• 한국균학회지
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• 제27권1호통권88호
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• pp.1-9
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• 1999

느타리버섯 8품종의 균사생장은 $25{\sim}30^{\circ}C$의 온도 범위와 $5.5{\sim}6.5$의 pH 범위에서 가장 우수하였다. 영양원의 선발시험에서 탄소원으로서는 황백당, 밀가루 및 옥수수가루가, 그리고 질소원으로서는 대두분이 공시균주의 균사생장이 가장 우수하였다. 농업적으로 이용성이 우수한 황백당 3%, 대두분 0.3%, 인산칼륨 0.05%, 황산마그네슘 0.05%를 배지 조성으로 하는 농업용 액체배지를 선발하였다. 삼각플라스크 배양에서는 250 ml의 erlenmeyer flask에서 보다는 250ml의 shake flask에서 직경 6 mm의 균사절편을 2개 접종하여 배양액량 100ml에서 배양했을 때 공시균주의 균사체 생산이 우수하였다. 그리고 erlenmeyer flask에서 배양방법을 달리하여 느타리버섯의 균사를 배양하였을 때, $45^{\circ}$ 경사배양한 처리구에서 균사체 생산이 가장 우수하였으며, 길이 $50mm{\times}$ 직경 10mm의 유리막대를 넣고 배양한 처리구에서는 균체량이 가장 적었지만 펄프형의 균사생육을 유도할 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.459-464
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• 2004

The objective of this study is to improve cephalosporin C (CPC) production byoptimization of medium and culture conditions. A statistical method was introduced to optimize the main culture medium. The main medium for CPC production was optimized using a statistical method. Glucose and corn steep liquor (CSL) were found to be the most effective factors for CPC production. Glucose and CSL were optimized to 2.84 and $6.68\%$, respectively. CPC produc­tion was improved $50\%$ by feeding of $5\%$ rice oil at day 3rd and 5th day during the shake flask culture of C acremonium M25. The effect of agitation speeds on CPC production in a 2.5-L bio­reactor was also investigated with fed-batch mode. The maximum cell mass (54.5 g/L) was obtained at 600 rpm. However, the maximum CPC production (0.98 g/L) was obtained at 500 rpm. At this condition, the maximum CPC production was improved about $132\%$ compared to the re­sult with batch flask culture.

• Journal of Plant Biotechnology
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• 제3권2호
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• pp.107-112
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• 2001

The kinetics of Ti-transformed Salvia miltiorrhiza cell cultures was studied in 250-$m\ell$ shake flasks by using B5 medium with addition of 30 gfL of sucrose. In the cell cultures, the maximum cell mass obtained was 11.5 g DW/L on day 15. The highest amount of phenolic compounds - rosmarinic acid (RA) and lithospermic acid B (LAB) reached 871.3 mg/L (day 15) and 121.3 mg/L (day 13), respectively. The total tanshinone production, i.e., intracellular plus extracellular cryptotanshinone, tanshinone 1, and tanshinone IIA, was 5.3 mg/L on day 13. For the cultivations in 2.4-L stirred bioreactors, the residual sugar level and medium conductivity were a little higher in a small turbine impeller reactor ($T_s$) than those in a large turbine impeller reactor ($T_L$), while a higher cell density was obtained in the $T_L$. For the production of tanshinones and phenolics, better results were obtained in the $T_L$ than in the $T_s$. In the $T_L$, similar or even a little higher production titers of tanshinones and phenolic compounds were achieved compared to those in the flasks. The results suggest that the shake flask results could be successfully scaled up to the $T_L$ reactor. Such a large impeller reactor like $T_L$ may be better than a small impeller one for the large-scale production of the valuable metabolites by the suspension cultures of Ti transformed S.miltiorrhiza cells. This is considered due to the beneficial culture environment in the $T_L$, such as low shear rates as estimated theoretically.

• KSBB Journal
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• 제14권3호
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• pp.365-370
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• 1999

To optimize the culture conditions for Beauveria bassiana 726, the effects of culture medium, pH, and temperature on mycelium and spore production were investigated. The optimum temperature and pH for the cultivation of B. bassiana 726 were 28 $^{\circ}C$ and 5.0, respectively. The optimized medium was composed of 1.0~2.0% total sugar from molasses, 0.5% corn steep liquor and 0.05% KH$_2$PO$_4$. In the cultivation of B. bassiana 726 with the optimum medium, the specific growth rate and substrate utilization were well-fitted with the proposed kinetic model in the shake flask and stirred tank reactor. When the fed-batch cultivation using carbon suorce, nitrogen source, and mineral salt as a feeding medium was compared with batch cultivation in stirred tank reactor, mycelium (12.7 g/L) and spore production (5.4$\times$$10^8/mL$) were enhanced up to 110% and 85%, respectively.

• 한국미생물·생명공학회지
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• 제21권5호
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• pp.486-493
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• 1993

A gram(+) bacteria that produced microbial flocculant was isolated from soil and classified as a Bacillus species and named as Bacillus sp. A56. The culture conditions of the strain for fluocculant production were studied in a shake flask. Optimum temperature and initial pH for flcculant production were 30C and 6.5, respectively. The optimized medium has gollowing composition: glucose 20g/l, NH4NO3 0.5g/l, K2HPO4 1.0g/l, KH2PO4 0.8g/l, MgSO4.7H2O 0.2g/l, MnSO4.4-6H2O 0.3g/l, CaCO3 0.5g/l, yeast extract 0.3g/l, tryptone 0.3g/l in tap water.

• Archives of Pharmacal Research
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• 제11권1호
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• pp.61-64
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• 1988

To investigate the antibiotic constituents of Korean basidiomycetes the carpophores of the wood-rotting basidiomycetes were collected from several locations of Korea, and from them 17 mycelial strains were isolated on potato-dextrose-agar plates supplemented with tetracycline ($20\;{\mu}g/m{\ell}$. The isolated strains were shake-cultured in glucosepeptone-yeast extract medium and then the antibacterial activities of the culture filtrates were assessed by disc-plate method. Among them, 12 strains (70.6%) were active, and basidiomycete strain LMCB-109 (Daedalea quercina) and LMCB-116 showed potent activities against all the six bacterial target organisms including Serratia marcescens.

• Mycobiology
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• 제37권2호
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• pp.89-93
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• 2009

The effect of fermentation parameters and medium composition on the simultaneous mycelial growth and exo-polymer production from submerged cultures of Ganoderma applanatum was investigated in shake-flask cultures. The optimum initial pH for mycelial growth and exo-polymer production was 5.0 and 6.0, respectively. The optimum temperature was $25^{\circ}C$ and the optimum inoculum content was 3.0% (v/v). The optimal carbon and nitrogen sources were glucose and corn steep powder, respectively. After 12 days fermentation under these conditions, the highest mycelial growth was 18.0 g/l and the highest exo-polymer production was 3.9 g/l.

• Journal of Microbiology
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• 제39권1호
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• pp.79-82
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• 2001

The influence of levulinic acid (LA) on the production of copolyester consisting of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) by Ralstonia eutropha was investigated. Addition of LA into the culture medium greatly increased the molar fraction of 3HV in the copolyester, indicating that LA can be utilized as a precursor of 3HV. In shake flask culture, the 3HV content in the copolyester increased from 7 to 75 mol% by adding 0.5 to 4.0 g/L LA to the medium containing fructose syrup as a main carbon source. A maximal copolyester concentration of 3.6 g/L (69% of dry cell weight) was achieved with a 3HV content of 40 mo1% in a jar fermentor culture containing 4.0 g/L of LA. When LA (total concentration, 4 g/L) was added repeatedly into a fermentor culture to maintain its concentration at a low level, the copolyester content and the 3HV yield from LA reached up to 85% of dry cell weight and 5.0 g/g, respectively, which were significantly higher than those when the same concentration of the LA was supplied al1 at once. The present results indicated that LA is more effective than propionate or valerate as a cosubstrate fur the production of copolyesters with varying molar fractions of 3HV by R. eutropha.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.42-48
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• 1998

In order to maximize the secretory expression of human serum albumin (HSA) in the yeast Saccharomyces cerevisiae, a series of HSA expression vectors were constructed with a combination of different promoters, 5' untranslated regions (5'UTR), and secretion signal sequences. The expression vector composed of the galactose-inducible promoter GALl0, the natural 5'UTR, and the natural signal sequence of HSA directed the most efficient expression and secretion of HSA among the constructed vectors when introduced into several S. cerevisiae strains. Although the major form of HSA expressed and secreted in the yeast transformants was the mature form of 66 kDa, the truncated form of 45 kDa was also detected both in the cell extract and in the culture supernatant. The level of the intact HSA protein in the culture supernatant reached up to 30 mg/l at 24 h of cultivation in a shake-flask culture but began to decrease afterwards, indicating that the secreted HSA protein was unstable in a prolonged culture of yeast.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.168-173
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• 1993

The expression kinetics of human lipocortin I (LCI), a potential anti-inflammatory agent, was studied in the shake-flask and fermenter cultures of Saccharomyces cerevisiae carrying a galactose-inducible expression system. The cell growth, expression level of LCI, and the plasmid stability were investigted under various galactose induction conditions. The expression of LCI was repressed by the presence of a very small amount of dextrose in the culture medium, but it was induced by galactose after dextrose became completely depleted. The optimal ratio of dextrose to galactose for lipocortin I production was found to be 1.0 (10 g/l dextrose and 10 g/l galactose). With optimal D/G ratio of 1.0 and the addition of galactose prior to dextrose depletion, LCI of about 100~130 mg/l was produced. LCI at a concentration of 174 mg/l was porduced in the fed-batch culture, which was nearly a twice as much of that produced in the batch culture. The plasmid stability was very high in all culture cases, and thus was considered to be not an important parameter in the expression of LCI.