• Journal of Animal Science and Technology
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• 제62권1호
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• pp.21-30
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• 2020

This study was conducted to evaluate effects of dietary protease (PR) on growth performance, nutrient digestibility, and intestinal morphology of weaned pigs. A total of 75 weaned pigs [7.06 ± 0.18 kg of average body weight (BW); 28 day old] were randomly allotted to 3 dietary treatments in a randomized complete block design (blocks = BW and sex): a diet based on corn and soybean meal to meet the requirement of crude protein (CP) as a positive control (PC; CP = 24.49%), a low protein diet as a negative control (NC; CP = 22.51%), and NC + 0.02% PR. The PR used in this study was a commercial product containing 75,000 protease units/g derived from Nocardiopsis prasina produced in Bacillus licheniformis. Pigs were fed the dietary treatments for 6 weeks and the diets containing 0.2% chromic oxide for the last week of this study. Blood, feces, ileal digesta, and ileum samples were collected from randomly selected two pigs in each pen on respective time points. Measurements were growth performance, apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of dry matter (DM), CP, and energy, frequency of diarrhea, packed cell volume (PCV), and ileal morphology of weaned pigs. Pigs fed PC and PR had higher (p < 0.05) final BW, average daily gain (ADG), and gain to feed ratio (G:F) during overall experimental period than those fed NC. Pigs fed PC and PR had higher (p < 0.05) AID or ATTD of DM, CP, or energy than those fed NC. Moreover, pigs fed PR had higher ratio between villus height and crypt depth (p < 0.05) and number of goblet cells (p < 0.05) than those fed NC. Addition of PR decreased (p < 0.05) frequency of diarrhea for the first two weeks after weaning compared with PC and NC. In addition, pigs fed PR had lower (p < 0.05) PCV on d 14 after weaning than those fed PC and NC. In conclusion, addition of PR in nursery diets with a low protein level significantly improved growth performance, nutrient digestibility, and intestinal morphology of weaned pigs.

• 한국식품영양학회지
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• 제10권4호
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• pp.521-527
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• 1997

주로 남해안의 천수만에서 많이 어획되는 새조개의 이용으로는 여체부의 긴발을 약간 데친 후동결하여 주로 수출하고 있으나, 그외 나머지 부분은 폐기되거나 사료로 이용되는 것으로 식량자원으로서 이용율이 매우 낮다. 따라서 본 연구에서는 새조개 연체부의 긴발을 제외한 나머지인 가공부산물을 효과적으로 이용하기 위한 한 방안으로서 효소를 이용한 액상조미료 제품의 속성 제조와 품질개선에 관하여 검토한 결과를 요약하면 다음과 같다. 새조개 전체 육중량에 대하여 연체부의 긴발을 제외한 부산물의 중량비는 32.7%였으며, 수분 함량은 83.1%, 조단백질 함량은 10.7%였다. 새조개 부산물의 가수분해 시간을 단축시키기 위하여 첨가한 효소인 Alcalase 및 Protease N.P. 모두가 가수분해 초기에 급격한 분해를 보여 가수분해 8시간까지 꾸준히 증가하였고, 그 이후 20시간까지는 거의 변화를 보이지 않았으며 적정 첨가농도는 4.0%였다. 새조개 가공 부산물을 이용한 액상 조미료의 풍미개선을 위하여 glucose를 첨가하여 가열에 의한 Maillard 반응을 이용하였을 때 냄새의 개선에 상당히 효과적이었으며, 기호성 증진을 위하여 가수분해물의 여액에 0.5% 첨가가 관능적으로 적당하였다. 최종제품의 품질로서 전질소량이 1,607mg%, 아미노질소량은 1,264mg%으로 원료에서의 질소이행율은 93.9%로 매우 높았으며, 제품의 총질소량에 대하여 아미노질소량이 차지하는 비율은 78.6%였다. 그리고 우리아미노산은 glutamic acid가 1,027.5mg%로 함량이 가장 높았으며, lysine, leucine, valine 및 aspartic acid 순으로 함량이 높았고, tryptophan, cystine, histidine 및 serine 순으로 함량이 적었다.

• Journal of Applied Biological Chemistry
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• 제59권4호
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• pp.285-288
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• 2016

단백질 분해효소는 단백질 내 아미노산의 펩티드 결합을 가수분해하며, 산업분야에서 가장 많이 사용되는 효소이다. 이전의 논문에서 부패한 나무로부터 Pseudoxanthomonas sp. WD12와 WD32를 분리하였다. 분비된 단백질 분해효소의 특성을 조사한 결과 WD12는 pH 9.0, $50^{\circ}C$, WD32의 경우 pH 8.0, $45^{\circ}C$에서 최적 활성을 나타내었다. 최적조건하에서 최고의 활성은 WD12는 768 unit/mL로 WD12의 활성이 WD32보다 2.6배 높았다. 금속 이온에 대한 분비효소 영향을 조사한 결과 두 균주 모두 KCl, NaCl, $CaCl_2$, $MnSO_4$를 첨가했을 때 활성이 증가하였으며, $AgNO_3$, $CuSO_4$, $FeCl_3$, $AlCl_3$를 첨가했을 때는 감소하였고, 최고의 활성은 $MnSO_4$의 첨가했을 때 두 균주 모두 활성 증가를 보인 반면 $FeCl_3$, $CuSO_4$는 활성저해를 보였다. 신종으로 생각되는 WD12 균주의 효소는 알칼리성 조건의 산업 환경에서 이용가능 하다고 생각된다.

• 생명과학회지
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• 제11권4호
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• pp.291-297
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• 2001

The marine bacterium isolated from Porphyra dentata showing green spot rot disease was identified as Pseudomonas sp. the strain have CNCase activity, xylanase activity and protease activity as well as agarase activity. But the strain has no pectate lyase activity. Porphyra dentata tissue inoculated this isolate was macerated after 1 week incubation. The characteristics of extracellular crude agarase of this isolate were examined, the optimal pH and temperature were pH7 and 3$0^{\circ}C$, respectively.

• 한국식품영양과학회지
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• 제6권1호
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• pp.27-33
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• 1977

The alkaline protease was isolated from the culture of Penicillium species (P-46) grown in the wheat bran media. The crude purification of this enzyme was carried out by extraction with distilled water and precipitated with 0.7-saturated ammonium sulfate, then dialysis for 3days. The activity of this enzyme was determined by Folin's colorimetric method. The results were as follows; 1. The optimum pH and temperature of this enzyme were pH 8.4 and $45^{\circ}C$. 2. This enzyme was stable at pH $7.0{\sim}9.0$. 3. This enzyme was not inactivated by treatment in lower temperature than $30^{\circ}C$. 4. The activity of this enzyme was strongly inhibited by $Hg^{++}$ and $Cu^{++}$, but slightly by $Ag^+$ 5. This enzyme was not inhibited by cystein, thiourea, ${\varepsilon}-aminocaproic$ acid, 2, 4-DNP, EDTA but strongly inhibited by PCMB.

• 한국축산식품학회지
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• 제41권1호
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• pp.164-171
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• 2021

Listeria monocytogenes is a representative foodborne pathogen and causes listeriosis. Enterococcus faecium CJNU 2524 was confirmed to produce a bacteriocin with anti-listerial activity. To establish optimal culture conditions for the production of the bacteriocin from E. faecium CJNU 2524, different media (MRS and BHI broth) and temperatures (25℃, 30℃, and 37℃) were investigated. The results showed that the optimal culture conditions were MRS broth and 25℃ or 30℃ temperatures. The crude bacteriocin was stable in a broad range of pH conditions (2.0-10.0), temperatures (60℃-100℃), and organic solvents (methanol, ethanol, acetone, acetonitrile, and chloroform). The bacteriocin activity was abolished when treated with protease but not α-amylase or lipase, indicating the proteinaceous nature of the bacteriocin. Finally, the bacteriocin showed a bactericidal mode of action against L. monocytogenes. Therefore, it can be a biopreservative candidate for controlling L. monocytogenes in dairy and meat products.

• 한국식품과학회지
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• 제37권3호
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• pp.377-388
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• 2005

누에가루는 단백질과 섬유질 함량이 높았고, pH는 누에가루가 8.31로 밀가루의 5.80보다 상당히 높았으며 누에가루에서 pretense가 많이 존재하는 것으로 나타났다. Amylograph에서 누에가루 증가시 최고점도는 높아지는 경향이었다. 이는 누에가루에 존재하는 ${\alpha}$-glycosidase 활성을 억제하는 물질에 의해서 밀가루의 ${\alpha}$-amylas 활성이 억제되어 최고점도가 높아진 것으로 생각되었다. 누에가루 첨가시 반죽의 신장도와 저항도의 급격한 감소로 반죽의 글루텐 구조가 매우 약화되어 제빵성이 크게 저하되는 것으로 나타났으며 이는 누에가루에 있는 protease의 지나친 활성으로 확인되었다. 열처리한 누에가루의 casein 분해능이 16.93 IU인데 비해, 열처리하지 않은 누에가루의 pretense 활성도는 23.87 IU였다. 따라서 열처리를 통하여 누에가루의 pretense를 불활성시켜 사용함으로서 반죽의 물성이 개선되고 빵의 부피 증가 및 품질을 크게 향상시킬 수 있는 새로운 방법을 규명하였다. 그러고 ascorbic acid, SSL 및 gluten을 첨가하여 품질 향상을 더욱 보완하였고, 발효 저해는 lactic acid를 첨가함으로서 반죽의 pH를 조절하여 발효력을 향상시켰다. 열처리로 protease를 불활성화 시킨 누에가루를 사용하여 제조한 빵의 관능검사 결과 대조구와 같은 수준의 선호도를 보였으며 누에가루의 적정 첨가량은 2%수준으로 나타났다.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.303-309
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• 2012

Keratinases are of particular interest because of their action on insoluble keratins and generally on a broad range of protein substrates. Alkalophilic and neutrophilic actinomycete strains isolated from different soil samples, rich in keratinaceous substances were screened for keratinolytic activity. An alkalophilic isolate, TBG-S13A5, was found to possess good keratinolytic activity and was able to utilize feather as the sole carbon and nitrogen source. TBG-S13A5 exhibited an off-white aerial mass color with a rectus-flexibilis type of spore chain. The morphological, microscopical and biochemical characters were comparable with that of Streptomyces albidoflavus. Fatty acid methyl ester profiling (FAME) and 16S rDNA sequence analysis confirmed its identity as a strain of S. albidoflavus. Under submerged fermentation conditions, maximum protease production was recorded on the $5^{th}$ day of incubation at $30^{\circ}C$, using basal broth of pH 9.0 with 0.25% (w/v) white chicken feather. This strain could affect feather degradation when the initial pH was 8 and above and maximum protease production was recorded when the initial pH was around 10.5. The effectiveness of the crude enzyme in destaining and leather dehairing were also demonstrated.

• Asian-Australasian Journal of Animal Sciences
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• 제27권12호
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• pp.1755-1762
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• 2014

The objective of this study was to investigate the effect of maize source and complex enzymes containing amylase, xylanase and protease on performance and nutrient utilization of broilers. The experiment was a $4{\times}3$ factorial design with diets containing four source maize samples (M1, M2, M3, and M4) and without or with two kinds of complex enzyme A (Axtra XAP) and B (Avizyme 1502). Nine hundred and sixty day old Arbor Acres broiler chicks were used in the trial (12 treatments with 8 replicate pens of 10 chicks). Birds fed M1 diet had better body weight gain (BWG) and lower feed/gain ratio compared with those fed M3 diet and M4 diet (p<0.05). Apparent ileal crude protein digestibility coefficient of M2 was higher than that of M3 (p<0.05). Apparent metabolisable energy (AME) and nitrogen corrected AME (AMEn) of M1 were significant higher than those of M4 (p<0.05). Supplementation of the basal diets with enzyme A or B improved the BWG by 8.6% (p<0.05) and 4.1% (p>0.05), respectively. The fresh feces output was significantly decreased by the addition of enzyme B (p<0.05). Maize source affects the nutrients digestibility and performance of broilers, and a combination of amylase, xylanase and protease is effective in improving the growth profiles of broilers fed maize-soybean-rapeseed-cotton mixed diets.

• Journal of Animal Science and Technology
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• 제47권2호
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• pp.221-232
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• 2005

This study was carried out to investigate the effect of replacing fish meal or soybean meal with feather meal or bromelain treated feather meal in broiler diets on the performances and nutrient utilization. Two hundred and twenty-five broilers were randomly allotted to five dietary treatrnents((1) control, basal diet; (2) PFM 50, 50 % of the fish meal replaced with bromelain treated feather meal; (3) PFM 100, 100% of the fish meal replaced with bromelain treated feather meal; (4) PSM 20, 20 % of the soybean meal replaced with bromelain treated feather meal; and (5) PSM 40, 40% of the soybean meal replaced with bromelain treated feather meal) in a 5-week feeding trial. In the overall period, body weight gain of the PFM 50(1,807 g), PSM 20(1,816 g) and PSM 40(1,823 g) were the highest and that of the PFM 100 was 1,744 g. The body weight gain of the control(1,698 g) was the lowest(p < 0.05) among treatments. Feed conversion was significantly(p< 0.05) improved when bromelain treated feather meal replaced 20% of the fish meal in the basal diet. Digestibilities of dry matter, ether extract, organic matter and phosphorus were not different among the treatments. Digestibility of crude protein of PFM 50(65.87 %), PSM 20(67.18 %) and PSM 40(67.56%) were the highest, and that of the control(54.49%) was the lowest(p < 0.05) among treatments. Arrunonia and hydrogen sulfide gases from the feces were significantly(p < 0.05) decreased in chicks fed the PFM 50, PSM 20 and GFM 40 diets, when observed after 3 weeks of feeding trials. Feed costs of the control and PFM 50 were 604 and 629 won, respectively but that of PSM 50 was 820 won. Therefore, replacement of fish meal with bromelain treated feather meal in the diets for chicks could be useful for economic production.