• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.11-17
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• 2015

In an attempt to shift the optimal pH of the xylanase B (XynB) from Aspergillus niger towards alkalinity, target mutation sites were selected by alignment between Aspergillus niger xylanase B and other xylanases that have alkalophilic pH optima that highlight charged residues in the eight-residues-longer loop in the alkalophilic xylanase. Multiple engineered XynB mutants were created by site-directed mutagenesis with substitutions Q164K and Q164K+D117N. The variant XynB-117 had the highest optimum pH (at 5.5), which corresponded to a basic 0.5 pH unit shift when compared with the wild-type enzyme. However, the optimal pH of the XynB-164 mutation was not changed, similar to the wild type. These results suggest that the residues at positions 164 and 117 in the eight-residues-longer loop and the cleft's edge are important in determining the pH optima of XynB from Aspergillus niger.

• The Korean Journal of Zoology
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• v.25 no.2
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• pp.63-70
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• 1982

The activity, properties, and distribution of midgut protease during metamorphosis in Pieris rapae L. are determined using spectrophotometer, ultracentrifuge and agar gel electrophoresis. Proteolytic activity of midgut reaches the peak just before ecdysis in 5th instar and prepupal stages each but 1 day after ecdysis in pupal stage. Also, optimum pH of midgut protease is pH 8.0 in 5th instar stage, pH 6.5 in prepupal stage, and pH 8.5 immediately before emergence respectively. Protease is found mostly in midght tissue in 5th instar stage but thereafter until just before emergence the enzyme only in lumen contents, suggesting that protease is synthesized in midgut tissue during larval stage and then released into lumen during pupation period.

• KSBB Journal
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• v.11 no.6
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• pp.649-653
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• 1996

Imnmobilization characteristics of Thiobacillus sp. IW which oxidizes sulfur compound was studied to use the bacterium in odor controlling equipment for the future. The optimum growth conditions for Thiobacillus sp. IW were pH7, $30^{\circ}C$ and the generation time was 38min, which was extremely fast compared with other sulfur oxidizing bacteria. Optimum growth conditions in activated carbon as a carrier was pH5, $35^{\circ}C$ and those in bioceramics was pH 7∼8, $35^{\circ}C$. Cell growth immobilized in bioceramics was more stable in pH, temperature change than that immobilized in activated carbon and total number of cells in bioceramics were also higher. Based on these results, the bioceramics is thought to be better carrier in immobilization of Thiobacillus sp. IW.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.33-38
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• 1983

As flocculent strains are likely to have considerable potential for internal cell recycle, kinetic studies on glucose medium with flocculent Saccharomyces uvarum were carried out in batch and continuous culture. Using a mathematical model, the kinetic parameters at each temperature and pH were estimated in order to establish optimal conditions. It was found that an overall optimum temperature for growth and ethanol production in the range 33-35$^{\circ}C$ was desirable. With regard to the effect of pH, ethanol production by S. uvarum was found to be relatively insensitive to pH value between 4 and 6, with an optimum pH of around 5. At these optimal conditions a maximum ethanol productivity of 12 g/$\ell$/h was determined using semi-batch process together with 5. uvarum.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.509-513
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• 1997

The photosynthetic bacteria, Rhodopseudomonas capsulata H161, were grown anaerobically in the Modified Ormerod medium for 5 days. The optimum temperature and pH for growth and carotenoid pigment of the organism were observed at 3$0^{\circ}C$, and around pH 7.4, respectively. The optimum condition of producing the carotenoid pigment, light intensity 5,000 lux. The photosynthetic bacteria, Rhodopseudomonas capsulata H161, produced large amount of carotenoid pigment, which identified to 4 carotenoid components containing; spheroidene, rhodovibrin, spirilloxanthin, lycopene.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.29-34
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• 2007

Objective : Kyenegum(Galli Stomachichum Corium) has been popularly used long as the digestive. The purpose of this study was to investigate the enzymatic characteristic of Kyenegum crude enzyme. Methods : To evaluate of the enzymatic characteristic of Kyenegum, we examined the activity of Kyenegum crude enzyme from optimum solvent, optimum temperature and pH of crude Kyenegum extract. Futhermore, we examined the effects of NaCI and acidity of crude Kyenegum extract. Results : The Kyenegum was composed with crude protein about 20%, crude lipid 2%. The optimum Kyenegum dry condition, optimum extract solvent, optimum temperature and optimum pH were $4{\sim}6$ hours at $60^{\circ}C$, commercial apple vinegar, $50^{\circ}C$ and 2.0. Conclusion : The result suggests that the Kyenegum crude enzyme extract very strong enzyme in temperature, NaCl and acidity, respectively.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.66-70
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• 2005

Optimization of culture conditions for pigment production of Monascus purpureus P-57 mutant was investigated in liquid culture. The optimum composition of medium for the pigment production was $4\%$ rice power, $0.1\%$ beef extract, $0.03\%$ glutamic acid, $0.1\%\;MgSO_4{\cdot}7H_2O,\;0.25\%\;KH_2PO_4$, the optimum initial pH was 5.0. And the optimum culture conditions was at $30^{\circ}C$ for 8 days under 150 rpm with shaking. M. purpureus P-57 mutant produced the highest pigment as 356.04 units at red pigment and as 268.20 units at yellow pigment, and produced high cell mass as 15.00 g/L in liquid culture under the optimum conditions.

• Analytical Science and Technology
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• v.13 no.2
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• pp.234-240
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• 2000

The efficiency of Photocatalytic Oxidation Process were investigated for the treatment of Aquatic Humic Substances (AHS). In UV-only system, pH 7-9 was the optimum pH range for TOC removal, and alkali range was the optimum pH for absorbance decrease. In UV/$TiO_2$ system, the optimum $TiO_2$ dosage was 50ppm and over 50ppm of $TiO_2$ dosage was not effective for removal of AHS. In UV/$H_2O_2$ system, optimum $H_2O_2$ dosage was 20mM, when over 20mM dosage, removal of TOC (Total Organic Carbon) and absorbance was decreased. Radical scavenger affected on the photo-oxidation of AHS. Removal rate of TOC and absorbance was decreased by addition of carbonate ions and TOC removal was more effected than that of absorbance.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.252-255
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• 1999

This study was carried out to investigate the physiological charateristics of Hericium erinaceus in sawdust media. The optimum temperature was $25^{\circ}C$ and the optimum pH was 5. Mycelial growth and density of H. erinaceus was quite good when oak tree sawdust were used as cultural substrates. The best mycelial growth in H. erinaceus were observed when wheat pollard was added as supplement on sawdust substrates. The optimum supplement ratios of wheat pollard and magnecium sulfate were 20% and 0.1% respectively, for H. erinaceus.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.320-323
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• 2003

The effects of pH on the binding of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) expressed from transgenic plant cell suspensions to cationic and anionic exchange resins were investigated. In terms of stability, the optimum pH was found to be 5-7. In the case of using buffer exchange, when CM-sepharose was used as a cationic exchange resin, the best binding pH was 4.8 (77%) and when DEAE-sepharose was used as an anionic exchange resin, the best binding pH was 5.5 (74%). Without using buffer exchange, the optimum pH was 4.6 and the adsorption yield was 84%. From these results, a possibility of overcoming the degradation and instability of secreted protein product by in firm adsorption was found.