• 한국미생물·생명공학회지
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• 제18권5호
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• pp.460-465
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• 1990

Asp.wentii와 Asp.nidulans의 원형질체 재생은 2-DG가 30$\mu g$/ml 첨가된 포자현탁액을 4시간 전배양 할 때 적당하였고 ergosterol, myoniositol, casamino acid, BSA가 함유된 CBE 재생용 배지에서 효과적이었으며, 30 이상 재생률을 나타내었다. 원형질체 융합은 10mM $CaCl_2$가 함유된 pH7.5의 30PEG 4000으로$37^{\circ}C$ 에서 10분간 처리했을 때 가장 양호하였으며, 융합빈도는 $8.2\times 10^{-4}$을 나타내었다. 가장 우수한 융합주인 FWN-56은 CMCase, avicelase, $\beta$-glucosidase 및 xylanase를 동시에 분비하였으며 친주에 비하여 활성이 2.3배, 1.5배, 1.8배, 2.5배 각각 증가하였고, 또한 MM에 4중 이상 보관 후의 segregant율이 1 이내였으므로 유전적 안정성은 높았으며, 분생포자 DNA함량은 1.4-1.6배였다. 또한 핵의 크기도 친주에 비하여 큰 것으로 보아 융합주임을 확인하였다.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.326-335
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• 2008

Bacillus subtilis AH18균주는 auxin, siderophore 그리고 cellulase를 동시에 생산하는 PGPR 균주이자 생물방제균주로 항진균성 siderophore의 특성을 확인한 결과 catechol type의 siderophore로 확인하였다. $Siderophore_{AH18}$ 의 정제는 Amberlite XAD-2, sephadex LH-20 column chromatography 그리고 HPLC를 통해 정제 및 정제여부를 확인하였으며, GC-MS, $^1H$-NMR, 그리고 $^{13}C$-NMR을 통해 구조 및 분자량을 확인하였다. 그 결과 B. subtilis AH18이 생산하는 siderophore은 분자량 883의 bacillibactin임을 확인하였으며, 포자발아억제활성을 나타냄을 확인하였다. B. subtilis AH18은 P. capsici에 의한 고추역병을 효과적으로 방제하였으며(방제력 55%), 이는 bacillibactin에 의한 효과가 포함되리라 추측된다.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• 한국미생물·생명공학회지
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• 제43권1호
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• pp.16-21
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• 2015

2세대 바이오매스 볏짚을 이용하여 전자선 조사 후 NMMO 처리 공정을 수행하고 이를 분석하였다. 볏짚은 전자선 500 kGy 조사 후 NMMO 처리를 한 경우 72시간의 효소당화를 거쳐 글루코스 60.8%와 자일로스 9.7% 포함 약 83.8% 정도의 당수율을 보였다. 이 전처리 공정은 유해한 화학물질을 사용하지 않아서 친환경적이며 전자선 조사와 NMMO 처리의 시너지 효과가 있음을 알 수 있었다. 그러나 전자선 조사량이 너무 높다는 단점이 있으며 추후에는 낮은 전자선 조사량과 여러 가지 단일공정을 통합한 새로운 복합전처리 방법 연구의 필요성이 있다. 따라서 이 단점을 보완한다면 전자선 조사라는 친환경적 방법과 더불어 NMMO 용액의 재활용성을 이유로 바이오에탄올 생산 등의 산업현장에의 적용 가능성이 높다는 것을 알 수 있었다.

• 한국식품과학회지
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• 제23권2호
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• pp.183-187
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• 1991

김치의 발효촉진과 억제효과를 검토하기 위하여 microwave에 의한 절임배추의 열처리, 효소 및 김치액의 첨가, 완충액과 몇 가지 무기염을 첨가하여 $25{\sim}35^{\circ}C$에서 발효하는 동안 pH의 변화를 측정하였다. 그 결과 순간 열처리와 amylase 및 celulase 첨가 단독으로는 김치발효 시간 단축에 뚜렷한 효과가 없었으나 이들을 병용하였을 때는 현저한 발효촉진 효과가 있었다. 김치액의 첨가는 pH 4.6의 것을 10%되게 첨가하고 발효시켰을 때 발효가 2배 정도 빨라졌고 맛과 냄새에서도 다른 pH의 김치액보다 좋았다. 완충액 중 phosphaste 완충액이, 무기염 중에서는 nitrite염, $Na_2HPO_4$가 김치발효를 현저히 억제시켜 김치 저장성 향상을 위한 첨가물로서의 가능성을 보여주었다.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.271-276
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• 2017

A highly thermostable ${\beta}-(1-4)-glucanase$ (NA23_08975) gene (fig) from Fervidobacterium islandicum AW-1, a native-feather degrading thermophilic eubacterium, was cloned and expressed in Escherichia coli. The recombinant FiG (rFiG) protein showed strong activity toward ${\beta}-{\small{D}}-glucan$ from barley (367.0 IU/mg), galactomannan (174.0 IU/mg), and 4-nitrophenyl-cellobioside (66.1 IU/mg), but relatively weak activity was observed with hydroxyethyl cellulose (5.3 IU/mg), carboxymethyl cellulose (2.4 IU/mg), and xylan from oat spelt (1.4 IU/mg). rFiG exhibited optimal activity at $90^{\circ}C$ and pH 5.0. In addition, this enzyme was extremely thermostable, showing a half-life of 113 h at $85^{\circ}C$. These results indicate that rFiG could be used for hydrolysis of cellulosic and hemicellulosic biomass substrates for biofuel production.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.134.1-134
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• 2003

The purpose of this study was to investigate the release of p-hydroxybenzoic acid and other compounds from cell wall materials(CWM) and their cellulose fraction from carrot with chemical and enzymatic hydrolysis. To investigate this effect on cell wall chemistry of carrot, alcohol insoluble residue(AIR) of CWM were prepared and were extracted sequentially with water, imidazole, CDTA(-1, -2), Na$_2$CO$_3$(-1, -2), KOH(0.5, 1.0 and 4M), to leave a residue. These were analysed for their carbohydrate and phenolic acids composition. Arabinose and galactose were the main noncellulosic sugars. Phenolics esterified to cell walls in carrot were found to consist primarily of p-hydroxybenzoic acid with minor contribution from vanillin, ferulic acid and p-hydroxybenzaldehyde. p-Hydroxybenzoic acid was quite strongly bound to the cell wall. The contents of p-hydroxybenzoic acid in 0.5M KOH, Na$_2$CO$_3$-2, IM KOH, and ${\alpha}$-cellulose were 2,097, 1,360, 1,140, and 717 $\mu\textrm{g}$/g AIR from CWM, respectively. Alkali labile unknown aromatic compound(C$\sub$7/H$\sub$10/O$_2$) was found in ${\alpha}$ -cellulose hydrolyzate digested with driselase and cellulase. This compound was also found in hydrolyzate of 2 M trifluoroacetic acid at 120$^{\circ}C$ for 2 hours. Driselase treatment solubilized only 46.6 $\mu\textrm{g}$/g of the p-hydroxybenzoic acid from carrot AIR. These results indicate that p-hydroxybenzoic acid was associated with neutral polysaccharides, long chain galactose and branched arabinan from graded alcohol precipitation.

• 생명과학회지
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• 제21권12호
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• pp.1716-1720
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• 2011

섬유소를 비롯한 단백질, 지질, 녹말을 분해할 수 있는 세균을 된장으로부터 분리하여 동정한 결과 Bacillus subtilis로 분류되었으며, Bacillus subtilis CK-2로 명명하였다. 분리균주는 $40\sim45^{\circ}C$의 비교적 넓은 온도 범위와 pH 6~9의 넓은 pH 범위, 그리고 NaCl 0~3% 범위에서 잘 자랐으며, 높은 자가분해효소 활성을 갖는 것을 알 수 있었다. B. subtilis CK-2가 분비하는 가수분해효소들은 대부분 세균의 생장과 거의 비례적으로 세포외 활성을 나타내는 1차 대사산물로 확인되었다. 이상의 결과로부터 B. subtilis CK-2는 농수임산물 폐기물이나 음식물 폐기물의 퇴비화, 사료 생산 등에 유용하게 이용될 수 있을 것으로 생각한다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.89-92
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• 2011

Cyclic AMP receptor-like protein (Clp), is known to be a global transcriptional regulator for the expression of virulence factors in Xanthomonas campestris pv. campestris (Xcc). Sequence analysis showed that Xanthomonas oryzae pv. oryzae (Xoo) contains a gene that is strongly homologous to the Xcc clp. In order to determine the role of the Clp homolog in Xoo, a marker exchange mutant of $clp_{xoo4158}$ was generated. Virulence and virulence factors, such as the production of cellulase, xylanase, and extracellular polysaccharides (EPS) and swarming motility were significantly decreased in the $clp_{xoo4158}$ mutant. Moreover, the mutation caused the strain to be more sensitive to hydrogen peroxide and to over-produce siderophores. Complementation of the mutant restored the mutation-related phenotypes. Expression of $clp_{xoo4158}$, assessed by reverse-transcription realtime PCR and clp promoter activity, was significantly reduced in the rpfB, rpfF, rpfC, and rpfG mutants. These results suggest that the clp homolog, $clp_{xoo4158}$, is involved in the control of virulence and resistance against oxidative stress, and that expression of the gene is controlled by RpfC and RpfG through a diffusible signal factor (DSF) signal in Xanthomonas oryzae pv. oryzae KACC10859.

• 한국식품영양학회지
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• 제24권1호
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• pp.117-123
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• 2011

This study was conducted to establish process conditions for plant-originated lactic acid production using a mixed culture of plant originated lactic acid bacteria, Lactobacillus sakei B2-16, and Lactobacillus plantarum P23, which were isolated from kimchi, and Bacillus subtilis, which was TP6 isolated from Denjang. Soybean medium was pretreated for 10 minutes at $110^{\circ}C$ and hydrolyzed with 0.2%(w/v) cellulase at $55\sim60^{\circ}C$ for at least 2 hrs. The quality of the final fermentation product was influenced by the inoculation ratio of the Lactobacillus sakei B2-16, Lactobacillus plantarum P23, and Bacillus subtilis TP6. The optimum microorganism inoculation ratio was 1:0.7:0.3, Lactobacillus sakei B2-16: Lactobacillus plantarum P23: Bacillus subtilis TP6, respectively. The sensory characteristics of the product were a refreshing sourness and a soft flavor.