• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.50-55
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• 2001

A new bacteriocin produced by Bacillus subtilis cx1, was partially purified and characterized. The bactericoin from B. subtilis cx1 was stable in the range of pH 2.5-9.5. B. subtilis csx1 retained its antimicrobial activity to long-term exposure at $-20^{\circ}C$ and $-70^{\circ}C$. However, B. subtilis cx1 was inactivated completely within 15 min over $60^{\circ}C$ and lost 50% of its antimicrobial activity within 15 min at $50^{\circ}C$, B. subtilis cx1 was inactivated by protease, trypsin, proteinase K and carboxypeptidase, which indi-cates its protein nature. Direct detection of the antimicrobial activity on Tricine -SDS-PAGE suggested an apparent molecular mass of about 9,500 dalton.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.472-477
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• 2004

To study the radiation related gene expression in mutants of Bacillus lentimorbus WJ5 induced by gamm radiation, the simultaneous gene expression was analyzed by DNA micro array. We constructed DNA chips including two thousand randomly digested genome spots of B. lentimorbus WJ5 and compared its quantitative aspect with seven mutants induced by gamma radiation $(^{60}/Co)$. From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in all mutants. Especially, genes involved in repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the induction of the direct and/or indirect repair related genes in mutants induced by gamma radiation could be remarkably different from the adaptive responses against acute exposure to radiation.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.209-217
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• 1985

Seventeen extracellular protein producing bacteria were isolated from soil samples, among which T219 strain having a strong capability of producing the protein was selected and identified for investigation of biological characteristics. The factors which affect the protein production were investigated and the results are summarized as follows. T219 strain which produces the most extracellular protein was identified as Bacillus sp. Optimum temperature and pH for production of the extracellular protein by T219 strain were $25^{\circ}C$ and 7.5 respectively. Almost no activities of protease and amylase were observed in the protein produced by the protein producing bacteria. In the medium containing yeast extract, the cell growth was moderately high, but almost no accumulation of protein was observed. However, polypeptone had significant effects on both the cell growth and the protein accumulation. The addition of glycine and L-isoleucine to the medium containing polypeptone, yeast extract and meat extract had a great effect on the protein production; 4mg/ml of protein accumulation was observed.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.176-181
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• 2004

This study was carried out to investigate the effect of yucca extract on the quality characteristics of Chungkookjang using Bacillus subtilis p01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${\alpha}-amylase$ and protease were also determined during aging of Chungkookjang. The amount of amino-type N increased gradually with time for aging. The content of amino-type N was slightly higher in Chungkookjang fermented by adding yucca extract than in the control without yucca extract. The content of ammonia-type N was slightly lower in Chungkookjang with yucca extract than in the control without yucca extract. The activities of amylase and protease were higher in Chungkookjang with yucca extract than in the control and the highest in Chungkookjang containing 0.5 mg/g of yucca extract. Organic acid contents in Chungkookjang was the highest at the initial period of fermentation. The contents of organic acids in Chungkookjang with yucca extract was higher than that in control for 48 hr of aging. The amounts of 2,5-dimethylpyrazine were increased by addition of yucca extract, while those of cis-3-hexanol were decreased.

• Journal of Microbiology and Biotechnology
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• v.31 no.6
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• pp.833-839
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• 2021

Bacillus subtilis CH3-5 isolated from cheonggukjang secretes a 28 kDa protease with a strong fibrinolytic activity. Its gene, aprE3-5, was cloned and expressed in a heterologous host (Jeong et al., 2007). In this study, the promoter of aprE3-5 was replaced with other stronger promoters (P_cry3A, P₁₀, P_SG1, P_srfA) of Bacillus spp. using PCR. The constructed chimeric genes were cloned into pHY300PLK vector, and then introduced into B. subtilis WB600. The P10 promoter conferred the highest fibrinolytic activity, i.e., 1.7-fold higher than that conferred by the original promoter. Overproduction of the 28 kDa protease was confirmed using SDS-PAGE and fibrin zymography. RT-qPCR analysis showed that aprE3-5 expression was 2.0-fold higher with the P10 promoter than with the original promoter. Change of the initiation codon from GTG to ATG further increased the fibrinolytic activity. The highest aprE3-5 expression was observed when two copies of the P₁₀ promoter were placed in tandem upstream of the ATG initiation codon. The construct with P10 promoter and ATG and the construct with two copies of P10 promoter in tandem and ATG exhibited 117% and 148% higher fibrinolytic activity, respectively, than that exhibited by the construct containing P10 promoter and GTG. These results confirmed that significant overproduction of a fibrinolytic enzyme can be achieved by suitable promoter modification, and this approach may have applications in the industrial production of AprE3-5 and related fibrinolytic enzymes.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.56-62
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• 2008

This study was carried out to investigate the changes in microflora, enzyme activity and sensory quality of four kinds of cheonggukjang during fermentation. Three different kinds of cheonggukjang were prepared with germinated soybeans using rice straw, Bacillus natto, B. natto plus Aspergillus oryzae, and the last one was prepared with non-germinated soybeans using rice straw. The pH values of cheonggukjang prepared with germinated or non-germinated soybeans increased up to 36 hr of fermentation and then decreased. The number of bacteria and molds increased significantly up to 24 hr of fermentation and then leveled off during fermentation. Acidic and neutral protease activities of all cheonggukjang continuously increased significantly during fermentation. ${\alpha}$- and ${\beta}$-Amylase activities of cheonggukjang decreased slightly during fermentation except cheonggukjang prepared with germinated soybeans using the mixed culture. The number of microflora, protease and ${\alpha}$-amylase activities were highest in cheonggukjang prepared with germinated soybeans using B. natto plus A. oryzae. The results of the sensory evaluation revealed that for overall acceptability, the cheonggukjang prepared with germinated soybeans using B. natto plus A. oryzae was similar to the cheonggukjang prepared with non-germinated soybeans using rice straw.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.108-112
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• 2013

Nuts are one of the most common sources of allergies in individuals of all ages. In order for a particular protein to render an allergic reaction, it must resist proteolytic digestion by intestinal enzymes. In this study, three well-known allergenic nuts, almonds, cashew nuts, and peanuts, were used as samples, and enzyme digestion with Bacillus protease and porcine pepsin was tested. A proteomic approach using two-dimensional gel electrophoresis and an MS/MS analysis was applied to visualize and identify the proteins that were resistant to enzyme digestion. Among the 150 protein spots tested, 42 proteins were assigned functions. Due to the lack of genomic databases, 41% of the identified proteins were grouped as hypothetical. However, 12% of them were well-known allergens, including AraH. The remainder were grouped as storage, enzymes, and binding proteins.

• 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 Microbiology and Biotechnology
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• v.15 no.3
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• pp.537-543
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• 2005

Subtilisin (EC 3.4.21.14) is the major extracellular alkaline serine protease of Bacillus species. Previously, we found that subtilisins did not migrate in the electrophoretic field in the Laemmili buffer system due to their high pI values (over 8.8); however, it formed a 'binding mode' at the top of the separating gel [5]. Utilizing this characteristic, four subtilisins from Bacillus sp. strains (e.g., B. subtilis 168, B. subtilis KCTC 1021, B. amyloliquefaciens KCTC 3002, and Bacillus sp. DJ-1 and DJ-4) were easily and quickly identified by an over-running electrophoretic technique with a miniscale culture supernatant (less than 20 ml) without any column chromatographic steps. Two subtilisins (DJ-l and a recombinant version) from Bacillus sp. DJ-l were characterized, and the enzymatic properties were determined by SDS-fibrin zymography and densitometric analysis. Based on this observation, the recombinant pro-subtilisin DJ-l showed the same 'binding mode,' similar to native subtilisin DJ-l. On the other hand, mature subtilisin DJ -1 without pro-peptide showed no enzymatic activity.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.326-339
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• 2024

This study was conducted to investigate the effects of protease supplementation and different nutrient density of diets in growing-finishing pigs. A total of one hundred-eight crossbred growing pigs ([Landrace × Yorkshire] × Duroc) with an initial body weight (BW; 18.74 ± 3.46 kg) were used for 15 weeks. Pigs were randomly assigned to six dietary treatments with 6 replicates of 3 pigs per pen in a 3 × 2 factorial through the following arrangement: Three groups of protease (1, Basal diets; 2, Protease A: 125 mg/kg protease derived from Streptomyces sps; 3, Protease B: 100 mg/kg protease derived from Bacillus licheniformis) at two different nutrient density diets (1, Basal requirement; 2, 0.94%-0.98% higher than requirement in dietary protein and 50 kcal/kg in energy). High nutrient (HN) diets showed higher average daily gain (ADG) (p < 0.05) and apparent total tract digestibility (ATTD) of crude protein (CP) (p < .0001) compared to basal nutrient (BN) diets during growing periods. Supplementation of protease showed higher BW (p < 0.05) and ADG (p < 0.05) compared to non-supplementation of protease during growing periods. Also, supplementation of protease showed higher ATTD of CP (p < 0.01), ATTD of gross energy (p < 0.05) and decreased blood urea nitrogen (BUN) level (p = 0.001) compared to non-supplementation of protease during finishing periods. Pigs which fed the protease showed decreased ammonia (NH₃) emissions (p < 0.05) during experiment periods and decreased hydrogen sulfide (H₂S) emissions (p < 0.01) during finishing periods. Interactions between nutrient density and protease were observed, which decreased the feed conversion ratio (p < 0.05) in HN diets without protease compared to BN diets without protease during weeks 4 to 6. Also, interaction between nutrient density and protease was observed, which resulted in improved ATTD of CP (p < 0.01) in response to PTA supplementation with HN diets during the finishing period. In conclusion, supplementation of protease reduces NH₃ in feces and BUN in whole blood by increasing the digestibility of CP and improves growth performance. Also, diets with high nutrient density improved growth performance and nutrient digestibility in growing periods.