• Journal of Mushroom
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• v.14 no.4
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• pp.244-248
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• 2016

In order to isolate thermophilic bacteria with high activity of CMCase and xylanase, spent mushroom substrates was collected from an oyster mushroom cultivation farm in Jinju, Gyeongnam, Korea. Among the isolates, one strain designated as YJ09 was selected by agar diffusion method. The isolate YJ09 was identified as a member of Bacillus licheniformis based on biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA sequence analysis showed that isolate YJ09 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus licheniformis with sequence similarity of 98.9%. Based on its physiological properties, biochemical characteristics and phylogenetic distinctiveness, the isolate YJ09 was classified as Bacillus licheniformis. The CMCase and xylanase activity of B. licheniformis YJ09 was slightly increased corresponding to the bacterial population from exponential phase to stationary phase in the growth curve of B. licheniformis YJ09.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.126-130
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• 2002

Regulation of invertase biosynthesis was studied in thermophilic and alkalophilic Bacillus sp. TA-11. Biosynthesis of the invertase was effectively induced in the presence of 10 mM sucrose for 180 min. Glucose repressed the invertase induction by sucrose and as late as addition time of glucose, the invertase formation was increased, indicating that glucose repression was occurred by inducer exclusion. Catabolite repression was reduced a little by the addition of cAMP for 180 min of induction.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.322-328
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• 1995

A thermophilic bacteria showing proteolytic activity against defatted soybean was isolated from soil. It was identified as Bacillus amyloliquefaciens based on its morphological and physiological characteristics. The Bacillus amyloliquefaciens NS 15-4 was cultivated at 50$\circ$C by rotary shaking in a medium containing defatted soybean. An extracellular protease from this strain was purified to homogeneity by ammonium sulfate precipitation, ion exchange, and hydrophobic interaction chromatographies. The molecular weight of the enzyme was estimated to be approximately 30,000 by SDS-PAGE and the N-terminal amino acid sequence of the enzyme was turned out to be AQSVPYGISQIKAPA. The optimum temperature and pH for the enzyme reaction were 60$\circ$C and 11, respectively, and its thermostability was increased by the addition of calcium ion. The enzyme was inactivated by phenylmethylsulfonylfluoride, suggesting it be a serine protease. Comparing with other commercial proteases, the enzyme showed relatively high proteolytic activity against defatted soybean, a water-insoluble protein substrate.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.196-201
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• 2007

An intracellular invertase was purified to homogeneity from the cell extract of an alkalophilic and thermophilic Bacillus sp. TA-11, which was classified as a new species belonging to Bacillus cereus based on chemotaxanomic and phylogenetic analyses. The purified enzyme with a recovery of 26.6% was determined to be a monomeric protein with a molecular weight of 23 kDa by SDS-PAGE and 26 kDa by gel filtration. The maximum enzyme activity was observed at pH 7.0 and $50^{\circ}C$, and the purified enzyme was stable at the pH range of 5.0 to 8.0 and below $60^{\circ}C$. $K_m$ and $V_{max}$ values of the enzyme for sucrose were 370 mM and 3.0 ${\mu}M$ per min, respectively. The enzyme activity was significantly inhibited by bivalent metal ions ($Hg^{2+}$, $Cd^{2+}$ and $Cu^{2+}$) and sugars (glucose and fructose).

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.103-110
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• 1990

For production of thermophilic and alkaline protease, Bacillus sp. strain AP-5 was isolated from a compost. The production of the protease was reached at maximum for 4 days at $55^{\circ}$ in standing culture. Chitin and Cellulose as carbon source, and Skim Milk as nitrogen source were favorable for the production of the enzyme. Optimal temperature and optimal pH of the enzyme was $55^{\circ}$ and 11, respectively. Metal ion didn't effect on the enzyme activity, the protease was very stable at heat treatment of 30 min at $55^{\circ}$.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.7-13
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• 1992

A moderately thermophilic, alkalophlic and powerful crystalline cellulose-digesting bacterium, Bacillus K-12, was isolated from filter paper wastes and found to be similar to Bacillus circulans or Bacillus pumilis, except for its ability to grow at a moderately high pH and temperature. The isolate grew at a pH ranging from 6 to 10 and at a temperature ranging from 35 to $65^{\circ}C$ and produced a large amount of cellulase components containing avicelase, xylanase, CMCase, and FPase when grown in avicel medium for 5 to 7 days at $50^{\circ}C$. The crude enzyme preparation from the culture broth hydrolyzed xylan, raw starch, pullulan and ${\beta}-1,3$ glucan such as laminarin. Furthermore, the enzyme hydrolyzed crystalline cellulose to cellobiose and glucose and had a broad pH activity curve (pH 6~9). The enzyme was stable up to $70^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.813-818
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• 2004

A systematic study of microbial fuel cells comprised of thermophilic Bacillus licheniformis and Bacillus thermoglucosidasius has been carried out under various operating conditions. Substantial amount of electricity was generated when a redox mediator was used. Being affected by operation temperature, the maximum efficiency was obtained at 50$^{\circ}C$ with an open circuit voltage of ca. 0.7 V. While a small change around the optimum temperature did not make much effect on the cell performance, the rapid decrease in performance was observed above 70$^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern strongly depended on the kind of carbon sources used in the initial culture medium. In the case of B. thermoglucosidasius, glucose alone was utilized constitutively as a substrate in the microbial fuel cell irrespective of used carbons sources. When B. licheniformis was cultivated with lactose as a carbon source, best charging characteristics were recorded. Trehalose, in particular, showed 41.2% coulombic efficiency when B. thermoglucosidasius was cultured in a starch-containing medium. Relatively good repetitive operation was possible with B. thermoglucosidasius cells up to 12 cycles using glucose as a carbon source, when they were cultured with lactose as an initial carbon source. This study demonstrates that highly efficient thermophilic microbial fuel cells can be constructed by a pertinent modulation of the operating conditions and by carefully selecting carbon sources used in the initial culture medium.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.447-451
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• 1996

Lytic activities of the egg white lysozyme from Korea-native Ogol fowl against the alkalophilic and thermophilic Bacillus sp. TA-11 were investigated and compared. Lytic activity of the Ogol fowl lysozyme for Bacillus sp. TA-11 was the highest for the cell of post-logarithm phase and optimum concentration of the lysozyme was 0.25%, Optimum reaction pH and temperature were 4.5 and 35$^{\circ}C$, respectively. Lytic activity of egg white lysozyme from fowl for Bacillus sp. TA-11 was the highest for the cell of stationary phase and optimum concentration of the lysozyme was 0.5%. Optimum reaction pH and temperature were 5.5 and 4$0^{\circ}C$, respectively.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.683-686
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• 2002

To achieve optimum operation of a thermophilic aerobic digestion (TAD) process for waste activated sludge (WAS), TAD experiments using Bacillus stearothermophilus (ATCC 31197) were carried out to investigate the optimum concentration of dissolved oxygen (DO). TAD reactors were operated at DO concentrations of 0, 1, 2, 3, 4, and 5 ppm, and the results showed that the WAS could be successfully degraded by a TAD system operated with a DO concentration of 1 ppm and above. When the TAD system with an optimum additive (2 mM Ca ion), selected from a previous study, and 1 ppm DO concentration were combined with a thermal pretreatment ($121^{\circ}C$, 10 min), the results exhibited upgraded total suspended solids and an enhanced protein degradation.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.122-125
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• 2022

The cellulose-fed microbial fuel cell (MFC) is a biotechnological process that directly converts lignocellulosic materials to electricity without combustion. In this study, the cellulose-fed, MFC-integrated thermophilic bacterium, Bacillus sp. WK21, with endoglucanase and exoglucanase activities of 1.25 ± 0.08 U/ml and 0.95 ± 0.02 U/ml, respectively, was used to generate electricity at high temperatures. Maximal current densities of 485, 420, and 472 mA/m² were achieved when carboxymethyl cellulose, avicel cellulose, and cellulose powder, respectively, were used as substrates. Their respective maximal power was 94.09, 70.56, and 89.30 mW/m³. This study demonstrates the value of the novel use of a cellulase-producing thermophilic bacterium as a biocatalyst for electricity generation in a cellulose-fed MFC.