• The Korean Journal of Ecology
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• v.17 no.2
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• pp.171-183
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• 1994

Soil condition, total number of bacteria, soil amylase activity and microbial biomass $(CO_2-C)$ were measured at soil of different forest types. And the difference of the allelopathic effect was determined between fresh leaf extract of Quercus acutissima and Pinus rigida to the bacteria isolated from soil of different forest types. 1. Total number of bacteria in Carpinus laxiflora forest soil was 4~7 times larger than that in pinus desiflora forest soil. 2. Soil amylase activity was positively correlated with total number of soil bacteria and soil organic matter content. The amylase activity at F layer was 4~5 times larger than that at H layer, and that at H layer was 2~4 times larger than that at A layer. 3. Seasonal changes of microbial biomass showed a peak in summer, and vertical distribution of microbial biomass decreased with increasing soil depth. The microbial biomass in Pinus densiflora forest soil was larger than that in Quercus serrata forest soil. 4. Fresh leaf extract of Pinus rigida and Quercus acutissima showed an acceleration or inhibition effect on the growth of soil bacteria, and that of !. acutissima inhibited larger number of soil bacterial strains than that of P. rigida. 4.2% and 25% of soil bacterial strains isolated from soil of P. rigida and Q. acutissima forests were inhibited by fresh leaf extract of P. rigida and Q. acutissima, respectively.

• Journal of Korean Medicine for Obesity Research
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• v.18 no.2
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• pp.64-73
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• 2018

Objectives: This study investigated the effect on microbial ecology, fermentation characteristics and anti-obesity of Platycodon grandiflorum (PG) fermentation with salt. Methods: PG was fermented for four weeks with 2.5% salt and the characteristics of fermented PG were performed by measuring pH, total sugar content, viable bacteria number and microbial profiling. Also, we measured total polyphenol, flavonoid and the percent of inhibition of lipase activity and lipid accumulation. Results: Salt added to PG for fermentation had an effect on pH, total sugar, total and the number of lactic acid bacteria. Total sugar and pH were reduced and number of total and lactic acid bacteria were increased after fermentation. The majority of bacteria for fermentation were Lactobacillus plantarum, Leuconostoc psedomesenteroides and Lactococcus lactis subspecies lactis regardless of salt addition. However, microbial compositions were altered by added salt and additional bacteria including Weissella koreensis, W. viridescens, Lactobacillus sakei and Lactobacillus cuvatus were found in fermented PG with salt. Total flavonoid was increased in fermented PG and lipid accumulation on HepG2 cells treated with fermented PG was reduced regardless of salt addition. Moreover, fermented PG without salt suppressed lipase activity. Conclusions: Addition of salt for PG fermentation had influence on fermentation characteristics including pH and sugar content as well as number of bacteria and microbial composition. In addition, fermented PG showed anti-obesity effect by increasing flavonoid content and inhibition of lipase activity and lipid accumulation.

• Environmental Engineering Research
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• v.19 no.1
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• pp.101-105
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• 2014

Three magnesium compounds, $MgO_2$, MgO, and $Mg(OH)_2$, which are supposed to supply oxygen continuously, were applied onto contaminated bay sediment and its ecology in order to activate the local microbial flora. Those compounds were found to reduce chemical oxygen demand (COD), total nitrogen (T-N), and total phosphorus (T-P). Magnesium oxide, in particular, reduced COD by 30% and T-N and T-P considerably. All compounds also suppressed the release of pollutants in the order $MgO_2$, MgO, and $Mg(OH)_2$. Analysis of microbial flora showed that the microbial group treated by $MgO_2$ and $Mg(OH)_2$ was predictably stable; meanwhile, that treated by MgO increased the number of species, but decreased the total number of microorganisms.

• Korean Journal of Microbiology
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• v.11 no.3
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• pp.129-133
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• 1973

The authors have investigated about the microbial contamination of goods which is a criterion of hygienic control. Conducting on investigation, a special attention has been paid on the rate of microbial contamination in the goods, especially in manufacturing process of the softdrink. The authors also made an experiment on total microbes which is the criterion of contamination in each step of the process and in raw materials together with materials to be used for subdividing. Results obtained were as follows : 1) The orgin of microbial contamination was found in bottle cap and in tap water, that is, there appeared 9 colony per ml in bottle cap and 31-74 colony per ml in tap water, respectively. 2) It was found that microbial contamination are 4 colony per ml in average through year. However, it appeared 1 colony per ml in winter and 8 colony per ml in summer. 3) Coliform groups are not detected in goods through a year. 4) There was no variation in number of total microbes after ion exchange resin passage in purification process of tap water. 5) The number of microbes in goods are decreased when the raw materials are treated in high temperature short time (HTST) sterilization.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.363-368
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• 2007

Traditional kochujang samples were collected from the folk village in Sunchang to find the major microbial composition and correlation between the taste and the microbial properties. Among the 29 samples, 17 samples showed Bacillus licheniformis as dominant strain with 11 samples Bacillus subtilis and 1 sample Staphylococcus pasteuri. Subdominant strain of 17 samples was Bacillus licheniformis with 12 samples Bacillus subtilis. Dominant strain numbers varied in rage of $6.60{\sim}8.38$ logCFU/g with subdominant strain number $5.90{\sim}7.86$ logCFU/g and total microbial number $6.64{\sim}8.56$ logCFU/g respectively. Bacterial type number varied in range of $6{\sim}18$ with the average 10.5 types. Fungi were found only in 2 samples and identified all to be Aspergillus oryzae. Yeasts were found in 25 samples. The dominant yeast strain of 23 samples was identified to be Zygosaccharomyces pseudorouxii and that of 2 samples Zygosaccharomyces rouxii. Yeast type variety showed that only single type was found in 15 samples, 2 types in 8 samples, 3 types in 1 sample and 4 types in 1 sample. Fungal number was 3.90 and 4.08 logCFU/g and yeast numbers varied in range of $3.90{\sim}6.43$ logCFU/g. The sensory scores of kochujang showed positive correlation with type numbers, but no significant correlation with the other microbial properties like total bacterial number, dominant bacterial number, subdominant bacterial number and dominant yeast number.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.455-460
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• 2010

This study was investigated the effect of the ultra filtration (UF) on extending shelf-life and increasing quality of Acer mono sap. To evaluate the quality changes of Acer mono sap before and after UF, crude ash, crude protein, minerals, free sugar, organic acid, pH, total acidity, browning index, turbidity and total microbial number were measured during storage periods at -1, 4 and $10^{\circ}C$. After UF, the ash, minerals, organic acid, total acidity, browning index and turbidity of Acer mono sap were slightly decreased, while the pH was slightly increased, and total microbial number was not detected. After UF, the pH, total acidity, browning index, turbidity and total microbial number of Acer mono sap were very stable during storage periods at -1 and $4^{\circ}C$. During the storage at $10^{\circ}C$, turbidity and total microbial number was slightly increased, while the pH of before UF was decreased and the total acidity, browning, turbidity and total microbial number was increased during storage periods. As the results of this study indicate application of UF on Acer mono sap could extend the shelf-life and quality without loss of natural minerals and useful components.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.93-98
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• 2005

Molecular ecological studies of microbial communities revealed that only tiny fraction of total microorganisms in nature have been identified and characterized, because the majority of them have not been cultivated. A concept, metagenome, represents the total microbial genome in natural ecosystem consisting of genomes from both culturable microorganisms and viable but non-culturable bacteria. The construction and screening of metagenomic libraries in culturable bacteria constitute a valuable resource for obtaining novel microbial genes and products. Several novel enzymes and antibiotics have been identified from the metagenomic approaches in many different microbial communities. Phenotypic analysis of the introduced unknown genes in culturable bacteria could be an important way for functional genomics of unculturable bacteria. However, estimation of the number of clones required to uncover the microbial diversity from various environments has been almost impossible due to the enormous microbial diversity and various microbial population structure. Massive construction of metagenomic libraries and development of high throughput screening technology should be necessary to obtain valuable microbial resources. This paper presents the recent progress in metagenomic studies including our results and potential of metagenomics in plant pathology and agriculture.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.885-892
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• 2006

In order to investigate whether or not Total Coliforms (T.C.) and Fecal Coliforms (F.C.) are compatible as indicator microorganisms of waterbome enteric viruses, a total of 192 surface water samples from 24 locations in Korea were tested for T.C., F.C., and human enteric viruses from July 2003 to January 2006. Altogether, the number of T.C. in each samples was ranged from $0{\sim}5.3{\times}10^4$ colony forming unit(CFU)/100mL, and the number of F.C. ranged from $0{\sim}5.0{\times}10^3CFU/100mL$ per sample. Thirty-three percent of the samples tested positive for human enteric viruses after the total culturable virus assay. The results of the statistical analysis showed that T.C. and F.C. had a significant correlation with turbidity and temperature, but the waterbome enteric viruses did not. When compared to the number of T.C. or F.C. per sample, the concentration of waterbome enteric viruses was not found to be correlated. In conclusion, it is suggested that T.C. and F.C. may not be sufficient microbial indicators of waterbome enteric viruses in the samples analyzed in this study. However, further research is needed to find other microbial indicators of waterbome enteric viruses and to develop more advanced and sensitive methods to detect waterborne enteric viruses.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.453-458
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• 1994

Intestinal microbial flora comprise one third of the large intestinal contents in human. They play a significant effects through beneficial and harmful action on the human health. This is the first study which examined the composition of the microflora of the general population in Korea. Bacteroides, Bifidobacterium, Eubacterium, Peptostreptococcus, Lactobacillus, Streptococcus, Escherichia coli, Staphylococcus, Clostridium perfringens, total aerobic bacteria and total anaerrobic bacteria were counted using various selective and non-selective media. Among the bacteria studied the number of Bifidobacterium were greatest in breast-fed infants(30-90 days old), whereas Streptocuccus and Bifidobacterium in bottle-fed infants. In 20-40 age group Bacteroides were predominant followed by Bifidobacterium and Eubacterium. In early group(over 65 years old) Bacteroides were predominant followed by Eubacterium and bifidobacterium. The frequency and number of Cl. perfringens were highest in dlderly group. These results confirm that the microfloral pattern in large intestine change during the life cycle of humans.

• Korean Journal of Organic Agriculture
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• v.9 no.3
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• pp.103-117
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• 2001

This study was inducted to investigate the effects of microbial fertilizers on the fields of young radish(Raphanus sativus L.), chemical components of plant and soil, and the microbial floras. Six microbial fertilizers, MPK+Husk+Palma, Husk+Palma, MPK+Compost, Compost, BIO Livestock Clean System(BLCS) cattle dropping, and Tomi were used. The yields of young radish were increased in six microbial fertilizer treatments. The fresh matter weight, the number of leaves, and the dry matter weight of young radish in BLCS cattle dropping treatment, the leaf length in MPK+Husk+Palma treatment, the sugar content in Husk+Palma treatment, arid the leaf width in Tomi treatment showed the highest amount, respectively. The effects of microbial fertilizers on chemical characteristics of young radish and soil were examined. Phosphoric acid amount of young radish in Tomi treatment was much higher than other treatments. Potassium amount of young radish showed high significance in all microbial fertilizer treatments compared with control, and shoved the highest in Compost treatment . Two components, phosphoric acid find potassium, in soil inoculated by microbial fertilizers showed significant. Phosphoric acid in the Tomi treatment and Potassium in Husk+Palma treatment were increased. The microorganic populations in soil inoculated with microbial fertilizers were examined. While the number of Bacillus in ceil was increased in MPK+Husk+Palma treatment, the numbers of total bacteria, actinomycetes, and fungi were increased in Tomi treatment.