• KSBB Journal
• /
• v.30 no.6
• /
• pp.283-290
• /
• 2015

In this study was selected the cellulolytic microorganism and investigated optimum condition of cellulase production for the cellulosic bioethanol production. A bacterial strain Paenibacillus jamilae BRC15-1, was isolated from soil of domestic reclaimed land. For optimizing cellulase production from the selected strain, various culture parameters were investigated such as culture medium, pH (pH 4~10), temperature ($25{\sim}50^{\circ}C$) and culture time (2~72 h). As a result, P. jamilae BRC15-1 efficiently produced cellulase from cellulosic biomass under following conditions: 24 h of culture time (pH 7, $40^{\circ}C$) in manufactured media of CMC (carboxymethyl cellulose) with peptone. Optimum saccharifying condition of crude enzyme produced from P. jamilae BRC15-1 was identified on pH 6 and $40^{\circ}C$ of reaction temperature, respectively. This crude enzyme from P. jamilae BRC15-1 was used for saccharification of pretreated sweet sorghum (Sorghum bicolor var. dulciusculum Ohwi) bagasse under the optimal condition. Finally, pretreated sweet sorghum bagasse including 0.1 g of glucan was saccharified by crude enzyme of P. jamilae BRC15-1 into 2.75 mg glucose, 0.79 mg xylose and 1.12 mg arabinose.

• Journal of Mushroom
• /
• v.15 no.4
• /
• pp.249-253
• /
• 2017

Twelve strains of bacteria with cellulase and xylanase activities were isolated from spent mushroom substrates collected from button mushroom cultivation farm, Buye, Chungcheongnam-do in Korea. Among them, one strain, designated NO12, with higher cellulase and xylanase activities was selected by agar diffusion method. The strain NO12 was identified to be a Bacillus sp. by biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA gene sequence analysis showed that strain NO12 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99.2%. Based on its physiological properties, biochemical characteristics, and phylogenetic distinctiveness, strain NO12 was classified within the genus Bacillus, for which the name Bacillus subtilis NO12 was proposed. The cellulase and xylanase activities of B. subtilis NO12 were slightly increased according to bacterial population from exponential phase to stationary phase in the growth curve for B. subtilis NO12. The xylanase activity continuously increased from the beginning of the exponential phase and exhibited maximum activity in the middle of the exponential phase.

• Microbiology and Biotechnology Letters
• /
• v.39 no.4
• /
• pp.330-336
• /
• 2011

Bacterial strains exhibiting fibrinolytic activity were screened from traditional Korean soybean sauce. The Fibrinolytic activities of the various isolated microorganism were further examined and the superior strain YJ11-21 was selected for further analyses. Gene sequence analysis of 16S rDNA of the YJ11-21 strain revealed Bacillus licheniformis. Optimal culture conditions were investigated in order to maximize the production of the fibrinolytic enzyme by YJ11-21. Amongst the carbon sources tested, glucose was the most effective for enzyme production and amongst the nitrogen sources tested, yeast extract was seen to be the most effective. A one percent addition of NaCl to the medium resulted in the highest fibrinolytic activity. Interestingly, a 10% addition of NaCl resulted in a high activity together with a high cell growth rate. Therefore, YJ11-21 is speculated of being a halotolerant. The optimum pH and temperature for enzyme production were a pH of 9.0 and $30^{\circ}C$, respectively.

• Microbiology and Biotechnology Letters
• /
• v.47 no.4
• /
• pp.596-602
• /
• 2019

In September 2017, the rhizospheric soil of Tetragonia tetragonoides (Pall.) Kuntze was further sampled. One hundred and thirty eight species of microorganisms were isolated from the soil. Indole-3-acetic acid (IAA) production, siderophore production, and phosphate degradation were examined in order to confirm bacterial growth from isolated microorganisms. As a result, most strains were able to produce auxins or siderophores and to solubilize phosphate. In addition, 138 isolated strains were treated with tobacco extract and conferred pathogen resistance to host plants upon treatment. As a result, 35 strains that were able to reduce pathophysiology by more the 60% were selected. Among them, 6 strains with high induced systemic resistance (ISR) activity were found. All of these strains belong to the genus Bacillus according to the 16S rDNA sequence analysis. Bacillus aryabhattai KUDC6619 showed outstanding effects with reduced infection in tobacco and pepper plants. Probably, these Bacillus species play a beneficial role by association with T. tetragonoides for its survival in the harsh conditions found on the island of Dokdo.

• The Korean Journal of Pesticide Science
• /
• v.20 no.4
• /
• pp.349-354
• /
• 2016

Triazole fungicides occupy an important portion in the global fungicide market and are relatively persistent in soil compared to the other fungicides, suggesting possible adverse effects of the fungicides on human health and environment. In this study, we tried to isolate microorganisms from orchard soils, which can decompose the triazole fungicides, tebuconazole, fluquinconazole, and difenoconazole. Only difenoconazole was completely degraded in the enrichment culture, from which several difenoconazole-degrading bacteria were isolated. They showed the same rep-PCR pattern thus only one strain, C8-2, was further studied. The strain was identified as Sphingomonas sp. C8-2 based on its 16S rRNA gene sequence and decomposed 100 mg/L of difenoconazole in a minimum medium to an unknown metabolite with a molecular weight of 296 within 24 hours. The inhibition effect of the metabolite against representative soil microorganisms significantly decreased compared to that of difenoconazole thus the bacterial strain is expected to be used for the detoxification of difenoconazole in soil and crop.

• Korean Journal of Food Science and Technology
• /
• v.23 no.6
• /
• pp.661-666
• /
• 1991

European style fermented sausages were made with normal pork, PSE and a 50 : 50 mixture, inoculated with Lactobacillus plantarum 1-74 and Staphylococcus simulans MIII and ripened for 21 days following commercial manufacturing procedures. In all treatments, pH droped sharply between 0 and 3 days during ripening. PSE sausages showed the lowest pH and Aw at the end of ripening than other treatment groups. Protein solubility, hardness, cohesiveness and chewiness were significantly (P<0.05) low for PSE sausages. Springiness was the highest for normal sausages but the other two treatment were not different. PSE sausages had poor texture low redness value during the ripening. The added sugars apparently dropped the pH fast in PSE sausages. Total bacterial count and lactobacilli increased from 0 day to the third day of ripening. The number of Staphylococcus sp. decreased in normal sausages by the end of the ripening period. Fermented sausages with PSE meat could be produced if the mixture had lower (<50%) amounts of PSE meat. In addition, added sugar must be reduced to prevent lowering the pH to a level that will affect processing and quality attributes of fermented sausages.

• Microbiology and Biotechnology Letters
• /
• v.35 no.1
• /
• pp.1-10
• /
• 2007

The 44 endophytic bacterial strains were isolated from surface-sterilized root of rice cultivated in seven different locations of Chungcheong province, Korea. Each isolate was introduced into rice seedlings grown gnotobiotically by inoculating scissor-cut first true leaf with cell suspensions, and the colonization capacity of each isolate in root tissue was analyzed at 7 days after inoculation. Sixteen out of 44 isolates were re-isolated from root successfully with the frequency of $10^{3-5}$ CFU/g tissue. Interestingly, seven out of 16 isolates were identified as Burkholderia species. The identity between inoculated strains and re-isolates was confirmed by genomic finger-printing and 16S rDNA sequence analysis. By a confocal laser scanning microscopic observation it was revealed that KJ001 strain, one of the sixteen isolates tagged with gfp colonized in root tissue especially around xylem. Six out of seven Burkholderia strains obtained in this study showed antagonizing activities against seven different fungal pathogens, contain nifH gene, and five of them enhanced growth of cucumber over 30%. The isolates showed no hypersensitive response on tobacco leaves and no pathogenecity in rice. From these results it was found that the endophytic Burkholderia strains will be useful in agriculture to develop a biocontrol agent or a bio-fertilizer.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.3
• /
• pp.535-541
• /
• 2017

Two Gram-staining-negative, red-pinkish, coccus-shaped, non-motile, and aerobic bacterial strains, designated $Ant21^T$ and Ant22, were isolated from the Antarctic coastal sea water. Strains $Ant21^T$ and Ant22 showed UVC and gamma radiation resistance. Phylogenetic analyses based on 16S rRNA gene sequences determined that these strains belong to the genus Deinococcus. Through the analyses of the 16S rRNA gene sequences, strains $Ant21^T$ and Ant22 were found to have 97.7% and 97.8% similarity to Deinococcus marmoris DSM $12784^T$ and 97.0% and 97.2% similarity to Deinococcus saxicola AA-$1444^T$, respectively. The sequence similarity with the type strains of other Deinococcus species was less than 96.9% for both strains. Strains $Ant21^T$ and Ant22 shared relatively high 16S rRNA gene sequence similarity (99.3%) and had a closely related DNA reassociation value of $84{\pm}0.5%$. Meanwhile, they showed a low level of DNA-DNA hybridization (<30%) with other closely related species of the genus Deinococcus. The two strains also showed typical chemotaxonomic features for the genus Deinococcus, in terms of the major polar lipid (phosphoglycolipid) and the major fatty acids ($C_{16:0}$, $C_{16:1}$ ${\omega}6c/{\omega}7c$, $iso-C_{17:0}$, and $iso-C_{15:0}$). They grew at temperatures between $4^{\circ}C$ and $30^{\circ}C$ and at pH values of 6.0-8.0. Based on the physiological characteristics, the 16S rRNA gene sequence analysis results, and the low DNA-DNA reassociation level with Deionococcus marmoris, strains $Ant21^T$ ($=KEMB\;9004-167^T$ $=JCM\;31436^T$) and Ant22 (KEMB 9004-168 =JCM 31437) represent novel species belonging to the genus Deinococcus, for which the name Deinococcus rubrus is proposed.

• Journal of Mushroom
• /
• v.13 no.4
• /
• pp.305-309
• /
• 2015

In order to isolate compost-promoting bacteria with high activity of cellulase and xylanase, spent mushroom substrates with sawdust were collected from mushroom cultivation farm, Jinju, Gyeongnam in Korea. Among of the isolates, one strain, designated CA105 was selected by agar diffusion method. The strain CA105 was identified as members of the Bacillus subtilis by biochemical characteristics using VITEK 2 system. Comparative 16S rRNA gene sequence analysis showed that isolate CA105 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rRNA gene sequence similarity of 98.9%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, isolate CA105 was classified within the genus Bacillus subtilis, for which the name Bacillus subtilis CA105 is proposed. The cellulase and xylanase activity of B. subtilis CA105 was slightly increased according to bacterial population from exponential phase to stationary phase in growth curve for Bacillus sp. CA105.

• Journal of Life Science
• /
• v.25 no.11
• /
• pp.1319-1323
• /
• 2015

Aquaculture continues to be an ever-growing sector. However, high-density farming increases disease outbreaks due to deteriorating water quality and internal stress. To prevent disease, the most common method chemotherapy is using antibiotic administration. In this study, probiotic bacteria were isolated from Korean traditional foods, such a Gochu pickle and cutlassfish salted seafood. Various bacteria were isolated, and their 16S rDNA sequences were analyzed. The antimicrobial activities of four isolates from Gochu pickle and seven isolates from cutlassfish salted seafood were assayed, in addition to the antibacterial activity of culture pellet and supernatant. The antibacterial activity of the pellet was higher than that of the supernatant. Isolate JKM-2 showed the highest antibacterial activity against Streptococcus iniae (43 mm), S. parauberis (40 mm), S. mutans (35 mm), and Vibrio vuinificus (26.5 mm). The sequences of the isolated strains were compared with those of Bacillus subtilis (97.71%), B. tequilensis (97.71%), Brevibacterium halotolerans (97.71%), B. subtilis (97.63%), B. subtilis (97.63%), B. mojavensis (97.54%), B. vallismortis (97.46%), B. nanillea (97.45%), B. methylotrophicus (97.37%), and B. ssiamensis (97.37%). Future through analysis and new strains confirmed the bacterial cell material investigation of JKM-3, and to ensure sufficient stability, it is desired to verify the utility value as a substitute material for antibiotics by application to the form of the industry.