• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.116-120
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• 2009

Response surface methodology (RSM) was applied to optimize alcohol fermentation of concentrated grape juice. Sugar concentration ($X_1$), agitation rate ($X_2$) and fermentation time ($X_3$) were chosen as the independent variables of the central composite design (CCD). Dependent variables were alcohol content ($Y_1$) and total acidity ($Y_2$). To optimize two dependent variables, desirability function was defined as $Y_1$=10.0% and $Y_2$=minimum. The optimum conditions for alcohol fermentation were $19.98^{\circ}Bx$ (sugar concentration), 104.1 rpm (agitation rate) and 89.67 hr (fermentation time). The predicted responses were 10.0% in alcohol content and 0.86% in total acidity. The coefficients of determination ($R^2$) were 0.948 and 0.958, which indicate that the model fit was highly significant (p<0.001). The experimental values were 10.1% for alcohol content and 0.88% for total acidity. These values were similar to the predicted values from RSM.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.962-970
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• 2016

Commercialized production of onion vinegar, which has biological activities formed through alcohol and acetic acid fermentation, requires standardization. The objective of this study was to determine optimal conditions of sugar contents ($11{\sim}15^{\circ}Brix$) and agitation rate (100~300 rpm) of fermenter in the alcohol-acetic fermentation for producing onion vinegar. The alcohol and total acidity contents increased, whereas contents of total sugars decreased during alcohol fermentation. Contents of alcohol of 13 and $15^{\circ}Brix$ reactants were about 8% in 36 hr and total acidities of all samples were below 0.2% in 60 hr. During acetic fermentation, total acidity increased with highest value at 9 days (3.2% in 100 rpm), 10 days (4.1% in 200 rpm) and 8 days (4.3% in 300 rpm), respectively. From these results, sugar contents ($13^{\circ}Brix$) were measured for alcohol fermentation and agitation rate (300 rpm) for fast fermentation method of vinegar. The contents of total phenols, flavonoids and quercetin in onion vinegar were 33.3 mg/100 g, 3.0 mg/100 g and 2.0 mg/100 g, respectively. Onion vinegar showed an antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, Escherichia coli and Enterobacter aerogenes. Antioxidant effect of onion vinegar was 26.23% in DPPH radical inhibition and 58.58% in superoxide dismutase like activity, respectively. Fibrinolytic activity was 1.51 plasmin unit/mL in onion vinegar. In conclusion, onion vinegar processed by alcohol and acetic fermentation had nutritional values and potential biological activities.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.118-125
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• 1998

This study investigates the react characteristics to suggest the condition of the utilization and disintegration of food garbage as composting by varying the supply amount of air of the fermentation reactors. With the initial temperature and agitation velocity maintained 50$\circ$C and 1 rpm, the supply amount of air gives variety to 0.5, 1, 2, 4 l/kg$\cdot$ min. In the case of the amount of air operated at the 0.5 l/kg$\cdot$ min, reaction temperature shows a rising to the maximum 66$\circ$C after the 48hr, and the oxygen used rate of the micro-organisms shows the largest level at 18.4% after the 8hr. In the case of $NH_3, H_2, H_2S$ and SO$_2$ among the react gas, the sanitary utilization shows the possibility of the microorganisms gas disintegration, with most high gas generate rate. In the case of the amount of air operated at the 1, 2 and 4 l/kg$\cdot$ min, initial react was advanced rapidly and the product of the 72 hr after shows big weight reduction. As the experimentation result, when the amount of air operated at the 1 l/kg$\cdot$ min over, the reduction by disintegration would be more effectively, for the reactor maintains the color tone and shape of the straw (bulking agent).

• Journal of Conservation Science
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• v.26 no.2
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• pp.133-142
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• 2010

This paper focused on desalination method for the underwater archaeological ceramics. The desalination method applied in this study takes additional conditions such as the amount of desalting water, temperature, and agitation conditions and compares the effects of desalt process. The result of efficiency rate appears that the twenty-times of the object weight of desalting water is more effective than that of ten-times one, but shows less economic compared to the cost. In addition, the research shows that the efficiency rate has been improved around 20 to 30 %, yet such improvement is not taken into account as an effective result considering the risk of damage from the physical and chemical impact and the consumption of energy in applying additional method.

• Polymer(Korea)
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• v.35 no.2
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• pp.152-156
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• 2011

We have performed microencapsulation of phenyl acetate using poly (urea-formaldehyde) as a shell material, and studied the effect of agitation rate,. core/shell mass ratio, surfactant concentration, and reaction time on capsule characteristics such as size, shell thickness, and surface morphology. The formation of microcapsules was confirmed by FTIR and TGA, and capsule characteristics were studied by optical microscopy and FE-SEM. Capsule size and shell thickness reduced with increasing agitation rate. As the mass of shell material was increased, shell thickness and nanoparticles on capsule surface increased. Capsule size and shell thickness decreased with increasing the concentration of a surfactant. Increasing reaction time caused increased capsule yield and shell thickness.

• KSBB Journal
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• v.10 no.4
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• pp.401-405
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• 1995

An open pond type photobioreactor for mass cultivation of S. platensis was designed and the growth parameters from different cultivation processes were compared. 0.30(1/day) of specific growth rate and 1.69(g/$\ell$) of maximum cell density were obtained from batch cultivation. In fed-batch cultivation, specific growth rate and maximum cell density were estimated as 0.22(1/day) and 1.75(g/$\ell$), respectively. Maximum biomass productively from continuous cultivation was obtained as 0.44 (g/$\ell$/day). It proves that an outdoors-mass cultivation of S. platensis considering optimal environmental condition is economically feasible. In addition, the biomass productivity was studied in two different mixing systems such as agitation and air sparging methods. The biomass productivity by an agitation method was better than that in an air sparging method.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.358-363
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• 2014

We was investigated parasporal inclusion proteins change to use industrial medium of new strain Bacillus thuringiensis CAB 565, CAB 566. To confirm medium's oxygen efficient consist of glucose and yeast extract, we was conducted oxygen transfer coefficients (KLa) of medium's concentration and impeller in 20 l-Jar fermentor. When to increase air flow rate and medium concentration, KLa rate is rise. Also it is effective on agitation rate 200 rpm, but KLa rate is decrease when to rise agitation rate. To hold dissolved oxygen rate (upper 50%), Air flow rate is steadily increase on culture to use microsparger. When 16 hour of culture stage, B.t. CAB 565 and B.t. CAB 566 harvested respectively $2.3{\times}10^{10}$, $1.8{\times}10^{10}$ viable cell/ml. When 54 hour, B.t. CAB565, 566 harvested respectively $1.9{\times}10^{10}$, $1.4{\times}10^{10}spore/ml$. To resulting carbon's concentration, It is the most effective that glucose concentration is contained 5% in medium.

• Journal of Environmental Science International
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• v.25 no.9
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• pp.1233-1239
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• 2016

This study aimed to evaluate changes in the TN and TP removal efficiencies, depending on whether or not a settling process is applied, in a sequencing batch reactor (SBR) process with a membrane bioreactor (MBR). Nutrient removal was considered in terms of developing an advanced water treatment system for ships in accordance with water quality standards set forth by 227(64). For these purposes, the TN and TP concentrations in the inflow and outflow water were measured to calculate the TN and TP removal efficiencies, depending on whether or not a settling process was used. Water discharged from a bathroom, which was constructed for the experiment, was used as the raw water. The experiment that included a settling process was conducted twice, and the operating conditions were: aeration for 90 min, settling for 30 min, agitation for 15 min, and settling for 15 min for one experiment; and aeration for 150 min, settling for 45 min, agitation for 15 min, and settling for 15 min in the other. Operating conditions for the experiment that did not include a settling process were: aeration for 180 min and agitation for 60 min. The concentration of the mixed liquor suspended solids (MLSS) in the reactor was 3,500 mg/L, while the aeration rate was 121 L/min and the water production rate was 1.5 L/min. For the two experiments where a settling process was applied, the average TN removal efficiencies were 44.39% and 41.05%, and the average TP removal efficiencies were 47.85% and 46.04%. For the experiment in which a settling process was not applied, the average TN removal efficiency was 65.51%, and the average TP removal efficiency was 52.51%. Although the final nutrient levels did not satisfy the water quality standards of MEPC 227(64), the TN and TP removal efficiencies were higher when a settling process was not applied.

• KSBB Journal
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• v.24 no.3
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• pp.303-311
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• 2009

A scaling up study for the exopolysaccharide (EPS) production by submerged culture of Ganoderma lucidum was carried out in jar fermenter systems (2.6, 20 and 75 L) under bi-staged pH process. Profiles of dissolved oxygen (DO) and volumetric coefficient of oxygen transfer ($k_La$) as a function of operating variables (agitation speed and aeration rate) was investigated, and a correlation between $k_La$ and operating variables was analysed statistically. Under bi-staged pH process, no limitation of DO was observed at agitation speeds tested in the range of 200 and 600 rpm, and the highest EPS production was obtained at the level of DO of $40{\sim}80%$. From the regression analysis, the relation between $k_La$, gas velocity (Vs), stirrer speed (N) and impeller diameter (Di) could be expressed as : $$k_La=0.555{\times}Vs^{0.42}{\times}(N^3{\times}Di^2)^{0.33}\;(R^2=0.925,\;p<0.05)$$ It was found that under 2.6 L jar fermenter, the optimum agitation speed and aeration rate was 400 rpm and 1 vvm, respectively, obtaining the EPS production of 15.43 g/L. Under the submerged cultivation of G. lucidum in jar fermenters of $2.6{\sim}75\;L$, the similar EPS yields at each fermenter were achieved during scaling up based on $k_La$, and $k_La$ value for maximum EPS production was $85.4{\pm}26.70\;h^{-1}$.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.191-195
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• 1995

Production of a high viscosity exoploysaccharide, methylan, by Methylobacterium organophilum from methanol was carried out in fed-batch cultures and the rheological properties of methylan fermentation broth were studied. Bacterial biomass showed little influence on viscosity, but the accumulation of methylan caused the increase of viscosity. With proceeding fermention, the viscosity at the same concentration of methylan was significantly increased and methylan solution showed slightly higher pseudoplasticity. The composition changes of methylan were investigated at various fermentation times. Contents of total sugar, reducing sugar and methylan were decreased but contents of acids(pyruvic acid, uronic acid and acetic acid) were increased with the culture time. It was considered that the increased content of acids resulted in the increase of the hyrodynamic domain in the solution due to charge repulsion. Consequently, the solution viscosity increased in propotion to the acids contents of methylan. Cell growth and methylan production were severely decreased by the limitation of dissolved oxygen. However, the cellular activity for methylan production was almost constant regardless of the level of dissolved oxygen. As a result, the high speed of agitation increased the methylan production, the specific production rate of methylan, and the methylan yield of the cell.