• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.466-469
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• 1999

Cladocera are important food organism for seed production of finfishes. freshwater cladocera such as Daphnia and Moina are well known food organisms for the larval rearing of freshwater fishes and are easy for mass culture. However, mass culture technique for marine cladocera are not yet developed, The only mass produced food organisms available these days for the larval production of marine finfishes are rotifer and Artemia. An estuarine cladoceran, Diaphanosoma celebensis, has a high possibility of being used as a food organism for the larval rearing of marine finfishes because this species is much easier to mass culture than marine ones. Therefore many studies are needed for this species. In this study, the effects of the volumes of culture container, 40, 1,500 and 15,000 ml, on the stable production of this species were tested and results are as follow: The maximum densities of this species in each of the culture volumes were reached after 14 days in 40 ml, 12 days in 1,500 ml, and 21 days in 15,000 ml with values of 3.4 $\pm$ 0.4, 14.2 $\pm$ 2.1 and 2.5 $\pm$ 1.6 per ml, respectively. The relative population growth index (RPGI) was stable in the culture volume of 1,500 ml. Moreover, possible harvesting number(individual/ml/day) was much higher in the 1,500 ml container than the other culture volumes. Therefore, optimum culture volume among the tested volumes for mass production of this species was 1,500 ml.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.868-877
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• 2013

To understand the effects of marine environmental and meteorological parameters on laver Porphyra yezoensis production at Nakdong River Estuary, we analyzed marine environmental (water temperature, salinity, nutrients, etc.) and meteorological properties (air temperature, wind speed, precipitation, sunshine hours) with yearly and monthly variations in laver production over 10 years (2003-2013). Air and water temperature, wind speed, sunshine hours and precipitation were major factors affecting yearly variability in laver production at the Nakdong River Estuary. Lower air and water temperatures together with higher levels of nutrients and sunshine and stronger wind speeds resulted in higher laver harvests. Salinity and nitrogen did not show clear correlations with laver production, mainly due to the plentiful supply of nitrogen from river discharge and the low frequency of environmental measurements, which resulted in low statistical confidence. However, environmental factors affecting monthly laver production were related to the life cycle (culturing stage) of Porphyra yezoensis and were somewhat different from factors affecting annual laver production. In November, a young laver needs lower water temperatures for rapid growth, while a mature laver needs much stronger winds and more sunshine, as well as lower temperatures for massive production and effective photosynthesis, mostly in December and January. However, in spring (March), more stable environments with fewer fluctuations in air temperature are needed to sustain the production of newly deployed culture-nets ($2^{nd}$ time culture). These results indicate that rapid changes in weather and marine environments caused by global climate change will negatively affect laver production and, thus, to sustain the yield of and predict future variability in laver production at the Nakdong River estuary, environmental variation around laver culturing farms needs to be monitored with high resolution in space and time.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.4
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• pp.185-193
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• 2002

With Increasing awareness towards environment-friendly and non-toxic pesticide azadirachtin obtained from neon tree (Azadirachta indica) is gaining more and more importance. Its broad-spectrum activity, Peculiar mode of action. eco-friendly and non-toxic action towards beneficial organisms has offered many advantages over chemical pesticides. All currently use commercial formulations based on azadirachtin contains azadirachtin extracted from seeds of naturally grown whole plants which is labour intensive process depending upon many uncontrollable geographical and climatic factors. Plant tissue culture can be a potential process for the pro-duction, offering consistent, stable and controlled supply of this bioactive compound, However the research on tissue culture aspects of production are in preliminary stage and requires culture and process optimization for the development of a commercially viable process. This review states the present status and future challenges of plant tissue culture for azadirachtin production.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.577-581
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• 2003

Streptomyces lividans is one of the most commonly-used streptomyetes strain as a molecular cloning and expression host. Unlike its close relative S. coelicolor, however, S. lividans rarely produces secondary metabolite such as actinorhodin in a typical glucose-containing culture condition due to insufficient expression of some antibiotic regulatory genes including afsR2. Although multiple copies of afsR2 or a glycerol-specific culture condition stimulated actinorhodin production in S. lividans, both failed to stimulate actinorhodin production in S. lividans cultured in a typical glucose-containing medium. To generate a culture-condition-independent actinorhodin-overproducing S. lividans strain the afsR2 gene was integrated into the S. lividans TK21 chromosome via homologous recombination, followed by the genetic confirmation. This S. lividans strain produced a significant amount of actinorhodin in both glucose-containing liquid and plate cultures, with higher actinorhodin productivity compared to the S. lividans containing multiple copies of afsR2. These results suggest that a chromosomal integration of a single copy of an antibiotic regulatory gene is a promising method for the development of a stable antibiotic-overproducing streptomycetes strain.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.65-70
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• 1985

The production media, partial purification and the enzymatic characteristics of laccase from Pleurotus ostreatus were investigated. Among various media tried the double strength onion media showed much higher production of laccase compared to glucose and/or CMC added media. The laccase from Pleurotus ostreatus has the optimum pH of 5.94 for the activity and appears to be stable at relatively broad pH spectrum (4.7-8.7). The experiments on the temperature stability shows that above 90% activity could be preserved after holding at $30^{\circ}C$ for 40 min., 60% activity was remained after 40 min. at $50^{\circ}C$. The Km value of the laccase from Pleurotus ostreatus was estimated to be 3.209mM and the molecular weight of laccase was estimated to be 55,000 by SDS-Polyacrylamide gel electrophoresis.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.1-5
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• 2008

Negative environmental consequences of fossil fuels and the concerns about their soaring prices have spurred the search for alternative energy sources. While other alternative energies-like solar, wind, geothermal, hydroelectric, and tidal-offer viable options for electricity generation, around 40% of total energy consumption requires liquid fuels like gasoline or diesel fuel. This is where bio-energy/biofuels is especially attractive, where they can serve as a practical alternative to oil. The production of liquid biofuels for transportation will depend upon a stable supply of large amount of inexpensive cellulosic biomass obtained on a sustainable basis. This paper reviewed development status of transportation bio-energy for vehicles, technical barriers to the production of cellulosic ethanol, and the global future of bio-diesel and ethanol production.

• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.169-175
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• 1991

Pediococcus acidilactici strain M produced a bacteriocin which was proteinaceous, heat stable, and exhibited antimicrobial activity against lactic acid bacteria, variety of food spoilage and pathogenic bacteria. The antimicrobial activity was not caused by $H_2$$O_2$ and organic acid, and was remained between pHs of 4.0 to 9. Molecular weight of crude bacteriocin was approximately 2, 500. Phenotypic assignment after plasmid cruing experiment demonstrated that a 53.7 kilobase (kb) plasmid, designated as pSUC53, was responsible for the sucrose fermentation phenotype ($Suc^+$) and a 11.1 kb plasmid, designated as pBAC11, was associated with bacteriocin production phenotype ($Bac^+$). Neither of the two plasmids were linked to antibiotic resistance.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.187-194
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• 2000

An actinomycetes strain, T-2, which produces transglutaminase (EC 2.3.2.13), was isolated from soil and identified as belonging to the Actinomadura sp., based on taxonomc studies. The conditions for the transglutaminase production and its enzymatic properties were investigated. The optimum components for the transglutaminase production were 2% glucose, 1% polypeptone and soytone, and 0.1% MnCl2. The optimum pH and temperature of the enzyme reaction were pH 8.0 and $45^{\circ}C$, respectively. The enzyme was stable within the pH range of 5.0-9.0 and $30^{\circ}C-45^{\circ}C$. The novel enzyme required no calcium ions for its activity. This enzyme polymerized various proteins such as casien, soy protein, hemoglobin, egg white, gelatin, and soybean milk.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1010-1016
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• 1999

Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.344-348
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• 1992

This paper describes a procedure to design a hovering flight controller for a model helicopter using LQG theory. Parameters of the model helicopter in hover are obtained using direct measurements and calculations proposed by other research. A feedback co is by using digital LQG theory. First, a full state feedback controller is designed to the discretized system taking desirable transient response and other assumptions into account. Then a full-state estimator is designed and revised until desirable response is obtained while global stability is maintained. Performance of the controller is tested by computer simulations. Experiments have been performed using a 3-degree-of-freedom gimbal that holds the model helicopter, and the controller exhibited stable hover capability.