• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.9-19
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• 2016

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37℃ and could maintain at least 96% activity after being placed at 37℃ for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, K_m, V_max, and k_cat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

• 미생물학회지
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• 제49권2호
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• pp.118-125
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• 2013

지난 2000년부터 2009년까지 10년간 광주광역시 지역의 급성설사환자로부터 분리한 총 596개의 살모넬라균주에 대하여 총 16종의 항생제에 대한 감수성 검사를 실시한 결과, 내성빈도가 가장 높았던 약제는 ampicillin (43%), tetracycline (35.9%), nalidixic acid (31.5%), 그리고 chloramphenicol (26.2%) 순으로 나타났다. 혈청형 간에 항생제 내성률에 차이가 있었는데 S. Enteritidis와 S. Typhimurium이 각각 가장 높은 내성률을 보인 약제는 ampicillin (51.1%)과 tetracycline (77.9%)이었다. 총 89가지 내성패턴이 관찰되었으며, 26% (155/596)의 살모넬라 분리주는 검사한 16가지 약제에 모두 감수성을 보였다. 약 21% (127/596) 및 15% (87/596)의 분리주는 각각 한 개 및 두 개의 약제에 내성을 나타냈다. 그 외의 살모넬라 분리주(227/596, 38%)는 세가지 이상의 약제에 내성을 나타냈다(다제내성균). 다제내성균이 가장 높은 비율로 나타난 혈청형은 S. Paratyphi B (76.5%), S. Typhimurium (58.2%), 그리고 S. Enteritidis (40.2%)의 순이었다. 가장 흔한 다제내성패턴은 ampicillin-chloramphenicol-nalidixic acid-ticarcillin (36/227, 15.8%)이었으며 이러한 패턴을 보였던 다제내성균의 대부분(35/36, 97.2%)이 S. Enteritidis이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.224-233
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• 2012

The limiting sequence and relative ratio of lysine (Lys), methionine (Met), and threonine (Thr) for calves about 2 mo of age fed milk replacers (MR) containing soy protein are not clearly defined. The objective of the study was to investigate the effect of supplementing MR containing 22% CP, half from soy protein concentrate (SPC, 40.56% CP, flour) and half from whey proteins, with Lys, Met, and Thr to estimate amino acid (AA) sequence and their relative ratio for calves about 2 mo of age. A method of partial deduction of AA was adopted. Twenty-four newborn calves (half males and half females, $40.7{\pm}0.9$ kg of BW) were fed 1 of 4 MR diets for 56 d (n = 6/diet). The diets were supplemented with all (positive control) or with 2 of the 3 AAs: Lys, Met and Thr, (i.e., PC (22% CP, 2.34% Lys, 0.72% Met and 1.80% Thr), PC-Lys (22% CP, 1.64% Lys, 0.72% Met and 1.80% Thr), PC-Met (22% CP, 2.34% Lys, 0.50% Met and 1.80% Thr), and PC-Thr (22% CP, 2.34% Lys, 0.72% Met and 1.26% Thr)). Calves were fed thrice daily; starter (20% CP, 1.03% Lys, 0.30% Met and 0.69% Thr), hay (3.23% CP, 0.29% Lys, 0.12% Met and 0.23% Thr) and water were offered free choice. Starter and hay were only offered beginning on d 36 (after 5 wk) and d 43 (after 6 wk), respectively. BW, body size and blood samples measures were taken every two weeks. Three-day total collection of feed refusals, feces, and urine were recorded starting at d 33 and d 54 of age, respectively. From the results, the limiting sequence and relative ratio between the 3 AAs in calves with different diet structures were calculated. The limiting sequence of the 3 AAs were ranked as Lys, Met and Thr; the proper ratio was 100:29:70 for MR-only diet and 100:30:60 for diets consisted of MR, starter and hay. Nitrogen digestion and utilization and nutrient digestibility were negatively affected by AA deletion treatments. From the evidence of this experiment, it did not appear that the AA limiting sequence was selectively altered by differences in diet structures such as would be encountered in practice. The relative ratio between the 3 AAs varied with the offer of starter and hay to calves, and the average ratio was 100:29.5:65 for calves during 2 to 10 wk of age.

• 한국축산시설환경학회지
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• 제1권2호
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• pp.117-124
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• 1995

톱밥우사의 우상바닥처리 형태와 톱밥의 효율적 이용을 구명하기 위하여 PVC lightsheet지붕에 우상바닥처리별로 톱밥 10cm+콘크리트바닥, 톱밥 30cm+콘크리트바닥, 톱밥 30cm+바닥에 각각 경산우 6두(1두당 톱밥우상 16.5㎥)씩을 공시하여 시험한 결과 톱밥우상내 온도는 톱밥 30cm+흙바닥 처리가 가장 높았고, 수분증발량은 톱밥 10cm+콘크리트바닥에서 가장 많았다. 톱밥우사에서의 사료섭취 장소 및 톱밥우상의 분뇨배설은 단위면적당 톱밥우상에서는 91% 사료섭취장소에서는 9%가 배설되었으며, 착유우의 1일 분뇨 배설량은(착유시간 제외) 분 31.45kg, 뇨 10.7kg, 계 42.23kg이었으며 우분의 수분함량은 83.96%이었다. 공시완료한 분뇨가 혼합된 톱밥의 성분함량은 우분비율이 많은 톱밥 10cm+콘크리트바닥에서 무기물 성분이 가장 많이 함유되었으며, 흙바닥 처리구의 토양 중 NO$_3$-N함량이 허용한계 (10ppm이하)이상으로 검출되어 수질오염 가능성이 나타났다. 톱밥우상의 처리방법별 년간 유지비용은 톱밥 10cm+콘크리트바닥 처리가 년간 가장 적게 소요되었으며, 톱밥의 효율적 이용, 톱밥 교체시 노력절감 등으로 보아 가장 유리한 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1482-1488
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• 2002

The aim of this study was to explore the effects of fiber sources on gut development and bacterial activity in the gastrointestinal tract of piglets. Eighteen crossbred (Duroc${\times}$Landrace${\times}$Yorkshire) barrows were fed a basal diet based on corn plus soybean meal or similar diets in which a portion of the corn and soybean was replaced by 5% wheat bran or 5% sugar beet pulp. The results indicate that pigs fed diets containing 5% wheat bran or 5% sugar beet pulp had lower liver weights than control pigs (p<0.01). The relative weight of the pancreas in pigs fed diets containing 5% sugar beet pulp was greater than that of control pigs or pigs fed diets containing 5% wheat bran (p<0.05). The pH of the ileal digesta of pigs fed the diet containing 5% wheat bran was higher than that of control pigs or pigs fed the diet containing 5% sugar beet pulp (p<0.05). The lipase activity in the distal jejunum, proximal, and distal ileum of pigs fed the control diet was higher than that of pigs fed the diets containing 5% wheat bran or 5% sugar beet pulp (p<0.05). The concentration of volatile fatty acids anterior to the caecum was greater for the pigs fed the diet containing 5% sugar beet pulp, while the concentration of volatile fatty acids posterior to the ileum was greater for the pigs fed the diet containing 5% wheat bran. This means that sugar beet pulp increased the bacterial fermentation precaecum, while wheat bran increased the bacterial fermentation post-ileum. The concentration of bacterial nitrogen and bacterial protein/total protein in ileal digesta of pigs fed the control diet was higher (p<0.05) than that of pigs fed the diets contained either fiber source. Bacterial protein/total protein in the feces of pigs fed the diet containing 5% sugar beet pulp was higher than that of pigs fed the control diet. This means that inclusion of 5% wheat bran or sugar beet pulp in diets influenced the development of the digestive tract of piglet. The mechanism by which dietary fiber reduced specific activity of lipase needs further consideration. Dietary fiber influenced the bacterial activity in the digestive tract of piglets, sugar beet pulp increased the fermentation in the upper gastrointestinal tract, and while wheat bran increased the fermentation in the lower gastrointestinal tract.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.434-442
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• 2008

The objective of this study was to determine the optimum ratio of methionine to methionine plus cystine for growing pigs. A nitrogen balance trial was conducted using a total of 21 barrows (Large WhiteLandrace) over two replicates. The initial body weight was $20.36{\pm}1.22kg$ (mean${\pm}$SD) in the first replicate and $23.54{\pm}1.02kg$ (mean${\pm}$SD) in the second. For each replicate, the 21 pigs were randomly assigned to one of seven dietary treatments with three observations per treatment. The diets included a methionine and cystine-deficient basal diet with all other essential nutrients meeting nutrient requirements and six diets formulated with graded levels of DL-methionine (0.00, 0.03, 0.06, 0.10, 0.13, 0.16%) and $L-Cystine{\cdot}HCl{\cdot}H_2O$ (0.19, 0.15, 0.11, 0.07, 0.04, 0.00%). This resulted in ratios of methionine to methionine plus cystine of 41.3, 29.6, 35.3, 41.2, 46.0, 51.6 and 57.5%. Each experimental period lasted 12 days consisting of a seven-day adaptation period followed by a five-day total collection of urine and feces. During the collection period, pigs were fed 900 g/day for the first replicate and 1,200 g/day for the second replicate. The feed was provided in three equal portions at 0800, 1500, and 2200 h daily. Pigs had ad libitum access to water after feeding. There was a linear (p<0.01) and quadratic (p<0.01) effect on daily gain and feed conversion as the ratio of methionine to methionine plus cystine increased. Pigs receiving the diets providing a methionine to methionine plus cystine ratio of 51.6% had the best daily gain and feed conversion. Plasma urea nitrogen was also lowest for this treatment. Nitrogen retention increased (p<0.01) as the relative proportion of methionine increased up to 51.6% and then a downward trend occurred at 57.5%. The quadratic regression model, as well as one- and two- slope regression line models, were used to determine the optimum ratio of methionine to methionine plus cystine. Eliminating the 35.3% methionine to methionine plus cystine treatment resulted in $R^2$ values in excess of 0.92. The optimal ratio of methionine to methionine plus cystine was estimated to be 54.15% for nitrogen retention and 56.72% for plasma urea nitrogen.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1729-1735
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• 2004

A total of 140 weaning pigs were used to determine the effects of digestive enzyme supplementation to corn-soybean meal diets on growth performance, physiological changes of small intestine, microorganisms and pH in the gastrointestinal tract. Two kinds of enzyme complex (A, B) were used in this experiment. Pigs were allotted in a completely random design (CRD) to five replicates with four pigs per pen. Diets and water were provided for ad libitum consumption. Treatments included 1) Control: without enzyme supplementation, 2) Enzyme A 0.05%, 3) Enzyme A 0.10%, 4) Enzyme A 0.15%, 5) Enzyme B 0.05%, 6) Enzyme B 0.10%, 7) Enzyme B 0.15% in the diets. A total of 24 crossbred barrows 25.78${\pm}$0.55 kg BW fitted with simple ileal T-cannulas were used to evaluate the effect the enzyme addition on the nutrient digstibility. Pigs were allotted 4 treatments (No enzyme, enzyme A 0.05%, enzyme A 0.1%, enzyme A 0.15%), 6 replicates according to a completely random design (CRD). Another digestibility trial was followed for enzyme complex B. Twenty pigs, average 31.92${\pm}$0.37 kg BW, fitted with simple ileal T-cannulas for digestibility trial. Neither enzyme A nor enzyme B affected on fecal or ileal digestibility of dry matter, gross energy, crude protein, crude fat and crude ash (p>0.05). The apparent fecal digestibilities of all the nutrients were higher in total feces collection method than in indirect method. At the end of feeding trial, 21 pigs were slaughtered for examining the morphological changes of small intestine and the concentration of microorganisms in the ileum and the colon. Growth performance, intestinal morphology and pH of ileum and colon were not affected by the either enzyme complex supplementation (p>0.05). These results suggested that enzyme complex A and enzyme complex B were of no benefit to early-weaned pigs when corn-soybean meal based diet was provided.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1138-1143
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• 2001

A total of 96 piglets were weaned at 19 and 13 days in Exp. 1 and 2, respectively, and allotted to one of four diets: three with different spray dried plasmas (SPs) and one with hydrolysed casein (HC). SPs were from pigs (SPP), mixed origin (SMP), and mixed origin with standardized level of immunoglobulins (SMPIG). All the diets contained 1.7% total lysine, 25% of the test protein source, 45% corn starch, 15% lactose, 2% sucrose, 7% soybean oil. At d 4 and d 2 in Exp. 1 and 2, respectively, piglets were perorally challenged with $10^{10}$ CFU E. coli K88. Growth performance, immunity, and health condition were measured for 15 days and 14 days in Exp. 1 and 2, respectively. To investigate apparent ileal digestibility and nutrient deposition, all piglets were sacrificed at d 14 in Exp. 2. In 1. 3 piglets died in HC diet and 1 in SPP diet. HC diet showed higher mortality (p<0.01) than other diets. In Exp. 2, no clinical sign of infection was detected, no difference for the content of E. coli K88 was found in feces at 4 and 6 days after the infection, and no E. coli K88 was found in the jejunum at the end of experiment. In both experiments, feed intake was lower for HC diet and ADG was 96, 106, 122 and 155 for HC, SPP, SMP and SMPIG diet, respectively (HC vs others, p<0.05; SMPIG vs other SP, p<0.01). Heal apparent digestibility of nitrogen in sacrificed piglets was higher for HC diet (p<0.05). After the challenge, K88-specific titers in saliva (Exp. 1) and in plasma (Exp. 2) were reduced in SMP and SMPIG. The piglets positive to the adhesion of the used E. coli strain to the intestinal brush borders had a significantly reduced growth (p<0.01) and a higher K88-specific IgA titer in plasma, in comparison with negative ones. This effect was independent of the diet. The data show the relevance of spray dried plasma sources and particularly of SP with standardized level of immunoglobulins for the feeding of early-weaned at the risk of infection by enterotoxigenic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1598-1604
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• 2001

Eight $12.4{\pm}0.6kg$ initial body weight crossbred barrows were used to determine the effect of soybean galactooligosaccharides on nutrient and energy digestibility, and digesta transit time. Four dietary treatments were utilized in this trial. Treatment one was a corn-soybean meal based diet (SBM) containing raffinose and stachyose at the levels of 0.16% and 0.75%, respectively. Treatment two (control) was a corn-HP300 (soybean concentrate protein) diet. In treatments three and four, 1.1% and 2.2% commercial stachyose was added to the control diet to provide total dietary stachyose at the levels of 1% and 2%, respectively. The soybean galactooligosaccharides (raffinose + stachyose) level in treatment one was slightly lower compared to that in treatment three. Three collection periods were run with two pigs for each treatment/period. There was a 4 d adjustment period followed by a 3 d collection period. The results showed that the nitrogen retention (86.79%) of pigs fed treatment two diet was higher than that of pigs fed treatment one by 5.2% (p<0.05). The nitrogen retention of treatment three was intermediate 83.09%. The apparent fecal digestibility of all amino acids in treatment two was numerically highest, followed by treatments three and four. However, there were no significant difference among groups (p>0.05). The dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) digestibility numerically decreased as the soybean galactooligosaccharides level increased, but were not significantly different (p>0.05). Chromium content in feces (from the inclusion of 0.3% chromic oxide in the diets) differed among treatments (p<0.05) at 15 h, 18 h, and 21 h after eating. This showed that the digesta transit time was differed significantly among treatments. Treatment four was the shortest, followed by treatment three, SBM and control. The results demonstrated that in the absence of antinutritional factors and soybean antigen protein, inclusion of 1% and 2% stachyose in corn-HP300 diet has no significant effect on the digestibility of DM, OM, CP, CF and amino acids. When the soybean galactooligosaccharide level in diet one and diet three were adjusted to be almost the same, antinutritional factors such as trypsin inhibitor and soybean antigen protein could decrease the nutrient digestibility and nitrogen retention rate of diet. High levels of soybean galactooligosaccharides shortened the digesta transit time in the intestinal tract. This trial suggested that the total level of soybean galactooligosaccharides (stachyose+raffinose) in the weanling piglet diet is better not to exceed 1% when common soybean meal is used as main protein source.

• Journal of Animal Science and Technology
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• 제45권1호
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• pp.123-130
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• 2003

수소 육성과 비육단계에서 필요로 하는 유지에너지 요구량을 구하기 위해 체중 100kg에서 400kg까지 100kg 증체 간격(100, 200, 300, 400 kg)으로 각 9두를 이용한 3처리(에너지 급여수준) 3반복의 에너지 균형 시험을 수행하였다. 에너지 급여수준은 대사에너지(Metabolizable energy; ME)로 1) 유지에너지 수준(Maintenance, 1.0M), 2) 유지에너지의 1.5배(1.5M), 3) 유지에너지의 2배(2.0M)을 섭취 할 수 있도록 1일 사료급여량을 정하였고, 조사료와 농후사료의 비율은 40:60을 유지하였다. 이와 같은 시험 설계를 기초로 각 체중별로 국내에서 주로 이용되는 볏짚(실험 I), 목건초(실험 II), 옥수수 사일리지(실험 III)의 조사료가 다른 조건에서의 유지에너지 요구량을 구하였다. 체중별 MEm은 체중 100kg시 99.80 kcal/ MBS로 가장 높았던 반면 체중 200kg시 가장낮아 94.48 kcal/$W^{0.75}$였고, Kg의 경우 0.36-0.57의 범위에 있었다. 체중별 성적을 종합 분석한 결과, 유지를 위한 대사에너지(MEm)는 95.80kcal, 증체를 위한 대사에너지 이용효율(Kg)은 0.44로 평가되어졌다.