• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1744-1749
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• 2010

The role of endophytic fungi in plant growth and development is well documented. However, endophytic fungi with growth promotion capacity have never been isolated from weeds previously. In the current study, we isolated 8 fungal endophytes from the roots of Monochoria vaginalis, a serious weed of rice paddy in Korea. These isolates were screened on Waito-C, in order to identify plant growth promoting metabolites. Two fungal isolates (M5.A & M1.5) significantly promoted the plant height and shoot length of Waito-C during preliminary screening experiments. The culture filtrates (CFs) of M5.A and M1.5 also promoted the shoot length of Echinocloa crusgalli. Gibberellins (GAs) analysis of the CFs of M5.A and M1.5 showed that these endophytic fungi secrete higher quantities of GAs as compared with wild-type G. fujikuroi KCCM12329. The CF of M5.A contained bioactive GAs ($GA_3$, 2.8 ng/ml; $GA_4$, 2.6 ng/ml, and $GA_7$, 6.68 ng/ml) in conjunction with physiologically inactive $GA_9$ (1.61 ng/ml) and $GA_{24}$ (0.18 ng/ml). The CF of M1.5 contained physiologically active GAs ($GA_3$, 1.64 ng/ml; $GA_4$, 1.37 ng/ml and $GA_7$, 6.29 ng/ml) in conjunction with physiologically inactive $GA_9$ (3.44 ng/ml), $GA_{12}$ (0.3 ng/ml), and $GA_{24}$ (0.59 ng/ml). M5.A and M1.5 were identified as new strains of Penicillium sp. and Aspergillus sp., respectively, based on their 18S rDNA sequence homology and phylogenetic analysis.

• Preventive Nutrition and Food Science
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• 제18권4호
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• pp.273-279
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• 2013

Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was $40^{\circ}C$. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at $60^{\circ}C$ and 60 min at $50^{\circ}C$. F1-1 protease was inhibited by $Mn^{2+}$, $Hg^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.82-91
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• 2019

Objective: This experiment was conducted to compare the structure and composition of ruminal microorganisms in goats with high and low neutral detergent fibre (NDF) digestibility. Methods: Nineteen crossbred goats were used as experimental animals and fed the same total mixed rations during the 30-day pre-treatment and 6-day digestion trialperiods. All faeces were collected during the digestion period for measuring the NDF digestibility. Then, high and the low NDF digestibility individuals were chosen for the high NDF digestibility group (HFD) and low NDF digestibility group (LFD), respectively. Rumen contents were collected for total microbial DNA extraction. The V4 region of the bacterial 16S rRNA gene was amplified using universal primers of bacteria and sequenced using high-throughput sequencer. The sequences were mainly analysed by QIIME 1.8.0. Results: A total of 18,694 operational taxonomic units were obtained, within 81.98% belonged to bacteria, 6.64% belonged to archaea and 11.38% was unassigned microorganisms. Bacteroidetes, Firmicutes, and Proteobacteria were the predominant microbial phyla in both groups. At the genus level, the relative abundance of fifteen microorganisms were significantly higher (p<0.05) and six microorganisms were extremely significantly higher (p<0.01) in LFD than HFD. Overall, 176 core shared genera were identified in the two groups. The relative abundance of 2 phyla, 5 classes, 10 orders, 13 families and 15 genera had a negative correlation with NDF digestibility, but only the relative abundance of Pyramidobacter had a positive correlation with NDF digestibility. Conclusion: There were substantial differences in NDF digestibility among the individual goats, and the NDF digestibility had significant correlation with the relative abundance of some ruminal microorganisms.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.567-575
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• 2018

Present study was performed to describe the morphological and molecular characterization of Toxocara tanuki (Nematoda: Ascaridae) from Korean raccoon dog, Nyctereutes procyonoides koreensis, naturally infected in the Republic of Korea (Korea). Juvenile and adult worms of T. tanuki were recovered in 5 out of 10 raccoon dogs examined and the larval worms were detected in 15 out of 20 muscle samples (75%). Small lateral alae were observed on the cranial end of the body in male and female adults and 2 long spicules (3.0-3.5 mm) were characteristically observed in the posterior end of males. In SEM observation, 18 pairs of proximal precloacal, a precloacal median, a postcloacal median and 5 pairs of postcloacal papillae were uniquely revealed in the posterior portion of males, but the proximal papillae were not shown in the lateral ends of females. Molecular analysis on the 18S rRNA partial DNA sequences was revealed the same finding in both samples, adult worms and muscle larvae, which are closely related to T. tanuki. In conclusion, it was confirmed for the first time that T. tanuki is indigenously distributed, the Korean raccoon dog is acted as the natural definitive host of this nematode in Korea and the morphological characteristics of T. tanuki were shown in specific structure for single postcloacal median papilla in male.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.855-861
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• 2022

A white-pigmented, non-motile, gram-negative, and rod-shaped bacterium, designated CYS-02^T, was isolated from soil sampled at Suwon, Gyeonggi-do, Republic of Korea. Cells were strictly aerobic, grew optimally at 20-28℃ and hydrolyzed Tween 40. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CYS-02^T formed a lineage within the family Comamonadaceae and clustered as members of the genus Variovorax. The closest members were Variovorax guangxiensis DSM 27352^T (98.6% sequence similarity), Variovorax paradoxus NBRC 15149^T (98.5%), and Variovorax gossypii JM-310^T (98.3%). The principal respiratory quinone was Q-8 and the major polar lipids contain phosphatidylethanolamine (PE), phosphatidylethanolamine (PG), and diphosphatidylglycerol (DPG). The predominant cellular fatty acids were C_16:0, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The DNA GC content was 67.7 mol%. The ANI and dDDH values between strain CYS-02T and the closest members in the genus Variovorax were ≤ 79.0 and 22.4%, respectively, and the AAI and POCP values between CYS-02^T and the other related species in the family Comamonadaceae were > 70% and > 50%, respectively. The genome of strain CYS-02^T showed a putative terpene biosynthetic cluster responsible for antioxidant activity which was supported by DPPH radical scavenging activity test. Based on genomic, phenotypic and chemotaxonomic analyses, strain CYS-02^T was classified into a novel species in the genus Variovorax, for which the name Variovorax terrae sp. nov., has been proposed. The type strain is CYS-02^T (= KACC 22656^T = NBRC 00115645^T).

• Journal of Plant Biotechnology
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• 제43권4호
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• pp.450-456
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• 2016

한국형 잔디에서는 다른 병에 비해 진전 속도가 빠르고 주로 뿌리에서부터 발병하여 잔디를 고사시키고 발병 후 구제하기 매우 어려운 라이족토니아잎마름병(라지패취)이 큰 문제로 대두되고 있다. 라이족토니아잎마름병(라지패취)은 Rhizoctonia solani AG2-2 (IV)병원균에 의해 발생하는데, 이 병원균에 강한 내병성 들잔디를 개발하기 위해 식물방어반응에 중요한 역할을 하는 것으로 알려진 PR-Protein 중 하나인 ${\beta}-1,3-glucanase$를 들잔디로부터 클로닝 하였다. ${\beta}-1,3-glucanase$는 바이러스나 균의 감염으로 인해 식물조직이 과민반응을 일으킬 때 세포내에서 생성되고 세포 외로 분비되어 세포 사이 공간에서 주로 병원균 저항성기능을 하는 것으로 알려져 있다. ${\beta}-1,3-glucanase$ 단자엽식물 중 내병성에 대한 연구가 되어있는 옥수수, 밀, 보리, 벼의 염기서열에서 공통으로 보존되어 있는 부분을 이용해 degenerate PCR을 수행하고 얻어낸 sequence를 통해 Full-length의 cDNA를 클로닝 하였다. E.coli overexpression을 수행하여 목표 단백질을 대량 정제하여 in vitro 활성 측정 및 항균테스트를 진행하였다. 또한, ZjGlu1 유전자의 기능을 해석하기 위해 각각의 유전자를 도입한 식물형질전환용 벡터를 제작하여 잔디 형질전환체 제작을 하였다. ZjGlu1 단백질을 이용하여 9개의 균주에 대해 항균활성 테스트를 진행 한 결과 R. cerealis, F. culmorum, R.solani AG-1 (1B), T. atroviride 에서 항균활성을 보였으며, 형질전환체를 이용해 18s 유전자의 발현량을 상대로 한 각 유전자의 기관별 발현량은 크게 차이없이 모든기관에 발현되는 것을 확인할 수 있었다.

• 한국미생물·생명공학회지
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• 제33권1호
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• pp.16-23
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• 2005

식물내생미생물을 이용하여 다양한 작물에 발병하는 탄저병을 방제하기 위한 미생물 살균제를 개발하기 위하여 건전한 식물체 조직으로부터 총 260개 균주를 분리하였다 이들은 액체배지에 배양한 후 오이 탄저병(Colletotrichum orbiculare)에 대하여 in vivo항균활성을 조사한 결과 28개의 균주가 $90\%$ 이상의 높은 방제활성을 보였다. 이들 28개의 균주의 배양액을 1/3로 희석하여 처리하였을 경우에는 18개 균주가 $70\%$ 이상의 방제활성을 보였다. 이들 18개의 균주에 대하여 고추 탄저병균(C. coccodes)에 대한 in vivo항균활성과 고추 탄저병균(C. acutatum)에 대한 in vitro 항균활성을 조사한 결과 EB215균주가 가장 우수한 활성을 보여주었다. 이 균은 생리$\cdot$생화학적 특성과 Biolog실험 및 16S rDNA 유전자 서열에 의해 Burkholderia cepacial 동정되었다. B. cepacia EB215균주의 배양액은 고추 탄저병 외에 벼 도열병(Magnaporthe grisea), 벼 잎집무의마름병(Corticium sasaki), 토마토 잿빛곰팡이병 (Botrytis cinerea) 및 토마토 역병 (Phytophthora infestans) 등에 높은 항균활성을 보였다. 현재 이 균주로부터 항균물질의 분리 및 구조 동정에 대한 연구를 실시하고 있다.

• 한국식품과학회지
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• 제44권4호
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• pp.488-492
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• 2012

전통방식으로 숙성되고 있는 한식간장의 표면으로부터 분리된 바위꽃과 메밀꽃이라 불리는 미생물을 18S rDNA ITS1과 ITS4 지역의 염기서열를 분석한 결과, 각각 Cladosporium 종들과 S. halophilus의 염기서열과 높은 상동성을 보였다. 이에 따라 바위꽃 미생물은 Cladosporium sp. NK1로, 메밀꽃 미생물은 S. halophilus NK2로 명명하였다. YPD 액체 배지를 이용한 최적 생장 pH와 온도에 있어서 Cladosporium sp. NK1은 각각 pH 6과 22-$27^{\circ}C$였고, S. halophilus NK2는 각각 pH 5-7과 $22^{\circ}C$였다. Cladosporium sp. NK1는 NaCl를 첨가하지 않은 YPD 액체배지에서 가장 잘 생장하였으나, protease 및 amylase 효소활성에 있어서는 각각 10%와 15% NaCl이 첨가된 YPD 배양액 시료에서 가장 높았다. S. halophilus NK2는 10% NaCl이 첨가된 YPD 액체배지까지 매우 잘 생장하였으며, protease 활성은 10% NaCl이 첨가된 YPD 배양액 시료에서, amylase 활성은 5% NaCl이 첨가된 배양액 시료에서 가장 높았다. Cladosporium sp. NK1과 S. halophilus NK2의 lipase 활성은 보이지 않았다. 간장의 관능평가 결과 Cladosporium sp. NK1 균주는 간장의 맛에서, S. halophilus NK2는 향미에서 유의적 차이를 보였다.

• 동아시아식생활학회지
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• 제18권5호
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• pp.753-759
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• 2008

본 연구는 식품 샘플에서 단시간 내에 간단한 방법으로 Campylobacter jejuni를 검출하기 위하여 10가지의 Campylobacter genus-specific primer와 C. jejuni species-specific oligonucleotide를 제작하였고, amplification efficiency test를 통하여 4종으로 축소한 후 다시 specificity, sensitivity analysis를 통하여 최종적으로 CB4, CJ1 2종의 oligonucleotide primer를 선별하였다. 선별된 oligonucleotide primer는 각각 Campylobacter genus specific, Campylobacter jejuni에 대한 species specific한 특성을 지닌다. 또한, sensitivity analysis를 통하여 isolated colony에서 reaction tube당 $10^0{\sim}10^1$까지의 detection limit을 확보하였다. 육류 시료에서는 Sensitivity가 $10^1{\sim}10^2$으로 떨어지는 양상을 보였으며, 이는 쇠고기나 돼지고기에 존재하는 hemoglobin이나 immunoglobulin 등의 PCR inhibitor의 영향에 의한 것으로 추정된다.

• 한국미생물·생명공학회지
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• 제37권3호
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• pp.204-212
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• 2009

대두의 발효를 통하여 생리활성을 가지고 있는 이소플라본 aglycone 함량을 높이기 위한 ${\beta}$-glucosidase와 대두에 다량 함유되어 있는 stachyose, rafinose와 같은 난소화성 oligosaccharides를 분해하기 위해 ${\alpha}$-galactosidase 효소 분비 미생물을 김치로부터 ${\alpha}$-galactosidase와 ${\beta}$-glucosidase를 생산하는 미생물을 탐색하였다. 탐색과정을 위해서 선별한 미생물을 16S rDNA sequencing 동정한 결과, Weissella cibaria 동정되어 Weissella cibaria K-M1-4로 명명하였다. Weissella cibaria K-Ml-4를 대두 액체배지에서 18시간동안 배양한 후, 생산한 효소는 배양액을 에탄을 침전, DEAE sepharose, sephacryl S-100HR column chromatography 통하여 ${\alpha}$-galactosidase의 경우, 정제도 5.3배, 수율 3.5% 그리고 ${\beta}$-glucosidase의 경우, 정제도 4.4배, 수율 2.9%로 정제되었다. ${\alpha}$-Galactosidase 효소특성은 $60^{\circ}C$에서 최대 활성을 나타내었으며, $80^{\circ}C$에서 30분 처리시 43% 잔존활성을 보였다. pH 8.0에서 최대 활성을 나타내었으며, pH 5.0-9.0에서 안정하였다. 금속이온에 대한 영향에서 $Fe^{2+}$과 $Cu^{2+}$을 첨가하였을 때 효소 활성이 증가하였다. p-Nitrophenyl-${\alpha}$-D-galacto-pyranoside (PNPG) 기질에 대한 Km은 0.98 mM이었고, Vmax는 $1.81{\mu}$mole/min 이었다. ${\beta}$-Glucosidase 효소 특성은 $50^{\circ}C$에서 최대 활성을 나타내었으며, $80^{\circ}C$에서 30분 처리시 46% 잔존활성을 보였다. pH 7.0에서 최대 활성을 나타내었으며, pH 5.0-9.0에서 안정하였다. 금속이온에 대한 영향에서 $Fe^{2+},\;Co^{2+},\;Cu^{2+}$을 첨가하였을 때 효소 활성이 증가하였다. p-Nitrophenyl-${\beta}$-D-gluco-pyranoside (PNPG)에 대한 Km값은 1.24mM이었고, Vmax는 $6.81{\mu}$mole/min 이었다.