• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.595-603
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• 2018

This study was conducted to understand the growth of attached microbial community in small and medium streams of Gyeonggi-do and the removal efficiency of fluoride with changes in growth. The sites monitoring were carried out for 12 weeks at the P1 and P2(P1 is the point where the discharge water flows. P2 is the downstream point of about 2 km flow), and investigated the water quality and the biomass analysis of the attached microbial community. The growth of the attached microbial community increased up to the 7th investigation, and it was observed that detachment phenomenon occurred. Influencing factors about growth of the attached microbial community were flow rate, velocity, and organic material(T-N & T-P). Meanwhile, fluoride content of attached microbial community also tended to increase until the 7th investigation, and decrease from the 8th. It is assumed that fluoride content has also be reduced with the detachment phenomenon of the attached microbial community. It is expected that this will contribute to the evaluation and management of the use of attached microbial community as a means of stream management. The application of techniques using the attached microbial community should include basic investigation of factors that may affect the growth of the attached microbial community and replacement of the attachment plate according to the time of removal.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.312-316
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• 2004

Sterilized raw ground pork was inoculated with Pseudomonas aeruginosa (PA) and Lactobacillus casei (LC) to investigate the relationship between microbial growth and 2-thiobarbituric acid reactive substances (TBARS) values. The analyses including microbial growth, pH, and TBARS values were performed during 3 weeks of storage at room temperature $(20^{\circ}C)$. The radiation-sterilized control sample did not show any microbial growth, but the samples inoculated at different levels (diluted twice vs non-diluted) exhibited differences until 1 week. However, the difference disappeared at weeks 2 and 3. The pH of raw ground pork inoculated with PA increased, but that of LC decreased. The pH of non-inoculated samples increased slightly after storage. The TBARS values in non-inoculated and LC inoculated with pork increased, but TBARS remained unchanged in samples inoculated with PA after 1 week. Results indicated that the microbial growth level and strains can influence the TBARS value of raw ground pork. Thus, it is important to use samples exposed to the same microbial conditions to compare the oxidation of lipids in meat samples.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.1-4
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• 2000

To know the effect of soil treatment with some microbial materials on growth and yield in Korean ginseng, the investigation was undertaken. Significant increases on growth and yield of Korean ginseng plants were achieved by treating soil with microbial materials. Soil treatment with microbial materials resulted in up to 32-68% increment in fresh weight of roots in a 5 month period. The mechanism by which these microbial materials enhance plant growth and root yield may be associated with changes in the composition of rhizosphere microbial flora.

• Preventive Nutrition and Food Science
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• v.13 no.2
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• pp.104-111
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• 2008

As a way to account for the variability of the primary model parameters in the secondary modeling of microbial growth, three different regression approaches were compared in determining the confidence interval of the temperature-dependent primary model parameters and the estimated microbial growth during storage: bootstrapped regression with all the individual primary model parameter values; bootstrapped regression with average values at each temperature; and simple regression with regression lines of 2.5% and 97.5% percentile values. Temperature dependences of converted parameters (log $q_o$, ${\mu}_{max}^{1/2}$, log $N_{max}$) of hypothetical initial physiological state, maximum specific growth rate, and maximum cell density in Baranyi's model were subjected to the regression by quadratic, linear, and linear function, respectively. With an advantage of extracting the primary model parameters instantaneously at any temperature by using mathematical functions, regression lines of 2.5% and 97.5% percentile values were capable of accounting for variation in experimental data of microbial growth under constant and fluctuating temperature conditions.

• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.399-409
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• 2004

This study was conducted to investigate the effect of different concentrations of microbial products on growth of chinese cabbage and microorganisms in soil. Two different levels of microbial products, such as 50 times and 100 times diluted solutions of chitosan, wood vinegar and EM activity liquid, were treated for foliar application. the results were summarized as follows : Among foliar applications of microbial products, 100 times diluted solution of chitosan was effective on growth of chinese cabbage comparing to other levels of dilutions and untreated control plot. The number of microorganism in the soil tended to increase under the treatment of microbial products compared to control plot. Especially, the numbers of the bacteria and actinomycetes were estimated $73.67{\times}10^3$ CFU/g and $34.00{\times}10^3$ CFU/g, respectively, under the treatment of 100 times diluted solution of chitosan.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1705-1710
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• 2015

The aim of the present study was to determine the effects of soil microbial agent with red ginseng marc on growth of watermelon during 5 months. The three treatments were distributed in a completely randomized design with four replicates per plot. After 1 week in planting dates, the growth of watermelon (full length, stem thichness, leaf length and lead width) showed no significant difference in all treatments. During elongation stage (20 days), soil microbial agent with red ginseng marc was increased by 5% in leaf thickness (May 23) and 7~14% in leaf length (May 16 and 23) when compared to other treatments. For changes in fruit bearing thickness, there were no differences among treatments. Characteristics of watermelon in harvest season have an effect on harvest and length, stalk length, naval length, weight, sugar content and yield, except for harvest and width. In particular, yields increased with treatments with two soil microbial agent (7~12%), indicating that soil microbial agent with red ginseng marc showed higher yield than the other treatments. In conclusion, red ginseng marc-treated soil microbial agents have a positive effect on the harvest season of watermelon and can provide useful information for the selection of the functional microbial properties and the registration of microbial fertilizer.

• Plant Resources
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• v.3 no.1
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• pp.59-65
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• 2000

The opening process of cut calla flower was faster at 30 t than at lower temperatures as it could be expected from its tropical origin. Gibberellin enhanced the flower opening, however, it also speeded up senescent. Silver thiosulfate was effective in prolonging the vase life of the cut calla flower. Silver thiosulfate reduced ethylene generation by the flower and inhibited microbial growth in the flower stalk. Reduction in ethylene generation and inhibition of microbial growth is thought to be responsible for the extension of the vase life of cut calla flowers by silver thiosulfate.

• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.139-145
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• 1999

The experiment was conducted to determine the effects of Plant growth and the microbial distribution in soils treated with microbial products, Mity-GroTM. The results from this experiment were as follows ; 1. Plant height of Tomato and Pepper were significantly increased at 30 days after planted in soils treated with Mity-GroTM. Therefore, treatment of microbial products, Mity-GroTM, was considered to contribute the plant growth at early stage. 2. Microbial distribution in soils treated with Mity-GroTM was significantly changed at specific mcirobial population. However, The ratio of bacteria/actinomycetes in the plot treated with Mity-GroTM was significantly enhanced.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.96-103
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• 2007

Plant growth-promoting rhizobacteria (PGPR) have the potential to be used as microbial inoculants to reduce disease incidence and severity and to increase crop yield. Some of the PGPR have been reported to be able to enter plant tissues and establish endophytic populations. Here, we demonstrated an approach to screen bacterial endophytes that have the capacity to promote the growth of pepper seedlings and protect pepper plants against a bacterial pathogen. Initially, out of 150 bacterial isolates collected from healthy stems of peppers cultivated in the Chungcheong and Gyeongsang provinces of Korea, 23 putative endophytic isolates that were considered to be predominating and representative of each pepper sample were selected. By phenotypic characterization and partial 16S rDNA sequence analysis, the isolates were identified as species of Ochrobacterium, Pantoea, Pseudomonas, Sphingomonas, Janthinobacterium, Ralstonia, Arthrobacter, Clavibacter, Sporosarcina, Acidovorax, and Brevundimonas. Among them, two isolates, PS4 and PS27, were selected because they showed consistent colonizing capacity in pepper stems at the levels of $10^6-10^7CFU/g$ tissue, and were found to be most closely related to Pseudomonas rhodesiae and Pantoea ananatis, respectively, by additional analyses of their entire 16S rDNA sequences. Drenching application of the two strains on the pepper seedlings promoted significant growth of peppers, enhancing their root fresh weight by 73.9% and 41.5%, respectively. The two strains also elicited induced systemic resistance of plants against Xanthomonas axonopodis pv. vesicatoria.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.428-437
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• 2007

The potential for humic substances to serve as terminal electron acceptors in microbial respiration and the effects of humic substances on microbial azoreduction were investigated. The dissimilatory azoreducing microorganism Shewanella decolorationis S12 was able to conserve energy to support growth from electron transport to humics coupled to the oxidation of various organic substances or $H_2$. Batch experiments suggested that when the concentration of anthraquinone-2-sulfonate (AQS), a humics analog, was lower than 3 mmol/l, azoreduction of strain S12 was accelerated under anaerobic condition. However, there was obvious inhibition to azoreduction when the concentration of the AQS was higher than 5 mmol/l. Another humics analog, anthraquinone-2-sulfonate (AQDS), could still prominently accelerate azoreduction, even when the concentration was up to 12 mmol/l, but the rate of acceleration gradually decreased with the increasing concentration of the AQDS. Toxic experiments revealed that AQS can inhibit growth of strain S12 if the concentration past a critical one, but AQDS had no effect on the metabolism and growth of strain S12 although the concentration was up to 20 mmol/l. These results demonstrated that a low concentration of humic substances not only could serve as the terminal electron acceptors for conserving energy for growth, but also act as redox mediator shuttling electrons for the anaerobic azoreduction by S. decolorationis S12. However, a high concentration of humic substances could inhibit the bacterial azoreduction, resulting on the one hand from the toxic effect on cell metabolism and growth, and on the other hand from competion with azo dyes for electrons as electron acceptor.