• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.38-44
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• 2017

Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.609-616
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• 1995

Effects of lactate concentration, temperature, counter ions, pH as well as voltage (current) in batch electrodialysis (ED) experiments with a 3-compartment unit were investigated. The applied voltage was found to be the most critical factor as expected. The electrodialysis rate increased with the lactate concentration of the source solution. The amount of lactate transferred was limited by the lactate concentration difference between cathode and permeate compartments. The electrodialysis rate did not heavily depend on temperature change. The electrodialysis rate of NH$_{4}$-lactate was faster than that of Na-lactate and both lactates showed the highest electrodialysis rate at a pH of 4.0. A little amount of non-ionic glucose diffused through the anionic membrane to the permeate compartment. To test the effectiveness of the in situ recovery of lactic acid from fermentation broth by ED, three cases of batch culture were carried out; pH control only, ED only, and pH control and ED. The case with both pH control and ED was more efficient than that with pH control only in the aspects of productivity and product yield.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.329-333
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• 2000

Alkaline bacterium producing a high pro-tease activity at low temperature was isolated by using enrichment culture from soil samples and identified as Bacil-lus sp. WRD-1 Cell growth was maximal at 10 hours and the optimal initial pH and culture time of culture condition for enzyme production was pH 7 and 10 hours, respectively. Temperature range of high enzyme activity were $10~40^{\circ}C$. The optimal pH and temperature for the enzyme activity were pH9 and $30^{\circ}C$.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.415-424
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• 2006

The purpose of this study was to investigate the fungal growth and enzyme production under different carbohydrate substrate conditions. The anaerobic fungus Neocallimastix sp. NLRI-3 isolated from the rumen of Korean native goat was incubated with different carbohydrate media containing 0.2% of glucose, starch, rice straw, filter paper, carboxymethyl cellulose(CMC), Sigmacell cellulose, xylan or xylose, respectively. The culture head gas production was the highest in the culture of filter paper medium, and the lowest in the culture of CMC medium at 96h incubation (P<0.05). The fungal zoospore production reached peak at 72h incubation, and its number was the highest in rice straw medium among the treatments (P<0.05). At 96h incubation, carboxymethyl cellulase(CMCase) activity was the highest in the culture of filter paper medium and the lowest in the culture of starch medium (P<0.05). While xylanase activity was the highest in the culture of rice straw medium and the lowest in the culture of xylose medium(P<0.05) at 72h incubation. There were no differences in culture supernatant protein expression among the treatments. However, the patterns of enzyme expression were different among the treatments with zymogram analysis. Six CMCases and 4 xylanase were detected from the results of zymogram analysis. Therefore the present study indicating that the fungal enzyme expression could be stimulated with insoluble substrates in the culture medium.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.488-494
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• 1993

A photosynthetic bacterium strain P17 having high growth rate and assimilating ability of organic acids was isolated from several soil samples, which was identified as Rhodospirillum rubrum. Cultural conditions of the strain P17 were examined for the production of starter culture used in the treatment of organic waste water. The addition of organic acids mixture as carbon source containing 0.2% Na-acetate, 0.1% Na-propionate and 0.2% Na-lactate and 0.1% of yeast extract as growth factor stimulated the cell growth. The maximal cell production was obtained at $30^{\circ}C$, pH 7.0, 2,500 lux of illumination and $50{\sim}100\;rpm$ of agitation. Under the optimal conditions of batch and fed-batch culture systems in a Jar fermentor, 5.17 g/l and 7.93 g/l of cells were obtained after S days of cultivation, respectively. In continuous culture system, the cell productivity was 0.206 g/l/h at a dilution rate of 0.21 $h^{-1}$. When R. rubrum P17 was cultivated in a soybean curd waste water, initial COD level(3,240 mg/l) of the waste water was reduced to 250 mg/l after 4 days of cultivation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.21-25
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• 2002

To maximize and sustain the productivity of Monascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, $50\%;$ pH, 6.0; inoculum size $1\;\times\;10^4$ spore cells $(grams\;of\;dry\;solid\;substrate)^{-1};$ sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW $(grams\;of\;initial\;dry\;substrate)^{-1}$ and, $47.6\;OD_{500}\;(DCW\;grams)^{-1}h^h{-1}$ respectively.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.81-88
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• 2015

To characterize the culture medium for the biosurfactant production by Bacillus pumilus IJ-1, the influences of various carbon, nitrogen and mineral sources were assessed. As a result, the highest biosurfactant production was observed after 96 h cultivation containing 0.5% (w/v) tryptone. The strain was able to grow and produce biosurfactant at 0-10% (w/v) NaCl, in the pH range of 5-10, and at $20-45^{\circ}C$. Optimal culture conditions for the biosurfactant production were at $20^{\circ}C$ and pH 9.0 after 72 h incubation and the surface tension of biosurfactant was 27.0 dyne/cm.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.819-826
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• 2009

An in vitro study was conducted to investigate the effect of malate or fumarate on fermentation characteristics, and production of conjugated linoleic acid (CLA) and methane ($CH_4$) by rumen microbes when incubated with linolenic acid (${\alpha}-C_{18:3}$). Sixty milligrams of ${\alpha}-C_{18:3}$ alone (LNA), or ${\alpha}-C_{18:3}$ with 24 mM malic acid (M-LNA) or ${\alpha}-C_{18:3}$ with 24 mM fumaric acid (F-LNA) were added to the 150 ml culture solution consisting of 75 ml strained rumen fluid and 75ml McDougall's artificial saliva. Culture solution for incubation was also made without malate, fumarate and ${\alpha}-C_{18:3}$ (Control). Two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were also added to the culture solution of each treatment. In vitro incubation was made anaerobically in a shaking incubator up to 12 h at $39^{\circ}C$. Supplementation of malate (M-LNA) or fumarate (F-LNA) increased pH at 6 h (p<0.01) and 12 h (p<0.001) incubation times compared to control and linolenic acid (LNA) treatments. Both malate and fumarate did not influence the ammonia-N concentration. Concentration of total VFA in culture solution was higher for M-LNA and F-LNA supplementation than for control and LNA treatments from 6 h (p<0.040) to 12 h (p<0.027) incubation times, but was not different between malate and fumarate for all incubation times. Molar proportion of $C_3$ was increased by F-LNA and M-LNA supplementation from 6 h (p<0.0001) to 12 h (p<0.004) incubation times compared to control and LNA treatments. No differences in $C_{3}$ proportion, however, were observed between M-LNA and F-LNA treatments. Accumulated total gas production for 12h incubation was increased (p<0.0002) by M-LNA or F-LNA compared to control or LNA treatment. Accumulated $CH_4$ production for 12 h incubation, however, was greatly reduced (p<0.0002) by supplementing malate or fumarate compared to the control, and its production from M-LNA or F-LNA treatment was smaller than that from LNA treatment. Methane production from LNA, M-LNA or F-LNA treatment was steadily lower (p<0.01 - p<0.001) from 3 h incubation time than that from the control, and was also lower for M-LNA or F-LNA treatment at incubation times of 6 h (p<0.01) and 9 h (p<0.001) than for LNA treatment. Methane production from LNA, however, was reduced (p<0.01 - p<0.001) from 3 h to 9 h incubation times compared to the control. Both malate and fumarate increased concentration of trans11-$C_{18:1}$ from 3 h to 12 h incubation (p<0.01), cis9,trans11-CLA up to 6 h incubation (p<0.01 - p<0.01), trans10,cis12-CLA at 3 h (p<0.05) and 12 h (p<0.01), and total CLA for all incubation times (p<0.05) compared to corresponding values for the ${\alpha}-C_{18:3}$ supplemented treatment (LNA). In conclusion, malate and fumarate rechanneled the metabolic $H_2 pathway to production of propionate and CLA, and depressed the process of biohydrogenation and methane generation. Linolenic acid alone would also be one of the optimistic alternatives to suppress the $CH_4$ generation.

• KSBB Journal
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• v.30 no.3
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• pp.103-108
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• 2015

Production of foreign proteins by transgenic plant cell cultures has several advantages such as post-translational modification, low risk of product contamination and low-cost production and purification. However, target proteins are degraded by extracellular proteases existing in the media. A solution to this problem is the use of perfusion culture and ion exchange chromatography for the application of integrated bioprocess using in situ recovery. With this method, production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was investigated in this study. First, optimization of cell concentration during the induction phase for the production of hGM-CSF was examined. As cell concentration increased, the level of hGM-CSF was decreased due to the presence of extracellular proteases. Induction using sugarfree media produced 33% more hGM-CSF. The effects of pH on the binding of hGM-CSF to cationic and anionic exchange resins were also investigated. In terms of stability, optimal pH was found to be 5~7. In the case of using buffer exchange when CM-Sepharose was used as a cationic exchange resin, optimal pH for binding was 4.8 and adsorption yield was 77%. When DEAE-Sepharose was used as an anionic exchange resin, it was 5.5 (74%). Without buffer exchange, optimal pH was 4.6 (84%). From these results, an integrated bioprocess using in situ recovery with simultaneous production and separation of foreign protein in transgenic plant cell suspension cultures was found to be feasible.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.96-101
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• 1998

Substrate inhibition of 2,4-dinitrophenol (DNP) degradation was investigated using activated sludge which had been adapted to mineralize DNP. DNP is a metabolic uncoupler, preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. After acclimation of the activated sludge, the effect of pH on toxicity of DNP at high concentration (75 mg/L) was investigated, over a pH range of 5 to 9. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 6.95 to 7.84; at pH 5.94 degradation of 75 mg/L DNP was significantly inhibited; at pH < 5.77, DNP degradation was completely inhibited after approximately 30% of the DNP was degraded. By comparison, no significant effect of pH variation in the same range was seen on glucose uptake by the activated sludge culture.