• 미생물학회지
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• 제21권4호
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• pp.213-220
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• 1983

Conditions for isolation of protoplasts from conidiospores of Trichoderma koningii ATCC 26113 were tested. Maximum production of conidial protoplasts was obtained by preincubation of conidiospores on liquid minimal medium for 8 1/2 hrs. and by reaction with cell wall lytic enzyme for 3 hrs. Among effective cell wall lytic enzymes (Driselase, p-Glucuronidase, Novozyme and Zymolyase), Driselase was the most effective one on the production of conidial protoplasts. The production of conidial protoplasts was also enhanced by addition of 2-Deoxy-D-Glucose $(25{\mu}g/ml)$ into liquid minimal medium. Over 70% of the initial swollen conidia, preincubated in liquid minimal medium supplemented with 2-Deoxy-D-Glucose $(25{\mu}g/ml)$, were converted to protoplasts by incubation with 2% (w/v) commercial lytic enzyme Driselase at $28^{\circ}C$ for 3 hrs. The reversion frequency of the conidial protoplasts was about 30 times (25-50%) higher than that of mycelial protoplasts (0.6-1.3%).

• 미생물학회지
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• 제22권1호
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• pp.57-66
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• 1984

Stigimatella aurantiaca는 calcium, barium, 또는 lithium이온이 포함된 배지에서는 빛을 비추어 주어도 stalk를 형성하지 않고 포자낭으로만 분화하였다. Calcium이온과 GMP가 함께 첨가된 배지(GMP 배지)에서는 빛의 유무에 관계없이 stalk와 포자낭을 지니는 fruiting body가 형성되었다. Calcium 이온과 pheromone 포함된 배지(pheromone배지)에서는 빛이 있는 경우에는 대부분의 세균들이 stalk로만 분화되었으나, 빛이 없는 경우에는 대부분 포자낭으로만 분화하였다. 세균집합체는 calcium과 potassium 및 sodium이 함꼐 첨가된 배지(CPS배지)에서보다 calcium 이온만 첨가된 배지 (calcium 배지)에서 더 많이 형성되었다. GMP 배지나 pheromone 배지에서는 calcium 배지에서보다 적은 수의 세균집합체가 형성되었고, 빛이 없는 경우에는 이 집합체의 형성이 소요된 시간이 단축되었다. 빛은 상기한 네가지 배지에서 공히 짧은 시간에 더 많은 세균집합체가 형성되도록 하였다.

• Journal of Microbiology
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• 제33권2호
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• pp.95-102
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• 1995

A probability identification matrix of acidophilic Streptomyces was constructed. The phenetic data of the strains were derived from numerical classification described by Seong et al. The minimum number of diagnostic characters was determined using computer programs for calculation of different separation indices. The resulting matrix consisted of 25 clusters versus 53 characters. Theoretical evaluation of this matrix was achieved by estimating the chuster overlap and the identification scores for the Hypothetical Median Organisms (HMO) and for the representatives of each cluster. Cluster overlap was found to be relatively small. Identification scores for the HMO and the randomly selected representatives of each cluster were satisfactory. The matrix was assessed practically by applying the matrix to the identification of unknown isolates. Of the unknown isolates, 71.9% were clearly identified to one of eight clusters. The numerical classification data was also used to design a selective isolation medium for antibiotic-producing organisms. Four chemical substances including 2 antibiotics were determined by the DLACHAR program as diagnostic for the isolation of target organisms which have antimicrobial activity against Micrococcus luteus. It was possible to detect the increased rate of selective isolation on the synthesized medium. Theresults show that the numerical phenetic data can be applied to a variety of purposes, such as construction of identification matrix and selective isolation medium for acidophilic antinomycetes.

• 미생물학회지
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• 제6권1호
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• pp.12-21
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• 1968

The accelerate effects on the growth rate and the capacity of fermentation of L. delbrukii and B. subtilis was investigated in the Henneberg's medium added by various amounts of cellular components of Chlorella and Scenedesmus and also was investigated in the media added micronutritional elements such as Mn, Fe and Mo, etc. The results in the comparative experiments are as follow; 1. Various amounts of Chlorella cell components in the media accelerated remarkably the lactic acid formation and growth of L. delbrukii. For example, lactic acid formation in the medium of contained 1 percent Chlorella cell components was promoted more than twice effects compare with control. 2. The formation of .alpha.-amylase by B. subtilis in the medium of 2 percent Chlorella cell contents was also promoted more than nine twice effects compare with control. 3. The formation of lactic acid of L. delbruckii in the medium of Scenedesmus cell contents was a little more than in the medium of Chlorella cell contents. 4. The lactic acid fermented level attained with the addition of 0.2-0.25 percent Chlorella cells was the effect of promoting fermentation attained of saturating level at 100$\mu$g. /ml. of Mn and 0. 1 $\mu$g./ml. of Fe.

• 미생물학회지
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• 제22권3호
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• pp.135-142
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• 1984

The effect of biotin on the growth and sporulation of Bacillus subtilis SNU816 was investigated. When B. subtilis SNU816 was cultured on glucose as a sole carbon source, the growth was retarded markedly and usually ceased at early log phawe. But by addition of biotin to this medium, normal, rapid growth was restored. The growth rate was increased proportionally according to the concentration of exogenous biotin until it reached to 0.05㎍/ml, at which about three fold rapid growth was achieved. Also biotin was required for optimum sporulation for it facilitated the complete utilization of both glucose(Glc) and glutamic acid(Glu). Without biotin in Glc+Glu medium, about 40% of glutamic acid was remained unutilized. The dipicolinic acid content of cells cultured in Glc+Glu medium without biotin was markedly small and sporulation was suppressed before free spore release. Since biotin could be partiallyreplaced by one of TCA cycle intermediates such as oxalacetic acid, citric acid, or glutamic acid in enhancing growth in Glc medium, it was postulated that this strain might have a defect in converting pyruvate to oxalacetate which process is known to be mediated by pyruvate carboxylase that requires biotin as a cofactor.

• 미생물학회지
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• 제32권2호
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• pp.97-101
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• 1994

경기도, 충청남도 일원의 벼 근권에서 400~900nmol $C_2H_4/hr/vial$의 아세틸린 환원 활성을 갖는 질소고정균인 Azospirillum 15균주를 분리하였다. 이 분리균주들은 $1.0{\times}3.0{\mu}m$크기를 갖는 vibrioid 형태이었으며 액체배양시 monopolar single 편모를 가졌다. 이 분리균주들은 생리적, 형태적 특성에 따라 두 그룹으로 분류되었는데, 그룹 I 균주들은 탄소원으로 glucose를 잘 이용하였고 biotin 요구성인 반면, 그룹 II 균주들은 glucose를 전혀 이용하지 못하였고 biotin 비요구성이었다. 또한 semisolid 무질소 배지에서 48시간 배양할 때 그룹 I 균주들은 원래의 vibrioid 형태에서 좀 더 길어지면서 S자 모양으로 변하는 pleomorphic 특성을 보인 반면, 그룹 II 균주들은 원래의 모양과 운동성을 유지하였다. 이상의 결과로부터 그룹 I 균주들은 Azospirillum lipoferum으로, 그룹 II 균주들은 Azospirillum brasilense으로 동정하였다.

• Journal of Microbiology and Biotechnology
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• 제6권1호
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• pp.12-18
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• 1996

A chitosanase-producing bacteria was isolated on chitosan agar plate from soil samples. The strain was spore-forming gram positive bacteria, catalase positive, and rod shape. The strain was identified as Bacillus cereus. The strain did not need an inducer for the synthesis of chitosanase. Chitosanase from Bacillus sp. HW-002 was constitutive enzyme. The optimal medium for the production of the enzyme was composed of 0.5$\%$ sucrose and $1.5\%$ yeast extract-tryptone (1:1 w/w) mixture at pH 6.5. After Bacillus sp. HW-002 was cultivated at $32^{\circ}C$ for 32 h, maximal productivity was gained to be about 27, 200 U/l. Chitosanase from Bacillus sp. HW-002 was a mixed growth-linked metabolite.

• 한국물환경학회지
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• 제36권4호
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• pp.275-283
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• 2020

Fecal coliforms are indicator bacteria to evaluate fecal contamination and microbiological safety in environment water. To examine fecal coliforms by membrane filtration, 1% rosolic acid solution dissolved in sodium hydroxide(0.2 M) should be added to m-FC medium according to Korean standard method. To reduce the exposure of researchers to harmful chemicals and expenditure of unnecessary cost, we evaluated if the rosolic acid solution is required to detect fecal coliforms. For 113 samples collected from five intake sources of Seoul, 42 samples of six tributaries, and 11 samples of sewage, the number of fecal coliforms was compared in medium with or without the reagent. As a result, the number was higher in m-FC medium without the reagent, but there was not a statistically significant difference. In the water intake, m-FC medium without the reagent could be used to examine fecal coliforms except in July, August and in case of rainfall. When heterotrophic plate counts exceeded 1,000 CFU/filter, or during rainfall, there was an effect of background bacteria in two types of the medium. However, it was more appropriate to use m-FC medium with the reagent to suppress gram-positive bacteria that can grow on medium without the reagent. In the tributary and sewage samples, the effect of the background bacteria was low, allowing the use of medium without the reagent regardless rainfall. Thus, it is necessary to present in standard method that the addition of rosolic acid solution in m-FC medium can be selected according to the characteristics of samples.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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• pp.101-104
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• 2004

Among biological hydrogen production processes, fermentative processes have some advantages. In this research, the hydrogen producing bacterium was isolated from domestic landfill area and identified as Enterobacter sp. The strain was named Enterobacter sp. SNU-1453. Important parameters for the hydrogen process include pH, temperature, concentration of initial glucose, and kind of sugars. The pH of the culture medium significantly decreased as fermentation proceeded due to the accumulation of various organic acids, and this inhibited the $H_2$ production seriously. When pH was controlled at pH 7.0, hydrogen production was 2614.5 m1/1 in 17 hours. The increase of glucose concentration resulted in higher $H_2$ production. The productivity of this strain was 6.87 mmol $H_2/l$ per hi on concentration of 25g glucose/l. Enterobacter sp. SNU-1453 could utilize various sugars. These results indicate that Enterobacter sp. SNU-1453 has a high potential as a fermentative $H_2$ producer.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.606-611
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• 1997

Entomogenous fungi which attack living insects are powerful means for microbiological insecticide. The purpose of this study is to establish the culture conditions and media for mass production of Beauveria sp. C208 which has a broad host range as a potential microbiological pesticide. The temperature and pH range for optimal cultivation of this strain were 28$circ$C and pH 5.0-7.0. For Beauveria sp. C 208, 2% rice straw and 0.6% tryptone were found as the proper carbon and nitrogen sources, considering cell mass, enzyme activities such as chitinase, protease and lipase, and spore concentration.