• Food Science and Biotechnology
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• v.18 no.4
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• pp.954-958
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• 2009

Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH ($pH_{UC}$) and controlled-pH ($pH_C$) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the $pH_C$ operations, the highest PAL activities were obtained under $pH_C$ 7.5 strategy where cell mass ($OD_{600\;nm}$) and PAL activity was 1.3 and 1.8 fold higher than those of $pH_{UC}$, respectively. The maximum PAL activity reached 123 U/g. The $pH_C$ 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of L-phenylalanine.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.128-134
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• 2008

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4g/l and 14.2g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.

• Korean Journal of Animal Reproduction
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• v.21 no.1
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• pp.25-30
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• 1997

This study was done to find out the preservation possibility of liquid boar semen at variabel room temperature of 9 to 16$^{\circ}C$. The percentages of sperm motility and NAR acrosome were highest in B tschwiler extender compared to B tschwiler＋Hepes, Andro＋Hepes and Andro extenders. The extenders with Hepes buffer showed detrimental effect for preservation of liquid boar semen. The pH of ejaculated sperm-rich fraction was 7.5. The pH of B tschwiler＋Hepes, B tschwiler, Andro＋Hepes and Andro extenders was 6.9, 7.5, 7.1 and 8.1, respectively. The pH of liquid boar semen with B tschwiler＋Hepes, B tschwiler, Andro＋Hepes and Andro extenders was 6.6, 6.9, 6.7 and 6.9 at 1st day of storage, and 5.5, 5.7, 5.6 and 5.8 at 7th day of storage, respectively. Gilts and sows were inseminated twice with liquid boar semen stored at 9~16$^{\circ}C$ in B tschwiler extender for 3~4 days. Farrowing rate, litter size and average pig weight at birth between AI and natural service did not differ significantly in gilt and sow, respectively. However, sow showed higher farrowing rate and litter size compared to gilt both in AI and in natural service. As a result of this study, we found out that liquid boar semen can be stored for 5~7 days at uncontrolled room temperature of 9~16$^{\circ}C$ in B tschwiler extender.

• KSBB Journal
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• v.16 no.2
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• pp.207-211
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• 2001

Statistical experimental design methods were employed to select the cultivation factors influencing latic acid production during the fermentation of kitchen refuses. Working volume and pH swings were identified as the main factors affecting lactic acid production. Optimum pH swing was pH 7.8 and working volume was 125 mL in a 250 mL flask. Under optimum condition, lactic acid was produced at 21.8 g/L, which was 6.2 times higher than produced during uncontrolled fermentation.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.45-50
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• 2000

A submerged cultivation of Ganoderma lucidum was carried out in an air-lift fermenter system, and the effects of different pH processes on extracellular branched ${\beta}$-1,3-glucan(EPS) production and mycelial growth(MDW) were investigated. The controlled pH process improved the production of branched ${\beta}$-1,3-glucan and biomass in comparison to the uncontrolled pH process. However, the maximum production of branched ${\beta}$-1,3-glucan were obtained by the bi-staged pH process. From these results, we confirmed that the bi-staged pH process was the most effective for improving the production of branched ${\beta}$-1,3-glucan from submerged culture of G. lucidum.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.180-185
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• 2015

BACKGROUND/OBJECTIVES: The aims of the present study are: 1) to quantify sodium consumption of patients with unstable or uncontrolled hypertension, 2) to investigate if reduced sodium intake can lower BP in these patients, and 3), to assess the acceptability and feasibility of this approach. SUBJECTS/METHODS: This study included 25 adults (age: 50+ years) with frequently elevated BP or patients with uncontrolled, uncomplicated hypertension despite drug treatment in a general practice setting. BP and salt intake (24h urinary excretion and food records) were measured at baseline and after a sodium reduced diet. RESULTS: Mean (${\pm}SD$) systolic (SBP) over diastolic (DBP) blood pressure (mmHg) at baseline was $150.7({\pm}9.5)$/$84.149({\pm}5.6)$. Mean urinary sodium excretion was 146 mmol/24h. A reduction of 28 mmol sodium excretion decreased SBP/DBP to $135.5({\pm}13.0)$/$82.5({\pm}12.8)$ (P < 0.001). After one month of no dietary advice, only in 48%, SBP was still ${\leq}140mmHg$. CONCLUSION: Assessment of sodium intake using food records, 24h urine collections and probing questions to identify use of sodium containing supplements or drugs are essential for tailored advice targeted at sodium intake reduction. The results of the present study indicate that reduced sodium intake can lower BP after 4 weeks in unstable or uncontrolled hypertensive patients.

• KSBB Journal
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• v.13 no.5
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• pp.511-517
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• 1998

Temperature and pH conditions were studied for an effective biosurfactant production by Pseudomonas aeruginosa YPJ-80. Efficient methods of biosurfactant separation were also investigated. pH-uncontrolled experiments at 35$^{\circ}C$ and an initial pH of 8 resulted in the best cell growth (3.6 g/L) and biosurfactant production (0.073 g biosurfactant/g cell). Biosurfactant separation was most efficient using solvent extraction with chloroform/methanol (2:1 vol%) followed by acidification using 1N HCl.

• Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.219-223
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• 2008

To increase the level of $CoQ_{10}$ production in mass culture, the effects of pH and light irradiation on $CoQ_{10}$ production by Rhodobacter sphaeroides were investigated in a 1-L bioreactor. $CoQ_{10}$ production was growth-associated, and the highest production of $CoQ_{10}$ (1.69 mg/g dry cell) was obtained under uncontrolled pH: this production was 1.7 times higher than that obtained at controlled pH 7. Therefore, pH was a key factor affecting $CoQ_{10}$ production. The effect of light irradiation on $CoQ_{10}$ production was negligible. This result offers an advantage for mass production of $CoQ_{10}$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.490-499
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• 2016

In this study, the marine ecological impacts of dephosphorized slag and steel slag on the initial life cycle of the rotifer Brachionus plicatilis and benthic copepod Tigriopus japonicus (in marine trophic structure as a first consumer) exposure to slag extracts have been considered using a marine ecotoxicological assessment. In the results of a screen test on slag extracts, the pH of an undiluted solution was measured to have high alkalinity (pH 8.89-12.16), but a toxic reaction to this undiluted solution before and after aging was divided according to test species. For non-aged slag, the toxic effect ($LC_{50}$) of neonate on B. plicatilis was seen to be severe with dephosphorized slag (20.8 %) than steel slag (63.8 %) with under pH-uncontrolled conditions. The toxic values of dephosphorized and steel slag were estimated to be 35.3 % and 36.0%, respectively, for nauplius with T. japonicus. However, the toxicity of slag extracts before and after aging were different for T. japonicus than for B. plicatilis based on the characteristics of the test materials, with pH-controlled conditions. In conclusion, the results of this study suggest that slag can be relatively stable after aging and may not be likely to influence marine environments, even given repetitive extracting under pH-uncontrolled conditions. This study confirms that a marine ecotoxicological assessment method applied to mechanically activated samples can give an idea of the resistance a marine environment has against the introduction of hazardous materials due to precipitation and weathering.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.6
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• pp.331-334
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• 2002

Culture conductivity and on-line NADH fluorescence were used to measure cellular growth in plant cell suspension cultures of Podophyllum hexandrum. An inverse correlation between dry cell weight and medium conductivity was observed during shake flask cultivation. A linear relationship between dry cell weight and culture NADH fluorescence was obtained during the exponential phase of batch cultivation In a bioreactor under the pH stat (pH 6) conditions. It was observed that conductivity measurement were suitable for biomass characterisation under highly dynamic uncontrolled shake flask cultivation conditions. However, if the acid/alkali feeding is done for pH control the conductivity measurement could not be applied. On the other hand the NADH fluorescence measurement allowed online-in situ biomass monitoring of rather heterogenous plant cell suspension cultures in bioreactor even under the most desirable pH stat conditions.