• Korean Journal of Materials Research
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• v.6 no.8
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• pp.768-778
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• 1996

Iron oxide (hematite, $\alpha$-${Fe}_{2}{O}_{3}$) particles were prepared directly from aqueous solution using a crystal growth controller. Paticles properties and reaction mechanisum of products as a function of basicity, formation process and mechanism of needle-lkie hematite were investigated. hexagonal hermatite particles were formed in teh range below pH 9.0, ellipsoidal or rectangular hematite particles in the range of pH 10.75-11.75 respectively. In the range above pH 12.50, acicular $\alpha$-FeOOH was formed. Basicity of product solution produced in the range of pH 10.7511.75 was increased slightly as compared with basicity of reastants due to hydroxly ion(OH-) formed by dissociation crystal growth controller. Citric acid which is acted as a crystal growth controller was adsorbed in the form of itrate anion(R-COO-) on the ferric hydroxide and exerted important role on the formation to the needle-like $\alpha$-${Fe}_{2}{O}_{3}$ particles in this reaction system.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.258-265
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• 2004

The experiment was conducted to investigate the effect of EC and pH of nutrient solution on the growth and quality of the single-stemmed rose grown in a rose factory installed with hydroponic system. The growth and quality of the single-stemmed rose were not significantly different from each other with the EC of the nutrient solutions $1.0\~3.5dS{\cdot}m^{-1}$, which resulted in concluding high concentration of the nutrient solution was not necessary. The optimum range of the EC for single-stemmed rose was $1.5\~2.0dS{\cdot}m^{-1}$ considering plant growth, photosynthetic and transpiration rates. The optimum range of the pH for good plant growth without any visible physiological disorder was $4.0\~6.0$. Therefore, to keep the pH of the nutrient solution for rose low compared to other plants was beneficial for plant growth and uptake of the mineral ions.

• 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 Food Science and Technology
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• v.28 no.3
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• pp.451-457
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• 1996

The effects of pH and L-cysteine HCI on the growth and stability of Biofidobacterium breve were studied. Significantly higher population was obtained by culturing at pH $6.0{\sim}6.5$ than at any other pH. The cultures that had been grown at pH $5.5{\sim}6.0$ were more stable during storage than those grown at other pH. The number of B. breve that had been grown at pH 5.5 and 6.0 remained as $2.4{\times}10^6ml/\;and\;1.4{\times}10^6ml,$ respectively, after 25 days of storage at $4^{\circ}C$. The ${\beta}$-galactosidase activity of B. breve grown at pH 5.5 and 6.0 was reduced only to $78{\sim}85%$ of the control after the same storage condition, whereas the culture grown at pH 7.0 exhibited a signficant decline in population and ${\beta}$-galactosidase activity during $4^{\circ}C$. The growth of B. breve was promoted by 0.05% L-cysteine HCI, and cells grown in MRS with $0.05{\sim}0.10%$ L-cysteine HCI were more resistant to hydrogen peroxide. With respect to the effect to the effect of osmoprotectants on the survival of B. breve subjected to freeze-drying, addition of 2 mM betaine of 2 mM trehalose increased the growth rate of cells grown under osmotic stress and also made the organism more osmotolerant. Furthermore, the betaine or trehalose increased the survivability of the cells after freeze-drying.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1439-1444
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• 2012

A total of 144 pigs ((Landrace${\times}$Yorkshire)${\times}$Duroc)] with an average initial BW of $8.45{\pm}0.57$ kg were used in a 5-wk growth trial. Pigs were randomly allocated to 4 treatments with 9 replications per pen in a randomized complex block design. Dietary treatments included: i) CON (basal diet), ii) ANT (CON+tylosin 1 g/kg), iii) H1 (CON+H. cordata 1 g/kg) and iv) T1 (CON+T. officinale 1 g/kg). In this study, pigs fed the ANT and T1 treatment had a higher (p<0.05) average daily gain (ADG) and gain:feed (G:F) ratio than those fed CON and H1 treatment. Dietary ANT and T1 treatment led to a higher energy digestibility than the CON group. No difference (p>0.05) was observed on the growth performance and apparent total tract digestibility with H1 supplementation compared with the CON treatment. The inclusion of ANT treatment led to a higher (p<0.05) lymphocyte concentration compared with the CON treatment. Dietary supplementation of herbs did not affect (p>0.05) the blood characteristics (white blood cell (WBC), red blood cell (RBC), IgG, lymphocyte). No difference was observed on (p<0.05) fecal microbial shedding (E. coli and lactobacillus) between ANT and CON groups. Treatments H1 and T1 reduced the fecal E. coli concentration compared with the CON treatment, whereas the fecal lactobacillus concentration was not affected by the herb supplementation (p>0.05). In conclusion, the inclusion of T. officinale (1 g/kg) increased growth performance, feed efficiency, energy digestibility similarly to the antibiotic treatment. Dietary supplementation of T. officinale and H. cordata (1 g/kg) reduced the fecal E. coli concentration in weaning pigs.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.168-172
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• 2002

Budding yeasts maintain an effective system to regulate intracellular pH in response to environmental pH fluctuation. In a previous study we reported that SHC1 plays a role in cell growth at alkaline condition, not at acid pH. We constructed a null mutant deleted an entire open reading frame for SHC1. To test whether the retardation in cell growth was caused by the absence of intracellular pH buffering capacity, we measured intracellular pH with a pH-sensitive fluorescent dye, C.SNARE. The intracellular pH of the mutant cell was much higher than that of wild-type cells, indicating that the mutant cells lack some types of buffering capacity. We also investigated the level of $Na^＋ and K^＋$ content with atomic mass spectroscopy after alkali shock. Wild-type cell showed a higher level of intracellular K^＋$ content, whereas there was no difference in $Na^＋$ level. The result suggested that K^＋$ is more important in the regulation of intracellular pH in yeasts.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.432-438
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• 2010

This study was carried out to understand the effect on soil chemical property, ion contents, and growth of Lonicera japonica by treatment of simulated acid rain and wood vinegar. It was treated total 30 times by one time per 2 weeks during 150 days from June to October dividing to various pH level of simulated acid rain (each pH 5.6, 4.5, 3.5 and 2.5) and the control site (pH 6.3). The wood vinegar diluted with 500 times was also treated total 10 times by one time per 2 weeks at the experimental sites. The soil pH was reduced as pH level of simulated acid rain was decreased. The organic content, total nitrogen, and Av. $P_2O_5$ in soil showed a tendency to increment. However, the soil improvement effect was exposed to be insufficient when a wood vinegar was treated. In the component of the plant body, $SO_4{^2}$ and $NO_3{^-}$ increased due to the simulated acid rain treatment and the increment ratio was reduced in the wood vinegar treatment plot. In addition, the cation contents showed a tendency to variation due to pH of simulated acid rain. And it showed more increment in the leaves than the root. The early fallen leaves and growth inhibition of L. japonica showed up after the simulated acid rain treatment but the growth of L. japonica increased after the wood vinegar treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.27-31
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• 1977

Experiments were conducted to investigate the effects of seed bed soils and soil pH on the rice growth and control of seedling rots. A 2:1 ratio mixture of clay loam and compost resulted in the best seedling growth and quality among the soils used. At soil pH between 4 and 5. no seedling rots occurred and plant growth was normal. At soil pH above 6, seedling rots occurred and characteristics of seedings was poor. Tachiga ren application before seeding or immediately after seeding reduced seedling rots significantly at the high soil pH.

• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.515-516
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• 2006

This experiment was carried out to find out proper culture soil for the flowerpot cultivation of Sedum kamtschaticum. Peatmoss was used for the culture soil. pH of the culture soils were adjusted to 4.5, 5.0, 5.5 and 6.0 using calcium hydroxide. Young plants of Sedum kamtschaticum were planted in the pots of 10cm in diameter. The experiment was conducted by the completely randomized design with 3 replications. Growth characteristics were investigated at intervals of 30 days after planting. As the pH of culture soil is lower, growth of Sedum kamtschaticum showed longer plant height and more number of leaves and branches. pH 4.5 to 5.0 appeared to be optimum range as soil reaction of Sedum kamtschaticum cultivation.

• Journal of Mushroom
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• v.3 no.1
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• pp.40-44
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• 2005

The results of examining selection of optimal mycelial growth condition excellent strain for determining the condition of Pleurotus cornucopiae are as follows. 1) Mycelial growth and density of P. cornucopiae were the highest in the medium of MCM(87.8mm/10d) followed by the order of PDA, YM, MEA and Czapek. 2) Optimal temperature for the mycelial growth and density of P. cornucopiae was shown to be $25^{\circ}C$, but the hyphae were dead at $5^{\circ}C$. The mycelial growth and density of KNAC2003 strain was the highest at $25^{\circ}C$(87.8mm/10d) followed by the order of 25, 30, 20, 35, 10 and $5^{\circ}C$. 3) Optimal pH for the mycelial growth and density was revealed to be 6.0(88.3mm/10d), but the mycelial growth and density were shown to be retarded in above or below pH 6.0.