• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.863-869
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• 2001

A systematic study of microbial fuel cells comprised of alkalophilic Bacillus sp. B-31 has been carried out under various operating conditions. A significant amount of electricity was generated when redox mediators were used. Among the phenothiazine-type redox dyes tested, azure A was found to be the most effective both in maintaining a high cell voltage and for the long-term operation. The maximum efficiency was and for the long-term operation. The maximum efficiency was obtained at ca. $50^{\circ}C$ giving an open circuit voltage of 0.7V. A small change in temperature did not significantly affect the cell performance, but a rapid decrease in performance was observed below $20^{\circ}C$ and above $70^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern depended strongly on the carbon source used in the initial culture medium. Regardless of the initial carbon sources, only glucose and trehalose were utilized as substrates. Galactose, however, was not substantially utilized except when galactose was used in the initial medium. Glucose, in particular, showed $87\%$ coulombic efficiency, which was the highest value ever reported, when Bacillus sp. was cultured in a maltose-containing medium. This study demonstrates that highly efficient microbial fuel cells can be constructed with alkalophilic microorganisms by fine-tuning the operating conditions and by carefully selecting carbon sources in the initial culture medium.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.121-126
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• 2006

Saikosaponin productivity was examined in a Bupleurum falcatum L. BFHR2 hairy root culture in response to changes in the sucrose content $(2{\sim}8%)$, nitrogen content $(0{\sim}250mM\;NH_4NO_3)$, phosphate content $(0{\sim}12mM\;NaH_2PO_4)$, and the potassium content $(0{\sim}87.2 mM\; KCl)$ of the culture media. We found that the conditions for maximal saikosaponin production differed from those for optimal root growth. Highest saikosaponin yield was achieved for 8% sucrose, 62mM $NH_4NO_3$ 1.2 mM $NaH_2PO_4$, and 0.5mM KCl.

• KSBB Journal
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• v.14 no.2
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• pp.241-247
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• 1999

Experimental studies were carried out to optimize the culture conditions of Corynebacterium diphtheriae for the production of diphtheria toxin. A new media which does not contain any meat digest products was selected. The main ingredient of new medium was enzymatic digests of casein known as NZ-Case. In fermenter experiments, the toxin production was increased with the increase of cell growth. The optimum initial pH of media, air flow rate and agitation speed were 7.0, 0.22, vvm and 400 rpm, respectively. The contents of iron and calcium-phosphate precipitate were important for maximal cell growth and toxin production. The optimum concentration of iron was 0.3 mg/L and calcium-phosphate precipitate could serve in gradual supply of iron to maintain the optimal culture condition which is required for enhanced yield of toxin production. In potency test, the potency of toxoid from fermentor culture was higher than that from static culture. When diphtheria toxin is produced by fermentor culture, it is possible to produce higher levels of toxin and better toxoid quality in terms of safety, yield, productivity and immunity.

• KSBB Journal
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• v.27 no.2
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• pp.97-102
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• 2012

In the present study, the biomass productivity of two green microalgae (Chlorella sp. and Dunaliella salina DCCBC2) were assessed in a 12 L tubular photobioreactor under optimum culture conditions. In the batch culture optimization process, the Chlorella sp. biomass was obtained as 1.2 g/L under atmospheric air as a sole $CO_2$ source and other culture conditions as follows: light intensity, temperature, pH, $NH_4Cl$ and $K_2HPO_4$ were 100 ${\mu}E/m^2/s$, $27^{\circ}C$, 7.0, 20.0 mM and 2.0 mM, respectively. On the other hand, 2.9 g/L of D. salina DCCBC2 biomass production was observed under the following conditions: light intensity, temperature, pH, $KNO_3$ and $K_2HPO_4$were 80 ${\mu}E/m^2/s$, $27^{\circ}C$, 8.0, 3.0 mM and 0.025 mM, respectively. At 1% $CO_2$ supply to the reactor, the Chlorella sp. production was reached 1.53 g/L with 25% increment under the same operating conditions. In addition, the maximum D. salina DCCBC2 biomass was observed as 3.40 g/L at 3% $CO_2$ concentration. Based on the aforementioned optimized conditions, the dilution rate and maximal biomass productivity of Chlorella sp. and D. salina DCCBC2 in the continuous cultivation were 0.4/d and 0.6 g/L/d and 0.6/d and 1.5 g/L/d, respectively.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.583-587
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• 1992

This study was conducted in order to optimize the media composition and cultural conditions for kasugamycin production by Streptomyces kasugaensis. The optimum culture conditions are pH 6.6 (before sterilization) and $28^{\circ}C$ for the production of kasugamycin. The kasugamycin concentration was not increased when silicone oil as antifoam agent was added. The addition of water during the cultivation in the various media showed a positive effect for the production of kasugamycin.

• ALGAE
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• v.21 no.1
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• pp.133-139
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• 2006

Outdoor cultivation of cyanobacterium Spirulina platensis was carried out for 40 days in a batch mode. A half concentration of the SOT based on the underground water was used as culture medium. Working volume was 5.7 tons with 0.2 m depth. During cultivation, mean water temperature, DO and light intensity were all in proper conditions for the S. platensis growth. The adjustment of pH to over 10 with Na2CO3 and addition of the 1.5% natural salt were very effective to delete contaminant organisms, Chlamydomonas moewusii and Chlorella minutissima occurred one after the other in the culture. The mean productivity of the biomass based on the dry cell weight from 14 to 25 days, after the contaminants were deleted, was 7.8 g ·m–2· d–1, which was relatively high productivity in that a half concentration of the SOT was used for the culture. Underground water used in the culture minimized contaminants invasion and addition of the 1.5% natural salt was effective to delete contaminants as well as acted as mineral supplement in outdoor cultivation of S. platensis. Harvesting using the floating activity of S. platensis was effective from mass floating in day time after overnight without agitation and illumination.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.92-98
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• 2005

This study was performed to get the basic information concerned to the optimum culture condition of Inonotus obliquus. Several solid media, PDA, MEA and Czapek-Dox, and three liquid media were adopted for the in vitro cultivation. Some main features of the fungal morphological characteristics under cultivation conditions were observed and described. Preliminary results showed that appearance of the mycelial mat, hyphal size and substrate pigmentation differed according to the media. The PDA medium was the most favorable substrate for the growth on solid culture, followed by MEA and Czapek-Dox media. Concerned to the addition of amino acids, 5 amino acids, such as alanine, alginine, isoleucine, leucine and threonine, enhanced to the mycelial growth. Isoleucine was shown the best fungal growth. An important morphological hyphal structure for the fungus, the setae, was found in abundance and diverse its shape and size. In liquid culture, fresh potato broth was the best growth stimulant of the fungus, followed by Malt extract and potato broth. Addition of yeast extract to the liquid media had improved the biomass, but not laccase production.

• KSBB Journal
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• v.21 no.2
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• pp.96-102
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• 2006

Recently, it has been known that Hericium erinaceum is a one of the very useful functional materials with great attention in mushroom processing industry. In present study, a liquid culture which was not studied systematically until now, was conducted as a method of cultivation for H. erinaceum, and also examined the characteristics of the liquid culture and conditions of process optimization. A good basal medium was selected through the cultivation of 16 species mushroom media and the optimum condition for medium and cultivation were chosen by response surface method. From these results, the optimum condition of medium for mushroom was 3% glucose, 0.2% yeast extract/peptone(1:1) and 0.1% $KH_2PO_4/MgSO_4$(1:1) and also the optimal culture condition was obtained at inoculum of 13.42%, temperature of $22.3^{\circ}C$ and pH of 5.7. The mycelial dry weight of 9 g/I was obtained under these conditions and this amount was about 1.7 times higher than that which were cultivated in basal medium for 8 days.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.121-129
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• 2011

As the molecular breeding was progressed, many plant transformation techniques were attained for improving transformation accuracy and used to produce useful transgenic plants. Day by day, new varieties were developed so new transformation techniques required for these newly developed varieties. Carnation (Dianthus caryophyllus L.) is a popular and economically important ornamental plant, all over the world. Keeping this in view, we selected 18 varieties of D. caryophyllus L. commonly available in the market and did optimization of culture conditions for more efficient tissue culture and to get higher number of plants via micro-propagation. Four varieties namely Yellowdotcom, Jakarta, Belmonte, Polartessino etc. were selected for organ culture studies from single cell line. The optimum growth was recorded in the MS media supplied with sucrose 3%, NAA 1.0 mg/L and TDZ 1.0 mg/L. except Belmonte, in which, BA 1.0 mg/L was found to be the best combination, in place of TDZ, rest ingredients were same. The most efficient coagulating agent used to obtain higher number of plant from callus was phytagel 0.3%. The most effective explant for higher shoot formation was stem in which 80.2% shoot formation was recorded. It also reduced culture periods by 6 days.

• Mycobiology
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• v.37 no.2
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• pp.114-120
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• 2009

Streptomyces albidoflavus C247 was isolated from the soil of the Gyeongsan golf course in Korea. Physiological, biochemical and 16S rDNA gene sequence analysis strongly suggested that the isolate belonged to Streptomyces albidoflavus. Preliminary screening revealed that the isolate was active against fungi and bacteria. Self-directing optimization was employed to determine the best combination of parameters such as carbon and nitrogen source, pH and temperature. Nutritional and culture conditions for the production of antibiotics by this organism under shake-flask conditions were also optimized. Maltose (5%) and soytone (5%) were found to be the best carbon and nitrogen sources for the production of antibiotics by S. albidoflavus C247. Additionally, 62.89% mycelial growth inhibition was achieved when the organism was cultured at $30^{\circ}C$ and pH 6.5. Ethyl acetate (EtOAc) was the best extraction solvent for the isolation of the antibiotics, and 100 ${mu}$/ml of EtOAc extract was found to inhibit 60.27% of the mycelial growth of Rhizoctonia solani AG2-2(IV) when the poison plate diffusion method was conducted.