• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.369-373
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• 1988

The gene for thermostable alpha-amylase from the thermostable bacterium Bacillus licheniformis has been cloned and expressed in Escherichia coli. The Alpha-amylase producing E. coli cells contained a 7.4 kb chimeric plasmid (pTA 322) which was composed of the vector pBR322 and a 3.1 kb EcoRI fragment of B. licheniformis DNA. The alpha-amylase from cloned fragement was shown to be indistlnguishable from that of B. licheniformis in the optimum temperature of 9$0^{\circ}C$, heat stability and the pH stability. The foreign gene was expressed efficiently in E. coli and stably maintained.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1250-1256
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• 2011

In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1405-1412
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• 2014

Lysozyme is a protein found in egg white, tears, saliva, and other secretions. As a marketable natural alternative to preservatives, lysozyme can act as a natural antibiotic. In this study, we have isolated Bacillus licheniformis TIB320 from soil, which contains a lysozyme gene with various features. We have cloned and expressed the lysozyme in E. coli. The antimicrobial activity of the lysozyme showed that it had a broad antimicrobial spectrum against several standard strains. The lysozyme could maintain efficient activities in a pH range between 3 and 9 and from $20^{\circ}C$ to $60^{\circ}C$, respectively. The lysozyme was resistant to pepsin and trypsin to some extent at $40^{\circ}C$. Production of the lysozyme was optimized by using various expression strategies in B. subtilis WB800. The lysozyme from B. licheniformis TIB320 will be promising as a food or feed additive.

• BMB Reports
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• v.37 no.6
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• pp.642-647
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• 2004

The lysine residues of Bacillus licheniformis $\alpha$-amylase (BLA) were chemically modified using citraconic anhydride or succinic anhydride. Modification caused fundamental changes in the enzymes specificity, as indicated by a dramatic increase in maltosidase and a reduction in amylase activity. These changes in substrate specificity were found to coincide with a change in the cleavage pattern of the substrates and with a conversion of the native endo- form of the enzyme to a modified exo- form. Progressive increases in the productions of $\rho$-nitrophenol or glucose, when para nitrophenyl-maltoheptaoside or soluble starch, respectively, was used as substrate, were observed upon modification. The described changes were affected by the size of incorporated modified reagent: citraconic anhydride was more effective than succinic anhydride. Reasons for the observed changes are discussed and reasons for the effectivenesses of chemical modifications for tailoring enzyme specificities are suggested.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.420-426
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• 1998

An extracellular glutamyl aminopeptidase (EC 3.4.11.7) producing bacterium was isolated from soil and identified as Bacillus licheniformis based on its morphological and physiological characteristics. The aminopeptidase was purified to homogeneity by ammonium sulfate precipitation, Phenyl Sepharose, Resource Q, and Superose 12 column chromatographies. The specific activity of the purified aminopeptidase was 9.2 unit/mg for glutamyl p-nitroanilide with 17.6 purification folds. The purified aminopeptidase had an estimated molecular mass of 64 kDa consists of two different subunits (42 kDa and 22 kDa), and its isoeletric point was 5.2 measured by isoelectric focusing. The optimum pH and temperature of the aminopeptidase were 8.0 and 55$^{\circ}C$, respectively. The aminopeptidase was inhibited by EDTA and 1,10-phenanthroline, suggesting it be a metalloenzyme. Comparing with other aminopeptidase, the enzyme showed relatively high activity against peptide having glutamic acid as N-terminal.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1105-1108
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• 2014

We investigated whether Bacillus spp., newly isolated from Korean traditional food resources, influence the resistance of hosts to foodborne pathogens, by using Caenorhabditis elegans as a surrogate host model. Initially, we selected 20 Bacillus spp. that possess antimicrobial activity against various foodborne pathogens, including Staphylococcus aureus. Among the selected strains, six strains of Bacillus spp. used in preconditioning significantly prolonged the survival of nematodes exposed to S. aureus. Based on 16S rRNA gene sequencing, all six strains were identified as B. licheniformis. Our findings suggest that preconditioning with B. licheniformis may modulate the host defense response against S. aureus.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.18-22
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• 1998

A mutant strain which hyperproduced thermostable ${\alpha}-amylase$ was obtained by chemical mutagenesis of Bacillus licheniformis. The mutant strain, SK-5, produced the enzyme about 50 times higher than the original strain. The mutant was longer and slimmer in shape, slower in growth compared to the original strain. Nucleotide sequence analysis of the SK-5 ${\alpha}-amylase$ gene revealed no changes in the the structural gene. The changes found in the promoter region might be responsible for the hyperproduction of the enzyme by the mutant. No structural changes in the enzyme structure could be observed when the secreted enzymes at various culture times were analyzed by Western blot.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.773-779
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• 2002

A gene (hap) encoding aminopeptidase from the chromosomal DNA of Bacillus licheniformis was cloned. The gene is 1,347 bp long and encodes a 449 amino acid preproprotein with a major mature region of 401 amino acids (calculated molecular mass 43,241 Da). N-Terminal sequence of the purified protein revealed a potential presence of N-terminal propeptide. The deduced primary amino acid sequence and the mass analysis of the purified protein suggested that a C-terminal peptide YSSVAQ was also cleaved off by a possible endogeneous protease. Tho amino acid sequence displayed 58% identity with that of the aminopeptidase from alkaliphilic Bacillus halodurans. This bacterial enzyme was overexpressed in recombinant Escherichia coli and Bacillus subtilis cells. Clones containing the intact hap gene, including its own promoter and signal sequence, gave rise to the synthesis of extracellular and thrmostable enzyme by B. subtilis transformants. The secreted protein exhibited the same biochemical properties and the similar apparent molecular mass as the B. lichenzyormis original enzyme.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.282-286
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• 1992

The reaction of N-hydroxysuccinimide with polyacrylic acid and polymethacrylic acid gave poly(N-acryloxysuccinimide)and poly(N-methacryloxysuccinimide), whose reaction with cephradine provided polyacryloylcephradine and polymethacryloylcephradine. The activities of these polymeric drugs were investigated in terms of minimum inhibitory concentration by the common twofold dilution technique. Polyacryloylcephradine revealed excellent antibacterial activity against Staphylococcus aureus ATCC 25923, Staphylococcus aureus FDA 209P, Bacillus subtilis ATCC 6633, Bacillus licheniformis ATCC 14580, Escherishia coli BE 1186 and Salmonella typhimurium TV 119. Polymethacryloylcephradine revealed excellent Staphylococcus aureus ATCC 25923, Staphylococcus aureus FDA 209P, Bacillus subtilis ATCC 6633, Escherichia coli Be 1186 and Salmonella typhimurium TV 119.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1035-1040
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• 2016

This study investigated the prevalence of foodborne pathogens and the bacterial community of traditional Doenjang collected from a longevity area in Korea as well as the antagonistic effect of traditional Doenjang isolates against Bacillus cereus to estimate the microbiological safety of traditional Doenjang. Aerobic bacteria showed $10^6{\sim}10^9CFU/g$, whereas coliform bacteria was not detected. Foodborne pathogens were not detected except B. cereus, which was detected in seven samples out of 10 Doenjang samples. A total of 327 isolates were identified from traditional Doenjang. The isolates consisted of Bacillus subtilis 155 (47.4%), Bacillus licheniformis 68 (20.8%), Bacillus amyloliquefaciens 46 (14.1%), and Bacillus pumilus 18 (5.5%). Antagonistic effect against B. cereus was detected in 20 (6.1%) of 327 isolates, which consisted of B. subtilis (12 strains), B. amyloliquefaciens (5 strains), and B. licheniformis (3 strains). The inhibitory zone for the antagonistic effect was 9.0~12.0 mm in diameter. Although a small amount of traditional Doenjang was tested in this study, these results indicated that the potential risk of B. cereus in traditional Doenjang is lower than generally presumed. It is necessary to monitor the antagonistic effect of traditional Doenjang isolates against B. cereus.