• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.238-248
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• 2014

The metalloid arsenic (Z = 33) is considered to be a significant potential threat to human health due to its ubiquity and toxicity, even in rural regions. In this study a rural region contaminated with arsenic, located at longitude $85^{\circ}$ 32'E and latitude $25^{\circ}$ 11'N, was initially examined. Arsenic tolerant bacteria from the rhizosphere of Amaranthas viridis were found and identified as Bacillus licheniformis through 16S rRNA gene sequencing. The potential for the uptake and removal of arsenic at 3, 6 and 9 mM [As(V)], and 2, 4 and 6 mM [As(III)], and for the reduction of the above concentrations of As(V) to As(III) by the Bacillus licheniformis were then assessed. The minimal inhibitory concentrations (MIC) for As(V) and As(III) was determined to be 10 and 7 mM, respectively. At 3 mM 100% As(V) was uptaken by the bacteria with the liberation of 42% As(III) into the medium, whereas at 6 mM As(V), 76% AS(V) was removed from the media and 56% was reduced to As(III). At 2 mM As(III), the bacteria consumed 100%, whereas at 6 mM, the As(III) consumption was only 40%. The role of pH was significant for the speciation, availability and toxicity of the arsenic, which was measured as the variation in growth, uptake and content of cell protein. Both As(V) and As(III) were most toxic at around a neutral pH, whereas both acidic and basic pH favored growth, but at variable levels. Contrary to many reports, the total cell protein content in the bacteria was enhanced by both As(V) and As(III) stress.

• Journal of Life Science
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• v.19 no.10
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• pp.1424-1431
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• 2009

Shrimp Jeot-Gal is a popular traditional Korean fermented seafood and has been used for seasoning. We isolated a bacterium showing strong extra-cellular fibrinolysis and chitinase activity from shrimp Jeot-Gal and the strain was designated SC082. SC082 was identified as Bacillus licheniformis by 16S rRNA sequence homology search. B. licheniformis SC082 exhibited optimum temperature, pH, and salt concentration at $37^{\circ}C$, pH 7.0, and 6%, respectively. Substrate specificity of the culture supernatant from B. licheniformis SC082 was detected in fibrin, skim milk, and chitin plate. The fibrinolytic activity was highly maintained up to $50^{\circ}C$ at a pH of 7.0 for 3 hr and was stable up to pH 9.0 at $37^{\circ}C$ for 3 hr. The chitinase activity was remarkably induced by addition of 1.0% colloidal chitin and the pH and temperature optima of the enzyme were 5.0 and $45^{\circ}C$, respectively. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis, this strain produced three fibrinolytic isozymes and two chitinase isozymes. The approximate molecular weights of the putative fibrinolytic enzymes were 23.0, 62.0, and 72.0 kDa and those of the chitinases were 62.0 and 55.0 kDa, respectively. The antioxidant activity of SC082 was also measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical. The DPPH radical scavenging was slightly increased in a dose-dependent manner.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.136-141
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• 2009

Marking biocontrol bacteria is an essential step to monitor bacterial behavior in natural environments before application in agricultural ecosystem. In this study, we presented the simple green fluorescent protein (GFP) reporter system driven by the promoter active in Bacillus species for tagging of the biocontrol bacteria. A constitutive promoter P43 from Bacillus subtilis was fused to an enhanced promoterless gfp gene by overlap extension PCR. The GFP expression was demonstrated by the high fluorescence intensity detected in B. subtilis and Escherichia coli transformed with the P43-gfp fusion construct, respectively. The GFP reporter system was further investigated in two bacterial biocontrol strains B. licheniformis and Pseudomonas fluorescens. When the reconstructed plasmid pWH34G was introduced into B. licheniformis, GFP level measured with the fluorescence intensity in B. licheniformis was almost equivalent to that in B. subtilis. However, GFP expression level was extremely low in other biocontrol bacteria P. fluorescens by transposon based stable insertion of the P43-gfp construct into the bacterial chromosome. This study provides information regarding to the efficient biomarker P43-gfp fusion construct for bio-control Bacillus species.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.385-390
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• 2010

Bacillus licheniformis fermenting soybean product with highest score in consumer acceptance had been isolated from homemade Cheongkookjang. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon sources, metal ions and phosphate were examined for protease production of the isolate. Potato starch increased the protease productivity, while glucose repressed it. Yeast extract was the most effective nitrogen source for enzyme production. The calcium was found to increase protease activity slightly while cell growth and enzyme production was completely inhibited by divalent ions such as $Zn^{2+}$, $Cu^{2+}$ and $Co^{2+}$. The maximum protease productivity was reached approximately 800 unit/mL in the optimized medium consisting of potato starch (1.5%), yeast extract (1.5%), $CaCl_2$(0.7%), $K_2HPO_4$(0.03%) and $KH_2PO_4$(0.03%). The protease activity of culture filtrate was gradually decreased after incubation for 28 h.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.68-72
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• 2010

The ${\beta}$-1,4-glucanase gene of Bacillus licheniformis B1 was expressed in Esherichia coli BL21, and a protein with a mass of 50 kDa that was soluble was overproduced. A protein with a mass of 37 kDa was secreted from B. licheniformis. It seems that the ${\beta}$-1,4-glucanase produced in E. coli contained the leader peptide and unprocessed carboxy-terminal region, but its processing occurred in the carboxyterminal in Bacillus. The optimal temperature of ${\beta}$-1,4-glucanase was $40^{\circ}C$. The enzyme still had 76% maximal activity at $60^{\circ}C$. The optimal pH of the enzyme was 7. The enzyme retained considerable activities over the weak-acidic, neutral, and weak-basic pH range. Acidic fungal cellulases are used in food, detergent, pulp, paper, textile industries. However, studies about neutral and alkaline cellulase are not enough. The cellulase developed in this study may be useful for industrial applications in the fields of biofuel development.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.216-219
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• 2012

Chungkookjang, fermented soybean, is high in microorganism, enzymes, daidzein, and peptides. Using yellow, black, Seoritae, small-black soybeans and Bacillus licheniformis B1, each Chungkookjang (YC, BC, SC, SBC) was prepared, and their fermentation patterns were compared. Changes of pH and browning material formation were taken as an indicative of fermentation. YC had a high pH increase at an early stage of fermentation, and a low change at a late stage. BC, SC, and SBC showed different patterns with a low pH increase at an early stage and a high pH increase at a late stage. Formation rate of browning material was fastest in YC and slow in the rest of BC, SC, and SMC. SC showed the highest value of browning material formation 1 d after fermentation. Anthocyanin in black soybeans seems to suppress the growth of bacteria at an early stage of fermentation. When anti-inflammatory daidzein contents were analyzed by HPLC, BC, SC, SBC showed higher values than YC. It was demonstrated that black soybeans can be fermented with B. licheniformis B1.

• The Plant Pathology Journal
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• v.26 no.3
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• pp.238-244
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• 2010

Spatial and temporal distribution of Bacillus licheniformis N1 was investigated over time on the leaves, petioles and crowns of the strawberry plants. Bacterial population on the strawberry plants was quantified over time by selective plating. Bacterial population of N1 containing a plasmid pWH43G carrying green fluorescent protein (GFP) declined relatively faster on the plant surface as compared to the Strain N1 itself. However, this result was found to be enough to utilize the strain to visualize bacterial colonization on the plant surface. When B. licheniformis N1 was treated together with Silwet L-77 at 0.03%, the bacterial population on plant surface persisted for up to 7 days. B. licheniformis N1 (pWH43G) containing Silwet L-77 was applied on the strawberry plants and the GFP expressing bacteria were visualized by confocal laser scanning microscopy. Bacterial persistence was also investigated in a growth chamber and in a plastic house after N1 bioformulation treatment on the strawberry plant. The Strain N1 colonized three different tissues well and persisted over 3 to 5 days on the strawberry plants. They formed bacterial aggregates on plant surfaces for at least 3 days, resulting in a biofilm to resist fluctuating plant surface environment. However, the bacterial persistence dramatically declined after 7 days in all tested tissues in a plastic house. This study suggest that B. licheniformis N1 colonizes the strawberry plant surface and persists for a long time in a controlled growth chamber, while it can not persist over 7 days on the plant surface in a plastic house.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1457-1466
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• 2018

In the present study, the stabilizing effect of four different biological osmolytes on Bacillus licheniformis ${\gamma}$-glutamyl transpeptidase (BlGGT) was investigated. BlGGT appeared to be stable under temperatures below $40^{\circ}C$, but the enzyme retained less than 10% of its activity at $60^{\circ}C$. The tested osmolytes exhibited different degrees of effectiveness against temperature inactivation of BlGGT, and sucrose was found to be the most effective among these. The use of circular dichroism spectroscopy for studying the secondary structure of BlGGT revealed that the temperature-induced conformational change of the protein molecule could be prevented by the osmolytes. Consistently, the molecular structure of the enzyme was essentially conserved by the osmolytes at elevated temperatures as monitored by fluorescence spectroscopy. Sucrose was further observed to counteract guanidine hydrochloride (GdnHCl)-and urea-induced denaturation of BlGGT. Taken together, we observed evidently that some well-known biological osmolytes, especially sucrose, make a dominant contribution to the structural stabilization of BlGTT.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.135-139
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• 2006

A alkalophilic strain, Bacillus licheniformis MH31 producing an alkaline protease was isolated from mine soil of Boryeong in Korea. Production of a high level of alkaline protease was achieved 42 h after incubation when the bacterium was grown at pH 9.0 and $35^{\circ}C$ in Horikoshi medium supplemented with 0.5%(w/v) starch and 1%(w/v) skim milk as carbon and nitrogen source, respectively. The molecular weight of partially purified enzyme was estimated to be 30 kDa by SDS-PAGE and its optimum pH was pH 10. The enzyme showed optimum temperature at $50^{\circ}C$, and was stable up to $60^{\circ}C$ after 1 h incubation. The protease was strongly inhibited by 1 mM of PMSF which was known well as strong inhibitor of serine proteases, but almost not inhibited by 5 mM of EDTA and 1,10-phenanthroline. When the protein hydrolysis products of 1% skim milk by partially purified protease was compared with available commercial proteases using HPLC analysis, most of hydrolysis products were detected below molecular weight of 10,000 and the hydrolysis ratio of purified enzyme was 24.8% lower than those(above 32%) of commercial proteases.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1092-1096
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• 2020

YjiC, a glycosyltransferase from Bacillus licheniformis, is a well-known versatile enzyme for glycosylation of diverse substrates. Although a number of O-glycosylated products have been produced using YjiC, no report has been updated for nucleophilic N-, S-, and C- glycosylation. Here, we report the additional functional capacity of YjiC for nucleophilic N- and S- glycosylation using a broad substrate spectrum including UDP-α-D-glucose, UDP-N-acetyl glucosamine, UDP-N-acetylgalactosamine, UDP-α-D-glucuronic acid, TDP-α-L-rhamnose, TDP-α-D-viosamine, and GDP-α-L-fucose as donor and various amine and thiol groups containing natural products as acceptor substrates. The results revealed YjiC as a promiscuous enzyme for conjugating diverse sugars at amine and thiol functional groups of small molecules applicable for generating glycofunctionalized chemical diversity libraries. The glycosylated products were analyzed using HPLC and LC/MS and compared with previous reports.