• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.668-676
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• 1992

For the purpose of optimizing poly-l3-hydroxybutyrate (PHB) production from Alcaligenes eutrophus, two-stage fed-batch culture was adopted. In this system, specifk growth rate was maximized during the first stage whereas specific production rate was maximized during the second stage. The optimal concentrations of glucose and ammonium chloride were 16.6 and 0.54 g/I in the growth stage and 20.0 and 0.07 g/l in the production stage, respectively. Proportional feedback control considering time lag was suggested for PHB production process and a simulator was developed for real-time control purpose.

• Korean Journal of Microbiology
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• v.40 no.1
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• pp.37-42
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• 2004

To differentiate commercial bifidobacteia for Bifidobacterium lactis Bb-12, Bif. longum Bb-536 and Bif. infantis Maeil-K9, we studied the various carbon source, the nitrogen sources and antibiotics. Amygdalin and fructose were good candidates for carbon sources, and tryptone was suitable for nitrogen sources to design a new selective media for three commercial bifidobacteria. In the case of the amygdalin-containing medium as carbon sources, Bif. lactis Bb-12 and Bif. infantis Maeil-K9 showed good growth, and in fructose-containing medium, Bif. longum Bb-536 showed good growth. In antibiotics resistance study, the addition of 1 mg/L doxycyclin was very effective for differentiation of each bifidobacteria. Doxycyclin did not affect the growth of Bif. lactis Bb-12 and Bif. infantis Maeil-K9, but Bif. longum Bb-536 was completely inhibited by doxycyclin. Finally to confirm the selection capability of newly designed selective media, temperature-shocked bifidobacteria were cultured on them. As the results, fructose or doxycyclin containing medium showed for high growth for temperature-shocked bifidobacteria, but amygdalin containing medium showed low growth of temperature-shocked bifidobacteria.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.239-245
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• 1998

The feasibility of enzymatic hydrolysis of cellulosic materials is dependent on the cost of cellulase, which is strongly influenced by the selection of proper carbon source in the cellulase production medium. When solka floc was used as a carbon source for the production of cellulase by Trichoderma reesei Rut C-30, a maximum of 53.2 U/ml of CMCase activity (4.8 U/ml of FPase activity) was obtained with a concentration of 1 % of solka floc. The cellulase activity decreased to 50% in the presence of 0.5% of glucose in the medium. The production of cellulase was considerably enhanced when solka floc and wheat bran were used together as a carbon source. A medium which contained 1 % of solka floc and 3 % of wheat bran yielded highest cellulase activity: CMCase activity of 76 U/ml and FPase activity of 12.5 U/ml.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.249-254
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• 2011

Mycophenolic acid blocking the synthesis of xanthosine monophosphate is a nonnucleoside inhibitor of inosine monophosphate dehydrogenase. Therefore mycopholoic acid is a drug currently used as immunosuppressive agent in transplantation of heart, kidney and liver. Mycophenolic acid has been industrially produced through fermentation process by fungus Penicillium brevi-compactum. In this study, the profile of mycophenolic acid fermentation was observed in 5L-jar fermentor to investigate the utilization of carbon and nitrogen sources and the production of mycophenolic acid. It was investigated that what kind of carbon sources was better to cell growth and mycophenolic acid production. Fructose was the best carbon source for mycophenolic acid fermentation, but it is the most expensive one. Thereafter molasses containing sucrose as the supply source of fructose was confirmed to be the best carbon source for the industrial production. Use of molasses increased the fermentation yield of mycophenolic acid more than two times higher than glucose. It was confirmed that urea was the best inorganic nitrogen source, which did not give rise to sudden drop of culture pH. Addition of urea increased the fermentation yield of mycophenolic acid about 3.6 times higher than addition of ammonium nitrate as control. Casein, peptone and casamino acid originated from milk protein increased the fermentation yield of mycophenolic acid about 3.4 times higher than control. Peptone and casamino acid, which are casein hydrolysates, increased cell growth considerably as well.

• Korean journal of applied entomology
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• v.11 no.1
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• pp.5-9
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• 1972

The experiment was conducted to investigate the physiological characteristics on 16 Isolates of bacterial wilt pathogen, pseudomonas solanacearum E.F. Smith, those obtained from infected stems of tomatoes, hot-Peppers and eggplants. PSA and Sucrose medium favoured by the most of the isolates, and various degree of gelatin liquefaction occurred by each of nine isolates those alble to liquefy gelatin among 16 isolates tested. The most of the isolates except one, did not reduce methylen blue. All isolates did not utilize lactose, saccharose, and starch, although all isolates utilize the galactose. The utilization of dextrin, esculin, glucose, mannitol, raffinose and salicin was depended on each isolate.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.171-176
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• 2003

Productivity of biosurfactant (rhamnolipid) by Pseudomonas aeuginosa F722 was investigated in the several culture conditions and culture composition. Biosurfactant production by P. aeuginosa F722 was amounted to 0.78 g/l as the result of the nitrogen sources and carbon sources without investing of optimum conditions. As for that one was investigated, biosurfactant production by P. aeruginosa F722 was amounted to 1.66 g/l. Biosurfactant production increased twofold because the composition of a modified C-medium was investigated efficiently. $NE_4$Cl or $NaNO_2$ inorganic nitrogens and yeast extract or trypton organic nitrogens were effective, but others inorganic nitrogens and organic nitrogens tested were not efficient far biosurfactant production by P. aeruginosa F722. The optimum concentration of $NH_4$Cl; inorganic nitrogen and yeast extract; organic nitrogen were 0.05% and 0.1%, respectively. In various carbon sources, others with the exception of hydrophobic property substrate (n-alkane) and hydrophilic property substrate (glucose, glycol) were not found to be effective fur biosurfactant production, and 3.0% was better in yield than other concentration of glucose. This yielded C-to-N ratios between 17 and 20. In our experiment, the highest biosurfactant production by P. aeruginosa F722 were observed in 5 days cultivation, containing glucose 3.0%, $NH_4$Cl 0.05%, and yeast extract 0.1% and C-to-N ratio was 20. Optimal pH and temperature for biosurfactant production were 7.0 and $35^{\circ}C$, respectively. Under the optimal culture conditions with glucose, biosurfactant production was amounted to 1.66 g/l. Velocity of biosurfactant production and strain growth increased after nitrogen depletion. The average surface tension of 30 mN/m after the 3 days of incubation under optimal culture condition was measured by ring tensionmeter.

• KSBB Journal
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• v.9 no.2
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• pp.133-139
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• 1994

Oligosaccharide formation and the production of transfructosylase and transglucosylase by Aureobasidium pullulans were studied in sucrose or maltose media, respectively. The initial uptake rates of substrate in sucrose-rich media were faster than that in maltose-rich media, also most parts of oligosaccharides formed and other monosaccharides released were utilized progressively as substrate during the cultivation periods. However, when the initial amount of sucrose was raised to $100g/\ell$, high concentration of monosaccharides were liberated, consequently high-level fructose was accumulated unused during fermentation. The biggest molecule of oligosaccharide synthesized was hexasaccharide in all cultivation media examined, of which the organism could not utilize isomalto-oligosaccharide of DP6 synthesized in a maltose-rich medium. The maximum amount of oligosaccharides produced was $58g/\ell$ when $100g/\ell$ of sucrose and $5g/\ell$ of maltose were used as initial substrate. From the early stage of growth both fructooligosaccharides and isomalto-oligosaccharides were synthesized and progressively utilized as substrates during the fermentation. Based on the experimental results, it was suggested that maltose could induce both transfructosylase and transg1ucosylase, whereas sucrose was unable to slimulate transglucosylase formation.

• KSBB Journal
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• v.23 no.1
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• pp.18-22
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• 2008

Various probiotic Lactobacillus spp. are known to produce exopolysaccharide (EPS) which has potential health promoting functionality. A Lactobacillus paracasei strain producing EPS was isolated from healthy human. This strain, named L. paracasei KLB58, was grown on modified MRS medium. Experiments were conducted under various growth conditions to optimize the EPS production. Our study showed that incubation temperature played an important role in EPS production. When incubation temperature was changed from $37^{\circ}C$ to $25^{\circ}C$, the increase of EPS production (28.1 mg/ml) was the highest in our experiment. The type of carbon source in the medium also affected EPS production. Galactose was the most effective for EPS production among the carbon sources examined. Using galactose, glucose, lactose and sucrose, the amount of released EPS was 38.9 mg/ml, 35.6 mg/ml, 21.76 mg/ml and 16.9 mg/ml, respectively. However, acidity in growth medium inhibited EPS productivity due to the low growth yield. When grown at pH 4, L. paracasei KLB58 could only produce EPS of 14.6 mg/ml. When the initial amounts of nitrogen and carbon sources were examined, EPS production was not significantly affected by nitrogen source while carbon source affected considerably.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.225-234
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• 1976

To elucidate ${\beta}$-glucosidase formation on various carbon scurces by cellulolytic bact-eia, Cellulomonas sp. CS1-1, the strain was grown on Nutrient Yeast Broth, carboxymethyl cellulose, avicel and cellobiose using a Ouickfit FVIL fermentor operated in batch, and the growth characteristics on those substrates and ${\beta}$-glucosidase distribution of extra and intracellular enzyme components were studied. The results were: 1) ${\beta}$-glucosidase was always intracellular, and was formed under all growth conditions tested, ii) but levels of relative activities were higher when the culture was grown on cellobiose and on avicel, iii) the relative activities were always maximum during the growth phase of the organism irrespective of the substrate used.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.293-298
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• 1986

Sisomicin, which is one of aminoglycoside antibiotics, was produced by Micromonospora inyoensis. The effects of carbon sources on sisomicin production were studied in batch cultures. Starch, dextrin and maltose were good carbon sources for the production of sisomicin. However, when glucose was used, the antibiotic productivity decreased significantly due to a carbon catabolite regulation. The carbon catabolite regulation depends mostly on carbon catabolite repression, but not on carbon catabolite inhibition. On the other hand, the growth-production curves of batch cultures show that sisomicin is produced most actively during the idiophase.