• 한국식품영양과학회지
• /
• 제21권4호
• /
• pp.377-380
• /
• 1992

To produce economically important acid with pear juice, an acetic acid bacterium was selected from many isolated acetic acid bacteria. The alcohoic fermentation was conducted by inoculating pear juice with Saccharomyces cerevisiae ATCC 4124, and then the pear vinegar was prepared by batch cultivation in flaskes with the isolated Acetobacter sp. The optimum conditions for high yield of acetic acid were studied experimentally in the batch shake flask . For seed purposes the Acetobactor sp. was cultivated for 2 -days and transferred to the acid production medium . Optimum alcohol concentration, initial acidity and temperature for the acid production were 8.0% , 2.0% and 28$^{\circ}C$, respectively. Under the same conditions, the addition of yeast extract (1%) was observed to produce relatively high yield of acetic acid.

• 산업기술연구
• /
• 제1권
• /
• pp.61-66
• /
• 1981

In order to use as a starter after drying, optimum growth conditions of Str. thermophilus and L. bulgaricus were investigated. The results were as follows. The growth of Str. thermophilus was reached at stationary phase after 12 hours incubation and L. bulgaricus was after 6 hours. Str. thermophilus was grown well, in the medium containing 10% of skim milk, 2% of sucrose, 0.1% of KCl and 0.015% (v./v.) of soy-sauce. In the case of L. bulgaricus, 10% of skim milk, 2% of glucose, 0.5% of bacto-peptone, 0.1% of $K_2HPO_4$ and 0.02% of pyridoxine was suitable for the maximum growth.

• 한국산학기술학회논문지
• /
• 제14권9호
• /
• pp.4156-4162
• /
• 2013

본 연구는 중형 크랭크샤프트 제작 과정에서 환봉을 가열하기 위한 최적의 유도가열조건을 결정하기 위한 것으로, 4가지 가열조건(가열코일 개수, 위치 등)에 대하여 수치해석적인 방법을 사용하여 전자기장 및 열전달해석을 순차적으로 수행하였다. 이러한 수치해석 결과로부터 일정시간 가열 후 크랭크샤프트 환봉 가열부에 발생하는 최고온도와 두께에 따른 내, 외부 최소 온도차를 평가하여 현장에 적용 가능한 가열코일의 위치 및 개수 등의 유도가열조건을 결정하였다.

• 펄프종이기술
• /
• 제33권5호
• /
• pp.25-29
• /
• 2001

Dimethyldioxirane (DMD), which is a source of active oxygen, is effective agent that can be used in chemical pulp bleaching. In this study, delignification of kraft bagasse pulp has been carried out by using DMD. The effect of the applied charge of DMD (as active oxygen) and pH of the delignification medium were studied. The optimum conditions of the applied DMD charge and pH of the delignification reaction were achieved at pH range from 8~9, 2% of DMD (as active oxygen) and the rest of delignification reaction conditions were $25^{\circ}C$, 60 min, and 12% pulp consistency. The development of brightness per unit kappa number removal (ΔBrightness/ Δ Kappa number) has highest value at the optimum condition. The study showed that the reactivity of kraft bagasse pulp be enhanced to wards alkaline hydrogen peroxide bleaching by pulp treatment with DMD.

• 미생물학회지
• /
• 제9권1호
• /
• pp.27-31
• /
• 1971

This experiment was carried out to research for the use of the mycelium and enzyme on the production of fermented feed. Among 354 strains isolated from natural sources, 3 strains of useful yeasts were selected and identified, and the cultural conditions of these strains were examined. The results obtained were as follows. 1) The strian No.55, No.112 and No. 340 selected were identified Endomycopsis fibuliger, Endomycopsis javanensis and Candida tropicalis, respectively. 2) The optimum pH and sugar concentration of the medium for the strain No.55, No.112 and 340 selected was around pH 6.5and Bllg.10.deg.. The optimum temperature for the growth of the strain No.55 and No.112 selected was 30.deg.C and was 25.deg.C of strain No.340. 3) The strain No.55 and No.112 were grown exceedingly well on the media containing 0.1 percent of (NH/sub 4/)/sub 2/SO/sub 4/.

• Journal of Biosystems Engineering
• /
• 제43권4호
• /
• pp.362-368
• /
• 2018

Purpose: Self-sufficiency in paper production is desired in Nigeria. This study was aimed at evaluating the performance of a locally fabricated batch pulp digester. Methods: The pulp yields of sheaths generated as waste in the production of bamboo (Bambusa vulgaris) laminates were determined at different liquor concentrations and treatment time after preliminary experiments to ascertain the conditions under which the sheath started to pulp. Moreover, the optimum pulping conditions and fiber characteristics were determined and estimated, respectively, to ascertain the pulp fiber suitability for paper production. Results: An optimum pulp yield of 65.1% was obtained at 50% NaOH and 25% $Na_2S$ liquor concentration (w/w) when the cooking time was 4 h. The results of fiber characterization of the pulp indicated an average fiber length of 2.19 mm with a low Runkel ratio of 1.63, both of which signify the suitability of the pulp for medium quality paper production. Conclusions: Softwood pulp can be blended with the fibers to improve the strength of the produced paper; further investigation should be carried out to use other non-woody plants for pulp and papermaking.

• 생명과학회지
• /
• 제25권6호
• /
• pp.673-679
• /
• 2015

본 연구에서는 재비늘버섯(Pholiota highlandensis)의 리그닌 분해 활성을 확인하고, laccase 생산을 위한 최적 배양 조건을 조사하였다. 재비늘버섯 균사체로부터 laccase를 생산하기 위한 배지조건을 조사한 결과, 다양한 합성 배지 중에서 Coriolus versicolor 배지(2% dextrose, 0.4% peptone, 0.6% yeast extract, 0.046% KH₂PO₄, 0.1% K₂HPO₄, 0.05% MgSO₄·7H₂O)가 가장 높은 laccase 활성을 나타내었다. Laccase생산에 대한 배양 조건을 최적화하기 위하여 Coriolus versicolor 배지의 조성 중에서 탄소원, 질소원, 인산원, 무기염에 대한 영향을 조사하였다. 탄소원, 질소원, 인산원, 무기염은 각각 2% fructose, 0.4% peptone 및 0.6% yeast extract, 0.05% NaH₂PO₄, 0.05% MgSO₄·7H₂O의 경우에 가장 높은 효소활성을 나타내었다. 본 균주는 몇 가지 방향족 화합물에 의해 laccase 생산이 유도되었고, guaiacol을 첨가할 경우 25℃에서 11일 동안 배양하였을 때 효소의 활성이 최대치(114.1 U/ml)에 도달하였다. 또한 본 균주의 laccase 생산을 위한 최적 pH와 온도는 각각 8.0과 35℃를 나타내었다. 최적 조건에서 배양된 균사체 배양 상등액을 Native-PAGE로 전기영동한 후 ABTS를 기질로 사용하여 활성염색을 수행한 결과, 약 90 kDa 부근에서 laccase 활성을 가지는 1개의 밴드를 확인하였다.

• Journal of Microbiology and Biotechnology
• /
• 제21권6호
• /
• pp.646-651
• /
• 2011

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 ${\mu}s$ pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 ${\mu}g$/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2001년도 추계학술발표대회
• /
• pp.471-474
• /
• 2001

강한 제초활성을 띠는 곰팡이 균주 YK101의 배양조건을 최적화하기 위하여 균사와 균체 생산에 대한 온도, 교반속도 그리고 배양배지의 영향을 조사하였다. YK101의 최적 배양온도와 교반속도는 각각 $28^{\circ}C$, 150rpm 이었다. 최적화된 배지조성은 1.0$^{\sim}$2.0% total sugar, 1.0% yeast extract 그리고 0.05% $MgSO_4$ ${\cdot}$ $7H_2O$이었다.

• KSBB Journal
• /
• 제13권5호
• /
• pp.497-501
• /
• 1998

A fungus with high phosphate solubilizing activites was isolated from soil using potato dextrose agar-calcium phosphate medium and identified to Penicillium sp. PS-113, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. The optimum temperature ad initial pH to solubilize rock phosphate in potato dextrose broth-rock phosphate medium were 30$^{\circ}C$ and pH 8.0, respectively. In these conditions phosphate solubilizing activities of Penicillium sp. PS-113 against four types of insoluble phosphate like tricalcium-phosphate, aluminium phosphate, hydroxyapatite and rock phosphate were quantitatively determined. As results, this fungus highly produced free phosphates to the culture broth with the concentrations of 1,283 ppm against tricalcium-phosphate, 585 ppm against rock phosphate, 528 ppm against aluminium phosphate, and 242 ppm against hydroxyapatite, respectively.