• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.221-226
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• 2000

Cephalosporin-C deacetylase (CAH) catalyzes the deacetylation of cephalosporin derivatives. A novel gene encoding the CAH from Bacillus sp. KCCM10143 was cloned and sepuenced. The uncleotide sequence contained an open reading frame encoding a polypeptide consisting of 217 amino acids and a molecular weight of 24 kDa which was in good agreement with the value obtained by sodium dodecylsulfate-polyacrylamide gel electrophoresis. An expression plasmid was constructed by inserting the CAH gene into the region of the pTrc99A expression vector. An active from of the CAH protein was expressed in the soluble fraction obtained after cell disruption. in fermentation using a 5-1 jar fementer, the transformant E. coli JM109 (pDST654) produced 4.12 U of CAH per ml of culture during 16 h of incubation.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.349-357
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• 2015

To reutilize fisheries waste, we isolated a bacterial strain from a coastal area located in Busan. It was identified as Bacillus licheniformis TK3-Y. Using plate assay and 500-mL flask experiments, we found that the isolate simultaneously possessed cellulolytic, proteolytic, and lipolytic activities with salt tolerance. 10% (v/v) inoculums, were used to examine the biodegradation characteristics of the TK3-Y strain on carboxymethylcellulose, skim milk, and olive oil media. The optimum conditions for pH, temperature, agitation speed, and NaCl concentration on each 1% substrate were 6, $50^{\circ}C$, 180 rpm, and 17.5%, respectively. Under optimal conditions, the TK3-Y strain showed 1.07 U/mL cellulolytic, 1,426 U/mL proteolytic, and 6.45 U/mL lipolytic activities. Each enzyme was stable within a range of 17.5-35% NaCl. Therefore, the salt tolerance ability of strain TK3-Y was superior to other related strains. In degradation of a mixed medium containing all three substrates, both the cellulolytic and proteolytic activities were somewhat lower than those on each single substrate, while the lipolytic activity was somewhat higher. From the above results, the TK3-Y strain appears to be a good candidate for use in the efficient treatment of fisheries waste in which components are not collected separately.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2043-2050
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• 2016

Exploring novel antibiotics is necessary for multidrug-resistant pathogenic bacteria. Because the probiotics in soybean food have antimicrobial activities, we investigated their effects on multidrug-resistant Acinetobacter baumannii. Nineteen multidrug-resistant A. baumannii strains were clinically isolated as an experimental group and 11 multidrug-sensitive strains as controls. The growth rates of all bacteria were determined by using the analysis for xCELLigence Real-Time Cell. The combination of antibiotics showed synergistic effects on the strains in the control group but no effect on the strains in the experimental group. Efflux pump gene adeS was absent in all the strains from the control group, whereas it exists in all the strains from the experimental group. Furthermore, all the strains lost multidrug resistance when an adeS inhibitor was used. One strain of probiotics isolated from soybean food showed high antimicrobial activity for multidrug-resistant A. baumannii. The isolated strain belongs to Bacillus subtilis according to 16S RNA analysis. Furthermore, E. coli showed multidrug resistance when it was transformed with the adeS gene from A. baumannii whereas the resistant bacteria could be inhibited completely by isolated Bacillus subtilis. Thus, probiotics from soybean food provide potential antibiotics against multidrug-resistant pathogenic bacteria.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.302-306
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• 2004

A total of forty strains of pigment-producing halophilic bacteria were isolated from the solar saltern and coastal seawater in Korea. The diversity of those bacteria were determined on the basis of PCR-RFLP and 16S rDNA sequences. The isolated strains were clssified into nine genera: Pseudoalteromonas, Photobacterium, Vibrio, Halobacillus, Bacillus, Paracoccus, Salinicoccus, Tenacilbaculum, and Flavobacterium. While more than $80\%$ of the pigment-producing halophilic bacteria isolated from the coastal seawater were classified as gram-negative Pseudolateromonas, most of the strains isolated from the solar saltern were classified into gram-positive Halo­bacillus. The other strain was KK7, which may be identified as novel species belonging to the genus, Salini­coccus.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.373-377
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• 2016

An extracellular metalloprotease, Btmp, was partially purified from the culture supernatant of Bacillus thuringiensis 29-126, isolated from animal feces collected in a zoological garden in Japan, by ultrafiltration, ammonium sulfate precipitation, and a set of chromatography on Sephadex G-75 and High-Q. The molecular mass of the protease was estimated to be 60 kDa by SDS-PAGE. The enzyme showed optimum activity at $50^{\circ}C$ and pH 6.0, and had a half-life of 14 min at $50^{\circ}C$. The enzyme activity was not influenced by $Na^+$, $K^+$, $As^+$, $Mg^{+2}$, $Ca^{2+}$, $Ba^{2+}$, and phenylmethylsulfonyl fluoride, but it was moderately inhibited by $Zn^{+2}$ at a concentration of 1.0 mM, while the activity was significantly inhibited to less than 50 % by $Cu^{2+}$, $Co^{2+}$, $Cd^{2+}$, and ethylenediaminetetraacetic acid. Interestingly, the enzyme was activated to 178 % by 1.0 mM of $Mn^{2+}$. From these results, it may be suggested that the protease is a novel extracellular manganeseactivated metalloprotease.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.144-145
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• 2017

A Bacillus subtilis strain, designated G24, was isolated from grape during a study on the fermentation of Cheongkukjang, Korean traditional fast-fermented bean paste. Also, a newly isolated bacteriophage SPG24, which was found to inhibit the fermentation process, uses B. subtilis G24 as a host. The complete genome sequence of the bacteriophage SPG24 was 152,060 bp in length, with a G+C content of 42.2%. This sequence included 232 ORF; 58 forward ORFs and 174 reverse ORFs.

• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.212-219
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• 2022

Recently, the efficacy of probiotics in treatment of neurodegenerative disorders has been reported in animal and clinical studies. Here, we assessed the effects of Bacillus coagulans JA845 in counteracting the symptoms of D-galactose (D-gal)/AlCl₃-induced Alzheimer's disease (AD) in a mice model through behavioral test, histological assessment and biochemical analysis. Ten weeks of pre-treatment with B. coagulans JA845 prevented cognitive decline, attenuated hippocampal lesion and protected neuronal integrity, which demonstrated the neuroprotective features of B. coagulans JA845 in vivo. We also found that supplementation of B. coagulans JA845 alleviated amyloid-beta deposits and hyperphosphorylated tau in hippocampus of D-gal/AlCl₃-induced AD model mice. Furthermore, B. coagulans JA845 administration attenuated oxidative stress and decreased serum concentration of inflammatory cytokines by regulating the Nrf2/HO-1 and MyD88/TRAF6/NF-κB pathway. Our results demonstrated for the first time that B. coagulans has the potential to help prevent cognitive decline and might be a novel therapeutic approach for the treatment of neurodegenerative diseases.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.69-82
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• 2023

Nitrilases are a hydrolase group of enzymes that catalyzes nitrile compounds and produce industrially important organic acids. The current objective is to optimize nitrilase production using statistical methods assisted with artificial intelligence (AI) tool from novel nitrile degrading isolate. A nitrile hydrolyzing bacteria Bacillus subtilis AGAB-2 (GenBank Ascension number- MW857547) was isolated from industrial effluent waste through an enrichment culture technique. The culture conditions were optimized by creating an orthogonal design with 7 variables to investigate the effect of the significant factors on nitrilase activity. On the basis of obtained data, an AI-driven support vector machine was used for the fitted regression, which yielded new sets of predicted responses with zero mean error and reduced root mean square error. The results of the above global optimization were regarded as the theoretical optimal function conditions. Nitrilase activity of 9832 ± 15.3 U/ml was obtained under optimized conditions, which is a 5.3-fold increase in compared to unoptimized (1822 ± 18.42 U/ml). The statistical optimization method involving Plackett Burman Design and Response surface methodology in combination with an AI tool created a better response prediction model with a significant improvement in enzyme production.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.400-401
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• 2001

Persicaria hydropiper juice was applied to develop a novel meidum for the mass cultivation of an antifungal bacterium, Bacillus lentimorbus G-74. In this research, a optimized culture condition of B. lentimorbus G-74 were detenninecl. Persicaria hyclropiper juice was contained 1.76% nitrogen, 0.15% phosphorus, 18,230 ppm potassium, 13,753 ppm calcium and 4,844 ppm magnesium. The optimal growth was obtained when the juice was a 30%(v/v) level. The optimum temperature and pH for the bacterial growth were $35^{\circ}C$ and 5.0, respectively.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.35-42
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• 2003

A 1,3 kb cellulase gene encoding novel bifunctional cellulase-chitosanase activity was cloned from biopolymer-producing alkali-tolerant B. lichenformis NBL420 in E. coli. A recombinant cellulase-chitosanase, named CelA, was expressed and purified to homogeneity. The activity staining and the enzymatic characterization of the purified CeIA revealed bifunctional activities on carboxymethyl cellulose (CMC) and glycol-chitosan. The similar characteristics of the enzymatic activities at the optimum pH, optimum temperature, and thermostability Indicated that CelA used a common catalytic domain with relaxed substrate specificity. A comparison of the deduced amino acids in the N-terminal region revealed that the mature CelA had a high homology with the previously identified bifunctional cellulase-chitosanase of Myxobacter sp. AL- 1.