• 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.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.482-487
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• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica ws studied. Maltose, yeast extract, and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in a flask culture were pH 5.0, $25^{\circ}C$, and 150 rpm in a medium containing (as in g/l) 30 maltose, 6 yeast extruct, 2 polypeptone, $0.5{\;}K_3HPO_4,{\;}0.2{\;}KH_2PO_4,{\;}0.2{\;}MnSO_4{\cdot}5H_2O,{\;}0.2{\;}MgSO_4{\cdot}7H_2O$. Exo-biopolymer production and mycelial growth in the above suggested medium were significantly increased in a 2.5-1 jar fermentor, where the maximum biopolymer concentration was 8 g/l. The morphological changes of the mycelium in the submerged culture were observed within pH ranges from 4.0 to 9.0; i.e., growth of the filamentous form was optimal at culture pHs of 5.0 and 6.0, whereas pellet was formed at other pHs.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1130-1135
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• 2008

The effect of pH on anaerobic hydrogen production was investigated under various pH conditions ranging from pH 3 to 10. When the modified Gompertz equation was applied to the statistical analysis of the experimental data, the hydrogen production potential and specific hydrogen production rate at pH 5 were 1,182 ml and 112.5 ml/g biomass-h, respectively. In this experiment, the maximum theoretical hydrogen conversion ratio was 22.56%. The Haldane equation model was used to find the optimum pH for hydrogen production and the maximum specific hydrogen production rate. The optimum pH predicted by this model is 5.5 and the maximum specific hydrogen production rate is 119.6 ml/g VSS-h. These data fit well with the experimented data($r^2=0.98$).

• Journal of Life Science
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• v.6 no.2
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• pp.79-86
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• 1996

A bacterium producing pullulanase was from soil, and was identified Bacillus cereus and named as Bacillus cereus JK36. The optimal culture conditions for the efficident production of pullulanase from B. cereus JK36 was obtained by cultivating with the medium composed of 1% pullulan, 1% teast extract, 1% bactopeptone, 0.1% NaH$_{2}$PO$_{4}$, 2H$_{2}$O, 0.02% MgSO$_{4}$\ulcorner7H$_{2}$O at 40$\circ$C, initial pH 6.5 for 70 hours. Using the culture supernatant as crude enzyme, the optimal pH and temperature of the pullulanase of this strain were 6.5 and 50$\circ$C. In effect of pH and temperature on the stability of the enzyme, the enzyme was stable in the range of pH6.0$\sim$9.5 and up to 40$\circ$C, respectively. The hydrolysis product on pullulan was mainly maltotriose.

• Journal of Korean Society of Forest Science
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• v.7 no.1
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• pp.8-18
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• 1968

This experiment is a comparative study of influence on the seedling in individual pH treatment of culture soil I. T-R ratio and growth 1. T-R ratio has almost similar tendency in its range according to tree species, but in individual treatment there were lots of differences. In the strong acidic and the strong alkali conditions T-R ratio was small. This means the seedling body is out of balance. 2. Where the resistance to H-ion was stronger, the growth of root-system, that is, the resistance of fine root was comparatively better. 3. The growth of root system was greatly influenced by pH, and in the condition of pH3, pH8, pH9, the growth was especially worse. 4. Ginkgo biloba, Pinus rigida and Pinus banksiana kept on growing in the strong acidic condition. 5. The growth season has higher pH of culture soil than the dormant season, and tree species which have strong resistance of acidic had better growth and had stronger resistance of draught in the acidic condition of culture soil ; especially, Pinus rigida and Pinus banksiana were worse in the alkali condition. II Seedling pH 1. According to the tree species, there were differences in seedling pH, and tree species, considred to be strong in resistance of draught, had been high in seedling pH. 2. Seedling pH of the growth season was higher than that of the dormant season. 3. Seedling pH was not significant in pH treatment of the culture soil.

• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.69-77
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• 1996

The result of isolated and selected to the strain having the emulsifying activity from soil's strain the strain was identified as Candida genus. The strain was investigated with culture condition at pH culture temperature, flow rate of air, strring rate etc., and physicochemical properties of the biosurfactant were examined. The optimum composition of medium for a strain cultivation were obtained as follow : glucose ; 100g/L, yeast extract ; 10g/L, urea ; 1.0g/L, KH$_{2}$PO$_{4}$ ; 50mg/L, MgSO$_{4}$ ; 500mg/L, and the op condition of cultivation was as follow : pH ; 3.0, temperatlue ; 24$\circ $C, strring rate ; 40rpm. The maximum yield of biosurfactant was obtained by pH ; 3.0-3.5, and temperature ; 25$\circ $C. The degree of emulsification of syntesized biosurfactant was increased clearly by increasing concentration of biosurfactant and it's stability was maintained for a long time. The surface tension of biosurfactant was varied with pH, especially it was showed that the surface tension was high at acidic pH.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.3
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• pp.348-363
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• 2017

We analyzed the mixed culture characteristics of isolated brewing fungi obtained from Korean traditional nuruk for their development as fermentation starters. In a previous study, we selected appropriate fungi strains based on their large fungi bodies and strong enzyme activities. These fungi strains were mixed cultured under various combination of ratios, pHs and temperatures. As a result, total acidities of R. delemar mixed culture media were higher than those of A. oryzae cultured at $20^{\circ}C$ and $37^{\circ}C$. The pHs of A. luchuensis 34-1 and A. oryzae 37-7 as well as R. delemar 58-8 and A. oryzae 37-7 mixed culture media gradually increased with the culture period. On the contrary, total acidities of the mixed culture media gradually decreased. ${\alpha}-Amylase$ activities of R. delemar 26-4 and R. oryzae 82-7 mixed culture media were strong at $20^{\circ}C$ and pH 4, glucoamylase activities of R. delemar 58-8 and A. oryzae 37-7 were strong at $37^{\circ}C$, pH 3 and 1:2 ratio, and acidic protease activities of R. delemar 26-4 and A. oryzae 78-5 were strong at $20^{\circ}C$, pH 4 and 1:4 ratio. This study provides the optimal mixed culture conditions for fermentation starters based on changes in pH and total acidity, favorable enzyme activities, and fungi varieties.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.487-499
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• 2016

The aim of the present study was to examine the effects of testosterone (T) and estradiol-$17{\beta}$ ($E_2$) on the production of progesterone ($P_4$) by granulosa cells, and of the $E_2$ on the production of $P_4$ and T by theca internal cells. In the first experiment, granulosa cells isolated from the largest ($F_1$) and third largest ($F_3$) preovulatory follicle were incubated for 4 h in short-term culture system, $P_4$ production by granulosa cells of both $F_1$ and $F_3$ was increased in a dose-dependent manner by ovine luteinizing hormone (oLH), but not T or $E_2$. In the second experiment, $F_1$ and $F_3$ granulosa cells cultured for 48 h in the developed monolayer culture system were recultured for an additional 48 h with increasing doses of various physiological active substances existing in the ovary, including T and $E_2$. Basal $P_4$ production for 48 h during 48 to 96 h of the cultured was about nine fold greater by $F_1$ granulosa cells than by $F_3$ granulosa cells. In substances examined oLH, chicken vasoactive intestinal polypeptide (cVIP) and T, but not $E_2$, stimulated in a dose-dependent manner $P_4$ production in both $F_1$ and $F_3$ granulosa cells. In addition, when the time course of $P_4$ production by $F_1$ granulosa cells in response to oLH, cVIP, T and $E_2$ was examined for 48 h during 48 to 96 h of culture, although $E_2$ had no effect on $P_4$ production by granulosa cells of $F_1$ during the period from 48 to 96 h of culture, $P_4$ production with oLH was found to be increased at 4 h of the culture, with a maximal 9.14 fold level at 6 h. By contrast, $P_4$ production with cVIP and T increased significantly (p<0.05) from 8 and 12 h of the culture, respectively, with maximal 6.50 fold response at 12 h and 6, 48 fold responses at 36 h. Furthermore, when $F_1$ granulosa cells were precultured with $E_2$ for various times before 4 h culture with oLH at 96 h of culture, the increase in $P_4$ production in response to oLH with a dose-related manner was only found at a pretreatment time of more than 12 h. In the third experiment, theca internal cells of $F_1$, $F_2$ and the largest third to fifth preovulatory follicles ($F_{3-5}$) were incubated for 4 h in short-term culture system with increasing doses of $E_2$. The production of $P_4$ and T by theca internal cells were increased with the addition of $E_2$ of $10^{-6}M$. These increases were greater in smaller follicles. These results indicate that, in granulosa cells of the hen, T may have a direct stimulatory action in the long term on $P_4$ production, and on $E_2$ in long-term action which may enhance the sensitivity to LH for $P_4$ production, and thus, in theca internal cells, $E_2$ in short term action may stimulate the production of $P_4$ and T.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.307-312
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• 2004

The bioreactor system for the large-scale plant tissue culture was developed to control the pH concentration and DO (dissolved oxygen), and air flowrate. The system controlling the proper air flow rate for each bulblet growth stage and monitoring the contamination of bioreactor using the pH change was controled by computer program. For the uniform bulblet distribution in bioreactor, the proper air flow rate was 300 cc/min at the beginning of bulblet culture, 400 cc/min after 20 days, 500 cc/min after 40 days, 600 cc/min after 60days, and 700 cc/min after 80 days. It was possible to maintain the pH concentration within 5.5$\pm$0.5 during the culture by control system of bioreactor.

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.23-27
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• 2002

To establish an in vitro mass production system of grape anthocyanin pigments through callus and cell suspension culture, the effects of nitrogen source and sucrose on fresh weight and anthocyanin production in cell suspension culture of 'Sheridan' grape level were studied. When the medium was devoid of $NO_3^-$, cell fresh weight was either remained stable (1% sucrose) or slightly decreased with culture time (2,3, and 4% sucrose). When $NH_4^-$ was lacking, 3% sucrose was most favorable for cell growth. When $NH_4^-$ was supplied as N source, the anthocyanin content of 2% sucrose containing medium was maintained 2 times higher than other levels till day 8 in culture, then that of 3 and 4% sucrose which peaked at day 12 thereafter. The anthocyanin content was low than $NO_3^-$-free media. Total anthocyanin content in $NH_4^-$-free medium was just about a half of that of $NH_4^+$ medium. Anthocyanin production of 2% sucrose in $NH_4^+$ medium was maintained about 3-fold till day 8, then decreased thereafter. In $NH_4^+$ medium, pH decreased gradually with final pH of 3.5 to 4.0, while pH in $NH_4^+$-free medium increased with final pH of 6.5 to 7.5.