• 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.

• Membrane Journal
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• v.31 no.6
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• pp.384-392
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• 2021

Growing pollution due to industrialization leads to difficulties in survival of mankind. Generation of clean water from wastewater by membrane separation process is emerging cost efficient technology. Membrane prepared from renewable resources are in lots of demand to reduce burden on synthetic polymers which is one of the source of environmental pollution. Bacterial cellulose (BC) is very pure and distinct form of cellulose nanofibrils (CNF). Nanopapers prepared from CNF are used ad ultrafiltration (UF) and nanofiltration (NF) membrane for different applications. High crystallinity of BC gives rise to excellent mechanical property, an essential criterion for wastewater treatment membrane. In this review, BC based membrane for application in dye, oil, heavy metal and chemical removal from wastewater is discussed.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.484-495
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• 2015

PURPOSE. This study was to evaluate the effects of bacterial cellulose (BC) membranes as a barrier membrane on guided bone regeneration (GBR) in comparison with those of the resorbable collagen membranes. MATERIALS AND METHODS. BC membranes were fabricated using biomimetic technology. Surface properties were analyzed, Mechanical properties were measured, in vitro cell proliferation test were performed with NIH3T3 cells and in vivo study were performed with rat calvarial defect and histomorphometric analysis was done. The Mann-Whitney U test and the Wilcoxon signed rank test was used (${\alpha}<.05$). RESULTS. BC membrane showed significantly higher mechanical properties such as wet tensile strength than collagen membrane and represented a three-dimensional multilayered structure cross-linked by nano-fibers with 60 % porosity. In vitro study, cell adhesion and proliferation were observed on BC membrane. However, morphology of the cells was found to be less differentiated, and the cell proliferation rate was lower than those of the cells on collagen membrane. In vivo study, the grafted BC membrane did not induce inflammatory response, and maintained adequate space for bone regeneration. An amount of new bone formation in defect region loaded with BC membrane was significantly similar to that of collagen membrane application. CONCLUSION. BC membrane has potential to be used as a barrier membrane, and efficacy of the membrane on GBR is comparable to that of collagen membrane.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.387-388
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• 2013

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.2
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• pp.17-23
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• 2015

Natural cellulose hydrogel membrane cannot be directly used for cell encapsulation because it has many large pores on the surface that immune biomolecules are able to penetrate into easily. For the reason, alginate was used for the control of pore size of the cellulose hydrogel membrane. The surface morphology of cellulose/alginate nanocomposite confirmed the successful control of the porosity of the membrane. The permeability of the cellulose/alginate nanocomposite was decreased but mechanical properties were increased compared with the bacterial cellulose membrane. The cellulose/alginate nanocomposite could be used for the functional membrane as a promising biomedical material in the future.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.573-583
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• 2017

Biofilm formation on the membrane surface results in the loss of permeability in membrane bioreactors (MBRs) for wastewater treatment. Studies have revealed that cellulose is not only produced by a number of bacterial species but also plays a key role during formation of their biofilm. Hence, in this study, cellulase was introduced to a MBR as a cellulose-induced biofilm control strategy. For practical application of cellulase to MBR, a cellulolytic (i.e., cellulase-producing) bacterium, Undibacterium sp. DM-1, was isolated from a lab-scale MBR for wastewater treatment. Prior to its application to MBR, it was confirmed that the cell-free supernatant of DM-1 was capable of inhibiting biofilm formation and of detaching the mature biofilm of activated sludge and cellulose-producing bacteria. This suggested that cellulase could be an effective anti-biofouling agent for MBRs used in wastewater treatment. Undibacterium sp. DM-1-entrapping beads (i.e., cellulolytic-beads) were applied to a continuous MBR to mitigate membrane biofouling 2.2-fold, compared with an MBR with vacant-beads as a control. Subsequent analysis of the cellulose content in the biofilm formed on the membrane surface revealed that this mitigation was associated with an approximately 30% reduction in cellulose by cellulolytic-beads in MBR.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.160-163
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• 2004

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.802-807
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• 2002

This study was conducted to see effects of dietary bacterial fiber produced by Gluconoucetobacter hansenii on gross structure, and disaccharidase activities of small intestine and body lipid status in rats. Bacterial fiber was prepared by drying and alkali treatment of floating membrane produced IS days after the bacterial culture using coconut juice media. Male Sprague-Dawely rats of 320+10 g were grouped into three and fed 0.5% (w/w) cholesterol diets with three different dietary fibers, i .e. cellulose, and pectin and bacterial fiber, at the level of 2% (w/w). During four-week experimental period, food intakes and body weight gains were not different among three groups. Total lengths and jejunal fragment weights of small intestine did not differ among the three groups but cecal weight was higher in bacterial fiber groups than those of the other two groups. Colon content and fecal dry weight were lower in bacterial fiber group. Sucrase activity of the jejunal mucosa was lower in bacterial fiber group but maltase activity was not different from those of the other two groups. Plasma total cholesterol level was lower and that of HDL-cholesterol higher in pectin group than those of cellulose and bacterial fiber groups, the latter of which did not differ. Both in plasma and liver triglyceride levels were lower in bacterial fiber group than cellulose and pectin groups, and liver cholesterol level was lower in pectin group. Relative liver weights and Plasma activities of GOT md GPT were not different among three groups. It is concluded that bacterial fiber used in the present study had hypotriglyceridemic effect that help improve lipid status in the body.

• Microbiology and Biotechnology Letters
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• v.46 no.2
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• pp.120-126
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• 2018

As a basic study for environment-friendly production of bacterial cellulose (BC) dressing with antimicrobial activity, we isolated and identified acetic acid bacteria which are resistant to silver ions and can biosynthesize silver nanoparticles. Furthermore, conditions of BC production by selected strain were also investigated. Strain G7 isolated from decayed grape skin was able to grow in the presence of 0.1 mM $AgNO_3$ which was identified as Acetobacter intermedius based on 16S rRNA gene analysis. BC production was the highest in a medium containing 2% glucose as a carbon source, 2% yeast extract as a nitrogen source, and 0.115% acetic acid as a cosubstrate. Structural properties of BC produced in optimal medium were studied using Fourier-transform infrared spectroscopy and X-ray diffractometer, and it was found that BC produced was cellulose type I that was the same as a typical native cellulose. When strain G7 was cultured in an optimal medium containing 0.1 mM $AgNO_3$, the color of the culture broth turned into reddish brown, indicating that silver nanoparticles were formed. As a result of UV-Vis spectral analysis of the culture, it was found that a unique absorption spectrum of silver nanoparticles at 425 nm was also observed. Scanning electron microscopic observations showed that silver nanoparticles were formed on the surface and pores of BC membrane.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.964-968
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• 2002

Colon drug delivery is advantageous in the treatment of colonic disease and oral delivery of drugs unstable or suceptible to enzymatic degradation in upper GI tract. In this study, multilayer coated system that is resistant to gastric and small intestinal conditions but can be easily degraded by colonic bacterial enzymes was designed to achieve effective colon delivery of prednisolone. Variously coated tablets containing prednisolone were fabricated using chitosan and cellulose acetate phthalate (CAP) as coating materials. Release aspects of prednisolone in simulated gastrointestinal fluid and rat colonic extracts (CERM) were investigated. Also, colonic bacterial degradation study of chitosan was performed in CERM. From these results, a three layer (CAP/Chitosan/CAP) coated system exhibited gastric and small intestinal resistance to the release of prednisolone in vitro most effectively. The rapid increase of prednisolone in CERM was revealed as due to the degradation of the chitosan membrane by bacterial enzymes. The designed system could be used potentially used as a carrier for colon delivery of prednisolone by regulating drug release in stomach and the small intestine.