• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.177-185
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• 2004

The effects of liquid culture conditions and nutrient sources on the formation of protein-binding polysaccharide (PS) in Cordyceps militaris were examined. The formation amount of PS was increased in proportion to the growth rate of mycelium, in case of higher aeration or lower acidity. The optimum growth temperature of the mycelia was 25$^{\circ}C$ for the formation of PS. The optimum carbon source and nitrogen source were glucose and peptone, respectively. The ratio of C/N was optimal with 3％ glucose to 0.5 ％ peptone. The sugar composition in the PS was greatly changed according to the carbon sources. The mycelium of Cordyceps militaris by liquid culture showed a higher electron donating ability than that by solid culture.

• ALGAE
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• v.24 no.4
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• pp.257-265
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• 2009

Marine microalgae are a key diet component in finfish and shellfish aquaculture. Cryopreservation of the microalgae is suggested by many other studies as the best method for long-term storage. To test cryopreservation efficacy, 19 taxas of marine microalgal species were examined. In the first experiment we compared dimethylsulfoxide ($Me_2SO$) and glycerol, which are most widely used as cryoprotectant agents (CPAs). The cryopreservation comprised two freezing procedures. Firstly, the samples containing the CPAs were kept at $4^{\circ}C$ for 10 min before being plunged into liquid nitrogen ($-196^{\circ}C$). Secondly, samples containing CPAs were pre-cooled ($-1^{\circ}C$ $min^{-1}$ to $-80^{\circ}C$ before being plunged into liquid nitrogen. Most of the species were successfully cryopreserved using $Me_2SO$, whereas the Prasinophyceae (T. striata and T. suecica) were successfully cryopreserved using glycerol. In general, the cooling method had no influence on the survival of the microalgae except in the case of the Tetraselmis species. In the second experiment, the cultured solution was divided before cryopreservation into concentrated and non-concentrated groups to identify the effect of cell density during cryopreservation. After 12 months of storage, the samples were again divided into centrifugation and non-centrifugation groups to learn the effect of $Me_2SO$ on the culture. Viability and growth of the microalgae were not influenced by cell density or the centrifugal removal of the $Me_2SO$ after thawing.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.33-36
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• 2001

The experiments were conducted to establish the in vitro culture system of apple rootstock M.9. The meristem tissue of M.9 were pre-treated in antiox: dant solution containing 100 mgL$^{-1}$ ascorbic acid and 150 mgL$^{-1}$ citric acid for 30 minutes, transferred to the MS liquid medium added with 0.1 mgL$^{-1}$ IBA, 0.5 mgL$^{-1}$ GA, and 30 gL$^{-1}$ sucrose, which shaked by 50 rpm for 2 weeks, and then, cultured in same composition of MS agar medium. This treatment stimulated shooting from the tissue, the most favorably, compared with other treatments. All young shoots produced normal roots when they were shake-cultured on the 1/2MS liquid medium added with 0.5 mgL$^{-1}$ IBA, 30 gL$^{-1}$ sucrose and 1,000 times diluted solution of Hormex by 50 rpm for one week, and subsequently transferred to the 8 gL$^{-1}$ agar medium of the same composition as pre-culture medium minus Hormex.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.368-375
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• 2005

Batch cultures were carried out to optimize the exo-polysaccharide production by liquid cultures of Pleurotus ferulae. Among the various carbon sources, when $5\%$ of glucose was used, the maximum mycelial growth and exo-polysaccharide concentration reached were 8.78 g/l and 3.59 g/l, respectively. Yeast extract and polypeptone were identified as the most suitable nitrogen sources. In particular, when a mixture of $1\%$ of polypeptone and $0.8\%$ of yeast extract was used, 9.52 g/l of mycelial growth and 4.09 g/l of exo-polysaccharide were obtained. In the case of mineral sources, K$_2$HPO$_4$ and MgSO$_4$$\codt$7H$_2$0 were found to be the best mineral sources for mycelial growth and exo-polysaccharide production. Under the optimized culture conditions, the agitation speed and aeration were investigated for mycelial growth and exo­polysaccharide production in a jar fermentor. The maximum mycelial growth and exo-polysaccharide concentration at 1.5 vvm and 200 rpm obtained were 13.2 g/l and 4.95 g/l, respectively, after 10 days of culture, which were $76\%$ and $79\%$ higher than those of the basal medium. The specific growth rate was decreased with the increase of mycelial growth. However, the specific production rate of the exo-polysaccharide was proportionally increased with the specific growth rate. The proposed model profiles showed good agreement with the experimental results for the mycelial growth and exo-polysaccharide production. The specific production rate using the optimized medium was higher than that of basal medium.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.272-276
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• 2011

Paeonia japonica has been widely used as a folk remedy for a long time. This study was performed to investigate antimicrobial substance of P. japonica extracted with petroleum ether, chloroform, ethylacetate, methanol or hot water. The antimicrobial activities of the P. japonica extracts were determined using a paper disc method and liquid culture. The methanol fraction at a concentration of 10 mg/mL showed the strongest antimicrobial activity against Salmonella typhimurim KCCM 11862. The ethylacetate fraction (5 mg/mL) showed the highest antimicrobial activity against Staphyloccoccus aureus KCCM 11593. In a study using liquid culture, the ethylacetate fraction from P. japonica showed the highest anti-microbial activity against S. aureus KCCM 11593 in a concentration range of 5~10 mg/mL. All fractions prepared from P. japonica inhibited the growth of S. aureus KCCM 11593 under our culture conditions.

• Mycobiology
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• v.49 no.4
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• pp.434-437
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• 2021

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C₁₈ cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A-C (1-3).

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1624-1631
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• 2021

Prodigiosin as a high-valued compound, which is a microbial secondary metabolite, has the potential for antioxidant and anticancer effects. However, the large-scale production of functionally active Hahella chejuensis-derived prodigiosin by fermentation in a cost-effective manner has yet to be achieved. In the present study, we established carbon source-optimized medium conditions, as well as a procedure for producing prodigiosin by fermentation by culturing H. chejuensis using 10 L and 200 L bioreactors. Our results showed that prodigiosin productivity using 250 ml flasks was higher in the presence of glucose than other carbon sources, including mannose, sucrose, galactose, and fructose, and could be scaled up to 10 L and 200 L batches. Productivity in the glucose (2.5 g/l) culture while maintaining the medium at pH 6.89 during 10 days of cultivation in the 200 L bioreactor was measured and increased more than productivity in the basal culture medium in the absence of glucose. Prodigiosin production from 10 L and 200 L fermentation cultures of H. chejuensis was confirmed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses for more accurate identification. Finally, the anticancer activity of crude extracted prodigiosin against human cancerous leukemia THP-1 cells was evaluated and confirmed at various concentrations. Conclusively, we demonstrate that culture conditions for H. chejuensis using a bioreactor with various parameters and ethanol-based extraction procedures were optimized to mass-produce the marine bacterium-derived high purity prodigiosin associated with anti-cancer activity.

• Korean Journal of Agricultural Science
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• v.26 no.1
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• pp.50-57
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• 1999

The purpose of this study was to determine the thermal inactivation of L. monocytogenes KCTC3443 in liquid culture heated in the controlled microwave system and in the conventional heating method. Furthermore, we have carried out a comparative study on the thermal and nonthermal microwave effects on microorganisms, pasteurized using a controlled microwave energy specially designed apparatuses and a water bath. For the automatic temperature control during microwave heating, the real time data acquisition and computation system is designed with BASIC routine. The automatic temperature control system used in the experiments perform relatively stable control at the experiment temperature of 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 minutes. The effects of microwave heating on liquid cultures was compared with that of conventional heating. The results show that microwave radiation, while being slightly quicker than conventional heating, still reduces effectively the number of pathogenic bacteria during heating for a limit time in liquid cultures. While no particular differences between microwave heating and conventional heating was not observed in the thermal inactivation of L. monocytogenes at 55, 65, $75^{\circ}C$ and $85^{\circ}C$ for 30 min., respectively. Microwave heating is, therefore, substantially not effective in inactivating L. monocytogenes in liquid culture than conventional heating method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.387-393
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• 2007

We examined the conditions for separating and preserving the male and female gametophytes of Kjellmaniella crassifolia. The highest percentage of zygote germination (85%) was on semi-solid medium composed of 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ after a 4-week culture. Zygote germination in PESI liquid medium was 93.5% at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$. The maximum zygote growth was $252{\pm}19.7\;{\mu}m$ on 1.0% transfer gel agar at $15\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$ after 5-week culture, and was $76.7{\pm}2.8\;{\mu}m$ in PESI liquid medium at $20\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$. The respective numbers of separated male and female gametophytes from germinated zygotes were 157 and 93 on 1.0% transfer gel agar and 14 and 28 in PESI liquid medium. The maximum growth of separated male and female gametophytes was $575{\pm}28.3\;{\mu}m$ at $5\;^{\circ}C$ and $60\;{\mu}mol/m^2/s$ and $686{\pm}35.4\;{\mu}m$ at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium after 3 weeks, respectively. The highest percentage fertilized was $93.3{\pm}5.8%$ at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium. These results show that the best conditions for the separation and preservation of gametophytes (male and female) consisted of culturing on 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.113-120
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• 2011

Present studies are carried out to find media components and culture methods for in vitro propagation of Athyrium niponicum and to establish the optimal economic masspropagation systems. Among pinnae, petiole and rhizome segments only rhizome segments produced young plants. Rhizome segments showed vigorous plant regeneration on 1/2MS medium and supplement to 1% sucrose and 50 $mg{\cdot}L^{-1}$ $NaH_2PO_4$ were promoted the plant regeneration from rhizome segments. Kinetin was better than BA for plant regeneration and combination with 2 ${\mu}M$ kinetin and 5 ${\mu}M$ IBA was most efficient for plant regeneration. Solid or liquid medium with or without 0.1% qactivated charcoal in modified 1/2MS medium (1% sucrose, 50 $mg{\cdot}L^{-1}$ $NaH_2PO_4$, 2 ${\mu}M$ kinetin, 5 ${\mu}M$ IBA, pH 5.8) were used to find the optimal culture methods. The plant regeneration from rhizome segments were most vigorous on solid medium without activated charcoal. The addition of activated charcoal were inhibited the plant regeneration from rhizome segments not only on solid medium but also liquid stationary or suspension culture.