• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.713-725
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• 2018

Lower termites require symbiotic microbes in their gut. The microbial communities in the termites must adapt to the termite temperature. Reticulitermes speratus KMT001 from Bukhan Mountain in Seoul may require a special symbiotic microorganisms for growth in low temperature Korean habitat. A metagenomics analysis showed a dramatic change in the symbiotic bacterial flora in the gut of R. speratus KMT001 in response to low temperatures of $4^{\circ}C$ or $10^{\circ}C$. Elusimicrobia, which are endosymbionts of flagellate protists, is the dominant phylum in the termite gut at ${\geq}15^{\circ}C$ but its population decreased drastically at low temperature. Four representative bacterial strains isolated from R. speratus KMT001 in a previous study produced maximum ${\beta}$-glucosidase levels within the temperature range of $10^{\circ}C-30^{\circ}C$. Elizabethkingia sp. BM10 produced ${\beta}$-glucosidase specifically at $10^{\circ}C$. This strain supported the existence of symbiotic bacteria for the low temperature habitat of the termite. This identified bacterium will be a resource for studying low temperature adaptation of termites, studying the gene expression at low temperatures, and developing an industrial cellulase at low temperature.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.526-529
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• 2002

Lysis of erythrocytes isolated from human, rabbit, and mouse blood samples was investigated with the culture supernatant of Xenorhabdus nematophilus in a primary form. Prior to use, the culture supernatant of the bacteria was concentrated and the concentrate was dialyzed against Tris-HCl buffer (10 mM, pH 8.1) by ultrafiltration using PM-5 membrane with a molecular weight cut-off of 5,000. At $30^{\circ}C$, the supernatant exhibited no lytic activity towards three types of erythrocytes. However, at $4^{\circ}C$, the supernatant showed selective lytic activity towards rabbit erythrocytes within 90 min. yet did not lyze human or mouse erythrocytes. Microscopic examination clearly revealed that most of the rabbit erythrocytes had been fumed into ghost forms.

• 대한화장품학회지
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• 제43권2호
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• pp.137-147
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• 2017

피부의 생태계는 미생물에게 다양한 형태의 서식처를 제공하며, 광범위한 미생물들이 살고 있다. 숙주인 사람은 이들과 공생관계를 이루고 있으며, 이들은 숙주에 많은 긍정적인 영향을 미친다. 피부에 분포하는 미생물들의 다양한 대사물질은 피부세포에 영향을 미치고, 피부장벽 기능, 노화방지 및 항염증에 광범위한 효능을 나타내는 것으로 알려져 있다. 본 연구에서는 사람의 피부에서 신규한 Sporichthyaceae bacterium strain K-07을 분리하였고, 해당 미생물의 16S rRNA 분석결과 Sporichthya속의 미생물과 상동성이 93.4%인 것으로 신규속(genus)으로 확인되었다. 그리고 신규로 분리된 K-07 배양액을 처리하였을 때, HaCaT cell에 어떤 변화가 나타나는지에 대한 분석을 실시하였다. 분리된 신규 미생물 strain K-07의 16S rRNA sequence 분석결과 상동성이 93.4% 이하로 확인되었고, 보고되지 않은 새로운 종으로 확인되었다. Filaggrin, cluadin1, claudin4, ${\alpha}SMase$, 및 CerS3 / HAS3 및 aquaporin3 / IL-6 및 TNF-${\alpha}$ / TSLP 및 TARC를 대상으로 strain K-07 배양액을 처리하여 변화를 관찰하였다. 그 결과 filaggrin, cluadin1, claudin4, ${\alpha}$SMase, 및 CerS3 / HAS3 및 aquaporin3에서는 음성 대조군 대비 우수한 증가 효과가 나타남을 확인하였다. 그리고 IL-6 및 TNF-${\alpha}$ / TSLP 및 TARC에 대해서도 우수한 억제능을 나타내는 것을 확인하였다. 결론적으로 신규 미생물 strain K-07 배양액은 피부 장벽활성 증진에 매우 효과적인 작용을 하며, 염증 억제에 우수한 효능을 나타내는 것으로 확인되므로 피부에 효과적인 소재로 사용될 수 있을 것이다.

• 한국토양동물학회지
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• 제3권1호
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• pp.19-24
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• 1998

The importance of the gut microorganism in the termite, Reticulitermes Speratus kyushuenesis Morimoto, was estimated by feeding with several antibiotics. Antibiotics which killed the bacterium, but not the fungi (Ampicillin, Kanamycin, Erythromycin), or killed both the microorganismw (Cephaloridine, Tetracycline) reduced the life span of the termite from 245 days to about 15 days. On the other hand, some antibiotics, penicillin and pimaricin, did not greatly reduce the life span of the termite.

• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.372-374
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• 2001

Three simple carboxamides incorporating the phenethylamine moiety have been isolated from strain XR-NC of a symbiotic bacterium Xenorhabdus nematophilus. Their structures were identified by spectroscopic data and synthesis. The compounds exhibited significant cytotoxicities against human cancer-cell line, viz. the gastric adenocarcinoma, colon adenocarcinoma and lung adenocarcinoma.

• 환경위생공학
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• 제16권3호
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• pp.22-27
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• 2001

It have been investigated how algal and bacterial symbiotic reaction influences on removal of organic carbon in river ecosystem. And artificial experimentation apparatus was made for algae'and bacteia'culture as lab scale. Investigating and researching minutely the change of concentration of organic carbon substrate and the change of population density of algae'and of bacteria'with this artificial experimentation apparatus, the next results could be obtained. 1. Successful decrease of DOC(dissolved organic carbon) could not be expected unless algal and bacterial biomass floe was nut formed effectively and unless biosorption was not proceeded effectively in the very culture system in which artificial synthetic wastewater was supplied continuously at constant rate. 2. In conditions of culture liquid of 1335 glucnse mg/L(type 1) and of 267 glucose mg:L(type 2), the algal dominant species was always Chlorella vulgaris in both types in which artificial synthetic wastewater were supplied continuously at constant rate and algae population density was around maximum 107 cells/mL. 3. It was around 108 ~ 107 cells/mL that the population density of heterotrophic bacterium. In culture medium systems type 1 and type 2 in which artificial wastewater were supplied continuously at constant rate, the same density appeared initially when using the population density of Escherichia coli w 3110 as indirect indicator. And this density decreased rapidly till the culturing date 35 days were passed away, while this density increased with gentle slope after same date and then the trend of change at type 2 was more severe than one at type 1. 4. When seeing such a change of population density of Escherichia coli w 3110, the growth of heterotrophic bacterium appeared as survival instinct pattern of broader requirement of nutrient at condition of low concentration of organic carbon substrate than condition of high concentration of same substrate.

• 한국응용곤충학회지
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• 제44권1호
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• pp.21-30
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• 2005

곤충병원성선충 {Heterorhabditis sp. KCTC 0991BP (He)와 Steinernema carpocapsae KCTC 0981BP (Sc)}에 의한 치사충과 선충의 공생세균(He공생세균=Photorhabditis sp.와 Sc공생세균= Xenorhabdus nematophila)에 의한 치사충에 대한 개미의 섭식행동을 알아보기 위하여 동래베네스트골프장과 안양베네스트골프장, 가평베네스트골프장, 울산골프장에서 치사 원인에 따른 개미의 방문수, 종류 및 선호성을 조사하였다. 방문하는 개미의 수나 종류 및 개미가 물고 간 먹이의 수는 치사원인에 따라 차이가 있었으며, 골프장이나 골프장내의 장소(페어웨이와 러프)간에도 차이가 있었다. 개미의 선호성은 모든 골프장에서 He에 의한 치사충에서 가장 낮았다. 동래베네스트 골프장의 6번 홀에서는 러프에서만 고동털개미(Lasius japonicu)($76{\pm}2.9\%$)와 검정꼬마개미(Monomorium floricola)($10\%$)가 치사충을 끌고 갔다. 러프의 치사충에 개미의 방문이 있었던 비율은 $87{\pm}3.5\%$였지만 페어웨이에서는 처리 16시간 후까지 모든 치사충에 개미의 방문이 없었다. 12시간 후까지 개미가 끌고 간 치사충의 비율은 He에 의한 치사충이 $16.7\%$로 Sc에 의한 치사충의 $40.0\%$, fenitrothion에 의한 치사충의 $53.3\%$, 자연치사충의 $56.7\%$에 비하여 낮았다. 안양베네스트골프장 6번 홀 러프에서는 주름개미(Tetramorium tsushimae)($33{\pm}6.9\%$)와 극동혹개미(Pheidole fervida)($17{\pm}8.7\%$), 일본왕개미(Camponotus japonicus)($10\%$), 곰개미(Formica japonica)($7{\pm}3.5\%$), 스미스개미(Paratrechina flavipes)($3{\pm}3.5\%$), 마쓰무라밑들이개미(Crematogaster matsumurai)($3{\pm}3.5\%$)가 치사충을 방문하였다. 개미가 치사충을 끌고 감이 없었던 비율은 $23{\pm}8.7\%$였고, Sc에 의한 치사충을 끌고 간 비율은 $40.0\%$, 냉동 치사충을 끌고 간 비율은 $16.7\%$, He에 의한 치사충을 끌고 간 비율은 $3.4\%$였다. 가평베네스트골프장 벚꽃나무 코스 9번 홀의 러프에서는 치사충을 방문하는 개미의 수가 매우 낮았는데, 주름개미와 스미스개미가 각각 한곳에서 발견되었다. 곤충병원성 선충의 접종 농도는 개미가 끌고 간 치사충의 비율에서 차이를 보이지 않았다. 한편, 치사충의 매장 유무는 개미의 섭식활동에 영향을 미쳤다. 동래베네스트골프장 6번 홀의 러프에서 토양 속에 묻은 치사충에서는 처리 16시간 동안 개미의 방문이 없었던 반면, 묻지 않은 치사충은 끌고 갔다. He와 Sc의 공생세균을 처리한 비스켓에 대한 개미의 방문은 선충의 치사충에 대한 방문과 동일한 경향을 보여, He의 공생세균인 Photorhabditis sp.처리에서 Sc 공생세균인 Xenorhabdus 처리보다 방문수가 적었다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.515.1-515
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• 1986

Thermostable tryptophanase was extracted from a thermophilie bacterium, strain T which was absolutely symbiotic with strain 5. The enzyme was purified 14.7 fold with 5.8% yield by chromatographies using ion exchange, gel filtration, and hydrophobic interaction columns, followed by high performance liquid chromatography on hydroxyapatite column. The purified enzyme has a molecular weight of approximately 210,000 estimated by gel filtration column chromatography, and the molecular weight of subunit was determined by SDS polyacrylamide gel electrophoresis to be 46,000, which indicates that the native enzyme is made of four homologous subunits. The tryptophanase was stable at 65o0 and the optimum temperature for the enzyme activity for 20 min reaction was 70$^{\circ}C$. The purified enzyme activity for 20 min ieaction was 70$^{\circ}C$. The purified enzyme catalyzed the degradation of L-tryptophan into indole, pyruvate and ammonia in the presence of pyridoxal phosphate. 5-Hydroxy-Ltryptophan, 5-methyl-DL-tryptophan, L-cysteine, S-methyl-L-cysteine, 5-methyl-DL-tryptophan, L-cysteine, S-methyl-Lcysteine, and L-serine were also used as substrates to form pyruvate. The amino acid composition of the tryptophanase was determined, and found to contain a high percentage of hydrophobic amino acids, especially in the proline content, which was much higher than that of Escherichia coli tryptophanase. In addition, the 35N-terminal amino acid sequence of the tryptophanase was completely different from that of E. coli tryptophanase.

• Journal of Microbiology and Biotechnology
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• 제21권8호
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• pp.869-873
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• 2011

Most medium formulations for improving culture of entomopathogenic nematodes (EPN) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. Most results, however, showed unstable yields and longer production time. Many of the results do not show the detailed parameters of fermentation. Soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydrolysate as protein sources were tested to determine the source to support optimal symbiotic bacteria and nematode growth. The protein hydrolysates selected did not improve bacterial cell mass compared with the yeast extract control, but soy flour was the best, showing 75.1% recovery and producing more bacterial cell number ($1.4{\times}10^9$/ml) than all other sources. The highest yield ($1.85{\times}10^5$ IJs/ml), yield coefficient ($1.67{\times}10^6$ IJs/g medium), and productivity ($1.32{\times}10^7$ IJs/l/day) were also achieved at enriched medium with soybean protein.

• The Plant Pathology Journal
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• 제17권2호
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• pp.67-70
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• 2001

Medicago truncatula is a diploid legume plant related to the forage crop alfalfa. Recently, it has been chosen as a model species for genomic studies due to its small genome, self-fertility, short generation time, and high transformation efficiency. M. truncatula engages in symbiosis with nitrogen-fixing soil bacterium Rhizobium meliloti. M. truncatula mutants that are defective in nodulation and developmental processes have been generated. Some of these mutants exhibited altered phenotypes in symbiotic responses such as root hair deformation, expression of nodulin genes, and calcium spiking. Thus, the genes controlling these traits are likely to encode functions that are required for Nod-factor signal transduction pathways. To facilitate genome analysis and map-based cloning of symbiotic genes, a bacterial artificial chromosome library was constructed. An efficient polymerase chain reaction-based screening of the library was devised to fasten physical mapping of specific genomic regions. As a genomics approach, comparative mapping revealed high levels of macro- and microsynteny between M. truncatula and other legume genomes. Expressed sequence tags and microarray profiles reflecting the genetic and biochemical events associated with the development and environmental interactions of M. truncatula are assembled in the databases. Together, these genomics programs will help enrich our understanding of the legume biology.