• KSBB Journal
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• 제19권4호
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• pp.295-300
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• 2004

해양유래미생물에서 gelatin 분해능이 우수한 균주 Vibrio vulnificus CYK 279H를 이용하여 최적 효소활성조건을 검토하였다. 온도와 초기 pH는 $25^{\circ}C$, 7.5에서 높은 것으로 나타났으며, 단당, 이당, 다당류를 첨가하여 탄소원의 영향에서는, 0.3% (w/v) galactose 에서, 유$.$무기 질소원으로는 0.6% (w/v) yeast extract와 4.0% (w/v) gelatin, 0.2% (w/v) (NH$_4$)$_2$SO$_4$에서 효소활성이 가장 높게 나타났다. 염 농도로는 2.0% (w/v) NaCl, 금속이온은 Fe$^{2+}$를 첨가하였을 때 효소활성이 증가되었다. 선정된 최적배양조건에서 Vibrio vulnificus CYK 279H를 배양한 결과, 18 h 배양시 73 Unit/1로 기본배지 20 Unit/1보다 활성이 3.7배 증가한 것으로 확인되었다.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.198-201
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• 1989

토양에서 분리, 동정한 Steptomyces sp. GI 32의 glucose isomerase 생산은 sorbitol 1%, yeast extract 0.4%, tryptore 0.6%, 1 mM Fe$_2$(SO$_4$)$_3$의 조성을 가진 배지에서 초기 pH 7.0으로 조절하여 35$^{\circ}C$에서 약 18시간 진탕배양시 효소생산량이 최고로 240 units/mg이었다. 효소는 ammonium sulfate 분획, DEAE cellulose chromatography 등의 과정을 거쳐 부분정제한 결과 3배정도 효소 비활성이 증가하였다. 효소활성의 치적온도는 7$0^{\circ}C$이며, 최적 pH는 8.0이었다. 특히 효소의 열안정성이 7$0^{\circ}C$에서 1시간 가열하여도 전혀 실활되지 않았다.

• 한국미생물·생명공학회지
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• 제6권1호
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• pp.1-8
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• 1978

섬유소분해효소 생산균인 Trichoderma sp. KI 7-2의 cellulase생성을 위한 탄소원으로는 순수한 섬유소보다 볏짚 보리짚 분말을 사용하는 것이 좋았으며 1% 첨가에서 심부배양한 액을 유안농도 20~60%로 떨어뜨린 침전에서만 cellulase의 활성이 나타났다. 이 조효소의 작용최적온도는 5$0^{\circ}C$, 최적 pH는 4.2였으며, 열에 대한 안정성은 5$0^{\circ}C$에서 2시간까지 100% 활성을 유지하였고 pH에 대한 안정성은 pH4~6에서 안정하였지만 pH 4이하 및 pH 6.0 이상에서는 불안정하였다. 이러한 성질의 효소를 생산하는 균주로서 볏짚 발효시키는 몇 가지 방법을 아울러 검토하였다.

• 대한환경공학회지
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• 제28권1호
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• pp.48-53
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• 2006

본 논문에서는 plasmatron을 사용하여 프로판의 개질에 의해 SynGas 생산의 최적의 조건을 연구하였다. 플라즈마는 공기와 아크 방전에 의해 생성되며 합성 가스의 상관 관계뿐만 아니라 수증기, $CO_2$ 또는 반응기에 촉매를 추가하여 프로판 전환에 미치는 영향과 수소의 수율, $H_2/CO$ 비에 대해 연구하였다. $O_2/C_3H_8$ 유량비, $H_2O/C_3H_8$ 유량비와 $CO_2/C_3H_8$ 유량비를 각각 $0.94{\sim}1.48,\;4.3{\sim}10$과 $0.8{\sim}3.05$로 변화하였을 때, $H_2O/C_3H_8$ 유량비의 변화 결과가 최대 $28.2{\sim}31.6%$의 $H_2$ 농도를 나타냈으며, 촉매를 추가하고 $H_2O/C_3H_8$ 유량비의 변화결과 $6.6{\sim}7.1%$의 최소 CO 농도를 나타냈다. 그리고 $H_2/CO$ 비는 $3.89{\sim}4.86$을 나타냈다.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.62-69
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• 1999

Clostridium butyricum NCIB 9576 evolved hydrogen gas and produced various organic acids from glucose, lactose, starch, and glycerol. Total amount of hydrogen gas produced from 1 and 2% glucose were 630 and 950ml $H_2$/l-broth, respectively, for the first 24 hrs of incubation and the maximum hydrogen production rates were 42 and 94ml $H_2$/hr/1-broth, respectively. Teh initial pH 6.8 decreased to 4.2~4.5 during the first 12~16 hrs of fermentation when the pH was not controlled, resulting in ceasing the cell growth and hydrogen evolution and in degradation of 82 and 40% glucose after 24hrs of incubation from 1 and 2% glucose, respectively. When pH was controlled to 5.5, glucose was consumed completely and resulted in increasing hydrogen production approximately 38~50% compared to the experiments without the pH control. C. butyricum NCIB 9576 produced hydrogen gas approximately 644, 1,700 and 3,080 ml $H_2$/l-broth with 0.5, 1 and 2% lactose, respectively and the maximum hydrogen production rates were 41, 141 and 179ml $H_2$/hr/l-broth, respectively. All of the lactose added was degraded completely during fermentation even though pH was not controlled. C. butyricum NCIB 9576 produced 183 and 709ml $H_2$/l-broth with 0.1 and 0.5% starch for 48 hrs, respectively, when pH was not controlled. The maximum rates of hydrogen gas production were 43 and 186ml $H_2$/l-broth, respectively and 80~100% of starch added was fermented. Approximately 107ml $H_2$/l-broth was produced using 1% glycerol by C. butyricum NCIB 9576 and the pH was maintained higher than 6.1 during fermentation without pH control. The degradation of glucose, lactose, starch and glycerol by C. butyricum NCIB 9576 were affected by the pH of fermentation broth and the organic acids released during fermentation. The pH of feremtntation broth dropped to 4.2~4.6 after 12~14 hrs incubation when glucose was used as a substrate while pHs were maintained above pH 5 under the same experimental conditions when lactose, starch and glycerol were used. The organic solvents and acids produced during glucose fermentation were mainly ethanol, butyrate, acetate and a little of propionate, while butyrate was the main organic acids during the lactose, starch, and glycerol fermentation by C. butyricum NCIB 9576.

• 미생물학회지
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• 제29권6호
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• pp.408-415
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• 1991

TOL plsmid size of Flavobacterium odoratum SUB53 was estimated as 83 Md and the optimum concentration of m-toluate degradation by TOL plasmid was 5 mM. $H_{2}$ production by Rhodopseudomonas sphaeroides KCTC1425 was largely dependent on nitrogenase activity and showed the highest at 30 mM malate with 7 mM glutamate as nitrogen source. Nitrogenase activities were inhibited by 0.3 mM $NH_{4}^{+}$ions, to be appeared the decrease of $H_{2}$ production. Conjugation of TOL plasmids from F. odoratum SUB53 and Pseudomonas putida mt-2 to R. sphaeroides showed the optimum at the exponential stage of recipient cells in presence of helper plasmid pRK2013. According to the investigation of catechol-1,2-oxygenase (C-1, 2-O) and catechol-2,3-oxygenase (C-2,3-O) activities of R. sphaeroides C1 (TOL SUB53) and C2 (TOL mt-2), the gene for C-2,3-O is located on TOL plasmid and gene for C-1, 2-O on the chromosome of R. sphaeroides. m-Toluate was biodegraded by TOL plasmid in R. sphaeroides C1 and C2, presumably to be produced $H_{2}$ gas from the secondary metabolites of m-toluate.e.

• 한국균학회지
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• 제27권6호
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• pp.383-385
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• 1999

Cheese 제조시 부산물로 생성되는 whey를 배지로 사용하여 Aspergillus niger를 이용하여 citric acid를 생산하는데 영향을 미치는 여러 가지 요인 중 중요한 요인인 온도와 pH의 영향에 대하여 고찰하였다 15일간 27, 30, 33, $36^{\circ}C$와 pH 2, 3, 4, 5에서 각각 배양하면서 소비된 lactose의 양과 생산된 citric acid의 양을 측정하였다. 생산된 citric acid의 최대 농도는 33.9 g/l(구연산 생산에 쓰여진 유당을 기준으로 할 때 68.26%)이었으며, shaking speed는 citric acid 생산에 직접 영향을 주기보다는 pellet 형성시 그 형태에 영향을 미치는 것으로 나타났다. 배양 온도가 $33^{\circ}C$, pH는 3일때 가장 많은 양의 citric acid가 생산되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.512-515
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• 2005

An in vitro study was conducted to determine the effect of C18-polyunsaturated fatty acid on direct incorporation into the rumen bacteria, bio-hydrogenation and production of CLA in vitro. Sixty milligrams of linoleic acid ($C_{18:2}$) or linolenic acid ($C_{18:3}$) were absorbed into the 0.5 g cellulose powder was added to the 150 ml culture solution consisting of 120 ml McDougall's buffer and 30 ml strained rumen fluid. Four uCi of 1-$^{14}C_{18:2}$ or 1-$^{14}C_{18:3}$ (1 uCi/15 mg each fatty acid) were also added to the corresponding fatty acids to estimate the direct incorporation into the bacterial lipids. The culture solution was then incubated anaerobically in a culture jar with stirrer at 39$^{\circ}C$ for 12 h. Ammonia concentration and pH of the culture solution were slightly influenced by the fatty acids. Amount of fatty acid incorporated into the bacteria was 1.20 mg and 0.43 mg/30 ml rumen fluid for $C_{18:2}$ and $C_{18:3}$, respectively during 12 h incubation. Slightly increased CLA (sum of cis-9, trans-11 and cis-10, trans-12 $C_{18:2}$) was obtained from the $C_{18:3}$ addition compared to that from $C_{18:2}$ after 12 h incubation in vitro.

• 생명과학회지
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• 제6권2호
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• pp.79-86
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• 1996

A bacterium producing pullulanase was from soil, and was identified Bacillus cereus and named as Bacillus cereus JK36. The optimal culture conditions for the efficident production of pullulanase from B. cereus JK36 was obtained by cultivating with the medium composed of 1% pullulan, 1% teast extract, 1% bactopeptone, 0.1% NaH$_{2}$PO$_{4}$, 2H$_{2}$O, 0.02% MgSO$_{4}$\ulcorner7H$_{2}$O at 40$\circ$C, initial pH 6.5 for 70 hours. Using the culture supernatant as crude enzyme, the optimal pH and temperature of the pullulanase of this strain were 6.5 and 50$\circ$C. In effect of pH and temperature on the stability of the enzyme, the enzyme was stable in the range of pH6.0$\sim$9.5 and up to 40$\circ$C, respectively. The hydrolysis product on pullulan was mainly maltotriose.

• 한국미생물·생명공학회지
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• 제37권1호
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• pp.62-68
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• 2009

소나무잔나비버섯(Fomitopsis pinicola) 균사로부터 laccase를 생산하기 위한 최적 배양조건을 조사하였다. 합성 배지 중 MCM이 가장 높은 laccase활성을 나타내었으며, MCM의 조성을 2% dextrose, 0.4% peptone, 0.05% $NaH_2PO_4{\cdot}H_2O$, 0.05% $CaCl_2$로 각각 대체하였을 때 효소활성이 가장 우수하였다. 따라서 F. pinicola로부터 laccase를 생산하기 위한 최적 배지조건은 2% dextrose, 0.4% peptone, 0.05% $NaH_2PO_4{\cdot}H_2O$, 0.05% $CaCl_2$이다. 이상의 배지를 사용하여 $25^{\circ}C$에서 8일 동안 배양하였을 때 효소의 활성이 최대에 도달함을 확인하였다. ABTS를 기질로 사용한 activity staining을 통해 소나무잔나비버섯 균사체의 laccase 활성의 분자량이 43-55 kDa임을 확인하였으며, 배양액 중의 최적 pH와 온도는 각각 pH 3.0과 $80^{\circ}C$이었다.