• Journal of Life Science
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• v.16 no.4
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• pp.579-583
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• 2006

The influence of disinfectant on bacterial concentration and carbon usage patterns by Biolog GN plates were investigated for biofilm on carbon steel pipe. Heterotrophic bacterial concentrations were not different among non-, monochloramine- (1.0, 1.5 mg/l) and free chlorine- (0.5, 1.0 mg/l) treated samples (P = 0.56, ANOVA). However treatment of 1.5 mg/l free chlorine and 2.0 mg/l monochloraime showed significantly lower densities than control (P < 0.01, ANOVA). By the stepwise increasement of disinfectant concentration, the carbon usage activities of biofilm microflora were decreased after increase without the decrease of bacterial concentration, following reduction of cell density. Carbon usage patterns were qualitatively and quantitatively different with similar bacterial concentrations. Principal component analysis suggested that type and concentration of disinfectant were main factors on the usage of carbons. Our result suggest that the differences of bacterial communities were different among the samples and the need of monochloramine for the reduction of biofilm in drinking water.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.767-778
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• 2014

Many biologists and various educational associations define evolution as a unifying theme as well as a central idea in biology. In this study, teacher education programs were developed as 18-hour courses on understanding the unified role and significance of evolution in biology, and their effectiveness was tested. As factors for the program content, enhancement of the acceptance of evolution, reinforcement of the conception of evolutionary theory, and recognizing and practicing evolution as the unifying nature of evolution were considered. Hands-on activities, self- and peer-evaluation, and projects based on the small teams including frequent questioning and feedback by instructors were considered methodological factors. Six in-service biology teachers and seven pre-service teachers took part in the programs of the graduate school of H university to testing their effectiveness. They were effective in improving the acceptance of evolution, the understanding of evolutionary mechanism, the perception on the unified role of evolution. The programs also induced a positive change in self-evaluation for knowledge of evolution and perception on importance of evolution in biology. Subsequent studies on whether the changed perceptions of the teachers who participated in the programs reflect on their biology classes in secondary schools after finishing the graduate program are required.

• Research in Plant Disease
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• v.11 no.2
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• pp.146-151
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• 2005

A new bacterial disease of sesame(Sesamum indicum) was observed on field-grown plants in Suwon, Hongchun and Yeonchun in 2000. Leaf symptoms initially appeared as water-soaked spots that gradually enlarged, became necrotic and were often bordered by a small zone of lemon yellow tissue. In the case of severe infection, dead leaves were defoliated. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for farther tests. Pathogenicity of strains was confirmed on 3-week-old sesame plants sprayed with bacterial suspensions containing $10^{8}cfu/ml$ of phosphate buffered saline. The Biolog and fatty acid analyses of the two strains(SL3451 and SL3476) 1mm sesame leaf blight showed that they could be identified as ft campestris pv. sesami because of their high similarity to the tester strain(X. campestris pv. sesami LMG865) with a match probability of $100\%$. The bacterium grew well between 18 and 36$^{\circ}C$, but optimum temperature was $27^{\circ}C$ on LB broth. This is the first report of bacterial blight of sesame in Korea. Symptoms of bacterial blight of sesame are difficult to differentiated with those of bacterial leaf spot caused by Pseudomonas syringae pv. sesami.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.545-550
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• 2002

A hemolysin producing bacterial strain which belong to Vibrio species was isolated from the Kum River estuary. In the process of identification, the strain did not show characteristics of known Vibrio species; thus, the strain was designated as Vibrio sp, E10 (V. kunsan) tentatively and further identification study was carried out by comparing its bacteriological characteristics. Morphologically Vibrio sp, E10 was comma shaped rod with a polar flagellium. Clear hemolysis zones were observed with the strain against human and sheep blood agar. Hemollytic toxicity was confirmed by strong vascular Permeability and fatal toxicity against mouse was also observed. Therefore the strain was a pathogenic vibrio. Growth conditions for Vibrio sp. E10 were ranged salinity of 0$\~$$4.5\%$, pH of 6.2$\~$9.2, temperature of 14$\~$42$^{\circ}C$, respectively, 16S rDNA partial sequence of Vibrio sp, E10 showed $99\%$ homology with dozens of V. cholerae species including V, cholerae El Tor N16961 and V, snmisnfus ATCC 33653T. This strain belonged to Proteobacteria; gamma subdivision; Vibrionacea: Vibrio. But, among knorn Vibrio species no identical styains were found when using automatic bacteria identification system ($MicroLog^{TM}$system, release 4.0, Biolog Inc., USA) which evaluated the ability of metabolizing 95 kinds of carbon and nitrogen sources. Vibrio sp, E10 showed 18 and 11 different responses as compared to V. mimicus and V, cholerae, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.431-441
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• 2006

This study investigated the physiological characteristics of biofilm microorganisms formed onto the different drinking water distribution pipe surfaces. The simulated drinking water distribution pipe system which had several PVC, STS 304, and GS coupons was operated at flow velocity of 0.08 m/sec (Re 1,950) and 0.28 m/sec (Re 7,300), respectively. At velocity of 0.08 m/sec, the number of viable heterotrophic bacteria in the biofilm over the 3 months of operation averaged $3.3{\times}10^4$, $8.7{\times}10^4$, and $7.2{\times}10^3CFU/cm^2$ for PVC, STS, and GS surfaces, respectively. The number of attached heterotrophic bacteria averaged $1.4{\times}10^3$, $5.6{\times}10^2$, and $6.5{\times}10^2CFU/cm^2$ on PVC, STS, and GS surfaces at the system with relatively high flow velocity of 0.28m/sec. The changes of physiological profile of biofilm-forming microorganisms were characterized by community-level assay that utilized the Biolog GN microplates. Biofilms that formed on different pipe surfaces displayed distinctive patterns of community-level physiological profile (CLPP), which reflected the metabolic preference for different carbon sources and/or the utilization of these carbon sources to varying degrees. The CLPP patterns have shown that the metabolic potential of a biofilm community was different depending on the pipe material. The effect of the pipe material was also characterized differently by operation condition such as flow rate. At flow velocity of 0.08 m/sec, the metabolic potential of biofilm microorganisms on GS surface showed lower levels than PVC and STS biofilms. For biofilms on pipe material surfaces exposed to water flowing at 0.28 m/sec, the metabolic potential was in order of PVC>GS>STS. Generally, the levels of the bacterial biofilm's metabolic potentials were shown to be notably higher on pipe surfaces exposed to water at 0.08 m/sec when compared to those on pipe surfaces exposed to water at 0.28 m/sec.

• Journal of Life Science
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• v.19 no.12
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• pp.1724-1730
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• 2009

The mannanase-producing bacteria, designated CS47, was isolated from the fresh feces of three horses (from a farm in Jinju National University). The isolate CS47 was facultatively anaerobic and grew at temperatures ranging from $20^{\circ}C$ to $50^{\circ}C$ with an optimal temperature of $38^{\circ}C$. The DNA G+C content of the isolate CS47 was 44 mlo%. The major fatty acids were anteiso-15:0 (39.6%), 17:0 (7.6%), and iso-15:0 (37.8%). The 16S rRNA gene sequence similarity between the isolate CS47 and other Bacillus strains varied from 93% to 98%. In the phylogenetic analysis based on these sequences, the isolate CS47 and Bacillus amyloliquefaciens clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate CS47 was classified within the genus Bacillus as Bacillus amyloliquefaciens CS47. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens CS47 were pH 6.0 and $50^{\circ}C$, respectively. The thermal stability of mannanase from B. amyloliquefaciens CS47 is valuable when using this enzyme in industrial application.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.15-26
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• 2014

The black soldier fly, Hermetia illucens, larvae may depend on indigenous bacteria in the intestine to feed and digest diverse food sources. To prove this hypothesis, we isolated and identified the intestinal bacteria of the black soldier fly for their digestive and antimicrobial abilities. The last instar larvae had long digestive tracts, which were about seven times longer than its body length. An individual of H. illucens larvae possessed a total of $5.0{\pm}10^6$ bacteria in the whole intestine, of which more than 98% bacteria were located in the hindgut. Three different bacterial isolates cultured on nutrient agar (NA) medium were detected in the intestine and identified as Morganella morganii, Providencia rettgeri and Bacillus halodurans by Biolog microbial identification system. Analysis of 16S rDNA sequences of the intestinal bacteria detected the additional bacteria of Proteus mirabilis, Providencia alcalifaciens, and Providencia sp. These intestinal bacteria cultured on NA medium exhibited high resistance to 4 antibiotics and inhibited growth of other microbes which are mainly plant pathogens. Also, these bacteria exhibited catalytic activities to degrade cellulose, lipid, proteins, and carbohydrates. These results suggest that H. illucens larvae possess intestinal bacteria that may play crucial roles in their digestive physiology.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.223-229
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• 2006

To develop multifunctional microbial inoculant, an insluble phosphate-solubilizing bacterium with antifungal activity was isolated from plant rhizospheric soil. On the basis of its morphological, cultural and physiological characteristics and Biolog analysis, this bacterium was identified as Pseudomonas fluorescens RAF15. P. fluorescens RAF15 showed antifungal activities against phytopathogenic fungi Botrytis cinerea and Rhizoctonia solani. The optimal medium composition and cultural conditions for the solubilization of insoluble phosphate by P. fluorescens RAF15 were 1.5% of glucose, 0.005% of urea, 0.3% $MgCl_2{\cdot}6H_2\;0.01%\;of\;MgSO_4{\cdot}7H_2O\;0.01%,\;of\;CaCl_2{\cdot}2H_2O$, and 0.05% of NaCl along with initial pH 7.0 at $30^{\circ}C$. The soluble phosphate production under optimum condition was 863 mg/L after 5 days of cultivation. The solubilization of insoluble phosphates was associated with a drop in the pH of the culture medium. P. fluorescens RAF15 showed resistance against different environmental stresses like $10-35^{\circ}C$ temperature, 1-4% salt concentration and pH 2-11 range. The strain produced soluble phosphate to the culture broth with the concentrations of 971-1121 mg/L against $CaHPO_4$, 791-908 mg/L against $Ca_3(PO_4){_2}$, and 844 mg/L against hydroxyapatite, respectively. However, the strain produced soluble phosphate to the culture broth with the concentrations of 15 mg/L against $FePO_4$, and 5 mg/L against $AlPO_4$, respectively.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.27-32
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• 2004

The antagonistic microorganisms against Salmonella gallinarum causing fowl typhoid were isolated from the gut of wild pheasant. The isolated L19, L33, L50 strains were showed the characteristics of isolated Gram negative, rods, catalase positive and oxidase negative. Finally, all strains were identified as Sphingomonas sanguis by $Biolog^{\circledR}$ system. The optimal carbon sources of Sphingomonas sanguis L19, L33 and L50 for the these growth ~ere glucose, saccharose, and fructose respectively. But the optimal carbon sources of S. sanguis L19,L33, L50 for the antagonistic material production were maltose, galactose, and saccharose respectively. The optimal nitrogen sources of S. sanguis L19, L33, L50 for the growth were yeast extract, yeast extract, and $NH_4H_2PO_4$ respectively. But the optimal nitrogen sources of S. sanguis L19, L33 and L50 for the antagonistic material production were $(NH_4)_2SO_4$ urea, $(NH_4)_2S_2O_8$ espectively.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.235-241
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• 2003

For the biological control of Phytophthora blight of red-pepper caused by Phytophthora capsici, an antibiotic-producing plant growth promoting rhizobacteria (PGPR) Bacillus sp. KL 39 was selected from a local soil of Kyongbuk, Korea. The strain KL 39 was identified as Bacillus megaterium by various cultural, biochemical test and API and Microlog system. B. megaterium KL 39 could produce the highest antifungal antibiotic after 40 h of incubation under the optimal medium which was 0.4% fructose, 0.3% yeast extract, and 5 mM KCl at 30 C with initial pH 8.0. The antifungal antibiotic KL 39 was purified by Diaion HP-20 column, silica gel column, Sephadex LH-20 column, and HPLC. Its RF value was confirmed 0.32 by thin-layer chromatography with Ethanol:Ammonia:Water = 8:1:1. The crude antibiotic KL39 was active against a broad range of plant pathogenic fungi, Rhizoctonia solani, Pyricularia oryzae, Monilinia fructicola, Botrytis cinenea, Alteranria kikuchiana, Fusarium oxysporum and Fusarium solani. The purified antifungal antibiotic KL39 had a powerful biocontrol activity against red-pepper phytophthora blight disease with in vivo pot test as well as the strain B. megaterium KL 39.