• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.275-281
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• 1988

To develop cellulase and xylanase-producing strain by protoplast fusion, alkalophilic Bacillus sp. F204 and K17 were treated with NTG(N-methyl-N'-nitro-N-nitrosoguanidine) and isolated anti-biotics resistant strains of S20 (Km$^r$ , Cm$^r$) and G70 (Str$^r$). The frequency of protoplast formation was about 95% when cells of mid-log phase were treated with 200$\mu\textrm{g}$/ml Iysozyme at 37$^{\circ}C$ for 30-45 minutes. Under addition of 0.4-0.5M sodium succinate, 0.5% casamino acid, 1.5% polyvinylpyrrolidone, 25mM MgC1$_2$ and 50mM CaC1$_2$ to the regeneration medium, the regeneration frequency of Bacillus sp. F204 and K17 was 24.9% and 26.2%, respectively. The fusion frequency was 6.6$\times$10$^{-6}$ in the presence of 30% polyethylene glycol 6000 containing 50mM $Ca^{++}$ at 45$^{\circ}C$ for 5 minutes. Cellulase complex and xylanase activities of fusant were compared with parental strains.

• Research in Plant Disease
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• v.27 no.2
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• pp.61-65
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• 2021

Root-knot disease caused by Meloidogyne incognita is major soil pathogen and cause severe economic damages to vegetable crops. In this study, we selected rhizobacteria for biocontrol of the root-knot nematode, M. incognita, and identified; performed bioassay of the bacterial extracts in cucumber seedlings. The crude extracts of strains CT16 and JC05 out of 180 strains inhibited egg hatching and increased juvenile mortality in vitro assay; based on 16S rRNA sequences analysis, the two strains were identified as Bacillus sp. CT16, and Neobacillus sp. JC05. After extracting the bacterial supernatants by using various organic solvents, n-butanol and n-hexane extracts of strain CT16 and n-butanol extract of strain JC05 showed inhibitory activity of egg hatching depending on concentrations. Subsequently, n-butanol extracts of two strains significantly suppressed formation of egg masses in cucumber seedling. Therefore, these results indicated that strains CT16 and JC05 could be used as potential biocontrol agents against M. incognita.

• Journal of Life Science
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• v.21 no.10
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• pp.1481-1486
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• 2011

Spent mushroom substrate (SMS) is a by-product remained after a crop of mushrooms. About seven thermophilic strains were isolated from SMS (Flammulina velvtipes). Among them, one isolate, designated UJ03, showed the antifungal activity against Aspergillus flavus and Aspergillus ochraceous producing mycotoxin on PDA medium, potentially. The strain UJ03 produced cellulase and xylanase as extracellular hydrolases. The strain UJ03 was identified as a member of the genus Bacillus by biochemical characteristics using Bacillus ID kit and VITEK 2 system. Comparative 16S rDNA gene sequence analysis showed that strain UJ03 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus amyloliquefaciens with sequence similarity of 98.9%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, strain UJ03 was classified within the genus Bacillus, for which the name Bacillus sp. UJ03 is proposed. The antifungal compound from Bacillus sp. UJ03 was similar to lipopeptide iturin A of Bacillus sp.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.188-193
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• 2001

To evaluate antimicrobial activities of chongkukjang slime fermented by different strains, growth characteristics were compared using various standard microorganisms with addition of chongkykjang slime. Chonghkjang slime was prepared by fermenting cooked soybean after inoculating with Bacillus circulans K-1, Baciilus spp N-1 and Bacillus subtilis CH-1, respectively. Significant antimicrobial activity was observed by chongkukjang slime on gram positive bacteria (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Micrococcus luteus), gram negative bacteria(Escherichia coli O157:H7, Salmonella Typhimurium, Pseudomonas fluorescens), and yeast (Pichia membranaefaciens, Saccharomyces cerevisiae, Candida albicans). In case of B. cereus growth inhibition of 80% was achieved by the addition of chongkukjang slime; on the contrary, to Escherichia coli O157:H7 only 20% inhibition was observed. Slime from Bacillus subtilis CH-1, in particular, inhibition of 40% toward bacteria and yeast, whereas slime from Bacillus circulans K-1, Bacillus spp N-1 showed only 20% inhibition.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.63-70
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• 1979

In order to improve the quality of greenish tobacco leaves, fermentation experiments by microbial treatment and periodical variations of fermentation temperature were performed. More than twenty strains were isolated from Hyangcho ( Sun cured Korean native leaves ) and Perique tobacco leaves. Among them, five strains which showed good growth in Nicotine Broth medium were selected. Identification experiments of these strains as well as checking the effects of fermentation by these treatment on the quality and aging rate of greenish tobacco leaves were carried out. The results were like following ; 1. Selected strains were identified as pseudomona.f for H-82, for P-4 and Bacillus for H-81. p- 4 and P-7. 2. Among the five strains, strain H- 82 showed the best effect on the forced aging and the quality of greenish tobacco leaves, The rate of oxygen uptaking, pH and nicotine contents were decreased. However, total volatile acids and petroleum ether extracts were increased. 3. After fermentation, taste from greenish tobacco leaf were removed and smoking characteristics were improved. Color was also changed from greenish yellow to dark brown.

• BMB Reports
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• v.44 no.5
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• pp.323-328
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• 2011

We screened four B. thuringiensis strains whose parasporal inclusions contained the S-layer protein (SLP), and cloned two slp genes from each strain. Phylogenetic analysis indicated these SLPs could be divided into two groups, SLP1s and SLP2s. To confirm whether SLPs were present in the S-layer or as a parasporal inclusion, strains CTC and BMB1152 were chosen for further study. Western blots with isolated S-layer proteins from strains CTC and BMB1152 in the vegetative phase showed that SLP1s and SLP2s were constituents of the S-layer. Immunofluorescence utilizing spore-inclusion mixtures of strains CTC and BMB1152 in the sporulation phase showed that SLP1s and SLP2s were also constituents of parasporal inclusions. When heterogeneously expressed in the crystal negative strain BMB171, four SLPs from strains CTC and BMB1152 could also form parasporal inclusions. This temporal and spatial expression is not an occasional phenomenon but ubiquitous in B. thuringiensis strains.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1577-1584
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• 2010

In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate ($S_2O_3$) oxidation, the production of ammonia ($NH_3$), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated salt-stressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.126-130
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• 1998

A noninsecticidal strain, Bacillus thuringiensis NTB-88, isolated from Korean soil, had a typical bipyramidal parasporal inclusion and its serotype is identical to B. thuringiensis subspmorrisoni (H8a8b). To elucidate differences between insecticidal and noninsecticidal strains, we compared strain NTB-88 to other toxic B. thuringiensis subsp. morrisoni strains (HD-12 and PG-14). Restriction endonucleases digested plasmid DNA patterns showed that strain NTB-88 was different from lepidopteran-toxic strain, HD-12, but it was similar to dipteran-toxic strain, PG-14. The gene type of strain NTB-88 was different from those of other insecticidal strains, Furthermore, the NH2-terminal amino acid sequence of crystal protein of strain NTB-88 had no relation to those of the previously known $\delta$-endotoxins in other toxic strains as well as HD-12 and PG-14 strains. Therefore, the noninsecticidal crystal protein in strain NTB-88 is novel and its property is different from insecticidal ones.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.177-182
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• 2016

Malodor emitted while producing fertilizer from hatchery egg waste treated with microorganism is an important limiting factor. To reduce this problem, we attempted to use two yeast strains, Saccharomyces cerevisiae, KACC 30008 and KACC 30068. Both yeast strains reduce ammonia gas emission 35.4% than only treated with bacterium, Bacillus amyloliquefaciens. When both strains were used together, that was reduced as 57.1%. KACC 30008 and 30068 strains reduced hydrogen sulfide 42 and 90.4%, respectively. Both strains together reduced hydrogen sulfide gas as 98.5%. KACC 30008 did not decrease methyl mercaptan emission. However KACC 30068 decreased 40% and both strains together decreased the gas emission as 66.7%. Overall, this study showed that yeast treatment could enhance the effect of B. amyloliquefaciens treatment in the reduction of malodorous gas emission.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.315-322
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• 2007

This study was carried out to investigate the functional activities of microorganisms isolated from kochujang, such as fibrinolytic, immunostimulating, and cytotoxical activities, and to apply these microorganisms to kochujang products. Ninety-one microbial strains with proteolytic activity were selected from 294 strains isolated from traditional and commercial kochujang. Three strains (TPP 0014, TPP 6013, and TPP 6015) with high fibrinolytic activity were tested for their immunostimulating and cytotoxical activities. For the assessment of macrophage activation, cytokines such as tumor necrosis factor, $interleukin-1{\alpha}$ and nitrogen oxide were measured with the murine macrophage cell line RAW 264.7. In addition, the cytotoxical activities of the three strains were examined by MTT assay on the colon cancer cell line SNU-C4 and normal cell line CHO-K1. Using an API identifying kit, two of the microbial strains (TPP 0014 and TPP 6015) were identified as Bacillus stearothermophilus and the other strain (TPP 6013) was identified as B. amyloliquefacience.