment, 34 g/l of monosaccharides were obtained. Pichia stipitis and Pichia angophorae were selected as optimal co-fermentation yeasts to convert all of the monosaccharides in the hydrolysate to ethanol. Co-fermentation was carried out with various inoculum ratios of P. stipitis and P. angophorae. The maximum ethanol concentration of 16.0 g/l was produced using P. stipitis and P. angophorae in a 3:1 inoculum ratio, with an ethanol yield of 0.47 in 72 h. Ethanol fermentation using yeast co-culture may offer an efficient disposal method for waste seaweed while enhancing the utilization of monosaccharides and production of ethanol.

• KSBB Journal
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• v.13 no.1
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• pp.44-51
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• 1998

Hydrolysis and adsorption reversibility experiments were run for initial enzyme activity of 4.48, 9.65, 11.19 and 17.14U/mL at a temperature 30$^\circ C$. The chitin particle size corresponded to a mean particle diameter of 0.127mm, and the initial concentration of chitin was 10mg/mL. After approximately 2hrs, the enzyme activity remained constant in a speudo-steady state. The amounts in the bulk [E] and the amounts of enzyme adsorbed on the chitin surface [E] are plotted on Lineweaver-Burk plot to yield a linear relationship with a correlation coefficient of 0.99, a slope of 2.79cm$^-1$ and an intercept of 0.08$\textrm{cm}^2$/U. From this parameters, the values of [E$_T$] and $K_E$ were calculated to be 12.5U/cm$^2$ and 34.88U/mL. respectively, Adsorption isotherm of the enzyme on the particles showed a well developed plateau of 1.35$\times$10$^-3$, 4.72$\times$10$^-3$, 4.42$\times$10$^-3$, 8.58$\times$10$^-3$U/cm$^2$ at 30$^\circ C$. To determine the specificity of chitinase for crystalline chitin, the free energy of adsorption was measured, and its was determined as about -14.62~-18.8kJ/mol.

• KSBB Journal
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• v.23 no.2
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• pp.131-134
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• 2008

Tea seed extract, a byproduct of tea processing, contains two kaempferol glycosides, camelliaside A and camelliaside B. Kaempferol was produced by enzymatic hydrolysis of glycosides. Optimum reaction conditions were investigated. $Pectinex^{(R)}100L$ was effective, producing kaempferol in 48 hrs. Optimum temperature and pH were $40^{\circ}C$ and 4, respectively. Ratio of substrate and enzyme affected the yield. Under optimum conditions, 1.6g kaempferol per 1 kg tea seed extract was produced and 80% of kaempferol precipitated. This result shows that kaempferol could be produced mildly and effectively using tea-processing byproduct.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.204-211
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• 2005

The technology of Solid-State-Fermentation (SSF) with corn straw by Pichia ohmeri T021 was studied in this article. After being crushed, the corn straw powder was added into vitriol solutions to hydrolysis, which the quality proportion of corn straw: water: vitriol (98%) is 20:80:1. The mixtures was incubated at 120$^{\circ}C$ for 1 hour, and the hydrolysis rate reached 19%. Following, the mixture was adjusted to pH 4.5 by sodium carbonate and added cellulase (25IFPU/g). The hydrolysis rate reached 15% after the mixture was incubated at 50$^{\circ}C$ for 25h. The mixture which hydrolysed by vitriol was inoculated by Pichia ohmeri T021 (5${\times}10^7$cell/g) and added cellulase (25 IFPU/g) at the same time. The ethanol yield reached 2.99g per 100 gram substrate after the fermenting grains was incubated at 33$^{\circ}C$, pH 4.5 for 5 days.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.68-75
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• 2010

This study sought to optimize the extraction and enzymatic treatment conditions of Panax ginseng leaves, stems, and roots for the production of fermented ginseng. The optimization enhanced the extraction of total saccharide, a nutrient and growth-activating factor for Lactobacillus bacteria. The hydrolysis of ginseng leaves, stems, and roots was tested with eight enzymes (Pentopan, Promozyme, Celluclast, Ultraflo, Pectinex, Ceremix, Viscozyme, and Tunicase). The enzymatic hydrolysis conditions were statistically optimized by the experimental design. Optimal particle size of ginseng raw material was <0.15 mm, and optimal hydrolysis occurred at a pH of 5.0-5.5, a reaction temperature of 55-$60^{\circ}C$, a Ceremix concentration of 1%, and a reaction time of 2 hr. Ceremix produced the highest dry matter yield and total saccharide extraction. Ginseng leaves were found to be the most suitable raw material for the production of fermented ginseng because they have higher carbohydrate and crude saponin contents than ginseng roots.

• KSBB Journal
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• v.15 no.6
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• pp.630-634
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• 2000

Chiral epoxides are useful chiral synthons in organic synthesis, and various biological methods have been investigated for their production. In this work, the enantioselective resolution of racemic styrene oxide was investigated using Aspergillus niger sp. for the production of optically pure (S)-styrene oxide. The enantioselectivity and initial hydrolysis rates of the racemic substrate were highly dependent of the pH, temperature, and the volume ratio of cosolvent. Experimental sets of pH, temperature, and the volume ratio of cosolvent were investigated using a central composite experimental design, and reaction conditions were optimized by response surface analysis. The optimal conditions of pH, temperature, and the volume ratio of cosolvent were determined to be 7.78, $28.32^{\circ}C$, and 2.4%(v/v), respectively, and optically pure (S)-styrene oxide (>99% ee) was obtained at 35% yield using this microbial enantioselective hydrolysis reaction.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1912-1918
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• 2020

Hyper-thermal (HT) acid hydrolysis of red seaweed Gelidium amansii was performed using 12% (w/v) slurry and an acid mix concentration of 180 mM at 150℃ for 10 min. Enzymatic saccharification when using a combination of Celluclast 1.5 L and CTec2 at a dose of 16 U/ml led to the production of 12.0 g/l of reducing sugar with an efficiency of enzymatic saccharification of 13.2%. After the enzymatic saccharification, 2,3-butanediol (2,3-BD) fermentation was carried out using an engineered S. cerevisiae strain. The use of HT acid-hydrolyzed medium with 1.9 g/l of 5-hydroxymethylfurfural showed a reduction in the lag time from 48 to 24 h. The 2,3-BD concentration and yield coefficient at 72 h were 14.8 g/l and 0.30, respectively. Therefore, HT acid hydrolysis and the use of the engineered S. cerevisiae strain can enhance the overall 2,3-BD yields from G. amansii seaweed.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.86-91
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• 2015

The MPPO (3-methyl-1-phenyl-2-phospholene-1-oxide) was prepared by using various polymerization inhibitors such as BHT (2,6-di-tert-butyl-4-methylphenol), TBC (4-tert-butylcatechol), and copper stearate. The MPPO was confirmed by the analysis using FTIR, $^1H$-NMR, and GC/MS regardless of the type of inhibitors. The yield of MPPO increased with the increase of reaction time, whereas the purity of MPPO decreased slightly. The yield and purity of MPPO increased with temperature, but the MPPO prepared by using copper stearate as a polymerization inhibitor exhibited no changes in the purity. The amount of inhibitors had no effect on the yield of MPPO. The purity of MPPOs increased with the amount of inhibitors, but the MPPO prepared by using BHT showed no changes of the purity. We found that the MPPO prepared by using copper stearate exhibited the highest catalytic activity for diphenylcarbodiimide synthesis.