• 한국환경농학회지
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• 제35권2호
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• pp.137-142
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• 2016

BACKGROUND: Identification of endophytic yeasts inhabiting the internal roots of the Mankyua chejuense tree requires techniques involving biotechnology. There is a need for a culture-based method to isolate and identify yeast strains associated with M. chejuense.METHODS AND RESULTS: We spread homogenized M. chejuense root samples onto glucose-peptone- yeast agar containing antibiotics, Triton X-100, and L-sorbose. A total of 152 yeast isolates were obtained and identified via phylogenetic analysis based on ITS gene sequencing. The results revealed that the root-associated yeast species included the genera Cyberlindnera (140 isolates), Candida (11 isolates), and Kluyveromyces (one isolate). Additionally, three yeast isolates showed high bioethanol production.CONCLUSION: We identified the specific yeast community associated with M. chejuense roots. These yeast isolates may have industrial applications as bioethanol producers. Our findings revealed that Cyberlindnera isolates included C. suaverolens and C. satumus, while Kluyveromyces isolates showed high bioethanol production.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.813-818
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• 2000

The objective of this study is to elucidate the characteristic performance of Roots-type vacuum pump with Cassini oval lobe shape. The modelled lobe shape of Roots-type vacuum pump is two-lobe spur gear. The numerical analyses are performed fer leak flows, using 4th-order Runge-Kutta method and are compared with experimental results. Results show that for the case of involute lobe shape the total amount of the leak flow conductance is greater than that of cycloid and Cassini oval lobe shapes.

• Mycobiology
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• 제30권2호
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• pp.70-75
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• 2002

The mycelia were directly isolated from eight species of fungal basidiocarps, confirmed to the ectomycorrhiza in the roots from the fields(forestry); Suillus bovinus, Paxillus involutus, Lactarius hysginus, Russula fragilis, Lepista nuda, Lyophyllum shimeji, Tricholoma matsutake, and Russula integra. The mycelia were pure-cultured with several transferring in various agars, and inoculated to the roots of pine(Pinus densiflora) seedling by in vitro method. After ten months growth under artificially aseptic conditions, all pine seedlings inoculated were stimulated at the growth-height, whereas those not inoculated were nearly dead. Also, the ramifications of ectomycorrhizal pine roots formed in the synthetic in vitro systems and were various according to the different mycelia. Synthesis of ectomycorrhiza were clearly confirmed in ten months growth, but not distinguished at this moment. It was clearly proved that the mycelia isolated caused the ectomycorrhizae in the roots of pine seedlings.

• Natural Product Sciences
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• 제28권2호
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• pp.89-92
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• 2022

In Asia, the roots of Paeonia lactiflora and Astragalus membranaceus have been used as therapeutic agents for thousands of years. Once the medicinal plants are harvested, they are dried and their ingredients are extracted by heat-mediated reflux extraction. However, the condensed structure of organic products (especially roots) limits the extraction of bioactive components. In this study, we assessed the effect of the puffing method (using high temperature and pressure) before the extraction process in relation to the profile and antioxidant capacity of active ingredients. We demonstrated that the additional puffing process before extraction methods improves the yield of polyphenol concentrations and antioxidant activities from the roots of P. lactiflora and A. membranaceus.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.780-788
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• 1995

The purpose of this study was to compare the apical seal following root canal shaping by different methods. From fourty extracted mandibular 1st and 2nd molars, fourty mesial roots whose canals have some degree of curvature were selected. The mesiobuccal root portion including mesiobuccal portion of a crown was sectioned in each molar. After access cavity preparation for the mesiobuccal canal, working length was determined with # 10 K-file. The sectioned roots were implanted in acrylic resin block and randomly divided into four groups. The canals of group I were shaped by step-down/balanced force, group II by stepdown/step-back, group III by step-back and group IV by conventional method. All of the shaped canals were obturated by Thermafil method and access cavities were filled with IRM. The roots were removed from acrylic resin block and placed in 100 % humidity for 7days. Except the root surfaces of apical 2mm, the root surfaces were nail-varnished 3 times. After the roots were placed in 700 torr vacuum pressure for 15 minutes, they were immersed in 2% methylene blue solution for 4 days. Nail varnishes were removed with acetone. After that, the roots were decalcified in 5 % nitric acid and dehydrated with alcohol series. Transparent specimens were made by methyl salicylate and the quality of apical seal was assessed by measuring the leakage linearly. The results were as follows. 1. The leakage in canals shaped by step-down/balanced force method was significantly less than that in canals shaped by step-back method(P<0.05) and was less but not statistically than that in canals shaped by step-down/step-back method (P>0.05). 2. The leakage in canals shaped by step-down/step-back method was less than that in canals shaped by step-back method, but there was no statistical significance(P>0.05). 3. The leakage in canals shaped by conventional method was significantly more than that in canals shaped by step-down/balanced force, step-down/step-back and step-back method (P<0.05).

• 식물조직배양학회지
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• 제28권2호
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• pp.103-108
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• 2001

카사바 (Manihot esculenta Crantz cv. MColl 22)의 마디절편을 제아틴 0.01%가 첨가된 MS 기본배지에서 2주간 현탁배양하여 경엽부 길이가 1.5∼2.5 cm로 생장된 유식물의 부정근을(1) 1∼l.5 cm길이만 남기고 짧게 전정, (2) 1∼2 mm 이내로 제거, (3)뿌리 발생부 전체를 절단한 후 마사토를 담은 유리병에 이식하여 비무균조건에서 순화생장시켰다. 그 결과 이식 7∼10일경부터 각 조건에서 새 뿌리가 발생되기 시작하여 6주 후에는 조건에 따라 73∼93%의 생존율을 나타냈다. 기내 발생 뿌리 가운데 손상 없이 토양에 이식된 것은 그대로 생존을 계속하여 유식물 생장에 도움을 주었으며, 제거된 부정근은 이식 후 신장이 중단되고 새로 뿌리가 발생되었다. 그러나 간혹 전정되고 남은 부분에 측근이 발생된 것이 관찰되었다. 각 조건에서 새로 발생된 기외 뿌리의 수와 길이 및 경엽부 길이와 마디 수에서는 서로 유의성 있는 차이를 나타내지 않았으나, 생체중에서는 전정>제거>절단의 순으로 약간의 차이를 보였다. 미세증식된 카사바의 기내발생 부정근을 적절히 전정 또는 제거한 후 이식하여 순화시키는 것은, 작업을 간편하게 할 뿐만 아니라 유식물의 생존율이 높고 생장에도 지장이 거의 없으므로 경제적인 미세증식 방법으로 유용하게 이용될 수 있다.

• Applied Biological Chemistry
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• 제41권8호
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• pp.600-604
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• 1998

Methanol extracts from 53 species of oriental medicinal plants in 34 families were tested for their fungicidal activities against Pyricularia grisea, Rhizoctonia solani, Phytophthora capsici, Phytophthora infestans, Collectotrichum dematium, Botryospaeria dothidea, Fusarium oxysporum f. sp. cucumerinum, Botrytis cinerea, Puccinia recondita, and Erysiphe graminis. In in vitro study using impregnated paper disc method, the efficacy varied with both plant pathogen and plant species tested. Methanol extracts of Asarum sieboldii roots, Sinomenium acutum roots, Pinus densiflora leaves, Rheum undulatum root barks, Coptis japonica roots, and Phellodendron amurense barks showed potent fungicidal activities against the various pathogens when treated with 10 mg/disc. In a whole plant test, methanol extracts of P. densiflora leaves and roots and C. japonica roots were highly effective against a variety of plant pathogens. As a naturally occurring fungicide, P. densiflora- and C. japonica-derived materials could be useful as new fungicidal products against various plant diseases induced by plant pathogenic fungi.

• 대한화장품학회지
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• 제27권2호
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• pp.45-56
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• 2001

산삼은 고유의 생약으로 민간 또는 한방에서 효능을 인정받아 왔으나 산삼의 희귀성으로 인하여 산삼에 대한 연구가 활발하지 못하였다. 따라서 본 실험은 식물 조직 배양 기술을 이용하여 산삼 부정근을 대량으로 배양하고 추출하여 화장품 원료로서의 적용 가능성을 연구하였다. 본 실험에서 사용한 산삼 부정근은 강원도 평창에서 채취한 110년생 천종삼으로 산삼으로부터 유래된 캘러스에서 부정근을 유도한 후 절취하여 생물 배양기에서 액체 현탁액으로 대량 배양하였다. 약 5주간의 배양기간을 거쳐 증식된 산삼 부정근을 세척하여 건조시킨 후 추출하여 산삼 부정근 추출물을 얻었다. 산삼 부정근 추출물의 미백 효과 측정을 위하여 tyrosinase 억제 실험과 DOPA 자동산화 그리고 B-16 melanoma cell를 이용한 미백 실험을 실시하였고 유해성 검증을 위해서 안전성 실험과 세포 독성 실험을 실시하였다. in vitro 상의 유해성 실험은 transformed mouse fibroblast L929를 배양하여 NR assay, MTT assay를, in vivo 상의 안전성 실험은 인체 첩포를 이용한 Patch test를 실시하여 피부 반응의 관찰을 통해서 자극 혹은 알레르기성 반응의 발생여부를 실시한 결과 무해하였으며 melanin 생성 억제 실험 결과 미백효과가 우수한 것으로 나타났다.

• Natural Product Sciences
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• 제25권2호
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• pp.122-129
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• 2019

The roots of Phlomis umbrosa (Turcz.) (Phlomidis Radix) have been traditionally used to treat cold, reduce swelling and staunch bleeding. Four iridoids (1 - 3 and 5) and six phenylethanoid derivatives (4, and 6 - 10) were isolated from the roots of P. umbrosa. A simple, sensitive, and reliable analytical HPLC/PDA method was developed, validated, and applied to determine 10 marker compounds in Phlomidis Radix. Furthermore, the isolates were evaluated for cytotoxic and anti-oxidant activities as well as DPPH-HPLC method. Among them, compounds 4 and 6 - 9 displayed potent anti-oxidant capacities using DPPH assay with $IC_{50}$ values of $27.7{\pm}2.4$, $10.2{\pm}1.1$, $18.0{\pm}0.8$, $19.1{\pm}0.3$, and $19.9{\pm}0.6{\mu}M$, and compounds 6, 8, and 9 displayed significant cytotoxic activity against HL-60 with $IC_{50}$ values of $35.4{\pm}3.1$, $18.6{\pm}2.0$, and $42.9{\pm}3.0{\mu}M$, respectively.

• The Plant Pathology Journal
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• 제23권3호
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• pp.223-225
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• 2007

Many plant growth-promoting rhizobacteria (PGPRs) have been known for beneficial effects on plants including biological control of soilborne pathogens, induced systemic resistance to plant pathogens, phytohormone production, and improvement of nutrient and water uptake of plants. We developed a simple and rapid method for screening potential PGPR, especially phytohormone producing rhizobacteria, or for analyzing their functions in plant growth using cucumber seedling cuttings. Surface-sterilized cucumber seeds were grown in a plastic pot containing steamed vermiculite. After 7 days of cultivation, the upper part 2 cm in length of cucumber seedling, was cut and used as cucumber cuttings. The base of cutting stem was then dipped in a microcentrifuge tube containing 1.5ml of a bacterial suspension and incubated at $25^{\circ}C$ with a fluorescent light for 10 days. Number and length of developed adventitious roots from cucumber cuttings were examined. The seedling cuttings showed various responses to the isolates tested. Some isolates resulted in withering at the day of examination or in reduced number of roots developed. Several isolates stimulated initial development of adventitious roots showing more adventitious root hair number than that of untreated cuttings, while some isolate had more adventitious root hair number and longer adventitious roots than that of untreated control. Similar results were obtained from the trial with rose cuttings. Our results suggest that this bioassay method may provide a useful way for differentiating PGPR's functions involved in the development of root system.