• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.67-71
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• 2001

Isolation and Growth Characteristics of AIkalophilic Bacillus sp. for Removal of Anthraquinone Dye. Kim, Jeong-Mog. School of Environmental Information, Taekyeung College, Kyungsan, 712-850, Korea -Alkalophilic strain degrading and decolorizing anthraquinone dye, Remazol brilliant blue R was isolated from natural system and named as Bacillus sp. ARB!. The optimal temperature and pH of Bacillus sp. ARBI were 35°C and 9.0, respectively. The pH of culture media during the fermentation were changed from 10 and 10.5 of initial values to 9.3 and 9.4 after 40 hrs, respectively. Decolorization efficiency in aerobic shaking culture of Bacillus sp. ARBI was markedly higher than that in standing culture. At the optimal culture condition, decolorization efficiency by the Bacillus sp. ARBl was 93% after 32 hrs batch culture. In the case of batch culture using real dye processing wastewater, dye decolorization efficiency of Bacillus sp. ARBl was 78% after 40 hrs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.753-757
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• 1999

The growth of rotifer, Brachionus rotundiformis was evaluated at different culture conditions. Rotifer was fed on condensed freshwater Chlorella. The productivity of rotifer in the high density culture system was compared to that of rotifer in the batch culture system, in which rotifer was fed on baker's yeast. The growth rate of rotifer increased as temperature increased in the culture system supplied with air or oxygen gas. The maximum density of rotifer in the culture systems supplied with air was in range of 16,300$\~$17,000 ind./ml at $24^{\circ}C$. In the culture systems supplied with oxygen gas, it ranged 26,300$\~$30,500 ind/ml at $28^{\circ}C$. When the concentration of dissolved oxygen in the culture system supplied with air reached to below 1 ppm or when the concentration of undissolved ammonia in the culture system supplied with oxygen gas reached 16.6$\~$22.6 ppm, the growth of rotifer decreased. When oxygen gas was supplied and pH was adjusted to 7, the maximum density of rotifer reached to 43,000 ind/ml at $32^{\circ}C$. The production costs for 10 billion rotifer in the high density culture and batch culture were 693,000 and 961,000 won, respectively. Therefore, it was concluded that the productivity of rotifer in the high density culture was higher than that in a batch culture.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.246.1-246
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• 1979

A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80％ higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.127-133
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• 2001

Pseudomonas aeruginosa KLP-2 possessing antimicro- bial activity against Legionella pneumophila was isolated from cooling tower-waters. The culture filtrates of P. aeruginosa KLP-2 showed antimicrobial activity against L. pneumophila Vibro cholerae non-Ol. Bacillus cereus, Bacillus subtilis and staphylococcus aureus. The culture filtrates of P. aeruginosa KLP-2 showed the highest anti-microbial activity against. L pneumophila among micoorganisms tested in this study. The optimal conditions of temperature, pH carbon source and nitogen source to obtain maximal antimicrobial activity from culture filtrates of P. aeruginosa KLP-2 were determined to be 35$^{\circ}C$ pH 7.0 % of glycerol and 0.6% of proteose peptone respec- tively. The antimicrobial activity of culture filtrates from P. seruginosa KLP-2 was highest against L. pneumophila when cultivated with shaking for 24 h and without shaking for 4 day at 35$^{\circ}C$.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.615-624
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• 2005

The cPCR technique was used to monitor rumen fermentation and attachment of Fibrobacter succinogenes to cellulose at different pH in the in vitro culture medium. The target fragments of 16S rDNA(445 bp) were amplified from genomic DNA of F. succinogenes with specific primers and internal controls(205 bp) were constructed. Cell counts were estimated from the amounts of genomic DNA, which was calculated from cPCR results. F. succinogenes in pH 6.8 and 6.2 showed apparently higher attachment than in pH 5.8 during all incubation time. There were some difference between pH 6.8 and 6.2 in the degree of attachment, but the different was not significant (P>0.05). Cellulose degradation increased in process of incubation time and the increasing rate was higher when initial pH was higher. The pH in culture medium decreased regardless of initial pH in course of incubation time. After 24 h of incubation, medium pH was dropped by 0.24, 0.58 and 0.16 units from original medium pH 6.8, 6.2 and 5.8, respectively. More gas was produced at higher initial pH in the same manner as in cellulose degradation. In summery, Initial pH of rumen culture in vitro significantly influenced cellulose digestion, gas production, pH change and bacterial attachment. Especially, low pH(5.8) resulted in much lower bacterial attachment and fiber digestion compared to higher medium pH.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.125-131
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• 2009

The aim of this study is to investigate the effect of porcine epididymal fluid (pEF) on in vitro-maturation and subsequent fertilization of porcine follicular oocytes. Porcine cumulus-oocytes complexes retrieved from antral follicles were cultured in tissue culture medium (TCM)-l99 supplemented with pEF of different concentrations. At 48 h after culture, development of oocytes to germinal vesicle (GV) breakdown, metaphase I, anaphase-telophase I, and metaphase II were examined Significant (p<0.05) increase in the proportion of oocytes developed to MII stage was observed in oocytes cultured in pEF-containing TCM-l99 than in oocytes cultured in pEF-free TCM-199 (46.2% vs 16.7%), which was a dose-dependent manner. Subsequently, the proportion of monospermic fertilization were significantly (p<0.05) increased in oocytes cultured in the TCM supplemented with pEF than those cultured in pEF-free TCM-199 (51.0% vs 24.1%). In the second series of experiment, the percentage of MII oocytes was significantly (p<0.05) increased after exposure of oocytes to pEF during the first 22 h period of culture than after exposure of oocytes to pEF during the next 24 h of culture, while no significant difference in the percentage of monospermy was observed. The results of this study demonstrate that pEF contains at least enhancing component(s) for nuclear maturation.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.1-7
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• 2002

The effects of DO and pH on the mass production of pullulan with high molecular weight and the morphology of A. pullulans ATCC 42023 were evaluated. A. pullulans showed a maximum production of pullulan (11.98 g/l) when the initial pH of the culture broth was 6.5 in a shake-flask culture. In a batch culture, the mixture of a yeast-like and mycelial cell forms was found at a pH of 4.5, and the maximum production of pullulan (13.31 g/l) was obtained. However, a high proportion of high molecular weight pullulan (M.W.>2,000,000) was produced at a pH of 6.5, with a yeast-like morphology. The maximum pullulan production yield ($51\%$) was obtained at a pH noncontrol (initial pH 6.5) and DO control (above $50\%$) condition. Pullulan degrading enzyme was activated when the pH of the broth was lower than 5.0 and the portion of low molecular weight pullulan was increased. The formation of a black pigment was observed at an initial stationary phase, at 40 h of fermentation. Therefore, the fermentation should be carried out in a pH noncontrol (initial pH of 6.5) and DO control (above $50\%$) condition, and should be harvested before reaching the stationary phase (around 40 h) for the production of high molecular weight pullulan.

• Journal of Microbiology
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• v.45 no.3
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• pp.199-204
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• 2007

The objective of this study was to evaluate the effect of soluble carbohydrates (glucose, cellobiose), pH (6.0, 6.5, 7.0), and rumen microbial growth factors (VFA, vitamins) on biohydrogenation of linoleic acid (LA) by mixed rumen fungi. Addition of glucose or cellobiose to culture media slowed the rate of biohydrogenation; only 35-40% of LA was converted to conjugated linoleic acid (CLA) or vaccenic acid (VA) within 24 h of incubation, whereas in the control treatment, 100% of LA was converted within 24 h. Addition of VFA or vitamins did not affect biohydrogenation activity or CLA production. Culturing rumen fungi at pH 6.0 slowed biohydrogenation compared with pH 6.5 or 7.0. CLA production was reduced by pH 6.0 compared with control (pH 6.5), but was higher with pH 7.0. Biohydrogenation of LA to VA was complete within 72 h at pH 6.0, 24 h at pH 6.5, and 48 h at pH 7.0. It is concluded that optimum conditions for biohydrogenation of LA and for CLA production by rumen fungi were provided without addition of soluble carbohydrates, VFA or vitamins to the culture medium; optimum pH was 6.5 for biohydrogenation and 7.0 for CLA production.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.373-377
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• 1999

This study was designed to develop functional drink from jujube extract through a simple submerged culture of three basidiomycetes species. The optimum Brix and pH of the jujube extract for culturing the Ganoderma lucidum appeared to be 5 Brix and pH 4. Ten days of culture period produced maximum mycelium. The optimum Brix and pH of the jujube extract for culturing the Coriolus versicolor appeared to be 5 Brix and pH 5. Ten days of culture period produced maximum mycelium. The optimum Brix and pH of the jujube extract for culturing the Phellinus igniarius appeared to be 3 Brix and pH 5. For the maximum mycelial production eighteen days of culture period was required for Phellinus igniarius. The antitumor activity of the polysaccharides extracted from the fermented drinks was demonstrated through the tumor cell line experiments. The $IC_{50}$ values of the jujube drinks fermented with Ganoderma lucidum and Phellinus igniarius against stomach cancer cell line appeared to be one fourth that of the jujube drink which was not fermented with basidiomycetes.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.277-280
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• 2000

Rhodospirillum rubrum KCTC 1372 produced hydrogen from glucose for first 48hrs culture under the anaerobic photosynthetic conditions, and after 48hrs culture the hydrogen production was decreased by the accumulation of producing organic acids in broth. Only 41% of glucose was consumed and 143mL/day/L hydrogen were produced after 96hrs culture. However the hydrogen production and glucose consumption were substantially increased when the pH of the culture broth were controlled to 6.8-7.2. After 96hrs culture, 450mL/day/L hydrogen were produced, and about 80% glucose was consumed. Specific hydrogen production rate was 48.33mL/hr/g cells under pH not controlled, but 45.42mL/hr/g cells under pH controlled.