• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.504-509
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• 1989

Fermentation condition of Streptococcus lactis IFO 12007 for nisin production was examined. The optimal glucose concentration was 60g/ι. The pH and temperature optimum were 6.5 and 31$^{\circ}C$, respectively. The maximum nisin activity in batch culture was 2000IU/$m\ell$. The fermentation quotients after 7 hours of fermentation in batch culture were; specific glucose uptake rate:0.59g/g/h , specific nisin productivity: 34924IU/g/h, product yield: 5944IU/g, growth yield:0.24, biomass:4.81g/ι. The specific growth rate was affected by pH and temperature and the activation energy for growth was 1.35kcal/mole. pH control was essential for nisin production. Fed-batch culture using 20g/$\ell$ glucose medium produced 1420IU/$m\ell$ after 14 hours. The continuous culture could be operated at below 0.38h$^{-1}$ for nisin production. The steady state nisin concentration and specific nisin productivity were 740IU/$m\ell$ and 45000IU/g/h. The growth yield and maintenance energy were 0.144 and 207mg glucose/g-cell/h.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.803-813
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• 2015

The growth of Irpex lacteus F17 and manganese peroxidase (MnP) production in a selfdesigned tray bioreactor, operating in solid-state conditions at a laboratory scale, were studied. The bioreactor was divided into three layers by three perforated trays. Agroindustrial residues were used both as the carrier of bound mycelia and as a nutrient medium for the growth of I. lacteus F17. The maximum biomass production in the bioreactor was detected at 60 h of fermentation, which was consistent with the CO₂ releasing rate by the fungus. During the stationary phase of fungal growth, the maximum MnP activity was observed, reaching 950 U/l at 84 h. Scanning electron microscopy images clearly showed the growth situation of mycelia on the support matrix. Furthermore, the MnP produced by I. lacteus F17 in the bioreactor was isolated and purified, and the internal peptide sequences were also identified with mass spectrometry. The optimal activity of the enzyme was detected at pH 7 and 25℃, with a long half-life time of 9 days. In addition, the MnP exhibited significant stability within a broad pH range of 4-7 and at temperature up to 55℃. Besides this, the MnP showed the ability to decolorize the polymeric model dye Poly R-478 in vitro.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.440-444
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• 1998

This experiment was carried out to elucidate the effect of electrolytic water on the growth and infection of Phytophthora capsici. Zoospores of P. capsici did not grow on potato dextrose agar when the pathogen was cultured after suspended in electrolytifc water (pH 2.5, 3.0, 3,5) with HCI solution. When the 100 ml of electrolytic water (pH 2.5, 3.0, 3.5) was irrigated on the red pepper plants that had been inoculated by P. capsici (103 zoospores/ml), the red pepper plants were not infected but irrigated with sterilized water (pH 6.5) the red pepper plants were infected. With this result, it could be concluded that the good sterilization effect on P. capsici might be obtained by applying electrolytic water.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.522-530
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• 1994

Bacteriocin-producing lactic acid bacteria, Lactococcus sp. HY 449, was isolated from dairy products. Using response surface methodology, the various concentrations of medium compo- nents (tryptone, glucose, yeast extract, tween 80, and initial pH) were tested to find the optimum conditions for maximum bacteriocin production and growth of Lactococcus sp. HY 449. Central composite design was used to control the concentrations of medium components in the experiment. Bacteriocin production and cell growth of Lactococcus sp. HY 449 were most affected by glucose and yeast extract. Estimated optimum growth conditions of Lactococcus sp. HY 449 were as follows; tryptone 1.08%, glucose 1.129%, yeast extract 0.674%, tween 80 0.11%, and initial pH 7.19. Also estimated optimum conditions for bacteriocin production were tryptone 0.937%, glucose 1.108%, yeast extract 0.163%, tween 80 0.09%, and initial pH 6.98.

• KSBB Journal
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• v.13 no.4
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• pp.431-437
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• 1998

Optimal media and cultural conditions for the production of prodigiosin-like pigment were established using Serratia sp. KH-95. Glucose and phosphate(K2PO4) stimulated the cell growth, but inhibited the production of pigment at concentration levels of above 10 g/L and 2.0 g/L, respectively. Addition of soy been oil or rice oil to the production medium accelerated cell growth up to more than 2-3 times, but the production of prodigiosin increased about 15-20% in spite of the good cell growth. The effect of pH on the production of pigment was investigated in a 5 liter-bioreactor. When the pH of culture broth was maintained below 8.0, most of pigment was attached to the surface of cells. When the pH of culture broth was above 8.5, however, about 70% of total pigment was suspended in the supernatant of the broth. The cell growth and production of pigment were inhibited at dissolved oxygen concentration of below 10% of air-saturation.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.131-139
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• 2000

The effects of the simulated acid rain on the growth response and water status of Glycine soja was observed in 2 months-old seedlings. The seedlings were treated with acid rain(pH 3.5), three times per week. Glycine soja showed significant reduction in the total length, total weight, dry weight, water contents and top/root ratio after treatment of simulated acid rain(pH 3.5) for 56 days. The growth of shoot was more susceptible to acid rain than that of roots. On the contray, Number of lateral roots, water saturation deficit and epidermis transpiration was higher than that of control(pH 5.6) after 56 days treatment of simulated acid rain.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.849-854
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• 2006

The effects of Haematococcus pluvialis extracellular products on microbial growth and bacteriocin production were investigated to improve bacteriocin synthesis during the growth cycle of Lactobacilli. Lactobacillus pentosus KJ-108, L. plantarum KJ-10311, and L. sakei KJ-2008 were cultured in MRS and enriched medium (ERM) with or without supplement of the extracellular products obtained from a late exponential phase culture of Haematococcus pluvialis in modified Bold's basal medium (MBBM). In both MRS and ERM, the extracellular products strongly enhanced the growth as well as the bacteriocin production of all the lactic acid bacteria tested. The enhancing effect was observed in ERM with pH adjusted at 5 and 6. In addition, some difference in growth effects with the extracellular products of H. pluvialis was observed between pH 5 and 6 in ERM, but no effect was observed in the minimal medium. The final biomass and the final concentration of bacteriocin activity were associated with the cell growth that was promoted by the extracellular products of H. pluvialis, and the enhanced cell growth of the three lactic acid bacterial strains induced the increase of the specific bacteriocin production. Therefore, bacteriocin production and activity were influenced by the addition of the extracellular products of H. pluvialis in the culture medium.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.105-111
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• 1977

Inhibitory effect of sugars on lipase production by Trichosporon cutaneum was observed in the previous study (Kim, 1972), and inhibition was distinctive by the addition of glucose, fructose, mannose, xylose and arabinose to the soybean meal medium among various carbon sources. These experiments were carried out to study the effect of sugars on cell growth and lipase production by the strain using the soybean extracts liquid medium under a shaking culture system. Changes in color and pH of the medium were caused by heat sterilization when various sugars were added. To elucidate the possible effect of these coloring matters on lipase production and cell growth: changes in pH of the culture, cell concentration and level of the enzyme activities were determined when the culture was grown for 48 hours at $30^{\circ}C$ on a reciprocal shaker. The results obtained were as follows: 1. Density of brownish color which formed during heat sterilization was varied with the variety of sugar used, ie, strong in pentose such as xylose: weak in hexose such as galactose, mannose, glucose: very weak in disaccharide such as maltose, sucrose. When the color density was stronger, decrease in pH after sterilization was marked. 2. Cell growth and lipase production was not so effect by the coloring matters as by sugars. 3. The more the cell mass of the culture, the lower the level of lipase production in the culture supernatant. 4. Among the sugars which caused the distinctive inhibition of lipase production, a slight relief of inhibition was noticed by the addition of xylose, whereas the cell growth was repressed. 5. When cell growth was better, decrease in pH of the medium was greater during cultivation.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.37-40
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• 2002

Sweet potato is a crop vegetatively propagated by vine cuttings, an ineffective method for maintaining pathogene-free stock plants. As an alternative method, single-node cultures of virus-free plantlets derived from apical meristem in sweet potato (cv. Yulmi) was examined. Effective pH range, sugar concentration and nodal order were investigated to establish an in vitro mass propagation system with high quality virus-free stock plantlets to farmhouse. Although the plantlets grew at wide range of pH, the most effective pH of the medium was 4.8 in single-node cultures. High sugar concentration of 60∼80 g/L resulted in increased growth response in shoot length, root length, number of node, leaf area and fresh and dry weight of shoot and root, whereas reducing sugar contents below 6% was showed reduced growth response. The first node including meristem tip was the best for the rapid growth of plantlets and the other nodes also showed a very similar growth response. Uniform plantlet can be obtained massively at the same time by culture of single node except for the first node including meristem tip. In conclusion, the most effective pH range and sugar concentration of medium for the growth of plantlets via single-node cultures was 4.8, 60∼80 g/L respectively. The first node was the best for the rapid propagation of plantlets in nodal order.

• KSBB Journal
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• v.10 no.2
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• pp.191-195
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• 1995

Using Pseudomonas sp. CH-414, the optimum culture conditions were investigated for the cell growth and the phospholipid production in batch culture by varying pH and aeration rate. With starting the cultivation under the conditions of pH 7.0 and 1vvm, pH was controlled to 6 or 8 at 30 hours of culture time. In the case of changing into pH 6.0, the phospholipid production was increased by ca. 20% with comparison to the case of pH 7.0. However, the biomass and the phospholipld concentration were rapidly decreased after 30 hours of culture time when pH was controlled to 8.0. As the aeration rate was increased, the biomass was increased while the phospholipid concentration was considerably varied and unstable. Especially, the concentration of phospholipid was rapidly decreased with 3vvm of aeration rate. Finally, under the culture conditions of pH 7.0 and 3vvm until 30 hours for the cell growth, which were controlled to pH 6.0 and 1vvm for the stable production of phospholipid beyond that time, the dry cell weight was $18.5g/\ell$ and the phospholipid concentration was $\0.83g/ell$ (45mg/g cell).