• Journal of Microbiology and Biotechnology
• /
• 제6권3호
• /
• pp.184-188
• /
• 1996

The Acinetobacter sp. BE-254 isolated from soil sources produced a bioemulsifier in the medium supplemented with n-hexadecane. This bioemulsifier was purified by the procedures of fractionation (ammonium sulfate and chilled acetone), extraction by hexane, and column chromatography on silica gel 60. The results from various color reactions indicated that the bioemulsifier was a glycolipid. The purified emulsifier was very stable at pHs ranging from 4 to 10 and under heat treatment at $100^{\circ}C$ for 30 min. Emulsification activity was also hardly influenced by pH. The critical micelle concentration (CMC) and surface tension at the point ($\gamma_{cmc}$) of the bioemulsifier were approximately 35 mg/l and 30 mN/m, respectively. The bioemulsifier showed a fairly good emulsification activity and stability in comparison with other commercial emulsifiers in the basic formula composed of emulsifier, oil, and water.

• 한국미생물·생명공학회지
• /
• 제44권2호
• /
• pp.180-184
• /
• 2016

본 연구에서는 신분류군 탐색을 위하여 유입하수 첨가 배지를 제작하였다. 유입하수 첨가배지에서는 일반 배지에서 분리 또는 동정되지 않은 13속 세균들을 배양하였으며, 특히 25에 비해 37℃에서 다양한 균주들을 배양할 수 있었다. 또한 유입하수 첨가 배지에서 총 12개의 분리 균주들이 97% 이하의 유사성을 나타내는 것으로 분석되었으며, 이들은 Tessaracoccus, Paracoccus 및 Candidimonas속(또는 Paralcaligenes속)과 유연관계가 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제27권2호
• /
• pp.365-371
• /
• 2017

Hydrogen has potential for preventive and therapeutic applications as an antioxidant. However, micro- and macroparticles of hydrogen in water disappear easily over time. In order to eliminate reactive oxygen species (ROS) related with the aging process, we used functional water containing nanoparticle hydrogen. Nanoparticle hydrogen does not disappear easily and collapse under water after long periods of time. We used murine embryonic fibroblasts that were isolated from 12.5-day embryos of C57BL/6 mice. We investigated the ability of nanoparticle hydrogen in water to suppress hydroxyurea-induced ROS production, cytotoxicity, and the accumulation of ${\beta}-galactosidase$ (an indicator of aging), and promote cell proliferation. The accumulation of ${\beta}-galactosidase$ in the cytoplasm and the appearance of abnormal nuclei were inhibited by daily treatment of cells with hydrogen water. When the aging process was accelerated by hydroxyurea-induced oxidative stress, the effect of hydrogen water was even more remarkable. Thus, this study showed the antioxidant and anti-senescence effects of hydrogen water. Nanoparticle hydrogen water is potentially a potent anti-aging agent.

• International Journal of Oral Biology
• /
• 제38권2호
• /
• pp.81-85
• /
• 2013

There are estimated to be about 700 species of bacteria in the oral cavity. Based on epidemiological investigations, some of these strains have been proposed as the pathogens responsible for oral diseases such as dental caries, gingivitis and periodontitis. Since electrolyzed hydrogen-rich water has been shown to have beneficial effects on human immunity, its use has increased. In our study, the antibacterial activity of hydrogen-rich water for oralagainst bacteria associated with oral disease was evaluated. The bacterial strains Streptococcus mutans, Fusobacterium nucleatum, Porphyromonas gingivalis and Tannerella forsythia were cultured in specific growth medium. S. mutans, F. nucleatum and P. gingivalis were soaked to thein both hydrogen water and tap water for 30 sec and then inoculated onto mitis-salivarius agar and brain heart infusion agar including supplemented withvitamin K and hemin, respectively. The numbers of bacterial colonies were then measured after cultivation for 48 hours. In the case of T. forsythia, which does not grow well on agar plates, inoculations into modified new oral spirochete (NOS) broth were performed and growth curve analysis was undertaken every day with a spectrophotometer. Hydrogen water showed antibacterial activity against all four bacterial strains in comparison with tap-water. We conclude from this that hydrogen water may have a positive impact on oral hygiene by helping to remove cariogenic bacteria and periodontopathogens.

• 생약학회지
• /
• 제41권4호
• /
• pp.275-281
• /
• 2010

To evaluate the immunomodulatory activity of a water extract (KMF-WE) of Korean mistletoe (Viscum album var. coloratum) fruit, we examined its ability to induce humoral and cellular immune response against keyhole limpet hemocyanine (KLH). Immunized mice with KLH admixed with KMF-WE (KLH/KMF-WE) showed significant induction of KLH-specific antibodies compared to mice immunized with KLH alone. The assay for determining isotypes of antibodies revealed that KMFWE augmented KLH-specific-IgG1 and -IgG2a production. In vitro T lymphocyte proliferation analysis against KLH revealed that the splenocytes of mice immunized with KLH/KMF-WE showed a significantly higher proliferative ability than those from mice immunized with KLH alone. The culture supernatants of splenocytes, which were harvested from mice immunized with KLH/KMF-WE, showed higher levels of both Th-1 type (IL-2, IFN-${\gamma}$) and Th-2 type (IL-4) cytokines in response to KLH stimulation compared to those from mice immunized with KLH alone. Also, in delayed-type hypersensitivity (DTH) assay, mice immunized with KLH/KMF-WE showed a significantly higher reaction to KLH than mice treated with KLH alone. These results suggest that KMF-WE possess immunoadjuvant activity to enhance both antigen-specific humoral and cellular immune responses against protein antigens (KLH).

• Journal of Microbiology and Biotechnology
• /
• 제4권4호
• /
• pp.316-321
• /
• 1994

We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

• 한국물환경학회지
• /
• 제25권2호
• /
• pp.329-334
• /
• 2009

Bacterial numbers, such as endospore-formers, and treatment efficiencies were investigated for Rotating Activated Bacillus Contactors (RABC) and other advanced wastewater treatment processes including anaerobic-anoxic-oxic (A2O), sequencing batch reactor (SBR) and biological aerated filter (BAF). Endospore-forming bacterial numbers in the RABC showed 129-fold higher levels than those of the existing advanced systems. RABC process demonstrated the highest bacterial numbers in its bioreactors (paired t-test, p<0.01). RBC biofilms and aeration tanks of the RABC system showed 131- and 476-fold higher than other existing advanced processes, respectively. Mean treatment efficiencies of the existing systems were 83.5% for chemical oxygen demand (COD), 59.1% for total nitrogen (TN) and 76.8% for total phosphorus (TP). However, RABC process removed 96.9% for COD, 96.9% for TN and 91.9% for TP for highly concentrated food wastewater (COD>1,500 mg/L, TN>150 mg/L, TP>50 mg/L). Treatment efficiency was significantly reduced when the numbers of Bacillus genus in the bioreactors decreased below $10^6CFU/mL$. The automated RABC (A-RABC), in which dissolved oxygen concentrations are automatically controlled, showed higher treatment efficiencies compared to the RABC process. The RABC system maintained sufficient bacterial numbers for the effective treatment of highly concentrated food wastewater. Moreover, final effluent was in agreement to water quality standards.

• 대한미생물학회지
• /
• 제21권1호
• /
• pp.97-106
• /
• 1986

Authors studies on the isolation of V. vulnificus from sea water, sea mud fishes, shellfishes and algae at the seasides of Pusan, Masan, Chungmu and Ulsan in Korea in 1985. Authors carried out test for isolated strains to bacteriological test, hemolysis test about erythrocytes of various animal, sensitivity test of various chemotherapeutic agents and serological test with antiserum of V. vulnificus. The resultls obtained were as follows: 1. V. vulnificus was isolated 15 strains from 399 total specimens: 110 cases of sea water, 40 cases of sea mud, 90 cases of fishes, 60 cases of shellfishes and 79 cases of various algae, respectively. 2. Nine strains were isolalted from sea water, 4 strains were isolated from sea mud and 2 strains were isolated from fishes, respectively. 3. Two strains among 15 strains isolated were lactose positive reaction. 4. All strains isolated were grown in concentration of $0.5%{\sim}7.0%$ NaCl, but were not grown 0% and 8.0% NaCl. 5. Hemolysis reaction about various erythrocytes was sensitived to guinea pig, human and rabbit erythrocytes, but was not sensitived to sheep erythrocytes. 6. Sensitivity test using with chemotherapeutic agents of "BioLab" Microbial Sensitivity Test Discs were generally sensitived to amikacin, ampicillin, clindamycin, erythromycin, gentamycin, kanamycin, streptomycin, tetracyclin and tobramycin, and were moderate to penicillin, but were resistant to methicillin and lincomycin, respectively. 7. The distribution of serotypes of V. vulnificus isolated were on antiserum of $0.1{\sim}07$ of V. vulnificus: 1 case of 01 and 2 cases of 07, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제9권2호
• /
• pp.127-131
• /
• 1999

Anaerobically grown cells of an Fe(III)-reducing bacterium, Shewanella putrefaciens IR-l, were electrochemically active with an apparent reduction potential of about 0.15 V against a saturated calomel electrode in the cyclic voltammetry. The bacterium did not grow fermentatively on lactate, but grew in an anode compartment of a three-electrode electrochemical cell using lactate as an electron donor and the electrode as the electron acceptor. This property was shared by a large number of Fe(III)-reducing bacterial isolates. This is the first observation of a direct electrochemical reaction by an intact bacterial cell, which is believed to be possible due to the electron carrier(s) located at the cell surface involved in the reduction of the natural water insoluble electron acceptor, Fe(III).

• Journal of Microbiology and Biotechnology
• /
• 제16권6호
• /
• pp.961-964
• /
• 2006

GDP-mannosyltransferase (GMT) is an enzyme responsible for the addition of a mannose to glucose ($\alpha$[1$\rightarrow$3]) during biosynthesis of the water-soluble branched polysaccharide acetan in Acefobacter species. In an effort to obtain a cellulose-overproducing bacterium, a mutant defective in GMT of Acetobacter xylinum KCCM 10100 was constructed by single crossover homologous recombination using part of the aceA gene encoding GMT amplified by polymerase chain reaction. The GMT-disrupted mutant produced 23% more cellulose, but 16% less water-soluble polysaccharide than those of the wild-type strain. Analysis of the sugar composition by gel permeation chromatography revealed that water-soluble polysaccharides produced by the GMT-defective mutant contained no mannose molecule.