• 현장농수산연구지
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• 제20권1호
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• pp.49-54
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• 2018

느티만가닥버섯 해송이 품종의 우수 균주를 선발하기 위하여 각기 다른 자실체에서 분리한 균을 Di-mono 교배하여 균을 선발하였다. 교배한 균주를 PDA에서의 균사생장 조사를 통하여 균사생장이 좋은 3균주를 선발하였다. PDA배지에서 10일간 배양했을 때 균사생장은 3번 균주가 62mm로 가장 빠르고, 7번 균주가 58mm, 그리고 2번, 10번, 9번순이었다. 선발된 3균주, 즉, KNCAF-H-3, KNCAF-H-7, KNCAF-H-2는 톱밥배지에서 10일간 배양한 결과 각각 79mm, 76mm, 73mm의 균사생장을 보여, 대조 품종인 그린피스 5호의 55mm보다 균사생장이 좋았다.

• 한국미생물·생명공학회지
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• 제4권3호
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• pp.105-110
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• 1976

곰팡이를 이용하여 섬유소분해효소를 생산할 목적으로 전국각처에서 수집한 102종의 시료로부터 총 221주의 곰팡이를 분리하였다. 이들 분리균주의 섬유소분해능을 여과 지붕괴법 ？ 액화법 및 cup method로서 1차 36균주를 선별하였고 1차 선별된 균주를 탄소원을 변경하여 배양한뒤 활성을 추정하여 2차로 15균주를 선별하였다. 15균주를 개선된 배지에서 배양한뒤 $C_1$, $C_{x}$ 및 filter paper-activity을 측정하여 최종적으로 $C_1$및 $C_{x}$ -Cellulase의 활성이 강한 균주인 Aspergillus sp. strain No. AS-9, Penicillium sp. strain No. KI-1-2 Trichoderma sp. strain No. KI-7-2, KI-7-5, 및 KI-4-IB을 선별하였다. 이상 최종적으로 선별된 균주중의 strain No. KI-4-1-1B 조효소액으로 ammonia 처리볏짚을 당화시킬 때 24시간 작용으로 26%가 당화되었다.

• 한국미생물·생명공학회지
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• 제1권1호
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• pp.37-42
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• 1973

본실험에서 얻어진 결과를 요약하면 다음과 같다. 1) Inulin을 분해하는 효소를 생산하는 Aspergillus속 1주를 선별하였다. 2) 선별된 묘주효소의 E.P차에 의한 침전은 pH8~5에서 효소단백질이 다량 회수되었다. 3) 선별된 묘주가 분비하는 Inulase활성최적 pH는 3.0부근이 었다. 4) 선별된 묘주의 Inulin 분해효소의 활성최적 온도는 $55^{\circ}C$였다. 5) 본 Sample효소의 열에 대한 안정성은 $50^{\circ}C$에서 10분간 열처리 하여도 안정하였다. 6) 본 Sample효소의 안정 pH는 2.5~4.5정도였다. 7) 본 Sample효소의 금속 ion에 대한 영향은 $Mg^{++}$는 Activator였으며 $Sb^{+++}$, $Bi^{+++}$.는 저농도에서는 inhibitor였으나 $10^{-4}$ M~$10^{-4}$ M 농도일때는 촉진시켰으며 더욱 금속 ion농도가 높아짐에 따라 inhibition하였으며 $Ag^{++}$, $Hg^{++}$의 경우에는 저농도($10^{-8}$ M)일 때는 Activation하였고 반면, 농도가 높아짐에 따라 저해효과가 더욱 컸으며 특히 $Hg^{++}$의 경우 $10^{-2}$ M 농도에서 약 80% 저해를 나타내었다.내었다.

• 미생물학회지
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• 제20권3호
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• pp.125-133
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• 1982

Mutational experiments were performed to imporve the cellulase productivity of Aspergillus phoenicis KU175, isolated from the southern part of Korea, as a high cellulase producer. By treatment ultra-violet light nad 4-NQO(4-Nitroquinoline-N-Oxide), mutation waas induced, and treatment ultra-violet light and 4-NQO (4-Nitroquinoline-N-Oxide), mutation was induced, and A.phoenicis KU175-115 was finally selected for its highest avicelase production. Avicelase production of the mutant was increased about 2 times compared with those of the wild strain. However, activities of other hydrolytic enzymes, such as amylase, protease and nuclease, of the mutant strain didn't show a marked difference compared with those of the nuclease, of the mutant strain didn't show a marked difference compared with the wild strain, except slight increase in ribonuclease activity and slight decrease in glucoamylase activity. Avicelases from the mutant strain selected were purified from wheat bran culture by successive salting out, followed by dialysis and column chromatography, and their charcteristics were compared with thosw of the wild strain. Avicelase was separated into three peaks in the mutant strain as well as in the case of wild strain. Avicelase II activity of the mutant strain was prominently higher than that of the wild strain, while avicelase I and III activities of those were equivalent. The optimal pH ranges and stability of avicelase II from the mutant strain were pH4-5 and pH3.5-6.0, respectively, as well as in the case of the wild strain. The optimal temperature and thermal stability of avicelase II from the mutant strain were $40{\sim}50^{\circ}C\;and\;20{\sim}55^{\circ}C$, respectively. These results were same as those of the wild strain. By the using of Eadie-Hofastee plot, $K_m\;and\;V_{max}$ of avicelase II from the mutant and the wild strain were calculated to be 2.29mg/ml and $4.84{\mu}g$ reducing sugar as glucose per min equally, from the line fitted to the data by the least square method. Activity of avicelase II from the mutant strain was slightly activated by $Mg^{++}\;but\;inhibited\;by\;Cu^{++}, \;Mn^{++}\;and\;Zn^{++}$, as well as in the case of the wild strain. Therefore, it was concluded that the mutant didn't induce the formation of another avicelase isozyme, or the changes in the properties of avicelase, but induce the changes in the productively of the same avicelase II by the action of regulatory gane.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.675-683
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• 2016

One osmotolerant strain from among 44 yeast isolates was selected based on its growth abilities in media containing high concentrations of sucrose. This selected strain, named SK-ENNY, was identified as Meyerozyma guilliermondii by sequencing the internal transcribed spacer regions and partial D1/D2 large-subunit domains of the 26S ribosomal RNA. SK-ENNY was utilized to produce high-fructose glucose syrup (HFGS) from sucrose-containing biomass. Conversion rates to HFGS from 310-610 g/l of pure sucrose and from 75-310 g/l of sugar beet molasses were 73.5-94.1% and 76.2-91.1%, respectively. In the syrups produced, fructose yields were 89.4-100% and 96.5-100% and glucose yields were 57.6-82.5% and 55.3-79.5% of the theoretical values for pure sucrose and molasses sugars, respectively. This is the first report of employing M. guilliermondii for production of HFGS from sucrose-containing biomass.

• 한국미생물·생명공학회지
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• 제14권5호
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• pp.377-383
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• 1986

토양으로부터 carboxymethyl cellulase 및 intra-cellular $\beta$-glucosidase생산능력이 높은 방선균 No. 109균주를 분리하고 이 균주의 배양상 내지는 형태적 특성, 생리적 특성 그리고 세포벽 구성성분 등을 조사, 균동정을 행한 결과 No. 109 분리균은 Streptomyces tanashiensis 또는 그 유연균으로 동정되었다.

• 동아시아식생활학회지
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• 제14권5호
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• pp.508-512
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• 2004

In other to produce vinegar using Schizandra chinensis Ballon(omija), acetic acid bacteria(AAB) were selected from several conventional vinegars, and total 30 acetic acid bacterial strains were isolated. Among the isolated strains, a strain was selected from medium containing omija juice which showed the highest productivity of acetic acid. The strain was identified as Acetobacter sp. C5-1b. Optimum conditions for acetic acid production of Acetabacter sp. C5-1b were involved with 30t: of fermentation temperature and shaking culture. The acidity of culture medium was reached to 5.3% after 8 days shaking cultivation at 30℃.

• 한국축산식품학회지
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• 제42권6호
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• pp.996-1008
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• 2022

Lactic acid bacteria are representative probiotics that have beneficial effects on humans. Nineteen strains among the 167 single strains from kimchi was selected and their physiological features were investigated. The selection of a strain was based on strong enzyme (lipase, α-amylase, and α-glucosidase) inhibitory activities and anti-obesity effects in the adipocytes. For the final selection, the strain Lactiplantibacillus plantarum KC3 was tested for its potential as a starter. To assess its functionality, a freeze-dried culture of L. plantarum KC3 was administered to a diet-induced obese mouse model receiving a high-fat diet. The animal group administered with L. plantarum KC3 showed significant body weight loss during the 12-week feeding period compared to the high-fat control group. This study investigated the physiological characteristics of selected strain and evaluated its potential as an anti-obesity probiotic in mice.

• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.78-85
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• 1993

In order to elucidate the mechanism which regulates the production of cyclodextrin glucanotransferase (CGTase) and to achieve overproduction of CGTase by releasing catabolite (glucose) repression, several catabolite repression resistant mutants were selected from newly screened Bacillus firmus var. alkalophilus H609, after NTG (N-methyl-N -nitro-N-nitrosoguanidine) treatment, using 2-deoxyglucose as a nonmetabolizable analog of catabolite glucose and as a selection marker. Five catabolite repression resistant mutants were selected from about 30, 000 2-deoxyglucose resistant colonies. Relative catabolite repression indices of the selected mutants were in the range of 8~80% assuming 100% for parent strain. The amount of CGTase produced by the mutant strain CR41, which was 250 units/ml, was three times larger than that produced by its parent strain. The mutation seems to have occurred in the regulatory region of CGTase gene and not in the structural region or the glucose transporting system in cell membrane. The enzymatic properties of CGTase excreted from parent and mutant strains were also compared.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.309-315
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• 2000

To isolate yeast strains producing high concentration of ethanol, 125 strains were subjected to screening. Initially 14 strains able to grow in a medium containing 15%(v/v) ethanol, 7 strains capable of growing in a medium containing 50%(v/v) glucose, 23 strains having relatively fast fermentation rates, 13 strains able to grow at $42^{\circ}C$ were selected. After secondary screening, 11 strains having relatively high ini-tial fermentation rate and producing high concentration of ethanol were selected. After tertiary screening 5 strains producing high concentration of ethanol were selected. These 5 strains were again for their ethanol produc-tion, residual sugar, and viability using fermentation medium containing 25% glucose. The strain producing the highest concentration of ethanol was 20-1 strain which produced 10.56%(v/v) ethanol in 4 days, and the highest viable strain was 11-1 which produced 10.35%(v/v) ethanol(13.1%. v/v) with the viability of 30.44% after 5 days of fermentation. Both of the 20-1 and 11-1 strains were identified as Saccharomyces cerevisiae.