• Journal of fish pathology
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• v.10 no.2
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• pp.125-135
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• 1997

The possibility of identification of families of antibacterial agent residues in fish tissue was studied by disk assay using three test organisms, Bacillus subtilis BGA, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778. In the present method, a simple clean-up procedure was performed to obtain the aqueous solution from homogenized flounder muscle sample(10g) in Mcilvaine buffer. Then, aqueous solution was fractionated into A and B to be used in disk assay by choloroform and Sep-Pak $C_{18}$ cartridge column after being defatted in hexane. The chloroform layer of fraction A was used for the analysis of macrolide antibiotics(ML), sulfa drugs(SA), chloramphenicol(CP), and quinolone antibiotics(QN). Adsorbed materials to Sep-Pak $C_{18}$ of fraction B were also employed for the analysis of penicillins(PC), tetracyclines(TC), and nitrofuran derivatives(NF) Minimun-detectable concentrations by the present method were, $0.1{\mu}g$/g for oxytetracycline, tetracycline, doxycycline, spiramycin and ciprofloxacin, $0.025{\mu}g$/g for erythromycin and ampicillin, $1.0{\mu}g$/g for sodium nifurstyrenate and florfenical, $0.25{\mu}g$/g for sulfamonomethoxie and sulfadimethoxine, $2.5{\mu}g$/g for oxolinic acid and flumequine, and $15{\mu}g$/g for piromidic acid, respectively. Three test organisms showed different sensitivity patterns for each family of antibacterial agent. Sensitivity patterns were B. cereus > B. subtilis > M. luteus for TC and NF, M. luteus > B, subtilis > B. cereus for ML and PC, B. cereus = B. subtilis > M. luteus for CP and QN, and B. subtilis > B. cereus＝M. luteus for SA. The present method utilizing these characteristics could be useful as a routine screening test for the determination of family of antibacterial agent residues in fish tissue.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.194-203
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• 2009

$HpaG_{Xooc}$, from rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola, is a member of the harpin group of proteins, eliciting hypersensitive cell death in non-host plants, inducing disease and insect resistance in plants, and enhancing plant growth. To express and secret the $HpaG_{Xooc}$ protein in Bacillus subtilis, we constructed a recombinant expression vector pM43HF with stronger promoter P43 and signal peptide element nprB. The SDS-PAGE and Western blot analysis demonstrated the expression of the protein $HpaG_{Xooc}$ in B. subtilis. The ELISA analysis determined the optimum condition for $HpaG_{Xooc}$ expression in B. subtilis WBHF. The biological function analysis indicated that the protein $HpaG_{Xooc}$ from B. subtilis WBHF elicits hypersensitive response(HR) and enhances the growth of tobacco. The results of RT-PCR analysis revealed that $HpaG_{Xooc}$ induces expression of the pathogenesis-related genes PR-1a and PR-1b in plant defense response.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.665-672
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• 2004

D-Ribose is a five-carbon sugar used for the commercial synthesis of riboflavin, antiviral agents, and flavor enhancers. Batch fermentations with transketolase-deficient B. subtilis JY1 were carried out to optimize the production of D-ribose from xylose. The best results for the fermentation were obtained with a temperature of $37^{\circ}C$ and an initial pH of 7.0. Among various sugars and sugar alcohols tested, glucose and sucrose were found to be the most effective for both cell growth and D-ribose production. The addition of 15 g/l xylose and 15 g/l glucose improved the fermentation performance, presumably due to the adequate supply of ATP in the xylose metabolism from D-xylulose to D-xylulose-5-phosphate. A batch culture in a 3.7-1 jar fermentor with 14.9 g/l xylose and 13.1 g/l glucose resulted in 10.1 g/l D-ribose concentration with a yield of 0.62 g D-ribose/g sugar consumed, and 0.25 g/l-h of productivity. Furthermore, the sugar utilization profile, indicating the simultaneous consumption of xylose and glucose, and respiratory parameters for the glucose and sucrose media suggested that the transketolase-deficient B. subtilis JY1 lost the glucose-specific enzyme II of the phosphoenolpyruvate transferase system.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.82-92
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• 1976

The study was carried out to investigate the changes of the various chemical components and the microflora during the aging period of Korean navive Kochuzang. (Red pepper soybean paste) Korean native maeju loaves were separated into surface and inner parts. Three kinds of Korean native Kochuzang were prepared from surface part, inner part, and ordinary of maeju. The selection and the indentification of the high enzyme producing strains from the microflora and characteristics of their enzymes were studied. I. The changes of the various chemical components during the aging period of Kochuzang. 1) The changes of pH in the 3 kinds of Kochuzang displayed rapid decrease for the first 10 days after preparing and gradual curve of decrease until 60 days, but slight increase for the next 30 days. The pH of the surface part Kochuzang was lower than that of inner part or ordinary Kochuzang. 2) The total acid contents in the 3 kinds of Kochuzang showed gradual increase until the 60 days but it slowly reduced after this time. 3) The total nitrogen contents in the 3 kind of Kochuzang showed gradual inerease up to the 60 days, but slight decrease after this time. 4) The changes of trichloroacetic acid soluble nitrogen in the 3 kinds of Kochuzang showed a remarkable increase for the first 10 days, however gradual increase after this time. 5) The increase of amino nitrogen contents in the 3 kinds of Kochuzang seemed to be remarkable until the first 30 days, however to be less remarkable after this time. 6) The contents of reducing sugar in the 3 kinds of Kochuzang showed remarkable increase until the first 50 days and it slowly reduced after this time. II. The changes of microflora during the aging period of Kochuzang. 1) Aerobic, anaerobic bacteria and mold in the 3 kinds of Kochuzang were increased until the first 30 to 40 days, but they were reduced after this time. 2) No yeast in the three kinds of Kochuzang appeared until the first 20 days. Yeast were proved to grow, when the pH value was decreased below 5.4 after the 30 days. Yeasts in the surface part and ordinary Kochuzang were gradually increased and those in the inner part Kochuzang were decreased as aging. III. The selection and identification of high amylase and protease producing strains from the microflora during the aging period of Kochuzang. 1) The amylase and protease highly producing strains from microflora were identified as Bacillus subtilis-P, Bacillus subtilis-G, Bacillus licheniformis-K, Aspergillus oryzae-B. 2) Amylase activity of Aspergillus oryzae-B was highest among the strains and the strains in order of the higher activity to the lower one were Bacillus subtilis-P Bacillus licheniformis-K, Bacillus subtilis-G. Protease activities of Aspergillus oryzae-B and Bacillus subtilis-P were about the same and the strains in order of the higher activity to the lower one were Bacillus licheniformis-K, Bacillus subtilis-G. 3) Amylase activity was inhibited more than protease activity was with NaCl concentration. Amylase activity was inhibited by 45 to 65 percent and protease activity by 40 to 46 percent at the concentration of 15 percent NaCl, which was the average concentration of NaCl in Kochuzang.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.163-170
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• 2016

This study investigated the quality characteristics of doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935 and Bacillus subtilis HJ18-9). Changes in enzyme activities (protease, cellulase, and ${\alpha}-amylase$), amino-type nitrogen and ammonia-type nitrogen contents, and reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and ${\alpha}-amylase$ play important roles in the composition of nutrients, as well as in the flavor and taste of doenjang. After 60 days of fermentation, protease activities in control doenjang, and doenjang fermented with B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $382.58{\pm}4.02$, $342.58{\pm}7.94$, and $392.58{\pm}1.91unit/g$, respectively (p<0.05). At the beginning of fermentation, protease activities were in the range of 156.88~182.71 unit/g. Cellulase and ${\alpha}-amylase$ activities of doenjang in HJ18-9 were higher than those in other samples. After fermentation, amino-type nitrogen in doenjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $143.25{\pm}1.62$, $141.86{\pm}2.14$, and $150.23{\pm}1.62mg%$, respectively (p<0.05). These results suggest that B. subtilis HJ18-9 is a suitable starter for the preparation of doenjang.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.207-211
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• 2005

The metabolites released from cultures of rhizosphere bacteria can inhibit plant growth. Bacillus subtilis IJ-31 inhibited plant growth by the production of hydrocinnamic acid (HCA). The production of HCA by plant-growth inhibiting rhizobacterium B. subtilis IJ-31 was optimized. $90.5\;{\mu}g/ml$ of HCA was obtained under the condition of 1% rice bran as carbon source, 0.5% tryptone as nitrogen source, 0.1% $ZnCl_2$ as metal source at $37^{\circ}C$ for 60 h (pH 7.0). The optimal condition for the HCA production by B. subtilis IJ-31 in the jar fermenter was established using response surface methodology (RSM) of statistical analysis system(SAS) program. The production of HCA by B. subtilis IJ-31 in the jar fermenter culture reached $102.99\;{\mu}g/ml$ when 2.24% soil extracts was added and agitation speed was 290 rpm under the same condition. And the experimental value of HCA production is $102.5\;{\mu}g/ml$ in the same culture condition. The production of HCA by B. subtilis IJ-31 is higher as 12% than that from the flask culture.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.892-896
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• 2003

High-level expression of the lipase B26 gene from Bacillus pumilus was achieved using Bacillus subtilis Chungkookjang isolated from the Korean traditional fermented bean paste, Chungkookjang. For the secretory production of recombinant lipase B26 in a Bacillus host system, pLipB26 was constructed by ligating the lipase B26 gene into the recently designed Escherichia coli-Bacillus shuttle vector, pLipSM, and that was then transformed into B. subtilis Chungkookjang. Among the various vector, medium, and host combinations, B. subtilis Chungkookjang harboring the pLipB26 exhibited the highest lipase activity in PY medium, and B. subtilis Chungkookjang secreted two times more enzymes than B. subtilis DB 104 under the same condition. When B. subtilis Chungkookjang harboring the pLipB26 was cultured in a 5-1 jar-fermentor containing 21 of a PY medium, the maximum lipase activity (140 U/ml) and production yield (0.68 g/l) were obtained during the late exponential phase from a cell-free culture broth. Although B. subtilis Chungkookjang also secreted extracellular proteases at the late exponential phase, these results suggested the potential of B. subtilis Chungkookjang as a host for the secretory production of foreign proteins.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.459-463
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• 2013

A study investigated the effects of a mixture of Lactobacillus plantarum (L. plantarum) and Bacillus subtilis (B. subtilis) on diarrhea incidence, immune response, and fecal microflora counts in post-weaning piglets. One hundred 28-day-old piglets were randomly assigned to five treatment groups: negative control (NC), free of antibiotics; positive control (PC), 0.03% chlortetracycline; LB 1, a mixture of L. plantarum and B. subtilis (LB) 0.5 kg/ton feed; LB 2, LB 1.0 kg/ton feed; and LB 3, LB 2.0 kg/ton feed. Diarrhea scores for LB 2 and LB 3 from the 2nd week were significantly reduced compared to NC (P<0.05). In terms of the level of IgG and IFN-${\gamma}$, all treatment groups were significantly higher than NC (P<0.05), and the IgG level of LB 3 was significantly higher than that of PC (P<0.05). Furthermore, fecal lactic acid bacteria (LAB) counts for LB 2 and LB 3 were significantly higher than those of NC and PC (P<0.05). In addition, fecal Enterobacteriaceae (ENT) counts for PC, LB 2 and LB 3 were significantly lower than those of NC (P<0.05). Based on the results from this study, it was concluded that a combination of L. plantarum and B. subtilis strains could be used as potential alternatives to antibiotics to prevent diarrhea incidence in piglets.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.335-342
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• 2009

Bioactive compounds were produced from carrot pomace by solid-state fermentation using Bacillus subtilis HA and Leuconostoc mesenteroides. The carrot pomace (CP) fermented by B. subtilis HA with 3% monosodium glutamate (MSG) showed higher production of various bioactive compounds, with 1.64 Pa·sn of consistency, 2.31% of mucilage content, 16.95 unit/g of fibrinolytic enzyme activity, 35.3 unit/g of proteolytic activity and 37.5 mg% of tyrosine content. The mucilage production was greatly dependent upon the concentration of MSG added. Most MSG added in CP was converted into mucilage (2.3%) including 0.83% poly-$gamma$-glutamic acid (PGA) with 1,505 kDa of molecular weight. The CP fermented secondly by Leuc. mesenteroides showed acidic pH and lower consistency. However, the fibrinolytic and proteolytic activities were increased. The secondly fermented CP showed the viable cell counts with $2.5{\time}108$ CFU/g of B. subtilis HA and $3.7{\time}109$ CFU/g of Leuc. mesenteroides, respectively. The freeze-dried fermented CP showed 2.88 Pa·sn of consistency, 24% of mucilage content and 104.9 unit/g of fibrinolytic enzyme activity, respectively. Also, the powder of fermented CP indicated viable cell counts of $8.0{\time}107$ CFU/g of B. subtilis and $4.0{\time}108$ CFU/g of Leuc. mesenteroides. Therefore, the fermented CP that was fortified with dietary fibers, fibrinolytic enzyme and probiotics could be utilized as valuable ingredients of functional foods in food or cosmetic industries.