• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.316-321
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• 1994

We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

• 한국균학회지
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• 제39권2호
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• pp.117-121
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• 2011

각종 버섯에서 항혈전 활성균주를 선별하기 위해 보관 균주 50여종과 임업협동조합에서 분양 받은 20여종의 균주를 대상으로 항혈전 활성을 검색한 결과, 항혈전 활성이 167 sec를 나타낸 상황버섯(Phellinus linteus)을 선별하였다. 본 균주가 생산하는 항혈전 활성의 본체를 파악하기 위해 pronase 처리와 periodate 산화를 행한 결과 pronase로 처리한 시료는 무처리군과 비교하여 차이가 없었던 반면 periodate로 산화시킨 시료는 항혈전 활성이 크게 감소함에 따라 P. linteus가 생산하는 항혈전 활성의 본체는 다당에 기인되는 것으로 추정되었다. 항혈전 생산을 위한 최적 배양조건은 soluble starch 3.0%, peptone 0.1%, $MgSO_4{\cdot}7H_2O$ 0.1%, $K_2HPO_4$ 0.1%, 초기 pH 7.0, 배양온도 $30^{\circ}C$ 및 교반속도 150 rpm이었다. 상기의 최적 배양조건에서 jar fermentor로 10일 배양하였을 때 390 sec의 항혈전 활성과 7.5 mg/mL의 균사체 생육을 나타내었다.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.407-412
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• 1988

트립토판 생산성을 향상시키기 위해 대장균 변이 주인 SB1007로부터 sulfanilamide 내성 균주를 유도하여 SA 3-39-16출 분리하고 이 균주로부터 tyrosine 영양요구주인 TY-90을 개발하였다. 시험관배양시 TY-90균주는 모균주보다 트립토판 생산량이 우수하였으나 발효조 배양시에는 모균주에 비해 낮은 양의 트립토판이 축적되었다. 발효조에서의 생산성 증대를 인해 또 다른 대장균 변이주인 SB2756으로부터 새로운 변이주의 개발을 모색하였다. 먼저 이중 영양요구성 균주인 SB2756의 revertant를 분리하여 그중 2,000mg/$\ell$ 농도의 $\beta$-thenylalanine에 내성을 갖는 TA-40-10을 분리하였고 이 균주로부터 phenylalanine 영향요구주인 TP-4를 개발하였다. 이 TP-4균주는 발효조에서 71시간 배양시 3.7g/$\ell$의 L-tryptophan을 생산하였다.

• 생명과학회지
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• 제17권6호통권86호
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• pp.798-804
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• 2007

토양으로부터 tyrosinase 저해제를 생산하는 방선균 F-97을 분리하여 이 균주로부터 tyrosinase 저해제 생산을 위한최적 조건을 검토하였다. 그 결과는 다음과 같다. 탄소원으로는 soluble starch가 가장 좋았으며, 그 최적 농도는 3.0%였다. 질소원으로는 유기질소원인 peptone이 가장 좋았으며 최적 농도는 0.36%로 나타났다. 무기염으로 K$_2$HPO$_4$가 가장 좋았으며 최적농도는 0.1 mM이었다. 최적온도 30${\circ}$C와70시간의 jar fermentor 내에서 배양 시 최고의 tyrosinase 저해제생산성을 나타내었다.

• 한국식품과학회지
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• 제6권4호
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• pp.219-230
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• 1974

국내외에서 수집한 유침 및 유전지대의 토양시료에서 n-paraffin자화성균주와 ethanol자화성균주를 분리하여 혼합배양을 시도하였고 선정된 균주에 대해서는 등정과 아울러 최적배지조성을 검토하였다. 최종적으로 선정된 균주중 n-paraffin자화성균주(strain No. 76)는 Candida tropicalis var. KIST 76으로, ethanol 자화성균주 (Strain No. 76H)는 Trichosporn cutaneum KIST 76H로 동정되었다. 최적배지조성에서 Candida tropicalis var. KIST 76을 단독배양하였을때 건조균체량은 배양 16시간 후에 16 g/l(대기질당 수율 71.1%), 이때의 단백질함량은 53.4%였으나 Candida tropicalis var. KIST 76과 Trichosporn cutaneum KIST 76H와 혼합배양하면 배양 12시간 후에 건조균체량은 20g/l(대기질당 수율 88.8%), 단백질 함량은 58.0%로 증가하였다.

• Journal of Microbiology
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• 제39권1호
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• pp.79-82
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• 2001

The influence of levulinic acid (LA) on the production of copolyester consisting of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) by Ralstonia eutropha was investigated. Addition of LA into the culture medium greatly increased the molar fraction of 3HV in the copolyester, indicating that LA can be utilized as a precursor of 3HV. In shake flask culture, the 3HV content in the copolyester increased from 7 to 75 mol% by adding 0.5 to 4.0 g/L LA to the medium containing fructose syrup as a main carbon source. A maximal copolyester concentration of 3.6 g/L (69% of dry cell weight) was achieved with a 3HV content of 40 mo1% in a jar fermentor culture containing 4.0 g/L of LA. When LA (total concentration, 4 g/L) was added repeatedly into a fermentor culture to maintain its concentration at a low level, the copolyester content and the 3HV yield from LA reached up to 85% of dry cell weight and 5.0 g/g, respectively, which were significantly higher than those when the same concentration of the LA was supplied al1 at once. The present results indicated that LA is more effective than propionate or valerate as a cosubstrate fur the production of copolyesters with varying molar fractions of 3HV by R. eutropha.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.199-202
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• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica was studied. Maltose, yeast extract and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in flask culture were pH 5.0, $25^{\circ}C$ and 150 rpm in a meidum containing of 30 g maltose, 6 g yeast extract, 2 g polypeptone, 0.5 g $K_2HPO_4$, 0.2 g $KH_2PO_4$, 0.2 g $MnSo_4\;{\cdot}\;5H_2O$, 0.2 g $MgSO_4\;{\cdot}\;7H_2O$ in 1-L distilled water. Exo-biopolymer production and mycelial growth in the suggested medium were significantly increased in a 2.5-L jar fermentor, where the maximum biopolymer concentration was 8 g/1.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.394-397
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• 2001

In order to maximize the cell growth and the biosurfactant production by the Pseudomonas aeruginosa BYK-2(KCTC 18012P), in the fed-batch fermentation processes were performed varying the feeding medium concentrations and the feeding rate. Feel-batch culture was performed with the optimal agitation speed of 200rpm and the aeration rate of 0.67vvm in a 7L Jar fermentor containing 3L of modified medium and 2.0-2.5%(v/v) fish oil as a carbon source. Addition of fish oil(2.5mL/l00mL modified medium), when fish oil was depleted, the cell and biosurfactant concentration were 6.1g/L and 22.7g/L, respectively.

• KSBB Journal
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• 제13권3호
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• pp.303-307
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• 1998

The fermentation conditions for the maximal production of the useful polysaccharides(water soluble polysaccharide and cell bound polysaccharide) from marine bacterium Zoogloea sp.(KCCM 10036) were investigated with a 5 L jar fermentor. The maximal production of these polysaccharides was obtained under the conditions of initial pH 7.8, 30$^{\circ}C$, 400 rpm of agitation speed, 2 Wm of aeration rate, 10%(w/v) of inoculum size and 2.5%(w/v) of glucose substrate and 10.38 g/L of total polysaccharide was produced. Apparent viscosity of the culture broth was increased with the production of these polysaccharides and the maximum value was reached to 22,500 cp.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.75-81
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• 1997

Streptomyces chibaensis J-59 did not grow in the culture medium containing only xylose or xylan as a carbon source, because it was defective in xylulokinase production; xylB mutant. S. chibaensis J-59 was able to produce xylanase and $\beta $-xylosidase as well as glucose isomerase. The glucose isomerase in S. chilbaensis J-59 was induced in the medium containing xylan or xylose which could be utilized as an inducer but not sa carbon and energy sources. So we tried to produce glucose isomerase whthout consumption of xylose or xylan as an inducer by using xylB mutant S. chilbaensis J-59. The optimum condition for the production of the glucose isomerase was attained in a culture medium composed of 1% xylan, 0.15% glucose, 1.5% corn steep liquor, 0.1% MaSO$_{4}$ $\CDOT $7H$_{2}$O, and 0.012% CoCL$_{2}$ $\CDOT $ 6H$_{2}$O(pH 7.0). The production of the enzyme reached to a maximum level when the bacteria were cultured for 42 h at 30$\circ $C. The enzyme production in a jar fermentor was increased twice as much as that in a flask culture.