• Journal of Mushroom
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• v.14 no.2
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• pp.70-74
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• 2016

A new method to utilize spent mushroom substrates (SMS) for ethanol production was investigated. Analysis of the chemical properties of SMS revealed that they were decomposed by the mushrooms during cultivation. In particular, the free sugar content in SMS was reduced to half of that in mushrooms. Of the tested SMS, the Pleurotus eryngii SMS was determined to be suitable for saccharification. Upon pretreatment with a 1% alkaline solution, Pleurotus eryngii SMS achieved 80.7% of its maximum saccharification ratio. The optimum pretreatment conditions for enzyme saccharification were 1% NaOH solution at $120^{\circ}$ for 60 min. Further studies are required to determine ethanol production using Pleurotus eryngii SMS.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2001-2005
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• 2013

The second-order rate constants ($k_{OH^-}$) for the reactions of Y-substituted-phenyl diphenylphosphinates (4a-4i) with $OH^-$ in $H_2O$ at $25.0{\pm}0.1^{\circ}C$ have been measured spectrophotometrically. Comparison of $k_{OH^-}$ with $k_{EtO^-}$ (the second-order rate constants for the corresponding reactions with $EtO^-$ in ethanol) has revealed that $EtO^-$ is less reactive than $OH^-$ although the former is ca. 3.4 $pK_a$ units more basic than the latter, indicating that the reactivity of these nucleophiles is not governed by their basicity alone. The Br${\o}$nsted-type plot for the reactions of 4a-4i with $OH^-$ is linear with ${\beta}_{lg}$ = -0.36. The Hammett plot correlated with ${\sigma}^-$ constants results in a slightly better correlation than that correlated with ${\sigma}^{\circ}$ constants but exhibits many scattered points. In contrast, the Yukawa-Tsuno plot for the same reactions exhibits an excellent linear correlation with ${\rho}$ = 0.95 and r = 0.55. The r value of 0.55 implies that a negative charge develops partially on the O atom of the leaving group. Thus, the reactions of 4a-4i with $OH^-$ have been concluded to proceed through a concerted mechanism.

• Textile Coloration and Finishing
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• v.14 no.4
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• pp.249-258
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• 2002

Natural silk is formed by two proteins : the crystalline fibroin (inside the silk thread) and amorphous sericin (as a tube outside the thread). The degumming process is used to eliminate the external sericin prior to dyeing ; generally it makes use of soaps at about pH 10. Sericin is the protein constituent that "gums"together the fibroin filaments of cocoon silk. It constitutes about 25% of the weight of the cocoon, is soluble in hot water and "gels" on cooling. The removal of sericin from raw silk, known as degumming, is a simple but important process usually employing hot dilute soap or alkaline solution and occasionally dilute acids or enzymic methods. During degumming, alkali is taken up by the sericin and the free acid from the soap is formed ; this may be deposited on the fiber, reducing the rate of degumming and protecting it from hydrolysis. Alkali is often added to maintain or restore the pH of the baths, but it is rarely used alone, since it leaves the silk rather harsh in handle. If complete sericin removal is required as for printing, sodium carbonate may be added. If the pH of the bath exceeds 11, the fibroin is attacked. Recently, According to the development of electrolysis, we can be obtained the electrolytic reduction water(above pH 11.5) and electrolytic oxidation water (below pH 3). The aim of this work was to study a degumming process using electrolytic water and a possibility of sericin recovery. The new degumming process used electrolytic water operates at $95^\circ{C}$ for 2hr. without any reagents. The wastewater of this process are formed by a solution of sericin in water. This conditions suggest the study of a possible recovery of this protein (sericin) which has an amino acid composition suitable for many used in cosmetics, textile finishing agents, animal feeding, etc. The degumming process using electrolytic water is available to reduce treatment costs and pollute and at the same time to recover sericin.

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.521-526
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• 2001

A method for the simultaneous and precise determination of lactone form and acid form monacolin K in red yeast rice by HPLC was developed in this study. The standard of acid form monacolin K was prepared by alkaline hydrolysis of its lactone form, which was purchased from Sigma company. The optimum HPLC system for the separation and quantification of acid form and lactone form monacolin K is based on the reversed-phase column, and the acidified mobile phase consisting of acetonitrile : 0.1% trifluoroacetic acid (TFA) water soln : 62 :38, the low limit detection amount was 5 ng (i.e.10 $\mu$l injection of 0.5 $\mu\textrm{g}$/ml) . And the optimal extracting system for monacolins in red rice was also presented here.

• BMB Reports
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• v.30 no.1
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• pp.46-54
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• 1997

Alkaliphilic Bacillus sp. S-1 secretes a large amount (approximately 80% of total pullulanase activity) of an extracellular pullulanase (PUL-E). The pullulanase exists in two forms: a precursor form (PUL-I: $M_r$ 180,000), and a processed form (PUL-E: $M_r$ 140,000). Two forms were purified to homogeneity and their properties were compared. PUL-I was different in molecular weight, isoelectric point, $NH_2$-terminal amino acid sequence, and stabilities over pH and temperature ranges. The catalytic activities of PUL-I were also distinguishable in the $K_m$ and $V_{max}$ values for various substrates, and in the specific activity for pullulan hydrolysis. PUL-E showed 10-fold higher specific activities than PUL-I. However. PUL-I is immunologically identical to PUL-E, suggesting that PUL-I is initially synthesized and proteolytically processed to the mature form of PUL-E. Processing was inhibited by PMSF, but not by pepstatin, suggesting that some intracellular serine proteases could be responsible for processing of the PUL-I. PUL-I has a different conformational structure for antibody recognition from that of PUL-E. It is also postulated that the translocation of alkaline pullulanase(AP) in the bacterium possibly requires processing of the $NH_2$-terminal region of the AP protein. Processing of the precursor involves a conformational shift. resulting in a mature form. Therefore. precursor processing not only cleaves the signal peptide, but also induces conformational shift. allowing development of active form of the enzyme.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.619-628
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• 2014

To identify lipase LipA (PFL_0617) from Pseudomonas protegens Pf-5, a lipA deletion mutant (Pf0617) and a complementary strain (Pf0617lipA) were constructed, and their effects on the lipase production were examined. Pf0617 remarkably decreased its whole-cell lipase activity, whereas Pf0617lipA made its whole-cell lipase activity not only restore to wild-type level but also get a further increment. However, the deletion and overexpression of lipA did not affect the extracellular lipase activity. In addition, the unbroken whole cells of these strains were able to catalyze the hydrolysis of membrane-permeable p-nitrophenyl esters, but could not hydrolyze the membrane-impermeable olive oil. These results confirmed that LipA was an intracellular lipase and Pf-5 could also be used as a natural whole-cell biocatalyst. To evaluate the potential of Pf-5 as a whole-cell biocatalyst and separately characterize the whole-cell LipA, the properties of the whole-cell lipases from Pf-5 and Top10lipA were characterized. The results demonstrated that both Pf-5 and Top10lipA exhibited high tolerance to alkaline condition, high temperature, heavy metal ions, surfactants, and organic solvents. Taken together, lipA can realize functional expression in E. coli Top10, and Pf-5 and Top10lipA as whole-cell biocatalysts may have enormous potential in applications.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1427-1437
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• 2014

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, ${\beta}$-glucosidase, xylanase, and ${\beta}$-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of ${\beta}$-glucosidase and core hemicellulases (xylanase and ${\beta}$-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external ${\beta}$-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.432-438
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• 2007

Environmentally important phthalic esters have been analyzed by GC-MS in terms of individual phthalic esters or total phthalic esters directly or after derivatization. Derivatization improves the chromatographic characteristics of the highly polar phthalic esters. This study focused on the GC-MS determination of the total phthalic esters and the individual phthalic esters simultaneously. The phthalic esters were hydrolyzed to phthalate and corresponding alcohols in 1 M NaOH solution at 90 oC for 30 min followed by extraction with ethyl acetate after acidifcation. The phthalic acid and alcohols were simultaneously silyl derivatized using bis(trimethylsilyl)trifluoroacetamide (BSTFA) to their corresponding silyl ester and ethers in the mixture of 60% acetone and 40% ethyl acetate at room temperature within 30 min. Because of the high reactivity of BSTFA with the phthalic acid and alcohols effective silyl derivatization was possible simultaneously. GC-MS analysis of the silyl derivatives of phthalic acid and alcohols was performed. The total phthalic ester content was estimated from the analytical result of phthalic silyl ester, while the individual phthalic ester was quantified from the analytical results of alcoholic silyl ethers. This technique was applied to spiked tab water and real seawater samples from the Lake Shihwa in Korea. The results were checked against the results from the direct GC-MS analysis of the phthalic esters and reasonable recoveries with high sensitivity were achieved. The recoveries were higher than 75% with low relative standard deviation (below 10%).

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.132-137
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• 1993

Several Prosapogenins and sapogenins obtained by acid hydrolysis or alkaline cleavage of Korean red ginseng saponins were separated and identified by spectral and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines, that is, A549, SK - OV - 3, L121O, P388 and K562. The significant difference of activity between stereoisooers was not approved and the activity was inversely proportional to the number of sugars binding to sapogenins. It was clear that diol type prosapogenins and sapogenins were more cytotoxic than triol type ones.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.63-73
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• 1994

Weight loss accelerating agents, TDACW and TTAMW were prepared by adding water to n-tetradecyldimethylbenzylammonium chloride(TDAC) and n-tetradecyltrimethylammonium methyl sulfate(TTAM) synthesized in our lab. On weight loss finishing of PET fiber with NaOH and TDACW or TTAMW, TDACW showed much more weight loss than TTAMW. Optimum concentration was about $8g/{\ell}$, treatment time 60~90min and treatment bath ratio 1:40~1:50. Density and crystallinity increased with weight loss and tensile strength decreased with weight loss. From the reaction mechanism of weight loss accelerating agent and PET fiber, weight loss accelerating agent was proved to function as a catalyst and the surface structures of PET fibers treated with weight loss accelerating agent were characterized with SEM.