• KSBB Journal
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• 제5권2호
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• pp.167-173
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• 1990

Acetobacter aceti OLS-130cell을 Ca-alginate gel에 고정시킨 후 유동층 반응기를 이용한 연속적인 식초생산 가능성을 검토하였다. Working volume 2L규모의 유동층 반응기를 사용한 회분식발효를 발효온도 3$0^{\circ}C$, 통기량 1.0VVM에서 초기 ethanol 및 초산농도 3g/l와 27g/l에서 수행한 결과 free cell인 경우 발효 80시간 경과 후 23g/l의 초산이 생성되었으며, 이때 overall productivity는 0.31g/l-hr였고, 고정화 초산균의 bead를 250g/l로 하여 발효를 수행한 결과는 발효 48시간 경과 후 23g/l의 초산이 생성되어 overal productivity는 0.48g/l-hr로서 free cell일 때보다 약 1.5배 높았다. 위의 초산발효조건에서 배양 48시간 이후부터 연속발효를 실시한 결과 배양 90일까지 초산함량 50~55g/l의 식초를 연속적으로 생산하는 것이 가능하였으며, 이때 dilution rate는 $0.12hr^-1$로서 초산생산성은 약 2.76g/l-hr로 최대값을 유지하였으며 회분식 발효에서 free cell인 경우보다는 초산생산성이 약 8.9배, 고정화 세포인 경우보다 약 5. 8배 더 높았다.

• Environmental Engineering Research
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• 제19권3호
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• pp.283-287
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• 2014

Cultivation of microalgae using wastewater exhibits several advantages such as nutrient removal and the production of high valuable products such as lipid and pigments. With this study, two types of wastewater from instant noodle factory; mixed liquor suspended solids (MLSS) and effluents after sedimentation tank were investigated for green microalga Scenedesmus sp. cultivation under laboratory condition. Optimal wastewater dilution percentage was evaluated in 24 wells microplate. MLSS and effluent without dilution showed the highest specific growth rate (${\mu}$) of $1.63{\pm}0.11day^{-1}$ and $1.57{\pm}0.16day^{-1}$, respectively, in which they were significantly (p < 0.05) higher than Scenedesmus sp. grown in BG11 medium ($1.08{\pm}0.14day^{-1}$). Ten days experiment was also conducted using 2000 ml Duran bottle as culture vessel under continuous light at approximately 5000 lux intensity and continuous aeration. It was found that maximum biomass density of microalgae cultivated in MLSS and effluent were $344.16{\pm}105.60mg/L$ and $512.89{\pm}86.93mg/L$ respectively and there was no significant (p < 0.05) difference on growth to control (BG11 medium). Moreover, cultivation microalgae in wastewater could reduce COD in wastewater by 39.89%-73.37%. Therefore, cultivation of Scenedesmus sp. in wastewater from instant noodle factory can yield microalgae biomass production and wastewater reclamation using photobioreactor simultaneously.

• ALGAE
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• 제33권4호
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• pp.319-327
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• 2018

Ettlia sp. YC001, a highly settleable and productive microalga, was shown to be effective in removing nutrients and capturing suspended solids from eutrophic pond water. The optimum conditions for the Ettlia sp. YC001 cultivation were investigated using water from a landscape pond. The pond water was supplemented with different N : P ratios by weight, and the biomass production and nutrient removal compared in batch cultures. The maximum removal rate of N and P was with an N : P ratio of 16 : 1. Plus, the turbidity dropped to near zero within 4 days. Meanwhile, chemostat cultivation showed that the biomass productivity and nutrient removal rate increased when increasing the dilution rate, where a dilution rate of $0.9d^{-1}$ showed the highest N and P removal rate at $32.4mg\;L^{-1}\;d^{-1}$ and $1.83mg\;L^{-1}\;d^{-1}$, respectively, and highest biomass and lipid productivity at $0.432g\;L^{-1}\;d^{-1}$ and $67.8mg\;L^{-1}\;d^{-1}$, respectively. The turbidity was also reduced by 98% in the chemostat cultivation. Moreover, auto-flocculation and pH were closely connected to the turbidity removal. As a result, this study identified the optimal N : P ratio for small pond water treatment using an Ettlia sp. YC001, while also establishing the optimal conditions for nutrient removal, turbidity reduction, and biomass production.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2010년도 학술논문요약집
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• pp.271-272
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• 2010

Sensitivity analysis by TSUNAMI clarifies the complex effects of key nuclides on the criticality probability quantitatively. As discussed above, the $K_{eff}$ of $UO_2$ fuel reaches the maximum value with 42w% concentration of intrusion water. The concentration of hydrogen affects the complexity of reaching criticality by its competition between the concentrations of $^{235}U$. Approximately if the weight percent of $H_2O$ in the mixture is less than 42%, the moderation effect of hydrogen surpasses its dilution effect on $^{235}U$. However, the importance of $^{235}U$ increases dramatically when the weight percent of water is bigger than 42%. In the sensitivity evaluation of $UO_2$ fuel employing TSUMAMI, there is a similar crosspoint of the sensitivity of $^{235}U$ and the sensitivity of $^1H$ where the criticality reaches summit. And the optimal water weight percent is determined to be 50%.

• 한국미생물·생명공학회지
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• 제9권2호
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• pp.77-82
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• 1981

Candide tropicalis was selected for its ability to utilize spent waste generated by the alcohol distillery using tapioca starch as a raw material. Optimum pH and temperature on batch culture of the organism were 4.0 and 3$0^{\circ}C$. The growth of the organism was markedly increased when 0.2% of ammonium sulfate, 0.002% of potassium phosphate dibasic, add 0.04% of magnesium sulfate were supplemented to the filtrate. At these conditions, maximum specific growth rate and saturation constant were 1.0 hr$^{-1}$ and 4.4 g.1$^{-1}$ , respectively. At a dilution rate of 0.5hr$^{-1}$ , a productivity of 1.84 g.1$^{-1}$ . hr$^{-1}$ was obtained and about 70% of carbohydrate was assimilated. Protein content of dried cell was about 60%.

• Journal of Microbiology and Biotechnology
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• 제7권3호
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• pp.209-211
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• 1997

A quantitative method for assaying bioemulsifiers in culture broth was developed and applied to cultivation of Pseudomonas aeruginosa YPJ80. SED(Standard Emulsification Dilution), an indirect measure of bioemulsifier concentration, was proposed. Production of bioemulsifier and rhamnolipid reached their maximum simultaneously. However, the bioemulsifier/rhamnolipid ratio decreased with cultivation time. This indicates the presence of another bioemulsifier other than rhamnolipid. The bioemulsifier seems to be protein-like activator which showed emulsification activity in addition to rhamnolipid.

• 한국미생물·생명공학회지
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• 제19권1호
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• pp.70-75
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• 1991

Continuous and simultaneous production of gluconic acid and sorbitol from glucose and fructose was carried out by using glucose-fructose oxidoreductase and glucanolactonase of Zymomonas mobilis. In order to utilize the enzymes without purification, Zymomonas mobilis was permeabilized with toluene. Optimum conditions for permeabilization and reaction kinetics of permeabilized Zymomonas mobilis were studied. In batch operation with the permeabilized cells immobilized in alginate beads, about 90% conversion was obtained within 35 h reaction. Continuous production of gluconic acid and sorbitol using the immobilized permeabilized cells was carried out. Optimum conditions for continuous operation with the imn~obilized cells were; pH 6.2 and temperature $40^{\circ}C$. Maximum productivities for gluconic acid and sorbitol were about 14.5 g/l/h and 14.8 g/l/h respectively at the dilution rate of 0.075 $h^{-1}$ when 300 g/l each of substrates was fed.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.106-110
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• 2003

The study was carried out immobilized Aspergillus niger used of milk-wastewater. The purpose of investigation is to optimize the ermentational conditions of milk-wastewater The optimal pH, temperature and dilution rate were 3.0, 30$^{\circ}C$ and 0.025 h$\^$-1/. The maximum amount and yield of citric acid produced by immobilizes Aspergillus niger ATCC 9142 were 4.5g/1 and 70.3%. Compared to shake-flask culture, yield was increased about 20%.

• Mycobiology
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• 제35권4호
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• pp.191-195
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• 2007

The colonization pattern and extent of decay produced in paddy stubble by soil inhabiting mycoflora were done by using nylon net bag technique. Among the three methods used for isolation of fungi, dilution plate technique recorded the highest number of fungi followed by damp chamber and direct observation method. Nutrient availability and climatic conditions (temperature, humidity and rainfall) influenced the occurrence and colonization pattern of fungi. Maximum fungal population was recorded in October ($48.99{\times}10^4/g$ dry litter) and minimum in May ($11.41{\times}10^4/g$ dry litter). Distribution of Deuteromycetous fungi was more in comparison to Zygomycetes, oomycetes and ascomycetes. In the early stage of decomposition Mucor racemosus, Rhizopus nigricans, Chaetomium globosum and Gliocladium species were found primarly whereas at later stages of decomposition preponderance of Aspergillus candidus, Torula graminis, Cladosporiun cladosporioides and Aspergillus luchuensis was recorded.

• 한국미생물·생명공학회지
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• 제27권2호
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• pp.136-144
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• 1999

Since the condition of immobilization must be optimized, it is very important to know whether and on how conditions bacterial cells retain their metabolic activity during immobilization process. A bioluminescence intensity had the maximum value when cell concentrations were between 1.0 and 1.2 measured at O.D660. The strontium alginate was used as an immobilization matrix and two independent factors for immobilization of Photobacterium phosphoreum with strontium alginate were optimized with the response surface methodology(RSM) considering degree of bioluminescence. As a result, the optimum concentration for immobilization was found to be 2.4%(w/w) for sodium alginate and 0.31M for strontium chloride, respectively. A dilution was carried out with 2.5%(w/v) NaCl solution that is an optimum environmental condition for growth of P. phosphoreum. Under the such condition of immobilization, hardness could be predicted as 4.66$\times$104N/$m^2$ and it took different time according to the volume of matrix to be immobilized completely.