• Journal of Species Research
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• 제7권2호
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• pp.114-122
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• 2018

As part of a larger study of indigenous prokaryotic species diversity in South Korea, various samples from Namhangang were subjected to analyses. Fresh water, underwater sediment, and moss-inhabiting aerobic and anaerobic bacteria were isolated. 22 of the isolates were identified as unrecorded bacterial species in Korea that had ${\geq}98.7%$ 16S rRNA gene sequence similarity with published species. The aerobic strains isolated were Kurthia gibsonii and Massilia plicata. Also identified were four facultative anaerobic strains: Bacillus hisashii, Enterococcus rotai, Paenibacillus vini, and Pediococcus pentosaceus. 16 strictly anaerobic strains were identified as Bacteroides xylanolyticus, Carnobacterium maltaromaticum, Clostridium argentinense, Clostridium beijerinckii, Clostridium butyricum, Clostridium cavendishii, Clostridium diolis, Clostridium frigidicarnis, Clostridium perfringens, Clostridium saccharoperbutylacetonicum, Clostridium sphenoides, Clostridium subterminale, Cutibacterium acnes, Paraclostridium bifermentans, Prevotella paludivivens, and Romboutsia lituseburensis. Based on the examination of morphological, cultural, physiological, and biochemical properties of the isolates, descriptive information of these previously unrecorded species is provided here.

• Journal of Ginseng Research
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• 제36권1호
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• pp.1-15
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• 2012

The major commercial ginsengs are Panax ginseng Meyer (Korean ginseng), P. quinquifolium L. (American ginseng), and P. notoginseng (Burk.) FH Chen (Notoginseng). P. ginseng is the most commonly used as an adaptogenic agent and has been shown to enhance physical performance, promote vitality, increase resistance to stress and aging, and have immunomodulatory activity. These ginsengs contain saponins, which can be classified as dammarane-type, ocotillol-type and oleanane-type oligoglycosides, and polysaccharides as main constituents. Dammarane ginsenosides are transformed into compounds such as the ginsenosides $Rg_3$, $Rg_5$, and $Rk_1$ by steaming and heating and are metabolized into metabolites such as compound K, ginsenoside $Rh_1$, proto- and panaxatriol by intestinal microflora. These metabolites are nonpolar, pharmacologically active and easily absorbed from the gastrointestinal tract. However, the activities metabolizing these constituents into bioactive compounds differ significantly among individuals because all individuals possess characteristic indigenous strains of intestinal bacteria. To overcome this difference, ginsengs fermented with enzymes or microbes have been developed.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.585-594
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• 2018

Objective: This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus. Methods: L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control) samples were monitored at $4^{\circ}C$ for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results: The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05). Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus-inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae, Pseudomonas spp. and B. thermosphacta during later storage (p<0.05), with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05). Conclusion: Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef.

• 한국식품조리과학회지
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• 제4권2호
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• pp.39-50
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• 1988

가정용 통배추김치와 동치미를 시료로 하여, 김치 발효의 최적기에 관여하는주요 유산균종을 분리, 동정한 후 그들 유산균에 대한 소금과 식품보존료(Sorbic acid, P-hydroxybutly benzoate, p-hydroxypropyl benzoate, Sorbic acid와 P-hydroxybutyl benzoate병용)에 대한 영향을 검토한 결과는 다음과 같다. 1. 배추김치와 동치미에서 분리·동정된 유산균은 Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus brevis, Streptococcus faecalis Pediococcus pentosaceus였다. 2. 유산균 생육과 식염과의 관계는 무염에서 보다는 소금 0.5∼2.0%에서 생장이 더 잘 되었다. 3. 유산균의 산생성능은 Lactobacillus plantarum이 산의 생성을 가장 많이 했다. 소금농도에 따른 유산균의 산생성능은 Leuconostoc mesenteroides는 소금 함량이 낮을수록 산을 많이 생성했고, 그 외 모든 균은 소금 0.5%∼2.0%에서 산의 생성량이 많았다. 4. 유산균에 대한 보존료의 영향을 Sorbic acid 0.05% 및, 1%의 단용과 Sorbic acid 0.05%와 POBB 0.004% 병용이 보존효과가 크게 나타났고, POPB 0.01% 가 가장 효과가 작았다. 소금이 첨가되면 보존효과가 더 좋게 나타났다. Lactobacillus plantarum이 모든 보존료에 대해 가장 영향을 적게 받았고, Leuconostoc mesenteroides가 가장 영향을 많이 받았다. 5. 이상의 결과에서 효과가 큰 보존료 Sorbic acid 0.05%∼l% 및 Sorbic acid 0.05%와 POBB 0.004%의 혼합물을 넣고, 김치를 숙성시키면. 여름철 김치의 산패를 다소 억제시켜서 저장 기간을 지연시킬 수 있으리라 기대된다.

• 대한수의학회지
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• 제52권4호
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• pp.231-238
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• 2012

The expression profiles of inflammatory cytokines viz. interleukins (IL)-6, IL-8, IL-12, granulocyte macrophage-colony stimulating factor, interferon-${\gamma}$ and tumor necrosis factor-${\alpha}$ in response to subclinical mastitis in indigenous cattle breed Kankrej (n = 6), Gir (Bos indicus) (n = 12) and crossbred (Bos taurus${\times}$Bos indicus) (n = 7) were investigated using quantitative real time PCR. Significant correlation (p < 0.05) was observed between total bacterial load and somatic cell count (SCC) in all three breeds of cattle. All the cytokines were observed to be up-regulated compared to cows with healthy quarters, however, level of their expression varied among three breeds of cattle. In Kankrej most cytokines were found to be transcribed to higher levels than in other two breeds; the milk had higher load of bacteria but not so high SCC, implying that Kankrej has a higher inherent resistance against mastitis. The results of present study indicated that mammary glands of crossbred cattle are more sensitive to bacterial infection than indigenous breed of cattle as they elicit immune response at lower bacterial load and result into higher SCC. Research on identification of factors responsible for differentially expressed cytokines profiles and use of cytokines as immunomodulatory tools can pave way for formulating control strategies against bovine mastitis.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.918-929
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• 2015

Microbial enhanced oil recovery (MEOR) is being used more widely, and the biological contributions involved in MEOR need to be identified and quantified for the improvement of field applications. Owing to the excellent interfacial activity and the wide distribution of producing strains in oil reservoirs, lipopeptides have proved to be an essential part of the complex mechanisms in MEOR. In this study, crude lipopeptides were produced by a strain isolated from an indigenous community in an oil reservoir. It was found that crude lipopeptides can effectively reduce the IFT (interfacial tension) to 10^-1~10^-2 mN/m under high salinity without forming stable emulsions, and the wettability of natural sandstone can be enhanced (Amott index, from 0.36 to 0.48). The results of core flooding experiments indicate that an additional 5.2% of original oil in place can be recovered with a 9.5% reduction of injection pressure. After the shut-in period, the wettability of the core, the reduction of injection pressure, and the oil recovery can be improved to 0.63, 16.2% and 9.6%, respectively. In the microscopic flooding experiments, the crude oil in membrane, cluster, and throat states contribute nearly 90% in total of the additional oil recovery, and the recovery of membranestate oil was significantly enhanced by 93.3% after shut in. Based on the results in macro and pore scale, the IFT reduction and the wettability alteration are considered primary contributors to oil recovery, while the latter was more dominant after one shut-in period.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.376-383
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• 2005

Alcaligenes sp. JMP228 carrying 2,4­dichlorophenoxyacetic acid (2,4-D) degradative plasmid pJP4 was inoculated into natural soil, and transfer of the plasmid pJP4 to indigenous soil bacteria was investigated with and without 2,4-D amendment. Plasmid pJP4 transfer was enhanced in the soils treated with 2,4-D, compared to the soils not amended with 2,4-D. Several different transconjugants were isolated from the soils treated with 2,4-D, while no indigenous transconjugants were obtained from the unamended soils. Inoculation of the soils with both the donor Alcaligenes sp. JMP228/pJP4 and a recipient Burkholderia cepacia DBO 1 produced less diverse transconjugants than the soils inoculated with the donor alone. Repetitive extragenic palindromic-polymerase chain reaction (REP-PCR) analysis of the transconjugants exhibited seven distinct genomic DNA fingerprints. Analysis of 16S rDNA sequences indicated that the transconjugants were related to members of the genera Burkholderia and Pandoraea. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that inoculation of the donor caused clear changes in the bacterial community structure of the 2,4-D­amended soils. The new 16S rRNA gene bands in the DGGE profile corresponded with the 16S rRNA genes of 2,4-D­degrading transconjugants isolated from the soil. The results indicate that introduction of the 2,4-D degradative plasmid as Alcaligenes sp. JMP228/pJP4 has a substantial impact on the bacterial community structure in the 2,4-D-amended soil.

• Membrane and Water Treatment
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• 제9권4호
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• pp.279-284
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• 2018

Membrane biofouling is a critical operational problem that hinders the rapid commercialization of MBRs. Quorum quenching (QQ) has been investigated widely to control membrane biofouling and is accepted as a promising anti-fouling strategy. Various QQ strategies based on bacterial and enzymatic agents have been identified and applied successfully. Whereas, this study aimed to compare indigenously isolated QQ strain i.e., Enterobacter cloaca with well reported Rhodococcus sp. BH4. Both bacterial species were immobilized in polymeric beads and introduced to two different MBRs keeping the overall beads to volume ratio as 1%. Efficiencies of these strains were monitored in terms of prolonging the membrane filtration cycle of MBR, release of extra-cellular polymeric substances, membrane resistivity measurements and mineralization of signal molecules and permeate quality. Indigenous strain (Enterobacter cloaca) was added to $QQ-MBR_E$ while Rhodococcus sp. BH4 was introduced to $QQ-MBR_R$. QQ bacterial embedded beads showed enhanced filtration cycles up to 1.4 and 2.3 times for $QQ-MBR_E$ and $QQ-MBR_R$ respectively as compared to control MBR (C-MBR). Soluble EPS concentration of 52 mg/L was observed in C-MBR while significantly lower EPS concentration of 20 and 10 mg/L was witnessed in $QQ-MBR_E$ and $QQ-MBR_R$, respectively. Therefore, substantial reduction in biofouling showed the effectiveness of indigenous strain.

• 대한환경공학회지
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• 제28권7호
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• pp.757-763
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• 2006

본 연구에서는 BTEX로 오염된 저질로부터 순수 분리한 BTEX를 탄소원으로 $NO_3$-N를 전자수용체로 이용하는 미생물의 오염토양에 대한 현장 적용 가능성을 평가하였다. 이와 함께 주입한 순수 분리 미생물과 토착 미생물과의 상호 관계를 관찰하기 위하여 시간 경과에 따른 오염된 토양에서의 미생물 군집 변화도 관찰하였다. 이를 위해 BTEX로 오염 가능성이 적은 지역으로부터 채취한 토양 시료 100 g에 benzene, toluene, ethylbenzene, o-xylene을 각각 일정량 주입한 후, 동정 분리한 Pseudomonas stutzeri strain 15(DQ 202712):Klebsiella sp. strain 20(DQ 202715):Citrobacter sp. strain A(DQ 202713)를 2;1:1의 비율로 주입하여 BTEX 분해 효율과 미생물 군집 변화를 관찰하였다. 실험결과, $NO_3$-N와 BTEX가 모두 존재하는 조건에서 동정 분리한 미생물에 의한 분해 효율이 가장 높게 관찰되었다. 그리고 PCR-DGGE를 통한 미생물 군집 변화 관찰 결과, 토양 내 존재하는 다양한 미생물들의 peak는 대부분 감소된 반면, 주입한 동정분리 미생물 peak는 증가되는 것을 관찰할 수 있었다. 그러나 주입한 미생물 3종 가운데 Pseudomona stutzeri만이 우점화 된 결과가 관찰되었다.

• 자원환경지질
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• 제42권5호
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• pp.435-444
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• 2009

토양 입자 표면에 형성한 토착 미생물 바이오필름에 의하여 중금속을 흡착하므로써 하부 생태계로 이동하지 않고 원위치에 고정화하는 실험을 수행하였다. 토양으로 충진한 컬럼에 초산염, 유산염, 포도당 등의 탄소원을 10일간 공급함으로써 토양에 바이오필름을 형성하였다. 바이오필름 형성 기간 중, 초산염, 유산염, 포도당을 공급한 컬럼의 유출 수량은 탈이온수를 공급한 컬럼의 유출수량에 비하여 각각 98.5%, 97.3%, 94.7%인 것으로 나타났다. 이러한 유출수량의 감소는 형성된 바이오필름에 의한 토양 공극 폐색에 의한 것으로 판단된다. 바이오필름이 형성된 토양 컬럼에 Cd, Cr(VI), Cu, Pb, Zn 용액을 주입하며 시간에 따라 유출수를 채집, 중금속을 정량하였다. 바이오필름 컬럼을 통과하여 나온 유출수 중 Cd, Cr(VI), Cu, Zn 농도는 탈이온수 컬럼에 비하여 낮았으며, 이는 토양 입자에 비하여 바이오필름에 의한 이들 중금속 흡착 효율이 높기 때문인 것으로 여겨진다. 바이오필름에 의한 중금속 제거 효율은 토착 미생물에 공급한 탄소원의 종류에 따라 다르게 나타났다. 이러한 연구 결과는 중금속으로 오염된 토양 내에 중금속을 원위치 고정화하는 기술 개발에 유용하게 적용될 수 있을 것으로 기대한다.