• Journal of Animal Science and Technology
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• 제45권4호
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• pp.537-542
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• 2003

개시시 체중 7.63, 0.41kg, 3원 교잡종 이유자돈(25일령) 60두를 공시하여, 이유자돈 사료내 재조합 인간 락토페리신 컬처(RHLC ; recombinant human lactoferricin culture)의 급여가 성장, 영양소 소화율 및 혈장내 면역글로블린 G 농도에 미치는 영향을 평가하기 위하여 20일간 사양시험을 실시하였다. 시험설계는 1) 항생제 무첨가구(NC), 2) 항생제 첨가구(PC; NC 사료 + 0.1% chlortetracycline), 3) 항생제 무첨가구 사료에 RHLC를 0.3% 첨가한 처리구 (RHLC0.3; NC 사료 + 0.3% RHLC), 4) 항생제 무첨가구 사료에 RHLC를 0.5% 첨가한 처리구 (RHLC0.5; NC 사료 + 0.5% RHLC)로 4개 처리로 하였다. 총 사양시험 기간동안, 일당증체량에 있어서는 항생제 첨가구와 비교하여 RHLC의 첨가수준이 증가함에 따라 높아지는 경향을 보였으나, 표준오차가 크기 때문에 유의적인 차이는 보이지 않았다. 일당사료섭취량에 있어서는 PC 처리구와 비교하여 RHLC0.3 처리구가 유의적으로 높았으며(P<0.05), 사료효율에 있어서는 PC 처리구와 비교하여 RHLC0.5 처리구가 가장 좋은 것으로 나타났다(P<0.05). 영양소 소화율에 있어서는 NC 처리구와 비교하여 PC, RHLC0.3 및 RHLC0.5 처리구가 유의적으로 높게 평가되었으며(P<0.05), 혈장내 면역글로블린 G 농도는 처리구간에 유의적인 차이를 보이지 않았다. 결론적으로, 이유자돈에 있어 재조합 인간 락토페린신 컬처가 항생제를 대체할 가능성이 있는 것으로 사료된다.

• 식물병과 농업
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• 제5권2호
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• pp.95-99
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• 1999

Chemical control of bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae was attempted by spraying of streptomycin sulfate ·oxytetracycline WP streptomycin WP streptomycin ·copper hydroxide WP kasugamycin SL kasugamycin·copper oxychloride WP and copper hydroxide WP. The control efficacies of the bactericides were variable depending upon the spraying schedule,. Application of streptomycin WP and streptomycin sulfate·oxytetracycline WP from middle April to early May was found to be the most effective in controlling the bacterial canker. For copper hydroxide WP the spraying from middle January to early February showed the highest control efficacy. Kasugamycin SL was the most effective in controlling the disease by spraying from middle April to early May but it was still relatibvely effective during other spray periods. Foliar application of copper hydroxide WP and copper-antibiotic formulaions after middle April caused severe phytotoxicity. Kasgamycil SL streptomycin WP streptomycin·copper hydroxide WP and copper hydroxide WP were potential bactericides which could substitute streptomycin sulfate·oxytetracycline WP. Selective applications of the bactericides according to their optimum spray time can enhance the control efficacies against bacterial canker of kiwifruit and retard the emergency of resistant strains of P. syringae pv. actinidiae to the bactericides. The optimum spray number of streptomycin sulfate·oxytetracycline WP was 3 times with 15-day-intervals or 4 times with 10-day-intervals. The result suggested that the potential bactericides to bacterial canker of kiwifruit should be also used according to their optimum spray schedules in order to get their highest control efficacies.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.803-811
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• 2014

Concerns over drug-resistant bacteria have stimulated interest in developing alternative methods to control bacterial infections. Endolysin, a phage-encoded enzyme that breaks down bacterial peptidoglycan at the terminal stage of the phage reproduction cycle, is reported to be effective for the control of bacterial pathogenic bacteria. Bioinformatic analysis of the SPN9CC bacteriophage genome revealed a gene that encodes an endolysin with a domain structure similar to those of the endolysins produced by the P1 and P22 coliphages. The SPN9CC endolysin was purified with a C-terminal oligo-histidine tag. The endolysin was relatively stable and active over a broad temperature range (from $24^{\circ}C$ to $65^{\circ}C$). It showed maximal activity at $50^{\circ}C$, and its optimum pH range was from pH 7.5 to 8.5. The SPN9CC endolysin showed antimicrobial activity against only gram-negative bacteria and functioned by cutting the glycosidic bond of peptidoglycan. Interestingly, the SPN9CC endolysin could lyse intact gram-negative bacteria in the absence of EDTA as an outer membrane permeabilizer. The exogenous lytic activity of the SPN9CC endolysin makes it a potential therapeutic agent against gram-negative bacteria.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.697-706
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• 2018

Lactobacillus pentosus K1-23 was selected from among 25 lactic acid bacterial strains owing to its high inhibitory activity against several pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, S. gallinarum, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridium perfringens, and Listeria monocytogenes. Additionally, among 13 strains of Aureobasidium spp., A. pullulans NRRL 58012 was shown to produce the highest amount of ${\beta}$-glucan ($15.45{\pm}0.07%$) and was selected. Next, the optimal conditions for a solid-phase mixed culture with these two different microorganisms (one bacterium and one yeast) were determined. The optimal inoculum sizes for L. pentosus and A. pullulans were 1% and 5%, respectively. The appropriate inoculation time for L. pentosus K1-23 was 3 days after the inoculation of A. pullulans to initiate fermentation. The addition of 0.5% corn steep powder and 0.1% $FeSO_4$ to the basal medium resulted in the increased production of lactic acid bacterial cells and ${\beta}$-glucan. The following optimal conditions for solid-phase mixed culture were also statistically determined by using the response surface method: $37.84^{\circ}C$, pH 5.25, moisture content of 60.82%, and culture time of 6.08 days for L. pentosus; and $24.11^{\circ}C$, pH 5.65, moisture content of 60.08%, and culture time of 5.71 days for A. pullulans. Using the predicted optimal conditions, the experimental production values of L. pentosus cells and ${\beta}$-glucan were $3.15{\pm}0.10{\times}10^8CFU/g$ and $13.41{\pm}0.04%$, respectively. This mixed culture may function as a highly efficient antibiotic substitute based on the combined action of its anti-pathogenic bacterial and immune-enhancing activities.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.848-854
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• 2005

We examined the effect of dietary Turkish propolis and flavomycin on growth performance, carcass characteristics, internal organ weights and some serum variables in quail (Coturnix coturnix japonica) birds. One hundred and fifty day-old quails were randomly divided into five groups, with ten replicate pens per treatment and three birds per pen. One group received the basal diet (antibiotic-free), the control. The flavomycin at 10 mg/kg diet and propolis at 0.5, 1 and 1.5 g/kg diet were added to the basal diet. Body weight gain, feed consumption and feed efficiency were determinated weekly. Carcass characteristics, internal organ weights and serum variables were determinated at the end of the study (35 day). The results showed that body weight gain, feed efficiency and carcass weight were improved significantly (p<0.01) when compared to control group for birds fed diets containing propolis and flavomycin between 14 to 35 days. The addition of 1 g/kg propolis to the diet resulted in significantly (p<0.01) better-feed efficiency as compared to control and other treatment groups. There were no significant differences in carcass yield, abdominal fat, liver gizzard, proventriculus and intestinal weight and intestinal pH among the groups. In addition, serum ALP, total protein, uric acid, cholesterol and triglyceride were not influenced by the any supplementation. However, birds fed with propolis tended to have higher serum HDL and lower level than birds fed the control diet. In conclusion, supplementation of propolis and flavomycin during the growth period showed similar effects on growth performance in quail. Therefore, it can serve as a natiral substitute for antibiotics in poultry diets.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1677-1684
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• 2018

Objective: To find biological functions such as antibacterial and antioxidant activities in several tropical plants and to investigate the possibility of antibiotic substitute agents to prevent and treat diseases caused by pathogenic bacteria. Methods: Plants such as Poncirus trifoliata fruit (Makrut), Zingiber officinale Rosc (Khing), Areca catechu L. (Mak), Solanum melongena L. I (Makkhuayao), and Solanum melongena L. II (Makhurapro) were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. The free radical scavenging activities were measured using 2-diphenyl-2-picryl hydrazyl photometric assay. Antibacterial activities with a minimum inhibitory concentration (MIC) were observed by agar diffusion assay against pathogenic strains of Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, Clostridium perfringens, and Pantoea agglomerans. Results: Poncirus trifoliata fruit methanol extract showed antibacterial activities against gram-negative and gram-positive pathogens. Additionally, this showed the strongest antibacterial activity against Burkholderia sp. and Haemopilus somnus with MIC $131{\mu}g/mL$, respectively. Areca catechu L. water extract showed antibacterial activities against Burkholderia sp., Haemopilus somnus, and Haemopilus parasuis. The MIC value for Haemopilus parasuis was $105{\mu}g/mL$ in this. Antioxidant activity of Zingiber officinale Rosc n-hexane extract showed 2.23 mg/mL effective concentration 50% ($EC_{50}$) value was the highest activity among tropical plants extracts. Total polyphenol content in Zingiber officinale Rosc methanol extract was $48.4{\mu}g/mL$ and flavonoid content was $22.1{\mu}g/mL$ showed the highest values among tested plants extracts. Conclusion: Taken together, these results suggest that tropical plants used in this study may have a potential benefit as an alternative antibiotics agent through their antibacterial and antioxidant activities.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.93-100
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• 2014

The banning of the use of antibiotics as feed additive has accelerated investigations of alternative feed additives in animal production. This experiment investigated the effect of pure citric acid or acidifier blend supplementation as substitute for antibiotic growth promoters on growth performance, fecal microbial count, and humoral immunity in weaned piglets challenged with Salmonella enterica serover Typhimurium and Escherichia coli KCTC 2571. A total of 60 newly weaned piglets (crossbred, 28-d-old; average 8 kg initial weight) were randomly assigned to four dietary treatments in a completely randomized design. Dietary treatments included NC (negative control; basal diet), PC (positive control; basal diet+0.002% apramycin), T1 (basal diet+0.5% pure citric acid), and T2 (basal diet+0.4% acidifier blend). All piglets were orally challenged with 5 mL of culture fluid containing $2.3{\times}10^8$ cfu/mL of E. coli KCTC 2571 and $5.9{\times}10^8$ cfu/mL of S. typhimurium at the beginning of the experiment. The PC group showed the highest ADG and ADFI, whereas gain:feed was improved in the PC and T1 group (p<0.05). All dietary treatments showed significant reduction in fecal counts of Salmonella and E. coli, compared to NC (p<0.05), with PC being better than T1 and T2. Significant elevation in fecal Lactobacillus spp. counts was shown by treatments with T1, T2, and PC, whereas Bacillus spp. counts were increased by treatment with T1 and T2 compared to NC and PC diet (p<0.05). Serum IgG concentration was increased by T1 diet (p<0.05), whereas IgM and IgA were not significantly affected by any of the dietary treatments (p>0.05). From these above results, it can be concluded that, as alternatives to antibiotics dietary acidification with pure citric acid or acidifiers blend did not fully ameliorate the negative effects of microbial challenges in respect of growth performance and microbial environment, however improved immunity suggested further research with different dose levels.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1202-1208
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• 2009

Synbiotics is the term used for a mixture of probiotics (live microbial feed additives that beneficially affects the host animal) and prebiotics (non-digestible food ingredients that beneficially affect the organism). This study investigated the effect of probiotics from anaerobic microflora with prebiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in weaning pigs. 150 pigs with an initial BW of 6.80${\pm}$0.32 kg (20 d of age) were randomly assigned to 5 dietary treatments as follows: i) US, basal diet+0.15% antibiotics (0.05% oxytetracycline 200 and 0.10% tiamulin 38 g), ii) BS, basal diet+0.2% synbiotics (probiotics from bacteria), iii) YS, basal diet+0.2% synbiotics (probiotics from yeast), iv) MS, basal diet+0.2% synbiotics (probiotics from mold), v) CS, basal diet+0.2% synbiotics (from compounds of bacteria, yeast and mold). The probiotics were contained in $10^{9}$ cfu/ml, $10^{5}$ cfu/ml and $10^{3}$ tfu/ml of bacteria, yeast and molds, respectively. The same prebiotics (mannan oligosaccharide, lactose, sodium acetate and ammonium citrate) was used for all the synbiotics. Pigs were housed individually for a 16-day experimental period. Growth performance showed no significant difference between antibiotic treatments and synbiotics-added treatments. The BS treatment showed higher (p<0.05) dry matter (DM) and nitrogen digestibility while ether extract and crude fiber digestibility were not affected by the dietary treatment. Also, the BS treatment decreased (p<0.05) fecal ammonia and amine gas emissions. Hydrogen sulfide concentration was also decreased (p<0.05) in BS, YS and MS treatments compared to other treatments. Moreover, all the synbioticsadded treatments increased fecal acetic acid concentration while the CS treatment had lower propionic acid concentration than the US treatment (p<0.05) gas emissions but decreased in fecal propionate gas emissions. Total fecal bacteria and Escherichia coli populations did not differ significantly among the treatments, while the Shigella counts were decreased (p<0.05) in synbiotics-included treatment. Fecal bacteria population was higher in the YS treatment than other treatments (p<0.05). The BS treatment had higher yeast concentration than YS, MS and CS treatments, while US treatment had higher mold concentrations than MS treatment (p<0.05). Therefore, the results of the present study suggest that synbiotics are as effective as antibiotics on growth performance, nutrient digestibility and fecal microflora composition in weaning pigs. Additionally, synbiotics from anaerobic microflora can decrease fecal noxious gas emission and synbiotics can substitute for antibiotics in weaning pigs.

• 생명과학회지
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• 제25권11호
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• pp.1319-1323
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• 2015

매년 어류 양식의 생산량은 증대되고 있으며, 생산량 증가를 위한 고밀도 사육은 수질 악화 및 어류들의 스트레스를 증가시켜 질병들이 잦아지게 된다. 이로 인한 경제적 피해는 어류 양식 어민들에게 있어 막대한 피해를 입게 되며, 이를 예방하기 위해 화학 요법인 항생제를 투여하게 된다. 본 연구에서는 항생제 대체 물질 및 안전 요법으로 알려진 프로바이오틱스를 분리하기 위해, 한국전통식품인 고추 장아찌와 갈치 젓갈에서 다양한 세균을 분리하였다. 분리 된 균주들은 16S rDNA 염기서열을 분석 및 동정하고, 상층액 및 균체로 나뉘어 항균 활성을 측정하였다. 고추 장아찌에서 분리된 4종과 갈치 젓갈에서 분리된 7종은 상층액 보다 균체에서 항균 활성이 높게 나타나는 것을 확인할 수 있었다. 그 중 JKM-2는 43 mm(S. iniae), 40 mm(S. parauberis), 35 mm(S. mutans), 26.5 mm(V. vuinificus)로 가장 높은 항균 활성을 나타냈다. 본 균주의 염기서열 분석 결과, Bacillus subtilis 97.71%, Bacillus tequilensis 97.71%, Brevibacterium halotolerans 97.71%, Bacilus subtils 97.63%, Bacillus subtlis 97.63%, Bacillus mojavensis 97.54%, Bacillus vallismortis 97.46%, Bacillus nanillea 97.45%, Bacillu smethylotrophicus 97.37%, Bacillu ssiamensis 97.37%로 분석되었다. 추후 JKM-3의 신종 균주 확인과 균체 물질 규명 및 분석을 통하여 충분한 안정성을 확보하고 양식 산업에 적용시켜 항생제 대체 물질로서의 이용가치를 확인하고자 한다.

• Journal of Animal Science and Technology
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• 제45권3호
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• pp.355-368
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• 2003

시험 1은 게르마늄흑운모를 자돈 사료에 첨가하였을 때 자돈의 성장 및 영양소 소화율에 미치는 영향을 평가하고자 실시하였다. 공시동물은 평균 체중 15.09$\pm$0.18kg의 3원 교잡종 자돈 60두를 공시하여 28일간 실시하였다. 시험설계는 기초사료에 게르마늄흑운모 무첨가구 (CON; basal diet), 기초사료에 게르마늄흑운모 0.1%(GB0.1), 0.3%(GB0.3), 0.6%(GB0.6), 1.0% (GB1.0) 첨가구로 5개 처리로 하였다. 전체 사양시험 기간동안, 일당증체량과 사료효율에 있어서는 처리구간에 유의적인 차이를 보이지 않았다. 시험 2는 육성돈 사료내 게르마늄흑운모의 항생제 대체효과를 평가하기 위하여 실시하였다. 공시동물은 평균 체중이 32.47$\pm$0.90kg인 3원 교잡종 육성돈 54두를 공시하여 35일간 실시하였다. 시험설계는 기초사료에 항생제 무첨가구(NC; basal diet), 항생제 첨가구 (PC; basal diet + 200ppm CTC), 게르마늄흑운모를 0.3% 첨가구(GB0.3; basal diet + 0.3% germanium biotite)의 3개 처리로 하였다. 사양시험 기간동안, 일당증체량에 있어서 NC 처리구와 비교하였을 때 PC 처리구와 GB0.3 처리구의 성장율이 각각 17%(385 vs 451, g/d), 14% (385 vs 438, g/d) 높았다(P<0.05). 일당사료섭취량에 있어서 NC 처리구와 비교하여 PC 처리구와 GB0.3 처리구가 유의적으로 높았다(P<0.05). 사료효율에 있어서도 NC 처리구와 비교하여 GB0.3 처리구가 유의적으로 높았다(0.323 vs 0.332)(P<0.05). 외관상 건물과 질소 소화율에 있어서 NC 처리구와 비교하여 PC 처리구와 GB0.3 처리구가 유의적으로 높았다 (P<0.05). 시험 3은 비육돈 사료내 게르마늄흑운모의 첨가가 성장, 영양소 소화율, 혈장 성상, 등지방 두께 그리고 분내 암모니아 가스 농도에 미치는 영향을 평가하기 위하여 실시하였다. 공시동물은 평균 체중이 78.65$\pm$1.32kg인 비육돈 72두를 공시하였다. 시험설계는 기초사료에 게르마늄흑운모 무첨가구 (CON; basal diet), 기초사료에 게르마늄흑운모 1.0% (GB1.0), 3.0% (GB 3.0) 첨가구로 3개 처리로 하였다. 사양시험 기간동안, 일당증체량에서는 GB1.0 처리구가 대조구와 GB3.0 처리구와 비교하여 유의적으로 높았으며 (P<0.05), 일당사료섭취량에 있어서는 대조구가 GB3.0보다 유의적으로 높았다 (P< 0.05). 사료효율에 있어서는 GB 첨가구가 대조구와 비교하여 유의적으로 높게 조사되었다 (P<0.05). 혈장내 Total-cholesterol 함량 변화는 대조구와 비교하여 게르마늄흑운모 첨가구가 유의적으로 감소하였다(P<0.05). 또한, LDL+ VLDL-cholesterol 함량 변화도 대조구와 비교하여 게르마늄흑운모 첨가구가 유의적으로 감소하였다(P<0.05). 혈장내 HDL-cholesterol 함량에 있어서는 대조구와 비교하여 게르마늄흑운모 첨가구가 유의적으로 증가하였다(P<0.05). 등지방 두께에 있어서는 대조구와 비교하여 GB1.0 처리구가 5.4% (27.19 vs 25.71mm)의 감소를 보였고, GB3.0 처리구가 대조구와 비교하여 16.1% (27.19 vs 22.81mm)로 유의적인 감소하였다 (P<0.05). 게르마늄흑운모의 분내 암모니아 가스 농도에 미치는 영향에 있어서는, 대조구와 비교하여 GB1.0 처리구가 64.1% (17.00 vs 6.10mg/kg), GB3.0 처리구가 61.8% (17.00 vs 6.50mg/kg) 유의적으로 감소하였다 (P<0.05). 결론적으로, 양돈사료내 게르마늄흑운모를 첨가하였을 경우, 자돈에 있어서는 성장에 영향을 미치지 않는 것으로 사료되며, 육성돈에 있어서는 항생제 대체효과를 갖는 것으로 나타난다. 또한, 비육돈 사료내 게르마늄흑운모의 첨가는 비육돈의 성장능력을 향상시키는 것으로 판단되며, 혈중 Total‐및 LDL+VLDL-chole- sterol 함량을 감소시키며, HDL-cholesterol 함량을 증가시키는 것으로 판단된다. 또한 등지방 두께가 감소되며, 분내 암모니아 가스 농도가 감소하는 것으로 나타났다.