• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.289-294
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• 2002

Cellulose production by Acetobacter pasteurianus was investigated in static culture using four bioreactors with silicone rubber membrane submerged in the medium. The shape of the membrane was flat sheet, flat sack, tube and cylindrical balloon. Production rate of cellulose as well as its yield on consumed glucose by the bacteria grown on the flat type membranes was approximately ten-fold greater than those on the non-flat ones in spite of the same membrane thickness. The membrane reactor using flat sacks of silicone rubber membrane as support of bacterial pellicle can supply greater ratio of surface to volume than a conventional liquid surface culture and is promising for industrial production of bacterial cellulose in large scale.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.139-146
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• 2000

산업적으로 유용한 미생물 유래 셀룰로오스를 생산 이용하기 위해 전국 각지 양조식초의 덧으로부터 세룰로오스의 생산성이 높고 조질의 균일성을 나타내는 균주를 분리하였다 분리균 GS11은 gram 음성이고 간균(0.6$\times$2.2~3.2 $\mu\textrm{m}$)의형태를 하고 있으며 편모를 가지고 있어 운동성을 보였다. 또한 세포내 지방산 조성은 다량의 불포화 지방산 {{{{ {C}_{18:1} }}}}과 포화지반산 {{{{ {C}_{16:0 } }}}}, {{{{ {C}_{14:0 } }}}} 이 대부분을 차지하였고 DNA 염기조성 (G+C) 함량은 58.4% 이였으며 ubiqunone 은 {{{{ { Q}_{10 } }}}}을 갖는 것으로 나타났다 이러한 형태학적 생리.생화학적 특성의 결과에 따라 본 균주는 Acetobacter xylinum GS11으로 동정되었다 A. xylinum, GS11 의배양기간 동안 셀룰로오스 생산성을 검토하고자 250mL 삼각플라스크에 균주를 접종하여 $30^{\circ}C$에서 12일간 정치배양하였다 그결과 기질인 glucose의 소비는 접종 후 급소하게 감소하여 셀룰로오스 생산에 이용되었으며 셀룰오스의 생산은 배양 9일 경에 2.8g/l로 최대의 생산량을 나타냈다.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.67-74
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• 1986

The study was carried out to investigate for the property of Bacillus strains, on the native growthed microflora in Korean native soybean paste, and Bacillus strains of the high enzyme producing, were selected and identificated, from the microflora, that is, identificated Bacillus strains beared resemblance to B. subtills, on the colony, appearance was pellicle, surface's spreading, color creamy-thin browned, colony elevation flated, and edge lobated, the identfficated B. subtills strain named for the B. subtilis SCF. For the protease activity of B. subtilis SCF, according to the variation with pH, the pH stability was pH 7~8, and on the its protease activity, optimum temperature was 40$\circ$C, on the other hand, temperature of the highest stability of the protease was 50$\circ$C.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.571-576
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• 1994

One strain of cellulose-producing Acetobacter was isolated from the traditionally fermen- ted grape vinegar in Korea. The isolated strain, designated as KI strain was identified as the Acetobacter xylinum with respect to physiological and biochemical characteristics. KI produced acetic acid from ethanol, and then decomposed acetate to CO$_{2}$ and H$_{2}$O. When the isolated strain was cultivated statically in broth culture, a thick cellulose pellicle was formed. KI was tolerance of 8% ethanol and 30% glucose, and the isolate was positive in ketogenesis from glycerol, $\gamma$-pyrone from glucose and fructose, and 2-ketogluconic acid from glucose. KI strain possessed straight-chain C$_{18:1}$, C$_{16:0}$, and C$_{14:0}$ fatty acid, and contained ubiquinone Q$_{9}$ and Q$_{10}$ as isoprenoid quinone. DNA base composition of KI strain was 57.6% G+C.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.259-264
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• 1989

The adherence of $^{3}H$-labeled oral streptococcal cells to protein-coated hydroxyapatite (HA) beads was studied by a standard adherence assay. The adherence equilibrium for S. mutans 10449 occured in about 2 hrs. The cell numbers adhering to SHA was 50% less than those on bare HA. Sailva from different subjects had varying effect on bacterial adherence. The use of saliva adsorbed with homologouis bacteria decreased S. mutans adherence by 38% ; this indicates the presence of salivary agglutinin in acquired pellicle formed on HA. Animal sera and BSA decreased S. sanguis adherence. BSA concentration as high as 10mg/ml caused up to 87% adherence inhibition. The desorption experiment of adhered bacteria confirmed the previous reports that the adhesive sites on HA beads for S. mutans were different from those for S. sanguis and that S. mutans could enhance the adherence of S. sanguis but not vice versa.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1037-1043
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• 2008

In this experiment, citrus juice was fermented by Gluconacetobacter hansenii TF-2, an isolate from tea fungus to develop a new type of acidic beverage. The juice broth is made by fermenting of $11{\sim}17%$ (v/v) juice and sweetened with sucrose (initial sucrose $10^{\circ}Brix$). The fermentation by G. hansenii TF-2 was initiated by adding 5% (w/v) of seed gel (pellicle, tea fungus) which was previously cultured in the same medium (fresh juice broth) and the fermentation was carried out in a dark incubator at $28{\sim}30^{\circ}C$ for about 15 days. During the fermentation a pellicle grew on the surface of the fermenting fluid and acids were produced. Fermented fluid (beverage) was centrifuged at 7,000 rpm for 15 min for further analyses. The highest amount of the other metabolites including organic acids were observed in 5 to 10 days. Major acids were acetic acid (fermented citrus beverage, CB). After 15 days of fermentation, organic acid content such as acetic acid in fermented beverage was measured to be $183.5{\sim}186.6\;ppm$. Free sugars content in CB were 56.8%, 35.1%, 40.7% and 63.2% of unfermented sucrose, glucose, fructose and sorbitol, respectively. When the growth rate of inhibitory effect of the fermented beverage was measured by using several species of food-related bacteria, the beverage fermented with CB exhibited the strongest inhibition against gram-negative (E. coli and Sal. Typhimurium). Its inhibition rate was between $71.9{\sim}94.0%$ at CB. Fermented beverage has shown effectiveness for antimicrobial activity against some species of food-related bacteria.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.275-280
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• 2009

The optimal medium compositions for the production of bacterial cellulose (BC) by a Acetobacter sp. V6, which was isolated from the traditionally fermented vinegar in Korea, were investigated in static cultures. The optimum medium compositions for BC production were 3% glucose, 3% soytone, 0.8% $K_2HPO_4$, and 0.4% ethanol, respectively. Adding $NaH_2PO_4$ or $KH_2PO_4$ had not shown the increase in BC production. Under the optimum medium compositions, the highest BC production was 44.67 g/$m^2$ in 8 days and the thickness of BC pellicle was about 1 cm. Structural properties of BC produced in the optimal medium were studied using Fourier-transform infrared spectroscopy and X-ray diffractometer. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose. No difference in the compositions between bacterial and plant celluloses, but BC showed unique micro-network structure and high crystallinity (82%).

• Journal of Microbiology
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• v.45 no.6
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• pp.492-498
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• 2007

GacS and GacA proteins form a two component signal transduction system in bacteria. Here, Tn5 transposon gacS and gacA (Gac) mutants of Pseudomonas sp. KL28, an alkylphenol degrader, were isolated by selecting for smooth colonies of strain KL28. The mutants exhibited reduced ability to migrate on a solid surface. This surface motility does not require the action of flagella unlike the well-studied swarming motility of other Pseudomonas sp. The Gac mutants also showed reduced levels of biofilm and pellicle formation in liquid culture. In addition, compared to the wild type KL28 strain, these mutants were more resistant to high concentrations of m-cresol but were more sensitive to $H_2O_2$, which are characteristics that they share with an rpoS mutant. These results indicate that the Gac regulatory cascade in strain KL28 positively controls wrinkling morphology, biofilm formation, surface translocation and $H_2O_2$ resistance, which are important traits for its capacity to survive in particular niches.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.165-169
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• 2000

Kombucha beverages were made from sweetened tea by Oriental, European and Tibetan tea fungus starters. The hot water extracts o green tea, black tea, Gugija and Omija were mixed with white and/or brown sugar, and were fermented under a static culture at 3$0^{\circ}C$. Titrable acidity, pH, color and cellulose production in kombucha beverages were evaluated. All tea fungus starters showed a higher acid production in green/black tea extracts rather than Gugija and Omija extracts. In green/black tea extracts Oriental tea fungus produced a kombucha beverage with a higher titrable acidity and lower pH than those of European and Tibetan tea fungus starters. By the static fermentation of green/black tea extract for 18 days, Oriental, Tibetan and European tea fungus starters produced cellulose pellicles of 0.43g, 0.16g, and 0.19 g (dry weight) on the top in the culture, respectively. As a mother starter, the cellulose pellicle was more efficient in acid production compared with tea fungus broth. Oriental/Tibetan mixed tea fungus showed the best acid production in the green/black tea extract supplemented with brown sugar.

• ALGAE
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• v.22 no.4
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• pp.325-331
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• 2007

Cryptoglena pigra Ehrenberg from Korea was a photosynthetic euglenoid alga, which had typical characteristics of the Euglenales. The ultrastructure examination of C. pigra revealed certain features which were distinctly photosynthetic euglenoid: one U-shaped chloroplast with thylakoid membranes; two paramylon grains appressed to both sides of the chloroplast; eyespot associated with the chloroplast but not part of it. Three flagellar roots were associated with the two basal bodies. The four-membered dorsal root arose from the dorsal body and extended anteriorly following the reservoir membrane. At the base of the reservoir the dorsal band was nucleated by the dorsal root and it ran anteriorly between the reservoir membrane and eyespot. The dorsal band was continued with the microtubules of the canal and the pellicle. The singlet dorsal microtubules at the transition level arranged into doublets by a successive linkage of the existing adjacent microtubules, and the doublets rearranged into the cytoskeletal microtubules that were continuous with four microtubules in pellicles. Finally, the sixteen ridges gave rise to the pellicular ridges. The five to six-membered ventral root extended anteriorly into a cytoplasmic pocket through the reservoir and lined a cytoplasmic pocket.