• Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.71-78
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• 2013

Subcritical water hydrolysis was carried out in a batch reactor to produce valuable materials, such as low-molecular weight (MW) peptides and essential amino acids with antioxidant properties, from heat-dried squid viscera. Hydrolysis of squid viscera was performed at 160 to $280^{\circ}C$ for 3 min. The yield was increased by increasing the temperature and pressure, while the protein content of squid viscera hydrolysate decreased with increasing temperature. Low-MW peptides were detected in all hydrolysates by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The highest yields of free and structural amino acids in heat-dried squid viscera hydrolysate were at $160^{\circ}C$ and were $411.95{\pm}1.15$ and $346.62{\pm}1.25$ mg/100 g, respectively. All essential amino acids were detected in viscera hydrolysates; leucine was the most abundant. Antioxidant activities of hydrolysates were highest at $220^{\circ}C$. Greater than $98{\pm}0.26%$ of the ABTS antioxidant activity was retained in hydrolysates after long-term heat treatment.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.183-192
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• 2014

For the structure determination of D-(+)-sucrose, which consists of ${\alpha}$-D-(+)-glucose and ${\beta}$-D-(+)-fructose, it was acetylated with acetic anhydride and triethyl amine, pyridine, zinc chloride, and sodium acetate as catalysts. The acetylated D-(+)-sucrose was acid-hydrolyzed using sulfuric acid and sodium chloride in methanolic solution. The structures of the reaction products were determined by $^1H$-NMR and $^{13}C$-NMR spectra. The yield of the acetylation indicated the high value in zinc chloride as 70% in zinc chloride catalyst. The acid-hydrolyzed product of the acetylated D-(+)-sucrose, 2,3,4,6,1',3',4',6'-octa-O-acetyl-D-(+)-sucrose, gave 2,3,4,6-tetra-O-acetyl-${\beta}$-D-(+)-glucose and it suggests that the acetylated D-(+)-sucrose was rearranged through the formation of oxonium ion by mutarotation in the 2,3,4,6-tetra-O-acetyl-${\alpha}$-D-(+)-glucose moiety and through the ring opening in the 1',3',4',6'-tetra-O-acetyl-${\beta}$-D-(+)-fructose moiety.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.223-228
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• 2004

Agricultural waste products, beech wood and walnut shells, were hydrolyzed at 40$^{\circ}C$ using mixed crude enzymes produced by Penicillium sp. AHT-1 and Rhizomucor pusillus HHT-1. D-xylose, 4.1 g and 15.1 g was produced from the hydrolysis of 100 g of beech wood and walnut shells, respectively. For xylitol production, Candida tropicalis IFO0618 and the waste product hydrolyzed solutions were used. The effects on xylitol production, of adding glucose as a NADPH source, D-xylose and yeast extract, were examined. Finally, a 50% yield of xylitol was obtained by using the beech wood hydrolyzed solution with the addition of 1% yeast extract and 1% glucose at an initial concentration.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2413-2420
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• 2018

Sida acuta, a common type of weed in Thailand, contains relatively high cellulose (42.7%) content. We pretreated NaOH to improve glucose recovery from S. acuta. The effect of pretreatment temperature and NaOH concentration was fundamentally investigated based on hydrolysis efficiency with recovery of solid fraction. The pretreatment condition was determined to be 3% NaOH at $60^{\circ}C$ for 9 h, which showed the highest glucose recovery. The hydrolysates obtained by enzymatic hydrolysis of S. acuta were applied to the fermentation of Saccharomyces cerevisiae K35, and a theoretical yield of 97.6% was achieved at 18 h. This indicated that the hydrolysates medium without detoxification had no negative effects on the fermentation. The production of biomass into bioethanol was evaluated based on the material balance of 1,000 g basis. Following this estimation, approximately 28 g and 110 g bioethanol could be produced by untreated and pretreated S. acuta, respectively, and this production was improved about 3.9-fold by NaOH pretreatment. These results again show the importance of pretreatment in biorefinery process.

• Environmental Engineering Research
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• v.24 no.3
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• pp.449-455
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• 2019

To investigate the effect of seaweed (SW) addition on anaerobic co-digestion of food waste (FW) and sewage sludge (SS), batch experiments were conducted at various substrate concentrations (2.5, 5.0, 7.5, and 10.0 g volatile solids (VS)/L) and mixing ratios ((FW or SS):SW = 100:0, 75:25, 50:50, 25:75, and 0:100 on a VS basis). The effect of SW addition on FW digestion was negligible at low substrate concentration, while it was substantial at high substrate concentrations by balancing the rate of acidogenesis and methanogenesis. At 10 g VS/L, $CH_4$ production yield was increased from 103 to $350mL\;CH_4/g$ VS by SW addition (FW:SW = 75:25). On the other hand, SW addition to SS enhanced the digestion performance at all substrate concentrations, by providing easily biodegradable organics, which promoted the hydrolysis of SS. $k_{hyd}$ (hydrolysis constant) value was increased from 0.19 to $0.28d^{-1}$ by SW addition. The calculation showed that the synergistic $CH_4$ production increment by co-digesting with SW accounted for up to 24% and 20% of total amount of $CH_4$ production in digesting FW and SS, respectively.

• New & Renewable Energy
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• v.16 no.4
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• pp.83-91
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• 2020

In this study, the reusability of the Fenton oxidation solution was evaluated to reduce the cost of the pretreatment process. Biomass was sequential subjected to Fenton oxidation-hydrothermal treatment and enzymatic hydrolysis to produce monosaccharides. The liquid solution recovered after Fenton oxidation contained OH radicals with a concentration of 0.11 mol/L. This liquid solution was reused for a new Fenton oxidation reaction. After Fenton oxidation, hydrothermal treatment was performed under the same conditions as before, and 9.34-13.63 g/L of xylose was detected. This concentration was slightly lower than that of a fresh Fenton oxidation solution (16.51 g/L) but was higher than that obtained by hydrothermal treatment without Fenton oxidation (2.72 g/L). The degradation rate during hydrothermal pretreatment involving Fenton oxidation was 36.02%, which decreased (29.24-31.05%) slightly when the liquid solution recovered after Fenton oxidation was reused. However, the degradation rate increased compared to that measured from hydrothermal treatment without Fenton oxidation (15.21%). Moreover, the yield after enzyme hydrolysis decreased in the following order: fresh Fenton oxidation-hydrothermal treatment (89.64%) > Fenton oxidation with reused solution-hydrothermal treatment (74.84%) > hydrothermal treatment without Fenton oxidation (32.05%).

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.279-283
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• 2007

Epoxide hydrolase (EH) gene of Caulobacter crescentus was cloned by PCR and expressed in Escherichia coli. The C. crescentus EH (CcEH) primarily attacked at the benzylic carbon of (S)-styrene oxide, while the CcEH preferentially attacked at the terminal carbon of (R)-styrene oxide, thus leading to the formation of (R)-phenyl-1,2-ethanediol as the main product. (R)-phenyl-1,2-ethanediol was obtained with 85% enantiomeric excess and yield of 69% from racemic styrene oxide via enantioconvergent hydrolysis by using recombinant CcEH as the single biocatalyst.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1781-1786
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• 2007

Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.272-276
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• 1994

The dried cinnamon was extracted with enzymes, salts, sugars and additives in order to find the most effective extraction material. Enzymatic hydrolysis of cinnamon suspension with cellulase, hemicellulase, pectinase, ${\beta}-1.4-glucosidase$, tannase and lipase showed a little increase of their cinnamic aldehyde contents. Solid yield, antioxidant activity and degree of browning were increased in hemicellulase treatment. Acid and alkali extraction of cinnamon showed a some increase in solid yields and antioxidant activity was increased by addition of glucose and Na-ascorbate. Cinnamic aldehyde contents and degree of browning were increased in extraction with Na-citrate addition.

• KSBB Journal
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• v.20 no.4
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• pp.311-316
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• 2005

Epoxide hydrolases (EHs) are versatile biocatalysts for the preparation of chiral epoxides by enantioselective hydrolysis from racemic epoxides. Various microorganisms were identified to possess a EH activity by multiple sequence alignment and analysis of conserved domain sequence from genomic and megaplasmid sequence data. We successfully isolated Gordonia westfalica possessing EH activity from various microbial strains from culture type collections. G. westfalica exhibited (R)-styrene oxide preferred enantioselective hydrolysis activity. Chiral (S)-styrene oxide with high optical purity $(>\;99\%)\;ee)$ and yield of $36.5\%$ was obtained from its racemate using whole-cell of G. westfalica.