• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.386-393
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• 2011

Three trials were conducted to determine the available energy of different wheat screening varieties collected from different locations of Khorasan in Iran. In experiment 1, chemical composition and the nitrogen corrected true metabolisable energy (TMEn) were evaluated. A precision-fed rooster assay was used, in which, each wheat screening sample was tube fed to adult roosters, and the excreta were collected for 48-h. In Exp. 2 and 3, five and two wheat screening verities-based diets with or without xylanase and phytase were fed to 16-day old battery reared chicks respectively, and total feed consumption and excreta were measured during next three days. The variable nature of wheat screening varieties led to significant differences in mean TMEn values (p<0.01). The TMEn values of samples determined with adult roosters varied by ${\pm}5.03%$ of the mean value ($3,097.65{\pm}49.32\;kcal/kg$) and ranged from 2,734.90 to 3,245.12 kcal/kg. There was a significant correlation (p<0.05) between crude fiber (CF), neutral detergent fiber (NDF), and acid detergent fiber (ADF) with TMEn, and the greatest correlation coefficient was observed between NDF and TMEn (r = -0.947; p<0.001). The optimal equation in terms of $R^2$ from using a single chemical analysis was obtained with NDF: TMEn = 4,152.09-27.80 NDF ($R^2$ = 0.90, p<0.0001), and the TME prediction equation was improved by the addition of the crude protein (CP) and ASH content to sequential analysis: TMEn = 3,656.97-28.65 NDF+32.54 CP+38.70 ASH ($R^2$ = 0.98, p<0.0001). The average AMEn values of 5 and 2 wheat screening varieties determined with young broiler chickens were $2,968.41{\pm}25.70\;kcal/kg$ and $2,976.38{\pm}8.34\;kcal/kg$ in Exp. 2 and Exp. 3, respectively. Addition of xylanase and phytase to wheat screenings resulted in significant (p<0.01) improvement in AMEn by 4.21 and 2.92%, respectively.

• 한국식품영양과학회지
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• 제37권11호
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• pp.1507-1514
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• 2008

본 연구에서는 산업적으로 사용될 수 있는 안정하고 활성이 높은 cholesterol oxidase를 생산하는 균주를 얻기 위해 토양 미생물로부터 균주를 선별하였다. 선별된 균주에 대하여 세포외 효소 활성을 측정한 결과 BEN 115로 명명한 균주가 가장 높은 효소 활성도를 나타내었다. 이 균주는 형태학적, 생리학적 특성과 배양형태 및 G＋C 함량을 분석한 결과 Nocardia속으로 확인되었다. 최적 효소 생산 조건을 조사한 결과 기존 yeast malt extract broth 조성인 0.4% yeast extract, 0.4% glucose, 1% malt extract에서 가장 높은 활성을 나타냈다. 본 균주에서 생산된 extracellular cholesterol oxidase는 SDS-PAGE와 Western blot 결과 분자량이 55, 57 kDa인 두 종류의 효소가 존재하는 것으로 나타났다. BEN 115에 대한 효소학적 특성을 연구한 결과 온도 안정성은 $55^{\circ}C$까지 효소 활성이 유지되었고, pH 안정성은 pH $3.5{\sim}9.5$의 범위까지 안정한 것으로 나타났으며 최적 온도와 최적 pH는 각각 35oC와 pH 5.5인 것으로 나타났다. 또한 detergent(Triton X-100, Triton X-114 그리고 Tween 80) 첨가 시 효소 활성이 첨가하지 않은 대조군보다 약 $1.6{\sim}2.0$배 증가하는 것으로 나타났다. Campesterol, sitosterol 그리고 stigmasterol에 대한 기질 특이성은 cholesterol(100%)과 상대적으로 비교 시 각각 50%, 50% 그리고 27%의 기질 특이성을 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.788-796
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• 2017

Objective: In order to improve fermentation quality of natural grasses, their silage preparation and fermentation quality in meadow steppe (MS) and typical steppe (TS) were studied. Methods: The small-scale silages and round bale silages of mixed natural grasses in both steppes were prepared using the commercial lactic acid bacteria (LAB) inoculants Chikuso-1 (CH, Lactobacillus plantarum) and cellulase enzyme (AC, Acremonium cellulase) as additives. Results: MS and TS contained 33 and 9 species of natural grasses, respectively. Stipa baicalensis in MS and Stipa grandi in TS were the dominant grasses with the highest dry matter (DM) yield. The crude protein (CP), neutral detergent fiber and water-soluble carbohydrate of the mixed natural grasses in both steppes were 8.02% to 9.03%, 66.75% to 69.47%, and 2.02% to 2.20% on a DM basis, respectively. All silages treated with LAB and cellulase were well preserved with lower pH, butyric acid and ammonia-N content, and higher lactic acid and CP content than those of control in four kinds of silages. Compared with CH- or AC-treated silages, the CH+ AC-treated silages had higher lactic acid content. Conclusion: The results confirmed that combination with LAB and cellulase may result in beneficial effects by improving the natural grass silage fermentation in both grasslands.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.775-784
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• 2017

A neutral xylanase (CcXyn) was identified from Coprinus cinereus. It has a single GH10 catalytic domain with a basic amino acid-rich extension (PVRRK) at the C-terminus. In this study, the wild-type (CcXyn) and C-terminus-truncated xylanase ($CcXyn-{\Delta}5C$) were heterologously expressed in Pichia pastoris and their characteristics were comparatively analyzed with aims to examine the effect of this extension on the enzyme function. The circular dichorism analysis indicated that both enzymes in general had a similar structure, but $CcXyn-{\Delta}5C$ contained less ${\alpha}-helices$ (42.9%) and more random coil contents (35.5%) than CcXyn (47.0% and 32.8%, respectively). Both enzymes had the same pH (7.0) and temperature ($45^{\circ}C$) optima, and similar substrate specificity on different xylans. They all hydrolyzed beechwood xylan primarily to xylobiose and xylotriose. The amounts of xylobiose and xylotriose accounted for 91.5% and 92.2% (w/w) of total xylooligosaccharides (XOS) generated from beechwood by CcXyn and $CcXyn-{\Delta}5C$, respectively. However, truncation of the C-terminal 5-amino-acids extension significantly improved the thermostability, SDS resistance, and pH stability at pH 6.0-9.0. Furthermore, $CcXyn-{\Delta}5C$ exhibited a much lower $K_m$ value than CcXyn (0.27 mg/ml vs 0.83 mg/ml), and therefore, the catalytic efficiency of $CcXyn-{\Delta}5C$ was 2.4-times higher than that of CcXyn. These properties make $CcXyn-{\Delta}5C$ a good model for the structure-function study of $({\alpha}/{\beta})_8$-barrel-folded enzymes and a promising candidate for various applications, especially in the detergent industry and XOS production.

• BMB Reports
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• 제38권2호
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• pp.177-181
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• 2005

Effects of common electrophoretic reagents, reducing agents ($\beta$-mercaptoethanol [BME] and DTT), denaturants (SDS and urea), and non-ionic detergent (Triton X-100), on the activity and stability of bovine plasmin (b-pln) and human plasmin (h-pln) were compared. In the presence of 0.1% SDS (w/v), all reagents completely inhibited two plns, whereas SDS (1%) and urea (1 M) denatured plns recovered their activities after removal of SDS by treatment of 2.5% Triton X-100 (v/v). However, reducing agents (0.1 M of BME and DTT) treated plns did not restore their activities. Based on a fibrin zymogram gel, five (from b-pln) and four (from h-pln) active fragments were resolved. Two plns exhibited unusual stability in concentrated SDS and Triton X-100 (final 10%) and urea (final 6 M) solutions. Two bands, heavy chain-2 (HC-2) and cleaved heavy chain-2 (CHC-2), of b-pln were completely inhibited in 0.5% SDS or 3 M urea, whereas no significant difference was found in h-pln. Interestingly, 50 kDa (cleaved heavy chain-1, CHC-1) of b-pln and two fragments, 26 kDa (light chain, LC) and 29 kDa (microplasmin, MP), of h-pln were increased by SDS in a concentration dependent manner. We also found that the inhibition of SDS against both plns was reversible.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1221-1228
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• 2013

Two lipase genes (bpl1 and bpl3) from Antarctic Bacillus pumilus strains were expressed in Bacillus subtilis. Both recombinant lipases BPL1 and BPL2 were secreted to the culture medium and their activities reached 3.5 U/ml and 5.0 U/ml, respectively. Their molecular masses apparent using SDS-PAGE were 23 kDa for BPL1 and 19 kDa for BPL3. Both lipases were purified to homogeneity using ammonium sulfate precipitation and HiTrap SP FF column and Superose 12 column chromatographies. The final specific activities were estimated to be 328 U/mg for BPL1 and 310 U/mg for BPL3. Both lipases displayed an optimum temperature of $35^{\circ}C$, similar to other mesophilic enzymes. However, they maintained as much as 70% and 80% of the maximum activities at $10^{\circ}C$. Accordingly, their calculated activation energy at a temperature range of $10-35^{\circ}C$ was 5.32 kcal/mol for BPL1 and 4.26 kcal/mol for BPL3, typical of cold-adapted enzymes. The optimum pH of BPL1 and BPL3 was 8.5 and 8.0, respectively, and they were quite stable at pH 7.0-11.0, showing their strong alkaline tolerance. Both lipases had a preference toward medium chain length ($C_6-C_{10}$) fatty acid substrates. These results indicate the potential for the two Antarctic B. pumilus lipases as catalysts in bioorganic synthesis, food, and detergent industries.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1568-1574
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• 2017

Objective: The effects of lactic acid bacteria (LAB) and cellulase enzyme on fermentation quality, microorganism population, chemical composition and in vitro gas production of sorghum silages were studied. Methods: Commercial inoculant Lactobacillus plantarum Chikuso 1 (CH), local selected strain Lactobacillus casei (L. casei) TH 14 and Acremonium cellulase (AC) were used as additives in sorghum silage preparation. Results: Prior to ensiling Sorghum contained $10^4LAB$ and $10^6cfu/g$ fresh matter coliform bacteria. The chemical compositions of sorghum was 26.6% dry matter (DM), 5.2% crude protein (CP), and 69.7% DM for neutral detergent fiber. At 30 days of fermentation after ensiling, the LAB counts increased to a dominant population; the coliform bacteria and molds decreased to below detectable level. All sorghum silages were good quality with a low pH (<3.5) and high lactic acid content (>66.9 g/kg DM). When silage was inoculated with TH14, the pH value was significantly (p<0.05) lower and the CP content significantly (p<0.05) higher compared to control, CH and AC-treatments. The ratio of in vitro methane production to total gas production and DM in TH 14 and TH 14+AC treatments were significantly (p<0.05) reduced compared with other treatments while in vitro dry matter digestibility and gas production did not differ among treatments. Conclusion: The results confirmed that L. casei TH14 could improve sorghum silage fermentation, inhibit protein degradation and decrease methane production.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1252-1264
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• 2020

Objective: To effectively utilize crop by-product resources to address the shortage of animal feed during the dry season in Africa, the community of natural lactic acid bacteria (LAB) of corn stover and sugarcane tops and fermentation characteristics of silage were studied in Mozambique. Methods: Corn stover and sugarcane tops were obtained from agricultural field in Mozambique. Silage was prepared with LAB inoculant and cellulase enzyme and their fermentation quality and microbial population were analyzed. Results: Aerobic bacteria were the dominant population with 10⁷ colony-forming unit/g of fresh matter in both crops prior to ensiling, while 10⁴ to 10⁷ LAB became the dominant bacteria during ensiling. Lactobacillus plantarum was more than 76.30% of total isolates which dominated silage fermentation in the LAB-treated sugarcane top silages or all corn stover silages. Fresh corn stover and sugarcane tops contain 65.05% to 76.10% neutral detergent fiber (NDF) and 6.52% to 6.77% crude protein (CP) on a dry matter basis, and these nutrients did not change greatly during ensiling. Corn stover exhibits higher LAB counts and water-soluble carbohydrates content than sugarcane top, which are naturally suited for ensiling. Meanwhile, sugarcane tops require LAB or cellulase additives for high quality of silage making. Conclusion: This study confirms that both crop by-products contain certain nutrients of CP and NDF that could be well-preserved in silage, and that they are potential roughage resources that could cover livestock feed shortages during the dry season in Africa.

• 한국의류산업학회지
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• 제22권4호
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• pp.534-539
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• 2020

Experimental research is needed to provide information on the removal of bloodstains since washing clothes contaminated with blood is necessary for medical related fields (such as ambulance workers and doctors) as well as for women of childbearing age. This study investigated efficient washing conditions for the removal of bloodstains with a focus on washing temperature, fiber type and blood ageing time. Polyester/cotton fabric showed the highest detergency from among three fabrics that were influenced by the composition of the fiber and the structure of the yarn and fabric. When examining the effect of detergent, it was concluded that the alkalinity over pH 10 was essential to remove bloodstains and that auxiliary agents such as soil antiredeposition agents and bleach had a significant effect on the removal of bloodstains. Washing temperature showed the highest detergency at 20℃ due to the activity of the enzyme without the denaturalization of blood. Blood-ageing influenced detergency by inducing changes in the adsorption area and chemical bond. A combination of methods such as quick removal after contamination, use of alkaline detergents including soil antiredeposition agents and bleach, and low-temperature washing could help remove bloodstains.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.337-345
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• 2021

Lipase (triacylglycerol lipase, EC 3.1.1.3) is an enzyme capable of hydrolyzing triacylglycerol, to produce fatty acids and glycerol and reverse the reaction of triacylglycerol synthesis from fatty acids and glycerol through transesterification. Applications of lipase are quite widespread in the industrial sector, including in the detergent, paper, dairy, and food industries, as well as for biodiesel synthesis. Lipases by yeasts have attracted industrial attention because of their fast production times and high stability. In a previous study, a lipase-producing yeast isolate was identified as Zygosaccharomyces mellis SG1.2 and had a productivity of 24.56 U/mg of biomass. This productivity value has the potential to be a new source of lipase, besides Yarrowia lypolitica which has been known as a lipase producer with a productivity of 0.758 U/mg. Lipase production by Z. mellis SG1.2 needs to be increased by optimizing the production medium. The aims of this study were to determine the significant component of the medium for lipase production and methods to increase lipase production using the optimum medium. The two methods used for the statistical optimization of production medium were Taguchi and RSM (Response Surface Methodology). The data obtained were analyzed using Minitab 18 and SPSS 23 software. The most significant factors which affected lipase productivity were olive oil and peptones. The optimum medium composition consisted of 1.02% olive oil, 2.19% peptone, 0.05% MgSO₄·7H₂O, 0.05% KCl, and 0.2% K₂HPO₄. The optimum medium was able to increase the lipase productivity of Z. mellis SG1.2 to 1.8-fold times the productivity before optimization.