• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.353-360
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• 1995

Tests were performed on 232 bacterial strains (71 strains of Pseudomonas tolaasii and 161 white line reacting organisms, WLRO) isolated from cultivated mushrooms. As results, P. tolaasii was divided into 5 groups on the basis of the phenotypical characteristics for the strains, and group 3 was the major one including 48 (62%) out of the total 71 strains. WLRO were classified into 23 groups, and group 10 was the major group (65 strains, 30% of the total WLRO tested). A white line was well formed at 22$^{\circ}C$ and at 4 mm distance between P. tolaasii and WLRO colonies in their dual culture on Pseudomonas agar F medium within 36-hr incubation, but not formed at $25^{\circ}C$ even for 72-hr incubation. The morphological, cultural and biological properties of P. tolaasii group 3, and the main group of WLRO, group 10, were different only in the light of pathogenicity. Also group 2 of P. tolaasii had the characteristics similar to group 24 of WLRO which was pathogenic to cultivated mushrooms, suggesting the P. tollaasiii and WLRO strains may be the same species although their white line forming ability and pathogenicity were more or less different from one another. Subculture of the strains in P. tolaasii group 1 induced the variation of their pathogenicity, white line forming ability and utilization of sodium benzoate and sodium tartrate, and thus it can be inferred that they were converted to strains having the characteristics of group 3 or WLRO groups.

• Environmental Engineering Research
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• v.11 no.5
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• pp.266-276
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• 2006

Commonly, the flocculant is dissolved in process or recycle water in industrial plant which has many ionic materials. Therefore, the polymer degradation in aqueous solution by chemical, mechanical or bacteriological may occur, sometimes rapidly. Even if the same flocculant is dissolved, the flocculation characteristics and the properties of dissolving polymer varied with the kind of dissolving water. In this study, we try to estimate the interaction between flocculants and ionic materials in dissolving water using self inversing emulsion polymer; polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride flocculants which have varying molecular weights and structures at a several conditions. The polymeric flocculant is dissolved in artificial dissolving water with Potassium Chloride (PC), Calcium Chloride anhydrous (CC), Potassium Hydroxide (PH), Sodium Chloride (SC), Sodium Bromate (SB) and Iron (II) Sulfate Heptahydrate (IS) as ionic sources. Experimental results indicate that the cationic and anionic ions in dissolving water induce the hydrolysis, degradation of cationic functional group and uncoiling of polymeric flocculants, therefore, the flocculation efficiency decreased by undesired polymer. According that result, it is important to estimate not only its structures and physical properties but also the qualities of dissolving water to optimize the efficiency.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.19-25
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• 1989

Twelve isolates of bacteria obtained from infected onions were classified into genus Erwinia based on diagnostic characteristics. Of twelve isolates studied, five were identified as E. carotovora subsp. carotovora, six as E. rhapontici and one as E. chrysanthemi on the bases of bacteriological properties. Symptoms caused by the genus Erwinia were different to be identified among the species. Therefore, we propose to name the disease of onion caused by E. carotovora subsp. carotovora, E. rhapontici and E. chrysanthemi as "bacterial soft rot of onion".

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.99-103
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• 1991

The pathogenic bacteria isolated from the rotted fruits and tubers of red pepper, tomato, eggplant and potato which were collected from farms of Chungnam province and the markets of Seoul, Pusan, Taejon, Chonju, Iri, Weonju, Jecheon, Chungju and Cheonan in Korea. These isolates were divided into ninety-eight isolates of Enoinia sp. and seven isolates of Pseudomonas spp. on the basis of their taxonomic characteristics. Among seven isolates of Pseudomonas spp., six isolates were identified as P. viridiflava and two were P. marginalis and ninety-eight isolates of Erwinia sp. as E. carotovora. subsp. carotovora on the basis of bacteriological properties.

• Journal of Industrial Technology
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• v.3
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• pp.87-94
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• 1983

Heating characteristics of red pepper paste packed in report pouches of various thicknesses and their storage stability were investigated to determine the adequate processing conditions that good bacteriological safty and minimal quality changes could be obtained, when sterilized by using a steam-air system retort. A heat penetration into pouch-packed red pepper paste was carried out through by a conductive heat transfer, indicating a simple logarithmic heating curve, and the smaller thickness revealed the higher heat penetration rate, suggesting the possibility of high temperature-short time sterilization of red pepper paste. The processing conditions with Fo-value of 4.5 or higher were sufficient for keeping up bacterial safty, but based on C-value, better quality retention was obtained at pouch thickness of 15mm under the processing temperature of $120^{\circ}C$. Subsequent storage study revealed that the red pepper paste packed in 15mm and processed at $120^{\circ}C$ with Fo=4.5 could be held without any spoilage and overall acceptance change, when stored for 6 months at room temperature under the relative humidity of 70%. After 3 months storage in $38^{\circ}C$ under saturation humidity, overall acceptance of red pepper paste were judged not to be maintainable on the acceptable level, but it may be suggested that above the results could be kept up a desirable quality without any remarkable deterioration.

• Research in Plant Disease
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• v.12 no.3
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• pp.185-188
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• 2006

In September and October 2005, melons(Cucumis melo L.) from the commercial greenhouses in Naju and Gwangju exhibited severe foliar necrosis and fruit rot. Leaf symptoms initially appeared as V-shaped, necrotic lesions and extending to the midrib. Symptoms on the fruit were occurred randomly as necrotic and sunken spots. Two isolates from diseased leaves and fruits were identified as Acidovorax avenae subsp. citrulli on the basis of bacteriological and genetic characteristics. Pathogenicity of the isolates was confirmed by inoculating on 3-week-old melon and cucumber seedlings. This is the first report of bacterial fruit blotch of melon in Korea.

• Journal of Veterinary Clinics
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• v.3 no.1
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• pp.243-253
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• 1986

In recent years much attention has been paid to swine respiratory infection caused by Haemophilus(H.) Pleuropneumoniae with rapid expansion of pork industry in Korea. The organism may cause an acute respiratory infection with high morbidity and mortality, or it may also cause chronic persistent infection, resulting in loss of body weight. The present study was performed to observe the etiologic situation of H. Pleuropneumoniae infection by evaluating bacteriological, serological examinations with the lungs and sera collected from slaughtered pigs in Daegu city, respectively. In addition, antibiotic susceptibility test was carried out against the isolated strains of H. Pleuropneumoniae. The results obtained are summarized as follows : 1. Only 10 strains of H. Pleuropneumoniae were isolated from the 120 cases of swine lungs examined, and biological and biochemical characteristics of the isolates were identical with that of standard strains(serovar 1 to 6). 2. Out of 336 swine sera examined, 108(32.1%) were shown to be positive against H. Pleuropneumoniae by latex agglutination test. 3. Antibiotic susceptibility test revealed that 10 isolates of H. Pleuropneumoniae were sensitive to 16 kinds of antibiotic such as ampicillin, benzylpenicillin, piperacillin, cephalothin, cefazolin, cefamandol, cefoperagon, lactomoxycefa, tetracycline, minocycline, chloramphenicol, gentamicin, kanamycin, amikacin, colistin and nalidixic acid, whereas cloxacillin, erythromycin, kitasamycin, lincomycin, oleand-amycin, and bacitracin were resistent.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.161-166
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• 1991

For the production of useful products from microorganism, a bacterial strain producing the biopolymer was isolated from soil. The bacteriological characteristics of the strain were examined and some chemical properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkali-tolerant Bacillus sp. The results of chemical composition, various color reactions and I.R. spectrum revealed that the biopolymer contained high protein content, low amino sugar and no uronic acid. However, the biopolymer was precipitated by treating with cetylpiridinium chloride and was found to be acidic.

• KSBB Journal
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• v.16 no.4
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• pp.370-375
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• 2001

For the production of new exo-biopolymers from microorganisms, an exe-biopolymer producing bacterial strain was isolated from the composter used in composting of organic wastes. Bacteriological properties of this strain and physicochemical properties of producing exo-biopolymer were investigated. The isolated strain was identified as Enterobacter sp. through its morphological, cultural and physiological characteristics. The results of color reactions, CPC (cetyl pyridinium chloride) precipitation and infra red absorption spectral analysis indicated that this exo-biopolymer was presumed as an acidic polysaccharide with uronic acid. This polysaccharide was identified as hetero-polysaccharide consisting of galactose, mannose and galacturonic acid by gas chromatography, and the molecular weight of exopolysaccharide purified by gel chromatography were about 370,000 daltons. The polysaccharide solutions(0.50-2.0%, w/v) exhibited non-Newtonian flow behavior with pseudoplastic property and showed the ability of gel formation at above 1.5% (w/v) of polysaccharide concentration.

• KSBB Journal
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• v.8 no.3
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• pp.209-216
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• 1993

For the production of biodegradable polymers from microorganisms a bacterial strain producing a biopolymer was isolated from soil. The bacteriological characteristics of this strain and physicochemical Properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkalophilic Alcaligenes sp. The Purified biopolymer treated with cetylpridinium chloride and acetone was identified as an acidic biopolymer having carboxyl groups and showed strong UV absorbance (at 210nm). The biopolymer was composed of 100% glutamic acid and glutamic acid existed as $\gamma$-polyglutamic acid($\gamma$-PGA) in the form of the $\gamma$-peptide bond. The equivalent weight of this $\gamma$-PGA was estimated about 350, indicating that one acidic fraction per 2.7 residue of $\gamma$-polyglutamic acid existed. The molecular weight was $6.5{\times}10^5$ Daltons.