• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.252-262
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• 2002

The growing interest in the application of arachidonic acid (ARA) in various fields of health and dietary requirements has elicited much attention on the industrial production of ARA-containing oil by the cultivation of Mortierella fungi. For the industrial production of ARA, various studies, such as isolation of a high-potential strain and optimization of culture conditions, have been conducted. Studies including the investigation of morphology are important because ARA is accumulated in the mycelia, and thus cultivation with high biomass concentration is essential for obtaining a high ARA yield. Combining the results derived from various studies, a high ARA yield was attained in an industrial fermentor. These ARA production techniques are applicable to the production of other polyunsaturated fatty acids (PUFAs), and will contribute to the improvement of fermentation technology especially in the field of fungal cultivation.

• 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.

• 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.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.72-78
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• 2003

In the process of producing chitosan from crustacean shell, the use of excessive acid and alkli is causing the problems of environmental pollution and of production cost. In this study, one way to solve these problems is to cultivate fungi, then, to extract chitosan from the cell wall. By means of flask incubation and batch cultivation, the optimum cultivation conditions for mass production of continuous cultivation was found. Four strains used for the production of fungal chitosan were Gongronella butleri IF08080, Absidia coerulea IF05301, Rhizopus delemar IF04775, Mucor tuberculisporus IF09256. In flask incubation to select strain of producing much chitosan by means of experiment of the effect of initial pH, Absidia coerulea IFO 5301 had highest yield in FCs, 258.1 $\pm$ 47.3 mg/200 $m\ell$l at pH 6.5. In flask incubation under the optimum cultivation condition, temperature 27$^{\circ}C$, culture time 6days, glucose 2%, peptone 1%, (NH$_4$)$_2$ SO$_4$ 0.5%, $K_2$HPO$_4$ 0.1 %, Nacl 0.1 %, MgSO$_4$ㆍ7$H_2O$ 0.05%, CaCl$_2$ㆍ2$H_2O$ 0.01 %, the yield of DCW brought the highest yields. In batch bioreactor, the optimum cultivation condition was that cell suspended solution was 70 $m\ell$, aeration rate 0.5 l/min, agitation rate 800 rpm, culture time 36 hr. In continuous bioreactor, the optimum substrate flow rate was 4 ι/day.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1566-1573
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• 2014

Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

• 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.

• Natural Product Sciences
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• v.24 no.4
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• pp.229-234
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• 2018

Ginseng products available in different forms and preparations are reported to have varied bioactivities and chemical compositions. In our previous study, four new dammarane-type ginsenosides were isolated from Panax ginseng, which are ginsenoside Rg18 (1), 6-acetyl ginsenoside Rg3 (2), ginsenoside Rs11 (3), and ginsenoside Re7 (4). Accordingly, the goal of this study was to determine the distribution and content of these newly characterized ginsenosides in different ginseng products. The content of compounds 1 - 4 in different ginseng products was determined via HPLC-UV. The samples included ginseng roots from different ginseng species, roots harvested from different localities in Korea, and samples harvested at different cultivation ages and processed under different manufacturing methods. The four ginsenosides were present at varying concentrations in the different ginseng samples examined. The variations in their content could be attributed to species variation, and differences in cultivation conditions and manufacturing methods. The total concentration of compounds 1 - 4 were highest in ginseng obtained from Geumsan ($185{\mu}g/g$), white-6 yr ginseng ($150{\mu}g/g$), and P. quinquefolius ($186{\mu}g/g$). The results of this study provide a basis for the optimization of cultivation conditions and manufacturing methods to maximize the yield of the four new ginsenosides in ginseng.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.472-481
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• 2022

Brown blotch disease, caused by Pseudomonas tolaasii, is one of the most serious diseases in mushroom cultivation, and its control remains an important issue. This study isolated and evaluated pathogen-specific bacteriophages for the biological control of the disease. In previous studies, 23 varieties of P. tolaasii were isolated from infected mushrooms with disease symptoms and classified into three subtypes, Ptα, Ptβ, and Ptγ, based on their 16S rRNA gene sequences analysis and pathogenic characters. In this study, 42 virulent bacteriophages were isolated against these pathogens and tested for their host range. Some phages could lyse more than two pathogens only within the corresponding subtype, and no phage exhibited a wide host range across different pathogen subtypes. To eliminate all pathogens of the Ptα, Ptβ, and Ptγ subtype, corresponding phages of one, six, and one strains were required, respectively. These phages were able to suppress the disease completely, as confirmed by the field-scale on-farm cultivation experiments. These results suggested that a cocktail of these eight phages is sufficient to control the disease induced by all 23 P. tolaasii pathogens. Additionally, the antibacterial effect of this phage cocktail persisted in the second cycle of mushroom growth on the cultivation bed.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.05a
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• pp.75-89
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• 1996

Factory style plant production system be aimed to produce standardized horticultural products with high quality and clean due to optimization of environment and the improvement of working efficiency, through overcome non-efficiency of production structure in conventional cultivation method. The suggest about actual techniques and development strategies of plant factory in Korea are as follows. (omitted)

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.111-115
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• 1991

The green alga, Dunaliella salina under fed-batch cultivation produced 51.12 mg of hydrocarbon per liter with maintaining 0.313 (g dry wt/l). About 20% of hydrocarbon production yield based on dry biomass was obtained from both batch and fed-batch processes. Optimum culture conditions of light intensity, pH and salt concentration were obtained as 0.0080 (kJ/$cm^2$/h), 8.0 and 1.4 (g of NaCl/l), respectively by response surface analysis. The production of hydrocarbons in D. salina was closely correlated to cell growth. Fed-batch cultivation produced more hydrocarbons and maintained better cell growth than a batch process.