• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1260-1268
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• 2014

Screening of a gene library from Paenibacillus sp. PBS-2 generated in Escherichia coli led to the identification of a clone with lipolytic activity. Sequence analysis showed an open reading frame encoding a polypeptide of 378 amino acid residues with a predicted molecular mass of 42 kDa. The esterase displayed 69% and 42% identity with the putative ${\beta}$-lactamases from Paenibacillus sp. JDR-2 and Clostridium sp. BNL1100, respectively. The esterase contained a Ser-x-x-Lys motif that is conserved among all ${\beta}$-lactamases found to date. The protein PBS-2 was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at $18^{\circ}C$. The enzyme is a serine protein and was active against p-nitrophenyl esters of $C_2$, $C_4$, $C_8$, and $C_{10}$. The optimum pH and temperature for enzyme activity were pH 9.0 and $30^{\circ}C$, respectively. Relative activity of 55% remained at up to $5^{\circ}C$ with an activation energy of 5.84 kcal/mol, which indicates that the enzyme is cold-adapted. Enzyme activity was inhibited by $Cd^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ ions. As expected for a serine esterase, activity was inhibited by phenylmethylsulfonyl fluoride. The enzyme was remarkably active and stable in the presence of commercial detergents and organic solvents. This cold-adapted esterase has potential as a biocatalyst and detergent additive for use at low temperatures.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.812-815
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• 2005

This study was conducted to see the influence of additives and fermentation periods on Mott grass silage (MGS) characteristics, its chemical composition and to compare the digestion kinetics of Mott grass (MG) and MGS in Nili buffaloes. Mott grass chopped with a locally manufactured chopper was ensiled using two additives, cane molasses and crushed corn grains each at 2, 4 and 6% of forage DM for 30 and 40 days in laboratory silos. The pH, lactic acid concentration, dry matter (DM), crude protein and fiber fractions of MGS were not affected by the type or level of additive and fermentation periods. The non-significant pH lactic acid concentration, and chemical composition of MGS indicated that the both molasses and crushed corn were utilized at similar rate for the growth of lactic acid bacteria and production of organic acids. The MG ensiled with molasses at 2% of fodder DM for 30 days was screened out for in situ digestion kinetics in Nili buffaloes. Ruminal DM and neutral detergent fiber (NDF) degradabilities of MGS were significantly (p<0.05) higher than that of MG. The DM and NDF rate of degradation, lag time and extent of degradation was nonsignificant between MGS and MG. The higher ruminal degradation of DM and NDF of MGS than MG was probably a reflection of fermentation of MG during ensilation that improved its degradability by improving the availability of easily degradable structural polysaccharides to ruminal microbial population. The results in the present study have indicated that MG ensiled with either 2% molasses or 2% crushed corn for 30 days has better nutritive value for buffalo.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.783-791
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• 2019

Objective: This study was to evaluate the fermentation dynamics, structural and nonstructural carbohydrate composition and in vitro gas production of rice straw ensiled with lactic acid bacteria and molasses. Methods: Fresh rice straw was ensiled in 1-L laboratory silos with no additive control (C), Lactobacillus plantarum (L), molasses (M) and molasses+Lactobacillus plantarum (ML) for 6, 15, 30, and 60 days. After storage, the silages were subjected to microbial and chemical analyses as well as the further in vitro fermentation trial. Results: All additives increased lactic acid concentration, and reduced pH, dry matter (DM) loss and structural carbohydrate content relative to the control (p<0.05). The highest organic acid and residual sugar contents and lignocellulose reduction were observed in ML silage. L silage had the highest V-score with 88.10 followed by ML silage. L and ML silage improved in vitro DM digestibility as compared with other treatments, while in vitro neutral detergent fibre degradability (IVNDFD) was increased in M and ML silage (p<0.05). M silage significantly (p<0.05) increased propionic acid (PA) content and decreased butyric acid content and acetic acid/PA as well as 72-h cumulative gas production. Conclusion: The application of ML was effective for improving both the fermentation quality and in vitro digestibility of rice straw silage. Inclusion with molasses to rice straw could reduce in vitro ruminal gas production.

• 농업과학연구
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• 제31권1호
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• pp.15-25
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• 2004

균류발효물질의 사료가치를 평가하고 착유우 사료에 대한 발효물질 첨가가 in vitro 반추위액 발효상태 증진 효과를 규명하기 위하여 비발효(Unfermented; UF)구와 Formitella flaxinea(FF)와 Sarcodon aspratus(SA)에 의한 톱밥+소맥피 배양물 성분변화와 48시간 발효 후 소화율을 측정하고 기본유우사료 (Basal diet)에 이들 발효물을 0, 1, 3 및 5%를 첨가하여 in vitro 건물소화율, pH 및 용해성 당류의 변화 등을 규명하여 다음과 같은 결과를 얻었다. 1. 발효물의 영양소 함량변화는 Neutral detergent fiber(NDF)에서 차이가 크게 나타났는데 SA와 UF(80.4와 82.2%)가 FF(88.3%)에 비해 낮게 나타났다(P<0.05). In vitro 반추위 소화시험(48시간)에서는 SA(21.2%)가 UF와 FF(17.9 및 12.2%)보다 높게 나타났다(P<0.05). 2. 균류 첨가 사료에 대한 건물소화율을 발효 24시간에서 기본사료(44.98%)에 비하여 FF 1%(49.18%)에서 높게 나타났으며(P<0.05), 기타 균류첨가사료에서는 높게 나타나는 경향을 보였다. 그러나 발효 48 및 72시간에서는 기본사료와 첨가사료간에 유의차가 나타나지 않았다. 3. 반추위 pH는 발효 24시간 및 48시간에서 기본사료(6.64 및 6.91)에 비하여 첨가사료가 낮은 경향(5.37~6.01 및 6.04~6.07)을 보였으며 (P<0.05), 발효 72시간에서는 SA 1%(6.74)가 기본사료(6.41)에 대하여 높게 나타났으나(P<0.05) 기타 첨가구에서는 유의차가 나타나지 않았다. 4. 가용성당 함량은 발효 24시간에서는 기본사료 첨가구에서 유의차가 보이지 않았으나 48시간은 기본사료(1.44%)에 비하여 SA 5%(1.71)에서 높게 나타났고 발효72시간에서는 기본사료(1.44%)에 비하여 첨가구사료(1.64~1.74%)가 모두 높게 나타났다(P<0.05). 5. 이상의 결과로 보아 균류발효물질의 사료나 사료 첨가제로서 in vitro 반추위 소화율 증진 효과가 나타났고 가용성당함량 증가효과도 보였다. 따라서 앞으로 첨가제를 순수한 균사로만 분리 제조하면 효과가 더욱 증진될 것으로 기대되며 톱밥균류 발효물질 전체를 사료의 5%내에서 이용효과도 기대된다고 판단되었다.

• 한국초지조사료학회지
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• 제30권1호
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• pp.25-34
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• 2010

최근에 청보리 사일리지는 국내에서 가장 많이 이용하는 조사료이지만 유기축산을 위한 유기조사료의 생산과 품질에 관한 연구는 미흡한 실정이다. 따라서 본 시험은 유기 청보리 사일리지의 적정 수확시기를 구명하고, 사일리지 품질 향상을 위하여 예건과 싸라기를 첨가하여 사일리지를 평가하였다. 시험구 배치는 12처리 3반복의 분할구 배치법으로 주구는 수확시기로 출수기, 유숙기 및 황숙기를 두었으며, 세구는 무처리, 예건, 싸라기 10%, 싸라기 15%를 두었다. 수확시 건물함량은 출수기, 유숙기 및 황숙기가 각각 12.8%, 21.9% 및 29.8%로 증가하였다. 청보리의 건물수량은 출수기, 유숙기 및 황숙기가 각각 10,346, 15,819 및 18,336 kg/ha였으며, TDN 수량은 6,288, 9,550 및 10,178 kg/ha였다. 유기 사일리지의 pH는 출수기, 유숙기 및 황숙기가 각각 4.70, 4.03 및 5.37로 유숙기가 가장 낮았다. 청보리의 수확시기가 늦어짐에 따라 조단백질, 조지방, NFC 및 TDN 함량은 감소하였으나, NDF 및 ADF 함량은 증가하였다. 그러나 조회분 함량은 유숙기가 가장 낮았다. 사일리지의 예건과 싸라기의 첨가는 조회분, NDF 및 ADF 함량을 감소시키고, NFC와 TDN 함량은 증가시켰다. 사일리지의 건물소화율은 수확시기가 늦어짐에 따라 감소하였으며, 예건과 싸라기 첨가에 의하여 건물소화율이 증가하였다. 유숙기가 다른 수확시기보다 젖산과 총유기산 함량은 높고 낙산 함량이 낮아 총유기산 중 젖산함량이 가장 높았다. 예건과 싸라기 첨가에 의한 젖산 함량 증가 효과는 출수기가 다른 수확기보다 효과가 있었다. 이상의 결과를 종합해 볼 때 유기 청보리 사일리지 제조를 위한 수확적기는 유숙기 이었으며, 예건과 싸라기 첨가에 의하여 청보리 사일리지의 품질을 향상시킬 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.46-54
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• 2014

This study was conducted to investigate the effects of eucalyptus (E. Camaldulensis) crude oils (EuO) supplementation on voluntary feed intake and rumen fermentation characteristics in swamp buffaloes. Four rumen fistulated swamp buffaloes, body weight (BW) of $420{\pm}15.0$ kg, were randomly assigned according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. The dietary treatments were untreated rice straw (RS) without EuO (T1) and with EuO (T2) supplementation, and 3% urea-treated rice straw (UTRS) without EuO (T3) and with EuO (T4) supplementation. The EuO was supplemented at 2 mL/h/d in respective treatment. Experimental animals were kept in individual pens and concentrate mixture was offered at 3 g/kg BW while roughage was fed ad libitum. Total dry matter and roughage intake, and apparent digestibilites of organic matter and neutral detergent fiber were improved (p<0.01) by UTRS. There was no effect of EuO supplementation on feed intake and nutrient digestibility. Ruminal pH and temperature were not (p>0.05) affected by either roughage sources or EuO supplementation. However, buffaloes fed UTRS had higher ruminal ammonia nitrogen and blood urea nitrogen as compared with RS. Total volatile fatty acid and butyrate proportion were similar among treatments, whereas acetate was decreased and propionate molar proportion was increased by EuO supplementation. Feeding UTRS resulted in lower acetate and higher propionate concentration compared to RS. Moreover, supplementation of EuO reduced methane production especially in UTRS treatment. Protozoa populations were reduced by EuO supplementation while fungi zoospores remained the same. Total, amylolytic and cellulolytic bacterial populations were increased (p<0.01) by UTRS; However, EuO supplementation did not affect viable bacteria. Nitrogen intake and in feces were found higher in buffaloes fed UTRS. A positive nitrogen balance (absorption and retention) was in buffaloes fed UTRS. Supplementation of EuO did not affect nitrogen utilization. Both allantoin excretion and absorption and microbial nitrogen supply were increased by UTRS whereas efficiency of microbial protein synthesis was similar in all treatments. Findings of present study suggested that EuO could be used as a feed additive to modify the rumen fermentation in reducing methane production both in RS and UTRS. Feeding UTRS could improve feed intake and efficiency of rumen fermentation in swamp buffaloes. However, more research is warranted to determine the effect of EuO supplementation in production animals.

• Asian-Australasian Journal of Animal Sciences
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• 제30권3호
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• pp.392-399
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• 2017

Objective: The objectives were to assess the effects of purified lignin from wheat straw (sodium hydroxide dehydrated lignin; SHDL) on in vitro ruminal fermentation and on the growth performance of feedlot cattle. Methods: In vitro experiments were conducted by incubating a timothy-alfalfa (50:50) forage mixture (48 h) and barley grain (24 h) with 0, 0.25, 0.5, 1.0, and 2.0 mg/mL of rumen fluid (equivalent to 0, 2, 4, 8, and 16 g SHDL/kg diet). Productions of $CH_4$ and total gas, volatile fatty acids, ammonia, dry matter (DM) disappearance (DMD) and digestion of neutral detergent fiber (NDF) or starch were measured. Sixty Hereford-Angus cross weaned steer calves were individually fed a typical barley silage-barley grain based total mixed ration and supplemented with SHDL at 0, 4, 8, and 16 g/kg DM for 70 (growing), 28 (transition), and 121 d (finishing) period. Cattle were slaughtered at the end of the experiment and carcass traits were assessed. Results: With forage, SHDL linearly (p<0.001) reduced 48-h in vitro DMD from 54.9% to 39.2%, NDF disappearance from 34.1% to 18.6% and the acetate: propionate ratio from 2.56 to 2.41, but linearly (p<0.001) increased $CH_4$ production from 9.5 to 12.4 mL/100 mg DMD. With barley grain, SHDL linearly increased (p<0.001) 24-h DMD from74.6% to 84.5%, but linearly (p<0.001) reduced $CH_4$ production from 5.6 to 4.2 mL/100 mg DMD and $NH_3$ accumulation from 9.15 to $4.49{\mu}mol/mL$. Supplementation of SHDL did not affect growth, but tended (p = 0.10) to linearly reduce feed intake, and quadratically increased (p = 0.059) feed efficiency during the finishing period. Addition of SHDL also tended (p = 0.098) to linearly increase the saleable meat yield of the carcass from 52.5% to 55.7%. Conclusion: Purified lignin used as feed additive has potential to improve feed efficiency for finishing feedlot cattle and carcass quality.

• 에너지공학
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• 제26권3호
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• pp.131-136
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• 2017

자동차 엔진오일은 엔진 시동 시 가장 중요한 윤활제이다. 최근 자동차 회사 와 윤활유 제조업체들은 교환주기를 연장하기 위해 첨가제를 사용하여 오일의 품질을 상당히 개선하고 있다. 대부분의 고객은 자동차 제작사의 정품오일을 사용하거나 전문가의 추천을 받아 사용한다. 본 논문을 통해 소비자가 고효율 윤활유를 선택하는 또 다른 기준점을 제안한다. 본 논문은 7개월 동안 실제 자동차의 운전 조건을 고려하여 오일의 6가지 화합물을 조사 비교 분석하였다. 물리적, 화학적 관점에서 실험을 수행했다. 현장에서 다양한 실험을 통해 광유와 합성유 화합물은 산화, 점도, 유동성 및 TBN에서 크게 구분된다. 이들은 엔진 부품 피스톤, 베어링 등의 마모에 영향을 준다. 다양한 오일을 비교하였을 때 인화점, 산화 안정성에서 합성유의 성능이 좋고 오염 물질인 Fe와 Al 화합물의 변화가 적은 것으로 나타났다. 오일의 첨가제는 광유와 합성유에서 청정분산제 Ca가 확연한 차이를 나타냈다. 극압제 Zn과 윤활 향상제 P는 유사하였다.