• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1479-1484
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• 2022

Bacterial cellulose (BC) is gaining attention as a carbon-neutral alternative to plant cellulose, and as a means to prevent deforestation and achieve a carbon-neutral society. However, the high cost of fermentation media for BC production is a barrier to its industrialization. In this study, chestnut shell (CS) hydrolysates were used as a carbon source for the BC-producing bacteria strain, Gluconacetobacter xylinus ATCC 53524. To evaluate the suitability of the CS hydrolysates, major inhibitors in the hydrolysates were analyzed, and BC production was profiled during fermentation. CS hydrolysates (40 g glucose/l) contained 1.9 g/l acetic acid when applied directly to the main medium. As a result, the BC concentration at 96 h using the control group and CS hydrolysates was 12.5 g/l and 16.7 g/l, respectively (1.3-fold improved). In addition, the surface morphology of BC derived from CS hydrolysates revealed more densely packed nanofibrils than the control group. In the microbial BC production using CS, the hydrolysate had no inhibitory effect during fermentation, suggesting it is a suitable feedstock for a sustainable and eco-friendly biorefinery. To the best of our knowledge, this is the first study to valorize CS by utilizing it in BC production.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.227-232
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• 2014

In this study, Gluconacetobacter sp. gel_SEA623-2 isolated from citrus that produces bacterial cellulose was used to examine the effect of initial concentration of acetic acid and mixed culture inoculated with Lactobacillus plantarum KCCM 80077 on productivity of bacterial cellulose. In mixed culture added with 0.5% acetic acid, the viable cell count increased from $2.4{\times}10^6CFU/ml$ to $1.1{\times}10^7CFU/ml$ after 14 days of culture, and total acidity was about 0.3% higher than single culture added with 0.5% acetic acid, which implies that additional lactic acid was produced by L. plantarum KCCM 80077. In single culture, although bacterial cellulose productivity was higher when the initial concentrations of acetic acid were 0.0% and 0.5%, than when it was 1.0%, there was no significant difference. However, in mixed culture, adding 0.5% acetic acid resulted in dry weight of $37.83{\pm}6.81g/L$ and thickness of $10.33{\pm}0.58mm$, showing a significant difference from that of single culture added with 1% acetic acid, $28.40{\pm}1.23g/L$ and $7.50{\pm}0.50mm$ (P<0.05).

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.394-398
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• 2002

Acetic acid bacteria have been isolated from running high-acid vinegar fermentation. The color of the isolated colony was beige-yellowish. Isolated cell was rod-shaped, small, pale, absolutely aerobic and gram-negative. Microscopically the cells appeared as non-motile and non-flagellated, preferentially occuring in pairs. The optimum temperature and pH for culture were 30$\^{C}$ and 2.7, respectively. The strain was able to grow in the presence of acetic acid, ethanol and glucose. Ethanol was oxidized to acetic acid which was not oxidized any more. The isolated strain utilized glucose, fructose, maltose, sucrose, mannitol and sorbitol as carbon source. Cellulose formation was not detected on bouillon. The DNA (G +C) content of isolated strain was determined to be 56.2 mol%. The strain isolated from industrial vinegar fermentation was identified as Gluconacetobacter europaeus.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1269-1275
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• 2006

The selection of multienzyme complex-producing bacteria under aerobic condition was conducted for improving the degradation of lignocellulosic substances. The criteria for selection were cellulase and xylanase enzyme production, the presence of cellulose-binding domains and/or xylan-binding domains in enzymes to bind to insoluble substances, the adhesion of bacterial cells to insoluble substances, and the production of multiple cellulases and xylanases in a form of a high molecular weight complex. Among the six Bacillus strains, isolated from various sources and deposited in our laboratory, Paenibacillus curdlanolyticus B-6 strain was the best producer of cellulase and xylanase enzymes, which have both cellulose-binding factors (CBFs) and xylan-binding factors (XBFs). Moreover, multiple carboxymethyl cellulases (CMCases) and xylanases were produced by the strain B-6. The zymograms analysis showed at least 9 types of xylanases and 6 types of CMCases associated in a protein band of xylanase and cellulase with high molecular weight. These cells also enabled to adhere to both avicel and insoluble xylan, which were analyzed by scanning electron microscopy. The results indicated that the strain B-6 produced the multienzyme complex, which may be cellulosome or xylanosome. Thus, P. curdlanolyticus B-6 was selected to study the role and interaction between the enzymes and their substrates and the cooperation of multiple enzymes to enhance the hydrolysis due to the complex structure for efficient cellulases and xylanases degradation of insoluble polysaccharides.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.311-320
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• 1994

This study was conducted to investigate the biochemical properties of isolated bacteria, low temperature tolerant methane-producing clostridia which were selected for using them as inoculum to anaerobic fermentation of agricultural and livestock wastes at low temperature. The results were; 1. Low temperature tolerant methane-producing clostridia were isolated from the samples which showed the high methanogenesis rate by enrichment culture at low temperature in cellulose medium. These clostridia, Clostridium botulinum SRC-64, Clostridium scatologens SRC-91 and Clostridium tyrobutyricum SRC-100, were isolated from swampy sediment at latitude $56.9^{\circ}N$, lake sediment IV at latitude $55.0^{\circ}N$, and tidal land soil II at latitude $37.0^{\circ}N$, respectively. The optimum growth temperature for these isolates was $37^{\circ}C$ and the minimum, around $10^{\circ}C$. They all had detectable amount of $F_{420}$, specific coenzyme of methanogens. 2. As anaerobic fermentation products of glucose SRC-64 produced $H_2$, acetic, isovaleric and caproic acid, SRC-91 produced $H_2$, propionic, butyric, valeric, and caproic acid, and SRC-100 produced only acetic and propionic acid. The isolates were produced $CH_4$ ranged from 2.6 to 8.68 n moles/ml for 2 days at $13^{\circ}C$.

• Journal of Life Science
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• v.23 no.12
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• pp.1486-1494
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• 2013

A high protease-producing strain was isolated and identified from the digestive tract of octopus vulgaris by detecting a hydrolysis circle of protease and its activity. The strain was identified by morphology observation, biochemical experiments, and 16S rRNA sequence analysis. The protease obtained from the strain was purified by a three-step process involving ammonium sulfate precipitation, carboxy methyl-cellulose (CM-52) cation-exchange chromatography, and DEAE-Sephadex A50 anion-exchange chromatography. The properties of protease were characterized as well. The strain Bacillus sp. QDV-3, which produced the highest activity of protease, was isolated. On the basis of the phenotypic and biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as follows: domain: Bacteria; phylum: Firmicutes; class: Bacilli; order: Bacillales; family: Bacillaceae; and genus: Bacillus. The isolate was shown to have a 99.2% similarity with Bacillus flexus. A high active protease designated as QDV-E, with a molecular weight of 61.6 kDa, was obtained. The enzyme was found to be active in the pH range of 9.0-9.5 and its optimum temperature was $40^{\circ}C$. The protease activity retained more than 96% at the temperature of $50^{\circ}C$ for 60 min. Phenylmethylsulfonyl fluoride (PMSF) inhibited the enzyme activity, thus confirming that this protease isolated from Bacillus sp. QDV-3 is an alkaline serine protease. Metal ions, $Mn^{2+}$ and $Mg^{2+}$, were determined to enhance the protease activity, whereas $Ba^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ were found to inactivate the enzyme.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.214-220
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• 2001

To develop the effective composting system, we isolated bacteria that have the abilities to degrade organic matters such as cellulose, carbohydrate, protein and lipid during the compositing of livestock manureAmong 24 strains, 6 bacteria have all the enzymatic activities of protease, amylase, cellulase and lipase.These microorganisms were identified as Corynebacterium varibilis, Bacillus spp., Pseudomonas spinosa,Acetobacter calcoaceticus and Athrobacter cumminsii All the enzymes produced by the bacteria showedactivities at the broad pH range and the maximal activities were obtained at $60^{\circ}C$. It seemed that after theincrease of temperature caused by fermentation of livestock manure, the enzymes started to degrade the rawmaterials, which are added for the control of humidity. However cellulase activity was maximum at $37^{\circ}C$,suggesting that the cellulase-producing bacteria work at an early stage of livestock manure fermentation toprovide the organic material for the growth of other bacteria. The production of the enzymes were growth-associated and maximal activities appeared at the early stationary phase of growth.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.208-212
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• 1998

In order to develop an effective antifungal antibiotics, over 700 isolates of bacteria, mold and actinomytes were screened from soil, and LAM 97-44 were selected as a strain producing the strong antifungal antibiotics against Candida albicans. Morphological, cultural and physiological characteristics of LAM 97-44 were investigated for the indentification. The cell size of LAM 97-44 was $2{\sim}3{\times}1{\sim}1.5\;{\mu}m$, and the shape of spore was of ellipsoidal. As a carbon source, LAM 97-44 utilized fructose, glucose, glycerol, maltose and raffinose but did not utilize arabinose, cellulose and xylose. The fatty acids of the cells included various iso-type and anteiso-type. Conclusively, the strain LAM 97-44 was proved to be Bacillus subtilis.