• Korean Journal of Pharmacognosy
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• v.27 no.1
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• pp.32-36
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• 1996

Various culture conditions for cell growth and berberine production in cork tree (Phellodendron amurense Rupr.) were investigated. Callus was induced from cambium tissue of cork tree, and cultured on LS liquid medium supplemented with 0.5 mg/1 2,4-D, 0.1mg/1 BA, and 3% sucrose. Several factors enhancing berberine production and cell growth in cork tree cell cultures were found. Some of them enhanced both cell growth and berberine production, but others resulted in a decoupling of cell growth and berberine production with significant in the specific levels. High level of nitrate (80mM), high level of phosphate (8.98mM), and sucrose (7%), 1.0mg/l IAA were effective in berberine production, whereas low level of nitrate (40mM), and phosphate (2.25mM), and high level of sucrose (7%) in the medium were effective in cell growth. Two stage culture(first stage for cell growth, and second stage for berberine production) increased berberine production almost twice (5.06mg/g dry weight) as much as single stage cultures in berberine production.

• KSBB Journal
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• v.13 no.5
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• pp.615-620
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• 1998

The readily fermentable carbon sources in swine were acetic acid, propionic acid and butyric acid at the average concentrations of 7.2 g/L, 2.2 g/L and 2.7 g/L, respectively. The swine waste also contained excess nitrogen and other mineral sources. In shake flask experiments, the optimal range of cell growth for Azotobacter vinelandii UWD were 1.0∼3.5 g/L of acetic acid, 0.7∼2.0 g/L of propionic acid and 0.5∼2.0 g/L of butyric acid. A mixture of these three acids simulating two times diluted swine waste supported the best cell growth but the amount of carbon sources was limited. In shake flask and fermentor experiments, an addition of 30 g/L of glucose increased the final cell dry weight 8 times while the final poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) concentration increased 86 times compared with using acid mixture only. A. vinelandii UWD preferred organic acids in the sequence of acetic acid, propionic acid, butyric acid, and valeric acid.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.96-103
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• 2001

Phaffia rhodozyma is the most promising microbial source of astaxanthin production, though wild-type strains are needed to increase the astaxanthin content for commercial production. To increase astaxanthin content for commercial production, a mutant strain of P. rhodozyma was selected and culture conditions of the mutant selected were optimized. P. rhodozyma was treated with mutagenic agent such as NTG, acriflavine, and UV in serial order and carotenoids hyper-producing mutant strain was selected based on the capabilities of cell growth on the agar plate containing chemical inhibitors and carotenoids production. Among the mutants tested, a mutant WS-2 was finally selected. Mutant WS-2 produced 1.26mg carotenoids/g-dry cell weight and this value was about- 4-folds higher than that of wild-type. The optimum culture conditions were $24^{\circ}C$ of temperature, 1.5vvm of aeration and 300rpm of agitation. In the optimized condition, cell and carotenoids concentrations were 7.62g/l and 14.9mg/l, respectively.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.68-73
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• 2004

Ferritin is an iron storage protein found in most living organisms. For expression and industrial use, human light chain ferritin (L-ferritin) was cloned from human liver cDNA library and expressed in Pichia pastoris strain GS115. The recombinant L-ferritin in Pichia pastoris was glycosylated. In a fed-batch culture, the cell mass reached about 57 g/l of dry cell weight, and the L-ferritin in the cell was increased to about 95 mg/l after 150 h. In an atomic absorption spectrometry analysis, the intracellular content of iron in the L-ferritin transformant was measured as $1,694{\pm}85\;\mu\textrm{g}g/g$, which is 5.4-fold more than that of the control strain. This L-ferritin transformant could serve as iron-fortified nutrients in animal feed stock.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.277-282
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• 1994

In batch cultures of Lactobacillus delbrueckii, cell growth and lactic acid production were affected by two main factors, inhibition by lactic acid and limitation by nutritional components. In order to increase th productivity significantly, a continuous stirred tank reactor with cell recycle was employed. A cell desnity of 145g dry weight/l and a volumetric productivity of 73 g/l$\cdot $h were obtained with an effluent concentration of 85 g/l lactic acid. The productivity achieved by this system was 23-fold higher than those obtained by the corresponding batch cultivations. Once the lactic acid concentration reached the steady steady state, lowering the yeast extract concentration caused the reduction of the lactic acid concentration without affection the biomass concentration. Finally, the formation of D-lactate was investgated. During the various cultures, a small amount of D-lactate always formed, even thought a majority of lactate was L-isomer, It was supposed that the relative amount of the D-lactate was affected by glucose limitation, and there seems to exist a certain relationship between the concentration of D-lactate and acetate.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.4
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• pp.579-582
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• 1989

Previous experiments have shown that aqueous sodium silicate ingested in drinking water may modify the gastrointestinal uptake and(or) tissue retention of certain trace elements, including heavy metals. The present experiment tested, with a mineral balance trial using sheep, the hypothesis that dietary silicic acid could modify uptake, retention and(or) biological effects of dietary Cd. Twenty-four wethers were fed a fibrous diet of ground alfalfa hay and cottonseed hulls to which either 0 or 150 ppm Cd was added as $CdCl_2$ and 0, .5 or 1% silicic acid (as dry matter of the diet). Body weight, feed intake, excretion of urine (volume) and feces (weight), digestibility of dry and organic matter, retention of nitrogen, and packed cell volumes of blood were not affected by either Cd or silicic acid (P<.10). Cadmium decreased (P<.05) Ca retention and increased (P<.01) Mg retention. Silicic acid decreased (P<.05) K retention. Silicic acid failed (P<.01) to modify the retention of added dietary Cd. Body retention of K, Mn and Ni in response to silicic acid varied with Cd levels. If Cd is interfering with mineral retention, silicic acid may be effective in preventing this interference.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.132-136
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• 1996

To investigate the characteristics of immobilized peppermint (Mentha piperita) cells, dry cell weight (DCW), change of cell viability, and oil productivity of the immobilized cells were determined. Peppermint cells were immobilized in polyurethane (PU) foams of $5{\times}5{\times}5$ mm and cultured in a shaking flask. The maximum DCW was 2.1 mg per foam piece after 20 days of cultivation and the cell density was approximately 420 mg per flask containing 200 foams in 200 ml medium. For the first five days of cultivation, the cell viability was about 80$%$ and decreased to 70$%$ during 5 to 20 days of cultivation. The maximum oil productivity, 148 mg/l was achieved after 40 days of cultivation. The immobilized cells were also cultivated in a bioreactor, equipped with a round spiral type impeller, containing 2, 400 PU foams. The cell viability after 30 days of cultivation with chitosan as an elicitor in the bioreactor was 67$%$ and DCW was 2.0 mg per foam piece. Though the cell viability was relatively high in the bioreactor system, the oil productivity was relatively lower than that of the flask system.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.556-562
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• 1989

The bioconversion of mandarin orange peel press liquor to single cell protein (SCP) by two yeast strains, F-60, and C-7, which were isolated from mandarin orange peel was carried out and compared with that of using Candida utilis IFO 0598. Experiments were directed toward the high yield of biomass and high protein in cultures of the strains mentioned above. Candida utilis IFO 0598, F-60 and C-7 strains were cultivated at 3$0^{\circ}C$, pH 5.2 for 3 days in shaking flasks. The effects of some nutrients on cell growth were studied. Cell mass and protein content per cell mass were increased by addition of urea 1%, KH$_2$PO$_4$ 0.1% and MgSO$_4$ㆍ7$H_2O$ 0.05%, When the F-60 strain cultured under the optimal conditions, cell mass, growth yield and protein content were 41.2g/l, 53.9%, 59.7%, respectively. Cell mass was also increased up to 15% by modifying the fermentation condition on the bench type 20l jar fermentor. Crude fat content (10.3%) of dried C-7 cell was higher than those of C. utilis and F-60, 4.9% and 5.6% respectively. Total protein content of the F-60 strain was 59.7% per dry weight. And we compared their amino acid compositions with that of FAO provisional pattern. In the case of the F-60 strains, amino acid contents such as lysine, leucine and isoleucine were much higher than those of methionine, cystine and tryptophan.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.223-229
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• 2006

In this study, we have conducted kinetics and modelling studies of Centella asiatica cell growth and substrate uptake, in an attempt to evaluate cell growth for a better understanding and control of the process. In our bioreactor cultivation experiment, we observed a growth rate of 0.18/day, a value only 20% higher than was seen in the shake flask cultivation trial. However, the observed maximum cell dry weight in the shake flask, 10.5g/L, was 14% higher than was achieved in the bioreactor. Ninety seven percentage confidence was achieved via the fitting of three unstructured growth models; the Monod, Logistic, and Gompertz equations, to the cell growth data. The Monod equation adequately described cell growth in both cultures. The specific growth rate, however, was not effectively predicted with the Logistic and Gompertz equations, which resulted in deviations of up to 73 and 393%, respectively. These deviations in the Logistic and Gompertz models may be attributable to the fact that these models were developed for substrate-independent growth and fungi growth, respectively.

• Journal of Nutrition and Health
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• v.31 no.3
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• pp.243-252
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• 1998

This study was conducted to investigated the short-term effects of early weaning and protein intake on organ and cell growth, nitrogen metabolism and physiological functions of rats. Five groups of early weaned rats separated from the dam on the 15th day postpartum were each given one five diets consisting of either one of the three levels of casein-low(8%), -normal (16%), and -high(32%), or a normal level (16%) of isolated soy protein(ISP) or egg yolk protein, for 7 days. The normal weaned rats were fed maternal breast milk for three weeks from birth. On the 22nd day postpartum , all the rats were sacrificed . The weight gain of the early weaned rats, especially the ones fed high protein, was observed to be significantly lower than that of the normal weaned rats. By the 15th day, of early weaning and especially in the ISP-fed rats, the total DNA contents of liver and kidney, which may be said to represent an index of cell numbers, significantly decreased, but their fresh and dry weight and protein/DNA ratio, allegedly representing an index of cell size, significantly increased , not affecting the cell number and cell size of brain. There were no differences in total serum protein and albumin concentrations between early and normal weaned rats. In the early weaned rats observed , the serum urea N and $\alpha$-amino N concentrations significantly increased in high protein-fed rats, and decreased in low protein-fed rats. Another observation was that no significant difference was noticed as regards to serum GOT activity, total bilirubin, uric acid, and creatinine concentration, which may represent indices of liver and kidney functions, among rat groups, GPT activity was an exception . These results suggest that premature weaning and the quality and quantity of dietary protein significantly affect organ and cell growth and nitrogen metabolism but does not seriously affect physiological functions in the neonatal development of rats.