• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.321-326
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• 2000

To examine the feasibility of the long-term production of the human granulocyte colony stimulating factor (hG-CSF) using the $_{L}-arabinose$ promoter system of Escherichia coli, flask relay culture and cyclic fed-batch culture were performed. In the flask relay culture, it was found that the pismid was maintained stably up to about 170 generations in an uninduced condition, whereby the cells could also maintain the capability of expressing hG-CSF expression were maintained stably up to at least 100 generations. In contrast, in the cyclid fed-batch culture, segregational plasmid instability was observed within about 4 generations after induction, even though the cell growth and hG-CSF production reached their maximum balues, 78.0 g/l of dry cell weight and 7.0 g/l of hG-CSF, respectively. It would appear that, when compared to the flask relay culture, the high-cell density and high-level expression of hG-CSF in the cyclic fed-batch cultrure led to the segregational plasmid instability; in other words, a severe metabolic burden existe on the cells due to the high-level expression of hG-CSF. Accordingly, based on these long-term cultures, the segregational and structural plasmid instability was observed and a strategy to overcome such problems could be designed.

• Journal of Genetic Medicine
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• v.2 no.2
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• pp.79-81
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• 1998

Genetic amniocenteses were performed in a series of 127 patients as a routine study. Samples from the patients were cultured by in situ method, flask method or both according to the state of amniotic fluid. The overall success rate of culture was 97.6% and no culture failure was observed in the flask method. It took 5 days first of all and 8.15 days average from set-up to harvest and there were 7.2 colonies per dish in in situ method. Therefore, it is suggested that in situ method which decreased the mean culture days and made clonal analyses possible, is a clinically available and even more reliable method in parallel with flask method in prenatal diagnosis.

• The International Journal of Costume Culture
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• v.2 no.1
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• pp.54-61
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• 1999

The purpose of this research was first to analyse and compare the types of microbes inherent among the unwashed and washed Kupori textiles, and second to investigate whether there is a difference between unwashed and washed Kupori textiles on the susceptibility of contamination by microorganism when exposed to the same microbial environment. Microbial identification procedure and the Shake Flask Test for investigating the effect of exposure to microbial environment were carried out separately. The result of microbial identification procedure indicated that a variety of bacteria and fungi were inherent in both unwashed and washed textiles and that the population of contaminated microorganism became more diverse after washing. The result of Shake Flask Test indicated that given the same exposure condition, the unwashed textiles tend to be more susceptible to bacterial contamination than the washed textiles. The results of the present study supported the current conservation procedures adopted in Korean museums which include washing and humigation procedures before long-term storage or display of exhumed textiles.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.398-401
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• 2003

Bacillus species predominantly outgrown in a night soil treatment system were isolated and characterized. Cell interactions took place among them and cell population changed under various culture conditions. Maximum removal of $NH_4\;^+-N$ and cell production occurred under the conditions of 30% DO and C/N ratio of 8. Additions of 0.8% peptone and 0.3% yeast extract to a basal medium influenced the growth of isolates and the removal of $NH_4\;^+-N$ in flask culture, and metal ions such as Ca, Fe and Mg also did. During the flask experiment of nitrogen removal under an aerobic condition, active nitrification by the isolates occurred largely in 1 h with the decrease of COD and alkalinity destructed was only 74.6% of theoretical value. From the nitrogen balance, the percentage of nitrogen lost in the flask culture was estimated to be 29.0%. This conversion of ammonia to $N_2$ under an aerobic condition was confirmed by GC analysis. The B3 process using the Bacillus species seemed to have some economic advantage.

• Journal of Life Science
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• v.14 no.1
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• pp.126-130
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• 2004

This study was carred out to get the basic conditions for the mycelial growth of Morchella esculenta in shaking flask culture. The optimal temperature and initial pH of mycelial growth of Morchella escuzenta were 25$\pm$1$^{\circ}C$ and 6.5, respectively. The optimal medium was BG medium. Among the carbon sources tested, fructose was favorable for the mycelial growth and optimal fructose concentration was 5.0% (w/v). As nitrogen sources, peptone and NH$_4$Cl appeared to be favorable and optimal concentration was 4.0% [(w/v), ratio of 1:1].

• Journal of Industrial Technology
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• v.21 no.A
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• pp.337-341
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• 2001

This study was carried out to screen the effective polymeric additives preventing wall growth during mycelial submerged cultivation of Ganoderma. lucidum. Effects of additives on mycelial growth and exo-polysaccharide (EPS) production in flask culture and jar fermenter system under 3 different pH processes were investigated, and changes of mycelial morphology were also examined. From flask culture of G. lucidum with additives of different concentrations, 0.1%(w/v) polyacrylic acid was effective for EPS production. As the polyacrylic acid of 0.1%(w/v) was added in medium, wall growth of G. lucidum mycelium grown in jar fermenter system could be protected. The addition of 0.1%(w/v) polyacrylic acid to medium was also improved the mycelial growth and EPS production in the later of submerged culture G. lucidum and no changes of mycelial morphology were observed.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.59-66
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• 1983

Cultural conditions for the production of extracellar $\beta$-galactosidase by Loctobacillus sporogenes, a spore forming lactic acid bacterium, were investigated with shaken flask and jar fermenter cultures. The fermentation medium giving maximum $\beta$-galactosidase yield was found to consist of 1 % lactose as a carbon source, 1.5% peptone as an organic nitrogen source. 0.2% ammonium sulfate as an inorganic nitrogen source, 0.8% ammonium phosphate dibasic as a phosphorus source, and 0.05% potassium chloride and 0.001% ferric chloride as mineral source. Optimal initial pH of the medium was 7.0 and the highest enzyme excretion was observed after 40 hours of cultivation at 37$^{\circ}C$. In this experiment, the 500$m\ell$ conical flask containing 50-200$m\ell$ of medium was shaken at 140 strokes per minute with 7cm amplitude in a reciprocating shaker. The maximum enzyme value attained was 38 U/$m\ell$ of the culture broth which was found to be slightly higher than the highest intermolecular enzyme activity (30 U/$m\ell$) observed after 24 hours of incubation. In the fermentor culture, the fermentation profile was shown to be similar to that observed in the shaken flask experiment. But the maximum extracellular enzyme activity was 45 U/$m\ell$ to be even higher than the value obtained with the shaken flask culture.

• KSBB Journal
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• v.5 no.3
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• pp.207-214
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• 1990

Growth properties of carrot hairy roots transformed by Agrobacterium rhizogenes were compared in flask and bioreactor. Oxygen transfer coefficient KLa was measured during the cultivation in bioreactor. In flask cultures, initially sucrose 30g/l was nearly exhausted after 20days. pH was dropped from initially 5.8 to 4.79 after 4 days, but it is stable after that time. Finally, after 28 days, hairy roots were grown about twelve times. In view of the results studied optimum conditions, hairy roots were maintained high growth rates in sucrose 50g/l, pH 5.8, total nitrogen 60mM. Also in bioreactor cultures, fixed stainless sieve in bottom and aerated 0.31 vvm, the results of cultivation by the use of sucrose 50g/l had grown about twenty-eight times and pH variations were liked in flask. As a results, growth rate of 1.756g fresh weight/day/g inoculum in bioreactor were higher about three times than 0.57g fresh weight/day/g inoculum in flask culture. KLa values were showed a tendency to decrease from 0.209 min-1 to 0.068 min-1.

• Journal of Life Science
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• v.14 no.3
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• pp.391-395
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• 2004

To overproduce the cyclodextrin glucanotransferase(CGTase) of Bacillus stearothermophilus NO2 in B. subtilis, the pJH-CGTl plasmid (8.14 kb) was constructed, in which the ORF of CGTase gene could be transcribed by strong constitutive promoter, P$\_$JH/. To overproduce CGTase from a recombinant B. subtilis, the effect of media on the cell growth and expression level of CGTase were investigated with various media (LB, 2${\times}$LB, 5% molasses+2% CSL, CS, LBG) in the flask culture. Among them, [5% molasses+2% CSL] medium revealed the maximum expression level of CGTase with 1.8 unit/$m\ell$ at 9 hr culture. In the batch culture on [10% molasses+5% corn steep liquor] medium the expression level of CGTase, the secretion efficiency, and plasmid stability were about 4.2 unit/$m\ell$, 90% and 90%, respectively, at 30 hr culture. The cell growth and expression level in the fermenter culture with the industrial molasses medium were increased by 2-folds over the flask culture.

• Korea-Australia Rheology Journal
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• v.14 no.1
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• pp.11-16
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• 2002

Cephalosporium acremonium is a filamentous microorganism producing cephalosporin C. The morphological differentiation of C. acremonium in submerged culture is closely related with the rheological properties of culture broth and production of cephalosporin C. In this study, the rheological and morphological properties of culture broth of C. acremonium were investigated. In the seed broths of shake-flask and fermenter culture, the Herschel-Berkley equation was in excellent agreement with experimental results in the whole range of shear rate. In the seed broths of shake-flask culture, morphological differentiation into arthrospores affected to changes of apparent viscosity. But results in the fermenter culture, morphological factors such as mean hyphal thickness and the number of tips gave more effect on changes of apparent vitacosity than differentiation into arthrospores. Overall, it suggested that the morphological parameters measured by image analysis can be used as a good parameter to indicate the rheological properties of culture broth of C. acremonium M25.