• Journal of Plant Biotechnology
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• v.50
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• pp.176-182
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• 2023

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica 'Fuji') leaf explants were developed in the present study. The effects of dark incubation periods in the early stages of culture, pre-treatment methods, the number of explants per culture container, the type of culture containers, and the orientation of the explants on culture media were evaluated to determine the optimal shoot regeneration conditions for 'Fuji' apple leaf explants. Light incubation of explants produced minimal response. However, dark incubation of explants for 4 weeks during the initial culture period enhanced shoot regeneration frequency. Comparing the number of explants per container, a higher percentage of shoot regeneration was obtained with nine explants per container compared with four explants per container. Pre-treatment, before culture, by dipping explants in a liquid regeneration medium containing 40 g/L of sorbitol for 2 hours produced the highest shoot formation rate, and the time of shoot formation was accelerated. The percentage of shoot regeneration and number of shoots per regenerating explant reached a maximum of 87.5% and 4.7, respectively. The regenerated shoots were elongated and rooted on a rooting medium of 1/4 MS with 0.2 mg/L IBA. The plantlets were successfully acclimatized, and the regenerated plants produced normal phenotypes.

• Journal of Mushroom
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• v.19 no.3
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• pp.126-133
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• 2021

In this study, we investigated the effect of solid culture medium on the production of cordycepin in Cordyceps militaris. The regression equation was expressed as follows: Y₁ = 755.3-58.6625X₁+4.79432E-14X₂-46.6625X₃-5.66269E-14X₁X₂-0.025X₁X₃+1.62475E-14X₂X₃-160.6625X₁²+0.0125X₂²-206.9625X₃², where, Y represents the value of cordycepin content (㎍/g), X₁ corresponds to the weight of M. alternatus in solid culture medium (g/bottle), X₂ to the water content of the solid culture medium (%), and X₃ to the culture period (day). The solid culture medium was optimized using the response surface methodology, and the optimal medium composition was as follows: the weight of M. alternatus in solid culture medium and water content were 16.2% and 100.7% (20.14 mL water/20 g solid culture medium), respectively, with a culture period of 39 days. Under these conditions, the cordycepin content of the fruiting bodies reached 150.0 ㎍/g (actual value). The supplementation of M. alternatus in solid culture for improved cordycepin content of C. militaris seems to be a promising alternative to wild and solid cultivation.

• Microbiology and Biotechnology Letters
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• v.8 no.3
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• pp.199-206
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• 1980

Some experiments on the citric acid production were carried out from soluble starch and molasses as raw materials. When soluble starch was used as substrate for the fermentation of citric acid by the strain M-80 which had assimilating ability of soluble starch in surface culture, the optimal culture media was 120g of soluble starch, 3.0g of (N $H_4$)$_2$S $O_4$, 2.0g of K $H_2$P $O_4$, 0.2g of MgS $O_4$.7$H_2O$, 1.5mg of F $e^{++}$, 1mg of Z $n^{++}$ and 20ml of methanol were added to 1 liter and optimal pH was 5.5. In about 8 days 61.8mg/ml of citric acid was produced. When treated molasses with potassium ferrocyanide was used as substrate for the fermentation of citric acid by the strain of M-315, the optimal condition in surface culture was 250g of molasses, 0.3g of N $H_4$N $O_3$, 0.05g of K $H_2$P $O_4$, 0.01g of MgS $O_4$.7$H_2O$, 0.5g of Potassium ferrocyanide and 30ml of methanol were added to 1.0 liter. On the other hand, the optimal condition in submersed culture was 250g of molasses, 0.3g of N $H_4$N $O_3$, 0.1g of K $H_2$P $O_4$, 0.01g of MgS $O_4$.7$H_2O$, 0.5g of potassium ferrocyanide, and 30m1 of methanol were added to 1.0 liter and optimal pH was all 5.0. After 9 days culture, 69.4mg/ ml, 39.6mg/ml of citric acid were separately produced in surface and submerged culture media.dia.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.349-353
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• 2003

The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.325-328
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• 2001

Teicoplanin is a glycopeptide antibiotic produced by Actinoplanes teichomyceticus novo sp. A TCC 31121. It is active against Gram-positive bacteria and it is under evaluation for use in man. Teicoplanin mixture in fermentation broth contains major amounts of teicoplanin $A_1$ and $A_2$ and a minor amount tcicoplanin of $A_3$. Commercial teicoplanin product is composed of five major components of very similar polarity, designated T-$A_2$-l, 2, 3, 4 and 5, and the more polor component, designated T -$A_3$. The culture conditions were studied in order that hydrophilic teicoplanin $A_2$ components are more produced but hydrophobic teicoplanin $A_1$ with lower bioactivity are less produced in submerged culture. Effects of culture pH and nutrients on the biosynthes ratio of teicoplanin $A_1$ and $A_2$ were confirmed in flask culture using MOPS buffer system through TLC, bioautography and bioassay. It was elucidated that optimal pH is 7.4 for teicoplanin $A_2$ biosynthesis but is 5.2 for teicoplanin $A_1$ biosynthesis, and that trace elements stimulate $A_2$ production but malt extract stimulate $A_1$production.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.22-26
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• 2004

The ligninolytic basidiomycete, Pleurotus ostreatus K-2946, was produced a manganese peroxidase (MnP) activity when grown in liquid culture with glucose-yeast-peptone (G-Y-P) medium. However, lignin peroxidase (LiP) was not detected in this culture medium. The purification progress of MnP was purified that included chromatography on Sepharose CL-6B, Superdex 75 prep grade and Mono-Q. MnP purified by column chromatography, was 36400 dalton and a pI of 3.95. The optimal pH and temperature of the purified MnP activity were 5.0 and $55^{\circ}C$. The characteristics of MnP produced was quite similar to those of MnP 3 isoenzyme produced by other strains of P. ostreatus.

• The Journal of Fisheries Business Administration
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• v.42 no.3
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• pp.79-93
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• 2011

Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

• Journal of Microbiology
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• v.40 no.1
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• pp.82-85
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• 2002

The aerobic batch growth of Issatchenkia orientalis DY252 with glucose and fructose medium was investigated at 32$\^{C}$ and pH 5.0. Aerobic ethanol production was evident with yeast I, orientalis. A diauxic lag of about 1 h between growth on glucose and growth on ethanol during batch culture was observed. However, no diauxic growth occurred with fructose. As the incubation temperature was increased from 32 to 39$\^{C}$, viability at the end of each batch culture declined significantly, from 93 to 43%, Unlike the effect of temperature, viability was not greatly affected by incubation pH, and cell yield values in a range of 0.45-0.48 were obtained. In order to overcome overflow metabolism, a fedbatch culture under glucose limitation was carried out. Compared with aerobic batch culture, about 10% improvement in cell yield was achieved with a fed-batch culture in optimal conditions.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.349-354
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• 2000

Culture conditions and nitrogen sources were optimized for production of erythritol, a natural sweetener, by Candida magnoliae M26. The optimal culture conditions were found to be culture temperature of $28^{\circ}C$, initial pH of 7, aeration of 1 vvm and agitation speed of 500 rpm in a 2.5 1 jar-fermentor. Glucose was chosen as the best carbon cource bsed on cell growth and erythritol productivity. Kight steep water(LSW) and corn steep liquor (CSL) which are by-products in starch processing from corn were tested as a nitrogen source substitute for yeast extract. The use of either LSW or CSL did not change the fermentation performance. The experimental results using LSW and CSL showed 1.5 times higher in cell growth and almost the same value in erythritol productivity com-pared with the control fermentation using yeast extract as a nitrogen source. These results suggested that either LSW of CSL could be used as a nitrogen source in a large-scale fermentation for erythritol production.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.220-227
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• 2009

In the process of oyster mushroom production, loading work of culture medium needs the most intensive labor power. Therefore, development of culture medium machine causes to reduce the manpower and cost. The main objective of this study is to develop the culture medium loading machine and investigate the optimal operation conditions and to evaluate the economic value of the machine. The results are summarized as follows: 1. Optimum transporting velocity of the conveyor was 0.61 m/s 2. Optimum speed of blower was 3183 rpm at the transporting velocity of 0.61 m/s with the loading quantity of 3.41 t/hr 3. Recommendable opening area ratio of pressure controller was 1/2 at the blower speed of 3183 rpm and the transporting velocity of 0.61 m/s 4. The break even point resulted in $240\;m^2$ of cultivating area compared to the method of with portable workbench, and $350\;m^2$ of cultivating area compared to the method of with a tractor and a truck.