• 한국토양비료학회지
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• 제48권5호
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• pp.485-491
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• 2015

This study was performed to investigate thermophilic bacteria from soil having broad antifungal spectrum against Rhizoctonia solani, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f.sp. lycopersici, and Botrytis cinerea. One isolate selected could resist heat shock of $60^{\circ}C$ for one hour, and had broad antifungal activity in dual culture assay against all tested fungal pathogens and was identified as Bacillus amyloliquefaciens Y1 using 16S rRNA gene sequence. Further investigation for antifungal activity of bacterial culture filtrate (BCF) and butanol crude extract (BCE) of various concentrations showed broad spectrum antifungal activity and fungal growth inhibition significantly increased with increasing concentration with highest growth inhibition of 100% against R. solani with 50% BCF and 11 mm of zone of inhibition against R. solani with 4 mg BCE concentration. Treatment of butanol crude extract resulted in deformation, lysis or degradation of C. gloeosporioides and P. capsici hyphae. Furthermore, B. amyloliquefaciens Y1 produced volatile compounds inhibiting growth of R. solani (70%), C. gloeosporioides (65%) and P. capsici (65-70%) when tested in volatile assay. The results from the study suggest that B. amyloliquefaciens Y1 could be a biocontrol candidate to control fungal diseases in crops.

• Animal Bioscience
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• 제37권2호
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• pp.240-252
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• 2024

Objective: The aim of this study was to investigate the impact of dietary nicotinic acid (NA) on apparent nutrient digestibility, rumen fermentation, and rumen microbiota in uncastrated Xiangzhong black cattle. Methods: Twenty-one uncastrated Xiangzhong black cattle (385.08±15.20 kg) aged 1.5 years were randomly assigned to the control group (CL, 0 mg/kg NA in concentrate diet), NA1 group (800 mg/kg NA in concentrate diet) and NA2 group (1,200 mg/kg NA in concentrate diet). All animals were fed a 60% concentrate diet and 40% dried rice straw for a 120-day feeding experiment. Results: Supplemental NA not only enhanced the apparent nutrient digestibility of acid detergent fiber (p<0.01), but also elevated the rumen acetate and total volatile fatty acid concentrations (p<0.05). 16S rRNA gene sequencing analysis of rumen microbiota revealed that dietary NA changed the diversity of rumen microbiota (p<0.05) and the abundance of bacterial taxa in the rumen. The relative abundances of eight Erysipelotrichales taxa, five Ruminococcaceae taxa, and five Sphaerochaetales taxa were decreased by dietary NA (p<0.05). However, the relative abundances of two taxa belonging to Roseburia faecis were increased by supplemental 800 mg/kg NA, and the abundances of seven Prevotella taxa, three Paraprevotellaceae taxa, three Bifidobacteriaceae taxa, and two operational taxonomic units annotated to Fibrobacter succinogenes were increased by 1,200 mg/kg NA in diets. Furthermore, the correlation analysis found significant correlations between the concentrations of volatile fatty acids in the rumen and the abundances of bacterial taxa, especially Prevotella. Conclusion: The results from this study suggest that dietary NA plays an important role in regulating apparent digestibility of acid detergent fiber, acetate, total volatile fatty acid concentrations, and the composition of rumen microbiota.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.648-658
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• 2016

Preservation of fresh algae plays an important role in algae seed subculture and aquaculture. The determination and examination of the changes of cell viability, composition, and bacterial species during storage would help to take suitable preservation methods to prolong the preservation time of fresh algae. Nostoc flagelliforme is a kind of edible cyanobacterium with important herbal and dietary values. This article investigated the changes of bacterial species and biochemical characteristics of fresh N. flagelliforme concentrate during natural storage. It was found that the viability of cells decreased along with the storage time. Fourteen bacteria strains in the algae concentrate were identified by PCR-DGGE and were grouped into four phyla, including Cyanobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. Among them, Enterococcus viikkiensis may be a concern in the preservation. Eleven volatile organic compounds were identified from N. flagelliforme cells, in which geosmin could be treated as an indicator of the freshness of N. flagelliforme. The occurrence of indole compound may be an indicator of the degradation of cells.

• 한국식품조리과학회지
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• 제21권5호
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• pp.662-668
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• 2005

To investigate the quality retention method of salted and semi-dried mackerel fillets, pH, volatile basic nitrogen (VBN), trimethylamine (TMA) and total bacterial counts in the fillets that were UV treated for 1, 3, and 4 hr were periodically measured during 48 days of refrigerated storage. The moisture, crude protein, crude lipid, and ash contents were 45.46 %, 18.87 %, 33.75 %, and 2.99 %, respectively. The freshness as determined by pH measurement could be maintained up to 25 days for the control and 31 days for the UV-treated fillets. VBN contents were continually increased over the storage time. The control reached the initial putrid level after 21 days while the UV-treated fillets after $25{\sim}31$ days. A similar tendency was shown for the changes of trimethylamine TMA contents, although the period differed slightly and the increase of the UV treatment time could decrease the TMA contents. The changes on the total bacterial counts of the fillets were maintained under 105 CFU/g during 48days. Especially, due to the effective decrease of the microorganism count by UV treatment at the beginning of the storage, UV -treated fillets showed lower bacterial counts than control over the whole period. E. coli. and Listeria were not detected in any fillets. Combining the above data and the sensory changes, the storage period of the fillets could be prolonged from 15 days at present to 30 days by UV treatments.

• 원예과학기술지
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• 제28권3호
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• pp.476-483
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• 2010

실내식물 9종의 근권부 하이드볼 배지에서 배양된 세균집단이 공기중 벤젠과 같은 휘발성 유기화합물의 제거효과에 미치는 영향이 조사되었다. 여러 식물 근권부의 배양토에서 배양된 세균 집단은 벤젠을 제거할 수 있었는데, $Spathiphyllum$ $wallisii$ Regel, $Pachira$ $aquatica$, $Ficus$ $elastica$, $Dieffenbachia$ sp. 'Marrianne' Hort., $Chamaedorea$ $elegans$ 식물들은 벤젠의 초기농도를 1.000으로 기준하였을 때, 세균 집단이 전혀 없는 배지의 대조구 초기 농도 대비 잔류율이 0.596이었으나 상기 언급한 식물들은 0.741-1.000으로서 벤젠의 농도를 현저히 감소시켰다(LSD, $P$=0.05). 이와 같은 경향은 식물의 종류에 따라 차이는 있었지만 톨루엔의 경우에도 비슷하게 나타났다. 이러한 결과를 바탕으로 $P.$ $aquatic$ 근권부의 배양토로부터 배양된 세균 집단을 $P.$ $aquatica$, $F.$ $elastica$, $S.$ $podophyllum$에 접종하였을 때 접종하지 않은 식물들에 비하여 벤젠과 톨루엔을 현저히 제거하는 효과가 나타나, 근권부의 미생물 집단을 이용하여 공기 중 휘발성 유기화합물(VOC)을 제거할 수 있음을 보여 주었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.92-102
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• 2019

Objective: To investigate changes in rumen fermentation characteristics and bacterial community by a sudden change to a high concentrate diet (HC) in Korean domestic ruminants. Methods: Major Korean domestic ruminants (each of four Hanwoo cows; $545.5{\pm}33.6kg$, Holstein cows; $516.3{\pm}42.7kg$, and Korean native goats; $19.1{\pm}1.4kg$) were used in this experiment. They were housed individually and were fed ad libitum with a same TMR (800 g/kg timothy hay and 200 g/kg concentrate mix) twice daily. After two-week feeding, only the concentrate mix was offered for one week in order to induce rapid rumen acidosis. The rumen fluid was collected from each animals twice (on week 2 and week 3) at 2 h after morning feeding using an oral stomach tube. Each collected rumen fluid was analyzed for pH, volatile fatty acid (VFA), and $NH_3-N$. In addition, differences in microbial community among ruminant species and between normal and an acidosis condition were assessed using two culture-independent 16S polymerase chain reaction (PCR)-based techniques (terminal restriction fragment length polymorphism and quantitative real-time PCR). Results: The HC decreased ruminal pH and altered relative concentrations of ruminal VFA (p<0.01). Total VFA concentration increased in Holstein cows only (p<0.01). Terminal restriction fragment length polymorphism and real-time quantitative PCR analysis using culture-independent 16S PCR-based techniques, revealed rumen bacterial diversity differed by species but not by HC (p<0.01); bacterial diversity was higher in Korean native goats than that in Holstein cows. HC changed the relative populations of rumen bacterial species. Specifically, the abundance of Fibrobacter succinogenes was decreased while Lactobacillus spp. and Megasphaera elsdenii were increased (p<0.01). Conclusion: The HC altered the relative populations, but not diversity, of the ruminal bacterial community, which differed by ruminant species.

• 식물병연구
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• 제28권1호
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• pp.1-18
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• 2022

휘발성물질은 자연에서 어디에나 존재한다. 생태학적으로 식물이나 미생물이 생산하는 휘발성물질은 식물-미생물이나 미생물-미생물간 대화에 중요한 역할을 수행한다. 정족수 인식신호는 세균과 세균 사이의 짧은 거리에서만 영향을 미치지만 휘발성물질은 20 cm 이상의 거리에서 생명체 간 신호전달이 가능하다. 이번 리뷰에서는 휘발성물질을 이용한 식물병진단과 진균, 세균, 바이러스병의 생물적방제의 최신 결과를 소개하였다. 더불어 이러한 휘발성물질을 농업에 적용하기 위한 다양한 기술들도 소개하였다. 휘발성물질의 캡슐화와 서방형 제제화 그리고 바이오나노 융합기술은 기존의 휘발성 물질 적용 한계를 넘게 해 줄 것이다. 종합하면 휘발성물질은 식물병을 효과적으로 방제할 수 있는 새로운 방법이다. 이번 리뷰를 통하여 농민들과 젊은 연구자들이 휘발성물질에 대한 이해를 높이고 향기농업으로의 전환을 앞당기는 계기가 되기를 희망한다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권4호
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• pp.495-504
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• 2017

Objective: Manipulating the fermentation to improve the performance of the ruminant has attracted the attention of both farmers and animal scientists. Propionate salt supplementation in the diet could disturb the concentration of propionate and total volatile fatty acids in the rumen. This study was conducted to evaluate the effect of calcium propionate supplementation on the ruminal bacterial community composition in finishing bulls. Methods: Eight finishing bulls were randomly assigned to control group (CONT) and calcium propionate supplementation (PROP) feeding group, with four head per group. The control group was fed normal the total mixed ration (TMR) finishing diet, and PROP group was fed TMR supplemented with 200 g/d calcium propionate. At the end of the 51-day feeding trial, all bulls were slaughtered and rumen fluid was collected from each of the animals. Results: Propionate supplementation had no influence the rumen fermentation parameters (p>0.05). Ruminal bacterial community composition was analyzed by sequencing of hypervariable V3 regions of the 16S rRNA gene. The most abundant phyla were the Firmicutes (60.68%) and Bacteroidetes (23.67%), followed by Tenericutes (4.95%) and TM7 (3.39%). The predominant genera included Succiniclasticum (9.43%), Butyrivibrio (3.74%), Ruminococcus (3.46%) and Prevotella (2.86%). Bacterial community composition in the two groups were highly similar, except the abundance of Tenericutes declined along with the calcium propionate supplementation (p = 0.0078). Conclusion: These data suggest that the ruminal bacterial community composition is nearly unchanged by propionate supplementation in finishing bulls.

• The Korean Journal of Ecology
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• 제16권3호
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• pp.275-285
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• 1993

To study allelopathic porential of naturally occurring substances emitted from Pinus koraiensis, the effects of water exrracts and volatile substances of the tree on callus induction and bacterial culture were examined. The induction and growth of callus were inversely proportional to the concentration of the extracts and of the essential oils supplemnted to Murashige and Skoog's media. However, low concentration(5μl/l) of essential oil promoted callus growth. In germiculture of several bavteria, the extracts of Pinus koraiensis markedly showed the inhibitory effects on bacterial growth. It was, therefore, confirmed that the KDICical substances of Pinus koraiensis tree clearly showed that biological toxic activity at high concentrations.

• 한국세라믹학회지
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• 제46권1호
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• pp.47-52
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• 2009

Lime paint surpassing others in execution efficiency, anti-bacterial, anti-mold and small quantity emission of VOCs(Volatile Organic Compounds) characteristics was developed using a limestone as raw materials. The lime paint prepared by mixing slaked lime($37{\sim}40\;wt%$), PVA:EVA(9 wt%:1 wt%), talc(23 wt%), $TiO_2$(14 wt%), zeolite (3 wt%), antifoaming agent(5 wt%), wetting agent (5 wt%) was indicated over 99.8% of anti-bacterial and anti-mold characteristics. Also, the environment-friendly function of the lime paint was confirmed by detection of small amount of TVOCs($0.01\;mg/m^2h$) and formaldehyde($0.008\;mg/m^2h$). Execution efficiency, economy-and environment-friendly characteristics of this lime paint can make up for defects of established paints. And, it also presents the advantage of a limestone as high value added materials.