• 한국식품영양과학회지
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• 제25권5호
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• pp.878-884
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• 1996

BailIus sp. IJ-3 균주는 균체외 효소로 대두단백 응고효소를 생산하고, 이 박테리아의 최적 효소생산에 대한 배지조성 및 배양조건을 검토하였다. 최대의 대두단백 응고효소를 생산하는 배지조성은 soymilk 20%(w/v), glucose 2.0%, yeast extract 5.0%, peptone 4.0% 및 potassium Phosphate, monobasic 1.0%였다. 초기 pH는 6.0이었고, $35^{\circ}C$ 배양에서 최대 효소활성을 보였다. 조정된 배지 조성에서 72시간 배양에 최대 효소활성을 나타내었으며, 기존배지 활성의 약 5.3배의 효소활성의 증가를 보였다. BaCilIus sp. IJ-3 균주효소는 7S globu1in에 대해 특이성을 갖고 있는 것으로 사료된다.

• 생명과학회지
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• 제30권10호
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• pp.896-904
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• 2020

본 연구에서는 가축의 면역증강용 생균제 개발을 위하여 Pediococcus acidilactici SRCM102607의 프로바이오틱스 특성 및 면역활성을 조사하였다. 전통발효식품으로부터 유산균을 분리 하였고, 분리 유산균을 대상으로 가축유해 미생물 5종에 대한 항균활성을 측정하였다. 우수한 결과를 나타내는 5종의 유산균을 1차 선별하였고, 이를 대상으로 생균제 소재 활용 가능성을 확인하기 위해 용혈성, 담즙산염 분해효소, 항산화 활성 분석을 실시하여 최종적으로 SRCM102607을 선별하였으며, 16S rRNA 유전자 염기서열 분석을 통해 Pediococcus acidilactici SRCM102607로 명명하였다. SRCM102607의 pH 2 조건에서 내산성은 1.54×10⁵ CFU/ml의 생균수를 보였으며, 0.5% 이상의 oxgall이 포함된 조건에서도 10⁵ CFU/ml 이상의 높은 생균수를 나타내었다. 또한, 선발균주의 산업적으로 활용할 수 있는 가능성을 검토하기 위해 항생제 내성 및 분해 효소능을 측정하였고 다양한 항생제에 대한 내성과 유해 효소를 생성하지 않음을 확인하였고, 최종적으로 면역 증강제로서의 활용 여부를 확인하기 위해 TNF-α 생성능(171.86±4.00 ng/ml)을 확인하였다. 본 연구를 기반으로 SRCM102607은 가축 생균제 소재로 활용 가능성과 면역활성이 뛰어난 유산균으로 생균제 산업에서의 잠재적 적용 가능성을 확인하였다.

• 생명과학회지
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• 제31권8호
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• pp.761-770
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• 2021

본 연구에서는 반응표면분석법을 이용하여 전통발효식품인 막걸리로부터 분리한 Bacillus amyloliquefaciens SRCM115785 균주에 대하여 protease 생산량을 증가시키기 위한 배지의 최적 농도를 확립하고자 하였다. 선정한 11개의 배지 성분 중 각 성분이 protease 생산에 미치는 영향에 대한 분석을 위해 Plackett-Burman design (PBD)를 설계하여 통계분석한 결과 glucose, yeast extract, beef extract를 protease 생산 향상을 위한 요인으로 최종 선별하였다. 선별된 3개의 성분에 대해 protease 생산을 위한 각 성분별 최적 농도를 결정하기 위해 central composite design (CCD)분석을 설계하여 protease 최대 생산을 위한 각 배지조성별 농도는 glucose 6.75 g/l, yeast extract 12.42 g/l, beef extract 17.48 g/l로 예측되었다. ANOVA 분석을 통해 실험모델의 적합성을 증명하였고, 설계한 최적배지에서 반복실험을 진행하여 protease 생산량을 측정한 결과 예측값과 매우 유사한 값을 나타냄을 확인하였다. 최종적으로 일반 배지에 비해 137% 환이 증가하였으며, 추가로 정량 분석 결과 기존 25.72 U/ml 대비 59.28 U/ml로 230.47% 증가함을 확인하였다. 본 연구를 통해 protease 생산량 증가를 위한 배지 성분의 최적화를 확립하였고, 이를 바탕으로 산업용 효소로서 protease의 효율적인 활용방안에 대한 기초자료로서 활용될 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1937-1943
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• 2007

A new strain, GS603, having ${\beta}$-glucosidase activity was isolated from soil of a ginseng field, and its ability to convert major ginsenoside $Rb_1$ to minor ginsenoside or gypenoside was studied. Strain GS603 was identified as an Intrasporangium species by phylogenetic analysis and showed high ginsenoside-converting activity in LB and TSA broth but not in nutrient broth. The culture broth of the strain GS603 could convert ginsenoside $Rb_1$i into two metabolites, which were analyzed by TLC and HPLC and shown to be the minor ginsenoside $F_2$ and gypenoside XVII by NMR.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.607-613
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• 2001

The biodegradation rates of diesel oil by a selected diesel-degrading bacterium, Pseudomonas stutzeri strain Y2G1, and microbial consortia composed of combinations of 5 selected diesel-degrading bacterial were determined in liquid and soil systems. The diesel degradation rate by strain Y2G1 linearly increased $(R^2=0.98)$ as the diesel concentration increased up to 12%, and a degradation rate as high as 5.64 g/l/day was obtained. The diesel degradation by strain Y2G1 was significantly affected by several environmental factors, and the optimal conditions for pH, temperature, and moisture content were at pH8, $25^{\circ}C$, and 10%, respectively. In the batch soil microcosm tests, inoculation, especially in the form of a consortium, and the addition of nutrients both significantly enhanced the diesel degradation by a factor of 1.5 and 4, respectively. Aeration of the soil columns effectively accelerated the diesel degradation, and the initial degradation rate was obviously stimulated with the addition of inorganic nutrients. Based on these results, it was concluded that the major rate-limiting factors in the tested diesel-contaminated soil were the presence of inorganic nutrients, oxygen, and diesel-degrading microorganisms. To resolve these limiting parameters, bioremediation strategies were specifically designed for the tested soil, and the successful mitigation of the limiting parameters resulted in an enhancement of the bioremediation efficiency by a factor of 11.

• KSBB Journal
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• 제25권3호
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• pp.230-238
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• 2010

A microbial strain having high keratinase activity was isolated from the soil of poultry factories of Gyeonggi or Chungcheong-do. The isolated strain was identified as Bacillus sp. based on its morphological and biochemical characteristics. In this study, the optimal conditions for the production of keratinase by this strain were investigated. The optimal medium composition for the keratinase production was determined to be 3.5% chicken feather as carbon source, 1.0% tryptone as organic nitrogen source, 1.0% $KNO_3$ as inorganic nitrogen source and 0.05% KCl, 0.05% $KH_2PO_4$, 0.03% $K_2HPO_4$ as mineral source and 0.01% yeast extract as growth factor. The optimal temperature and pH was $40^{\circ}C$ and 8.5 with shaking culture (200 rpm), respectively. The maximum keratinase production reached to 123 units/ml after 42 hr of cultivation under the optimal condition. When the hair was used as the sole carbon source, the maximum enzyme activity was 88 units/ml after 120 hr and in this case, the hair added in the medium was not degraded completely but got thinner than the control by 20%.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1324-1329
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• 2008

This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

• The Plant Pathology Journal
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• 제36권2호
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• pp.185-191
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• 2020

Streptomyces griseus S4-7, a well-characterized keystone taxon among strawberry microbial communities, shows exceptional disease-preventing ability. The whole-genome sequence, functional genes, and bioactive secondary metabolites of the strain have been described in previous studies. However, proteomics studies of not only the S4-7 strain, but also the Streptomyces genus as a whole, remain limited to date. Therefore, in the present study, we created a proteomics reference map for S. griseus S4-7. Additionally, analysis of differentially expressed proteins was performed against a wblE2 mutant, which was deficient in spore chain development and did not express an antifungal activity-regulatory transcription factor. We believe that our data provide a foundation for further in-depth studies of functional keystone taxa of the phytobiome and elucidation of the mechanisms underlying plant-microbe interactions, especially those involving the Streptomyces genus.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.371-377
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• 2012

The present study describes medium-chain-length polyhydroxyalkanoates (mcl-PHAs) production by the Pseudomonas Gl01 strain isolated from mixed microbial communities utilized for PHAs synthesis. A two-step fed-batch fermentation was conducted with glucose and waste rapeseed oil as the main carbon source for obtaining cell growth and mcl-PHAs accumulation, respectively. The results show that the Pseudomonas Gl01 strain is capable of growing and accumulating mcl-PHAs using a waste oily carbon source. The biomass value reached 3.0 g/l of CDW with 20% of PHAs content within 48 h of cultivation. The polymer was purified from lyophilized cells and analyzed by gas chromatography (GC). The results revealed that the monomeric composition of the obtained polyesters depended on the available substrate. When glucose was used in the growth phase, 3-hydroxyundecanoate and 3-hydroxydodecanoate were found in the polymer composition, whereas in the PHAs-accumulating stage, the Pseudomonas Gl01 strain synthesized mcl-PHAs consisting mainly of 3-hydroxyoctanoate and 3-hydroxydecanoate. The transcriptional analysis using reverse-transcription real-time PCR reaction revealed that the phaC1 gene could be transcribed simultaneously to the phaZ gene.

• 대한미생물학회지
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• 제22권3호
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• pp.225-232
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• 1987

Authors studied on the isolation of V. damsela from sea water, fish and shellfish at the Keoje Hae keumkang on the southern sea and at Hongdo island and Heucksan island on the western sea of Korea from May to September in 1986. Authors investigated for the isolated strains to bacteriological identification, hemolysis about various erythrocytes and antibiotic susceptibilities. The results obtained were as follows: 1. V. damsela was isolated 14 strains from total 383 specimens; 233 cases of sea water, 40 cases of fish and 110 cases of shellfish, respectively. Eight strains were isolated from sea water and 6 strains were isolated from shellfish. 2. The biochemical characteristics which differentiate it from other Vibrio species were indole negative, ornithine negative, Voges-Proskauer positive, arginine positive, galactose positive, glucose positive, maltose positive, mannose positive, trehalose positive, and growth in nutrient broth with 1% to 6% NaCl. 3. On hemolysis reaction on blood agar media using human, rabbit and guinea pig erythrocytes, human erythrocytes were 11 strain positive, rabbit erythrocytes were 12 strain positive and guinea pig erythrocytes were 13 strain positive. 4. Senistivity test using with chemotherapeutic agents of "BioLab" Microbial Sensitivity Test Discs were generally sensitived to amikacin, ampicillin, cephalothin, chloramphenicol, clindamycin, erythromycin, gentamycin, kanamycin, methicillin, penicillin, streptomycin, tetracycline and tobramycin, respectively, but were resistant to lincomycin.