Earticle

수산물 가공시 부산물로 얻어지는 어피(魚皮)를 보다 효율적으로 이용하기 위하여 효소로 대구피를 가수분해할 때 가수분해조건을 구명하였으며 그 가수분해물을 이용한 천연조미료(모조간장 및 복합조미료)의 개발을 시도하였다. pH-drop법으로 대구피분해에 있어서의 collagenase, trypsin 및 pronase의 활성을 비교해 본 결과 pronase가 가장 활성이 높았으며 이 pronase의 Km 및 Vmax 값은 각각 1.82 mgN/ml, 0.06 mgN/mL/min였다. Pronase에 의한 대구피 가수분해조건은 반응온도 50℃, 반응시간 3시간, pH6, 효소농도 0.03%였으며, 이 조건하에서의 가수분해도는 78.8%였다. 그러나 대구피를 collagenase로 1시간 분해시킨 후 pronase로 처리할 경우 가수분해도는 90.83%였다. 이때 가수분해물의 분자량은 8,000 dalton이었다. 아미노산 조성은 glycine(27.95%), glutamic acid(10.94%), proline(10.48%), aspartic acid(7.47%), serine(7.39%)이 전체 아미노산의 64.23%였으나 쓴맛을 내는 valine, methionine, isoleucine, leucine, phenylalanine, histidine 등은 13.05%에 불과하였다. 가수분해물과 기타 부원료로 제조한 모조간장원액과 시판 100% 양조간장을 8:2(v/v)로 혼합한 모조간장은 시판대두간장에 비해 최소유의차 검정 결과 맛, 색 및 종합평가면에서 5% 유의수준내에서 유의차가 없었다. 가수분해물 31.7% 함유한 복합조미료도 시판 복합조미료와 관능적으로 비교해 본 결과 복합조미료로서의 손색이 없는 제품이었다.

A study on the optimum hydrolysis conditions of fish skin through the aid of enzymes and the development of a natural seasoning using the hydrolysate has been carried out for the effective utilization of fish skin. Using the "pH-drop" techniques the collagenase and pronase were identified as most suitable for this purpose. The Km and Vmax values of pronase were 1.82 mgN/ml and 0.06 mgN/mL/min, respectively. The hydrolysis conditions of the cod skin for the pronase were as follows: reaction temperature, 50℃; reaction time, 3hrs; pH 6; enzyme concentration, 0.03%. The degree of hydrolysis at these conditions was 76.8%. But after hydrolyzing cod skin with collagenase for 1hr, when the pronase was treated, the degree of hydrolysis was 83.13%. The molecular weight of the hydrolysate was 8,000 daltons. Among the amino acids in the hydrolysate, glycine(27.95%), glutamic acid(10.94%), proline(7.39%), aspartic acid(9.47%) and serine(7.39%) were responsible for 64.23% of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only 13.05%. From the results of the sensory evaluation, the imitation sauce which was made of 20% fermented soy sauce prepared from the hydrolysate was at least similar to the traditional soybean sauce in product quality. The complex seasoning containing 31.7% of the hydrolysate was nearly equal to complex seasonings on the market, too.

The liquid-liquid extraction of lipase A from Candide cylindracea and lipase B from porcine pancrease was carried out using reversed micellar organic solvents. Effects of various factors such as ionic strength, pH, and species and concentration of surfactant, on lipase solubilization were studied. A cationic surfactant cetyl-trimethyl ammonium bromide (CTAB) in isooctane/nhexanol(1:1) was found to be an effective solvent and its optimum concentration was 50 mM. KCl among various salts tested was the most effective and the efficiency of solubilization of lipase increased with decreasing the ionic strength of salts. The maximum activity and solubiliz ation of protein were obtained at pH 8. The stripping efficiency has a maximum value at pH 4 and increases with KCl concentration in the range of 0.2∼1.0 M. After the solubilization and stripping, the overall recovery efficiency of mass and specific activity of lipases was 62% and 66%, respectively.

본 연구에서는 생물막 유동층 반응기를 이용하여 주정공장폐수를 처리함에 있어 상향유속과 유기물 부하의 변동에 따른 미생물의 성상과 유기물 처리효율을 조사하고, 미생물 성장과 유기물 처리효율을 조사하고, 미생물 성상에 따른 미생물 농도의 변화를 계산하여 이를 실측한 미생물 농도와 비교하였다. 상향유속에 따라 미생물 농도, 미생물막 두께는 민감한 반응을 보였고, 미생물 농도를 높게 유지하기 위해서는 상향유속을 낮게 유지하는 것이 효과적이나, 이에 따라 미생물막도 증가하나 유기물의 제거율은 상대적으로 증가하지 못하므로 적절한 상향유속을 유지하는 것이 유기물 제거율이 측면에서는 유리한 것으로 고찰되었다. 또한 기존 활성슬러지법에서 주정폐수를 처리할 때는 유기물 부하율 1.5kgCOD/m3ㆍday,에서 70% 이하의 COD처리효율을 나타내는데 반해, 생물막 유동층 반응기에서는 6kgCOD/m2ㆍday, 이상에서도 80%의 COD처리효율을 나타내었다.

The purpose of this study is to investigate biomass characteristics and organic removal efficiency by changing superficial upflow velocity and organic loading rate in treating alcoholic distillery wastewater. Since the biomass concentration and the thickness of biofilm are very sensitive to superficial upflow velocity, a high concentration of biomass could be achieved by decreasing superficial upflow velocity that lowered the organic removal efficiency. Therefore, superficial upflow velocity should be controlled as to give optimum conditions and removal efficiency. Generally, activated sludge system shows 70% COD removal efficiency at 1.5kgCOD/m3ㆍday, but the fluidized-bed biofllm reactor shows 80% COD removal efficiency even at 6kgCOD/m2ㆍday.

This study is on the investigation of hydrogen production and substrate removal by photosynthetic bacteria. After using of Rhodospillum rubrum KS-301 and IFO 3986, which are photosynthetic bacteria as strains, R. rubrum KS-301 was turned out a better strain. And result of experiment in which glucose and sodium lactate, components of wastewater, were used limiting substrates, showed that the productivity of hydrogen was indifferent with the kind of substrates. In batch experiments using free cells and immobilized whole cells, the decrease in hydrogen productivity was observed in the latter case. From the results of these experiments, specific growth rate of cells, specific utilization rate of glucose, and specific production rate of hydrogen were calculated. And each rate was expressed in the form of Monod equation of which parameters were estimated. Also the optimum condition of hydrogen production for free cells was 30℃, pH 7, and 12,000 Lux, and the optimum immobilized condition was as follows: initial immobilized cell concentration 1.0g/L, sodium alginate concentration 2% and light intensity 12,000 Lux.

PVA degrading bacteria were isolated from water system, and identified as Pseudomonas cepacia and Pseudmonas pseudomallei, which were named as Pseudomonas sp. G5Y and Pseudomonas sp. PW. It was found out that those two kinds of bacteria have a symbiotic relationship to degrade PVA. For the mixed culture of these bacteria, the optimal conditions of pH, temperature, nitrogen source, and polymerization degree of PVA were found to be 7.5, 35℃, ammonium sulfate, and 500, respectively. Also, the growth of these bacteria was promoted by trace elements such as vitamin B1, B12, pyridoxine, and p-aminobenzoate, respectively. The specific growth rate of mixed bacteria was inhibited when the concentration of PVA was more than 20g/l. The substrate inhibition kinetics of the mixed culture was {{{{= { 0.065 S} over {2.56+S+( { S}^{2 }/156) } { hr}^{-1 } }}}}

Xanthomonas Campestris에 의한 Xanthan gum 생산에서 질소원의 영향에 관한 연구 결과를 요약하면 아래와 같다. Sodium glutamate를 질소원으로 채용한 xanthan gum 생산발효에서 세포 생산량에 대한 생산물 생성량, 세포 생산량에 대한 탄소원 소비량은 초기질소농도에 독립적이었다. 0.4-1.0g/L의 So범위에서 B1와 B1는 상수를 보였고 sodium glutamate질소원과 peptone질소원 사이에서 질소원 차이에 따른 차이는 없었다. Xanthan gum생산수율은 탄소/질소농도가 10-16일 때 최대값을 보였다. Peptone질소원은 sodium glutamate질소원보다 세포 성장에 더 효율적이다. Peptone만을 질소원으로 사용한 발효와 혼합질소원을 질소원으로 사용한 발효가 생산물 생산수율 및 발효시간이 유사하므로 xanthan gum생산시 혼합질소원을 질소원으로 사용할 경우 xanthan생산원가를 절감할 수 있다

The effects of nitrogen sources(sodium glutamate and peptone) on the production of xanthan gum were investigated. The fermentation using sodium glutamate as a nitrogen source is longer than that of peptone. In the initial nitrogen concentration of 0.4-1.0g/L, Bs was about 2.0 and Bs was 1.2. The optimal yields were obtained when the carbon source/nitrogen concentration was 10-16. The fermentation time and product yields in the fermentation medium of mixed nitrogen source [sodium glutamate-N(0.75g/L)+peptone-N(0.25g/L)] were similar to those of peptone.

Pervaporation can be successfully utilized to recover alcohol from fermentation broths and dilute process streams. Polydimethylsiloxane (thickness: 60um), such as hydrophobic membrane have been employed in this application to produce an enriched product. The fermented alcohol was continuously extracted, and simultaneously concentrated by pervaporation, from the membrane bioreactor, and the extracted alcohol concentration was 6 to 10 times higher than in the broth. This experimental conditions were 6-10 Torr vacuum line, pH=5, 32℃, 3.5 liters of working volume, 200rpm of agitator speed, and 0.14 wm aeration flow rate.

자란(B. striata)의 미성숙종자로 부터 유도한 embryogenic callus를 현탁배양하고 이와같은 embryogenic cell suspensions로부터 분리한 원형질체에 electroporation 방법을 사용하여 reporter genes이 들어있는 pBI121 plasmid DNA 를 도입하고 그 발현을 확인하였다. 배양된 세포에 있어서 GUS의 활성은 plasmid DNA양의 증가와 함께 높게 나타났으며, 200-300 voltage/1180 uF에서 GUS의 활성 및 원형질체의 생존율(viability)이 가장 좋았다

Embryogenic cell suspension cultures of B. striata were established as transferred selected embryogenic callus into liquid medium. Protoplasts isolated from embryogenic cell suspensions were electroporated in buffered solutions containing plasmid DNA of pBI121. Transient GUS (beta-glucuronidase) activity measurement and selection for kanamycin resistent showed that expression of foreign genes and stable transformation were achieved. GUS transient gene expression was increased by increasing DNA concentration of pBI121 plasmid and affected by the level of the applied voltage. An optimal level of GUS activity was obtained after electroporation with a pulse of 200-300 voltage/1180 uF. Protoplast viability was up to the 80% at the optimal voltage.

Emulsan is an extracellular emulsifying agent produced by the hydrocarbon-degrading Acinetobacter species RAG-1. In this study emulsan production of Acinetobacter calcpaceticus RAG-1 was investigated under various culture modes such as batch, fed-batch, membrane cell recycle, and continuous culture. The productions of emulsan under both ethanol-sufficient fed-batch and membrane cell recycle cultures were all 15.0U/ml, which was 53% increase in emulsan activity compared to that of pH controlled batch culture. Emulsan production was found to be strongly dependent on the residual ethanol concentration. In continuous culture the emulsan productivity increased with dilution rate.

A new process was developed to degrade PVA(polyvinyl alcohol) in desize wastewater. Two symbiotic bacteria of Pseudomonas strain G5Y and PW were immobilized on the media by adsorption. A natural zeolite was chosen as the best media considering cell adhesion capacity, sedimentation rate, and material cost. PVA and COD removal efficiencies of this system for synthetic wastewater were 84% and 85% at the retention time of 6 hr, when the volumetric loading rate was PVA 8g/L·day and COD 8g/L·day, and cell density was 19,775 mg/L. In case of desire wastewater, they were 78% and 72% at the retention time of 6 hr, respectively, when the volumetric loading rate was PVA 8g/L·day and COD 13.2g/L·day, and cell density was 32,899mg/L. In case of desize wastewater, PVA and COD removal efficiencies were lower than synthetic wastewater, but cell density of the desize wastewater was lower than that of the synthetic wastewater, because there were insufficiency of necessary nutrition and variety of desize materials in the desize wastewater. A pilot test was successfully performed showing 88% and 82%, PVA and COD removal efficiencies at the retention time of 24 hr, when volumetric loading rate were 4.7 PVA g/L·day and COD 6.9g/L·day, and cell density was 12,,324 mg/L.

방사선 중합체로 고정화한 Rhizopus oryzae의 유산생성 방사선 공중합 고분자로 Rhizopus oryzae를 흡착 고정화하였다. 이 고정화 균체는 고정화하지 않은 생균체보다 반응시간도 짧았으며 제품수율도 아주 높았다. 즉 글루코스를 주 탄소원으로 한 경우 고정화 하지 않은 균체 배양은 반응후 96시간에 탄소원을 거의 소비하고 유산생성 수율이 약60%에 다다랐으나 고정화 균체는 반응후 48시간 안에 수율이 약 88%이상으로 되었다. 또 중합체 중 모노머의 비율이 5-10%의 것이 고정화에 좋은 결과를 보였다.

Lactic acid production yield was examined for commercial use by immobilizing Rhizopus oryzae with radiation induced polymer. The supporting material was synthesized by the low temperature radiation polymerization method, in which the microorganism was entrapped physically by contacting together in culture broth shaking for 24 hours. Support polymers with 5∼10vol-% monomers were able to increase their catalytic activities, consuming 65g/1 of glucose, producing 56g/1 of lactic acid, thus yielding 88% of product in general. But in free culture, the microorganism consumed almost all carbon sources and produced lactic acid only 60% even after 96 hours. The yield of the experiment under discussion was significantly high compared with conventional immobilization procedure

The extraction of indole alkaloids from Catharanthus roseus using the supercritital carbon dioxide with ethanol was performed in various temperature and pressure conditions. The contents of vindoline in the extracts were determined by HPLC. In this study, the flow rate of cosolvent ehtanol was 20.4lul/min, about 3 wt.% of flow rate of supercritical carbon dioxide. However the effect of ethanol on the yield of extracted vindoline was not significant.

Bitid"bactcria를 이용한 요구르트 제조를 위하여 B. bitidwη의 우유내에서 최시 배양조간과 B. bitidum. L. acidophilus 및 Str. thermophihilus의 혼합배양시의 최적 조건을 조사하고 요구르트 제조에 적합한 조건을 조사하여 다음과 같은 결과을 얻었다. B. bitidum의 성장을 위한 탈지유아 농도는,15% 농도가 12%농도보다 산진전은 잘 되었으나 균의 생존력에서 12% 농도가 적합한 것으보 나타났다. B. bifidum 의 성장에 대한 L-cysteine.HCl, yeast extract, glucose와 BIOS 2000의 성장촉진물 침가효과는 BIOS 2000을 첨가한 것이 산 진전면과 균수 유지면에서 B. bhifidum익 성장에 큰 효과가 있었다. B. bifidum, L.acidophilus와 Str. thermophilus를 혼합하여 배양한 것이 산 진전과 균수면에서 B. bifidum 단독 배양한 것보다 좋게 나타났다. B. bifidum. L. acidophilus 와 SIr. thermophilus의 세 균주 혼합배양액을 이용한 요구르트 제조시 접송량은 5%. 배양온도는 37℃ 와 배양시간은 8시간이 석당하였다 . 이 경우 세 균주의 비율은 B. bifidu: L. acidophilus. Str. thermophilus가 2:1:1의 비율이 균수유지와 산 진전면에서 가상 좋은 결과를 보였다

The optimal condition for manufacturing the yoghurt by using B. bifidum and L. acidophilus was studied. Optimal growth condition of B. bifidum and fermentation effects of B. bifidum, L. acidophilus and Str. thermophilus in mixed culture were investigated separately. Fermentation conditions of B. bifidum were optimized in 12% reconstitued skim milk. The addition of BIOS 2000 to 12% skimmilk was effective on the growth and acid production of B. bifidum. There was asymbiosis among B. bifidum, L. acidophilus and Str. thermophilus in mixed culture which resulted in higher viable cell numbers and acid production. The optimum production of yoghurt was achieved by incubation at 37℃ for 8 hours with 5% mixed starter culture (B. bifidum+L.acidophilus+Str. thermophilus). In this case the effective ratio of B. bifidum: L. acidophilus: Str. thermophilus was 2:1:1 on both acid production and viable cell counts.

이상의 실험 결과로부터 다음과 같은 결과를 얻었다. 1. TiO2-SiO2-AL2O3-B2O3-CaO-Na2O계에서 분상을 일으켰을 때 600℃, 6시간 열처리시켰을 때 최대의 비표면적을 나타냈다. 2. 저온에서 열처리 시간이 증가하면 비표면적은 증가하고 고온에서는 열처리 시간이 증가하면 비표면적은 감소하다가 다시 증가한다. 3. 상분리 및 비표면적은 열처리 시간보다 열처리 온도에 더욱 민감하였다.

Porous glasses were prepared from TiO2containing borosilicate glass by the phase separation. Pore distribution and surface area of porous glasses were invesigated by SEM and porosimeter. As temperature and heating time increase. The pore size and volume increased, but the specific surface area decreased above the critical temperature. The specific surface area and pore size showed more sensitive change on the variation of heating temperature than of heating time.