• Mycobiology
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• v.47 no.4
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• pp.512-520
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• 2019

Statistical experimental methods were used to optimize the medium for mass production of a novel laccase3 (Lac3) by recombinant Saccharomyces cerevisiae TYEGLAC3-1. The basic medium was composed of glucose, casamino acids, yeast nitrogen base without amino acids (YNB w/o AA), tryptophan, and adenine. A one-factor-at-a-time approach followed by the fractional factorial design identified galactose, glutamic acid, and ammonium sulfate, as significant carbon, nitrogen, and mineral sources, respectively. The steepest ascent method and response surface methodology (RSM) determined that the optimal medium was (g/L): galactose, 19.16; glutamic acid, 5.0; and YNB w/o AA, 10.46. In this medium, the Lac3 activity (277.04 mU/mL) was 13.5 times higher than that of the basic medium (20.50 mU/mL). The effect of temperature, pH, agitation (rpm), and aeration (vvm) was further examined in a batch fermenter. The best Lac3 activity was 1176.04 mU/mL at 25 ℃, pH 3.5, 100 rpm, and 1 vvm in batch culture.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.91-94
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• 2002

Arachidonic acid is a polyunsaturated fatty acid(PUFA) containing twenty carbon atoms with four double bonds. The family of w-6 PUFA, including arachidonic acid as well as r-linoleic acid, was served as intermediates in the formation of several key prostaglandin and leukotrienes. Several fungal strains of the genus Mortierella accumulate high amounts of arachidonic acid. In this study experiments were carried out to optimize the culture conditions for the mass production of fungus Mortierella alpina DSA -12 and lipid production with high proportion of polyunsaturated fatty acids, especially arachidonic acid. The batch culture was carried out in 500 L fermenter containing 50 g/L glucose, 18 g/L corn-steep powder and 100 mg/L MnS04 under $25^{\circ}C$, aeration rate of 0.5 vvm and agitation speed of 200 rpm without pH control. As a result, we could be obtained 22 g/L of cell mass with high contents of lipid 12.1 g/L) and arachidonic acid (5.1 g/L) The intermittent fed-batch culture was performed in the medium containing 20 g/L glucose and 10 g/L corn-steep powder. The final glucose concentration was 170 g/L and pH was maintained at 5.5 ${\sim}$ 6.0 by adding 14% ammonia solution. It was shown relatively high cell concentration (70.5 g/L) with high contents of lipid (45.8 g/L) and arachidonic acid 08.3 g/L). Therefore, when compared to batch cultures, the high concentration of arachidonic acid could be obtained by fed-batch culture using M. alpina DSA -12. These results imply that the fed-batch culture of M. alpina DSA -12 was feasible in industrial purpose and could be employed in the commercial production of arachidonic acid.

• KSBB Journal
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• v.25 no.1
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• pp.47-54
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• 2010

The mycelial dispersed growth of Cordyceps sinensis was optimized in submerged batch culture at initial pH of 5.0, 150 rpm, and $25^{\circ}C$. The morphological data showed much more dispersed growth of C. sinenesis at initial pH of 5.0. Also, projected area, main hyphal length and number of tips for the mycelial growth of initial pH 5.0 were higher than those of other initial pHs. The industrial medium for mycelial production of C. sinensis was determined to be molasses of 100 g and crushed brewery yeast of 10 g per liter as carbon and nitrogen sources, respectively. With these culture conditions, the maximum production of mycelia was approximately 30.0 g per liter by batch culture in 5-liter jar fermenter with no controlled pH. This result suggests that large-scale mycelia production of C. sinensis may be possible in submerged batch culture. The hot water extract of mycelia from C. sinensis was mainly composed of 83.0% carbohydrate, 11.8% protein, 1.9% lipid, and 2.4% ash and there were present glucose, mannose, galactose, and arabinose as molar ratio of 8.79 : 2.59 : 1.34 : 1.0 in the carbohydrate, respectively. In the experiment using spleen cell and macrophage, the extract showed potent mitogenic and immuno-stimulating activities and among various components, an important factor that contribute to the immunological activities was turned out to be carbohydrate moiety.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.13-20
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• 1995

The purpose of this study was to evaluate the potentials of food wastes as an animal feed. The food wastes from the Inha University and Hanyang University Hospitals were used for this fermentation study. As the additive, approximately 40~50% of dry bean curd dregs and sawdust was mixed for moisture adjustment, certain amount(l/300 of the total content) of inoculum was added into the 140L volume fermenter and fermented for 40~48 hours with the temperature of $46{\sim}52^{\circ}C$ maintained. Fermentation product with the dry bean curd dregs had the lower content of crude protein, crude ash, calcium and phosphorus than the commercial pig feed. Fermentation product with sawdust had the lower content in most components than the commercial pig feed except crude fiber content. Based upon these findings, it was considered that only the fermentation product with dry bean curd dregs as the additive could be used for the animal feed aid.

• Journal of the Korean Society of Food Culture
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• v.14 no.5
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• pp.461-466
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• 1999

As a part of investigation to use sardine(Sardinops melanoslicta) more effectively as a food source, this study was undertaken the processing condition of rapid- and low salt-fermented liquefaction of sardine. To prepare rapid fermented products, the chopped whole sardine was added 8% NaCl and then preheating treatment at $40^{\circ}C,\;45^{\circ}C$ and $50^{\circ}C$ in the manufactured fermenter(180L) for 9 hrs, and then fermentation at $33^{\circ}C$ for 90 days. The chemical changes such as amino nitrogen(amino-N), volatile basic nitrogen(VBN), and histamine in the hydrolysates of fermented sardine were analyzed as well as viable cell count and organoleptic evaluation during fermentation to compare the quality between control and preheating samples. During fermenting, the amino-N in the hydrolysates increased rapidly during the first 30 days and slowly thereafter. The highest content of amino-N appeared at 75 days in control sample and $60{\sim}75$ days in preheating samples. The changes of VBN in the hydrolysates increased rapidly during first 15 days in control samples and 30 days in preheating samples. However they were generally low level in preheating samples. Histamine content in the hydrolysates of the control samples increased markedly after 15 days, but preheating samples were generally low level, and then $75{\sim}90$ days of fermentation reached to the maximum which was about $2.0{\sim}3.0$ times lower than that of control samples. As for the organoleptic flavor evaluation, the control and preheating at $40^{\circ}C$ samples were unpleasant odor after 15 and 60 days, respectively. But preheating at $45^{\circ}\;and\;50^{\circ}$ samples were fresh odor after 90 days fermentation.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.33-43
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• 1999

A strain (designated SK3l) which produces an excellent adsorption substance was isolated from soil samples and identified as Bacillus specied. The major adsorption substance (biosorbent SK3l) produced by Bacillus sp. SK31 was purified by ethanol precipitation and cetylpyridinium (CPC) precipitation. The adsorption charactics of zinc and lead ions on bioadsorbent SK3l were investigated. The equilibrium isotherms showed that bioadsorbent SK3l took up zinc and lead from aqueous solutions to the extent of about 52 mg/g and 112 mg/g. respectively. The culture conditions at the flask level of Bacillus sp. SK3l were investigated for the production of polysaccharide bioadsorbent, SK3l. The optimum pH and temperature for sorbent production were 7.5 and $30^{\circ}C$, respectively. The important carbon and nitrogen sources for sorbent formation were glucose and ammonium nitrate, respectively. In the optimized medium, sorbent production was improved three folds in comparison with the basal medium. In the jar fermenter, the highest sorbent production was obtained at 60 h cu1tivation time and the amount of biosorbent SK3l at that time was 9.2 g/$m\ell$.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.158-163
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• 2001

The effect of phosphate on the production of avermectin B1a was studied. Response surface methodology was applied to optimize the concentration of organic nitrogen sources. The portion of B1b in total avermectins was decreased from 5.8% to 3.0% by the addition of 1.5 g/ι inorganic phosphate to the production medium. Among organic nitrogen sources, soybean meal was the most effective on avermectin biosynthesis. Results showed that B1a productivity was increased by 44.8% in a laboratory scale fermenter cultivation of Streptomyces avermitilis YA99-40 through fed-batch process. A maximal B1a productivity was obtained by repeated 30 and 20 g/ι of glucose feeding at 136 and 206 hour, respectively. The B1a productivity was increased by 86.3% and the proportion of B1a in the total avermectins was improved from 38% to 45% with respect to the control process. These results would be very useful for enhancing productivity of B1a in an up-scaled processes.

• Journal of Microbiology
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• v.44 no.4
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• pp.439-446
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• 2006

In this study, the growth kinetics of Lactobacillus rhamnosus and lactic acid production in continuous culture were assessed at a range of dilution rates $(0.05 h^{-1}\;to\;0.40h^{-1})$ using a 2L stirred tank fermenter with a working volume of 600ml. Unstructured models, predicated on the Monod and Luedeking-Piret equations, were employed to simulate the growth of the bacterium, glucose consumption, and lactic acid production at different dilution rates in continuous cultures. The maximum specific growth rate of L. rhamnosus, ${\mu}_{max}$, was estimated at $0.40h^{-1}$I, and the Monod cell growth saturation constant, Ks, at approximately 0.25g/L. Maximum cell viability $(1.3{\times}10^{10}CFU/ml)$ was achieved in the dilution rate range of $D=0.28h^{-1}\;to\;0.35h^{-1}$. Both maximum viable cell yield and productivity were achieved at $D=0.35h^{-1}$. The continuous cultivation of L. rhamnosus at $D=0.35h^{-1}$ resulted in substantial improvements in cell productivity, of 267% (viable cell count) that achieved via batch cultivation.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.46-50
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• 2003

Lactococcus lactis SA72 from Jeot-gal (Korean traditional fermented fish foods) produces lacticin SA72. The influence of several parameters on the fermentative production of lacticin SA72 by Lactococcus lactis SA72 was studied. MRS medium among several media was selected for enhanced bacteriocin production. The mean growth rate and bacteriocin productivity of L. lactis SA72 increased as the initial pH of the media increases. The highest lacticin SA72 activity was detected 3,200 AU/ml at pH 6.0, $32^{\circ}C$, and 1% (inoculum size, v/v) in the jar fermenter. Enhanced production of lacticin SA72 was investigated by a fed-batch cultivation with the intermittent feeding of the concentrated glucose solution. Under the optimized conditions, lacticin SA72 activity finally reached to 6,400 AU/ml.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.54-60
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• 2006

In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.