• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.264-270
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• 2003

A quantitative survey of the protozoa microfauna at bioreactor of advanced sewage treatment plant was carried out during a period of 11 months. In this study, 32 genera were identified, including 17 ciliates. The abundance of the important protozoa were compared with the operating parameters and water quality of the effluent of the plant using statistical procedure. Statistical analysis revealed a relationship between the abundance of some genera and removal rate. In particular, correlation analysis on the quality of effluent and protozoa indicated that Lepadella may be used as the bioindicator of TP removal and Trochilia, Entosiphon, Colepus may be used as the bioindicator of TN removal when water temperature was below $20^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.819-823
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• 2011

The present study evaluated the seasonal changes of the soil microbial population by selected media in an organic farming system (OFS) with rye rotation cropping management compared to those in a conventional farming system (CFS) with chemical fertilizers, pesticide and herbicide from May 2009 to October 2010 in an upland field. With the exception of fungi, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. were higher in the OFS soil during soybean-growing stages. In addition, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. in the OFS soil were nearly two times more than those in the CFS soil on reproductive growth stages. Our findings suggested that Bacillus spp. should be considered as responsible factor for microbial population differentiation observed between the OFS and the CFS in upland fields.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.814-818
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• 2011

The seasonal changes were evaluated in the soil microbial populations by selected media in an organic farming system (OFS) with no-till management compared to those in a conventional farming system (CFS) with tillage and synthetic amendments in a flooded paddy from 2009 to 2010. The populations of aerobic bacteria and fungi in the OFS were significantly higher than those in the CFS at the harvesting stages, whereas those of Gram-negative bacteria was significantly higher in the OFS than in the CFS before the submerging stages. In addition, populations of aerobic bacteria, Gram-negative bacteria, and fungi tended to rapidly decreased after the submerging stages may be due to insufficient oxygen. Gram-negative bacteria should be considered as potential factor responsible for the microbial population differentiation observed between the OFS and the CFS in flooded paddy fields.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.267-273
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• 1997

Various physico-chemical and microbiological parameters of a composting system were compared with respect to their potential use for the monitoring and evaluation of composting processes for cattle manure. The temperature changed within a range of $30-65^{\circ}C$ during the whole composting process, and the period of active composting (>$40^{\circ}C$) persisted for 16 days. The concentrations of total carbon, total nitrogen, and organic matter decreased by 15% during active composting, but significant changes in C/N ratio were not observed. The decrease of temperature in the latter period of active composting caused a decrease of $NH_4^+-N$ and an increase of $NO_3^--N$ in the composting pile. When temperature exceeded $50^{\circ}C$, the population of thermophiles was higher than that of mesophiles by more than 1 or 2 orders of magnitude. Correlation analyses showed that amylase activity correlated positively with the population of mesophiles and reducing sugar content, but negatively with the population of thermophiles. Amylase activity was higher at the beginning of active composting, whereas cellulase, xylanase and ligninase activities which showed close relationship with each other, increased continually during active cornposting, suggesting the distinction of temporal niches between amylose-degrading and lignocellulose-degrading bacteria in the same habitat.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.43-48
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• 2008

Standard sample for quality control of total coliform measurement was procured by addition of nalidixic acid and cephalexin as bacteriostatic agents to Escherichia coli cultured broth. After making the standard sample, the number of E. coli was measured by fluorescence microscopic count method and plate count method by 12 hr interval. The numbers of E. coli remained unchanged for at least for 48 hr at room temperature which ranged from 3.5 to $4.2{\times}10^5\;cells/ml$ and from 1.0 to $1.2{\times}10^4\;CFU/ml$ by direct fluorescence microscopic count method and plate count method, respectively. This result suggests that microbial standard sample with bacteriostatic agents of nalidixic acid and cephalexin is usable for quantitative quality control.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.391-397
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• 1989

Population of Aeromonas and environmental parameters were investigated at three sites from August 1986, to December, 1986 in Naktong Estuary. The variation range of Aeromonas was $4.3\times10^{2}-4.6\times 10^{4}$ MPN/100ml. The result of ANOVA indicates significant differences among the populations of Aeromonas in each site. The highest population of Aeromonas occurred at site 2, and the lowest at site 3-B. To scrutinize the effects of environmental parameters on the distribution of Aeromonas spp, principal component analysis and multiple stepwise regression were used. The results showed that distribution of Aeromonas spp. was mainly influenced by outflow of freshwater and inflow of inorganic nutrients and correlated with heterotrophic bacteria, available nitrogen, fecal coliform bacteria, and temperature.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.317-324
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• 2001

We have previously developed three stage methane fermentation system capable of digesting food wastes effectively and then releasing high organic wastewater as a final product. In this study, we tried to devise an ecological water treatment system, which can efficiently remove the nitrogen and phosphorus contained in the organic wastewater. The system was made of microbiological filters, algae, and waterfleas. Of two species of alga tested, Selenastrum capricornutum showed higher growth rate and more efficiently removed the nitrogen from the wastewater than by Chlorella sp. In addition, the highest growth rate and the nitrogen removal efficiency could be obtained when high concentrations of $Mg^{2+}\; and\; Ca^{2+}$ were added to the diluted wastewater and the molar ratio of nitrogen to phosphorus was adjusted to 10 : 1. In this study the population relationship between alga and water flea was also examined in a test tube. The initial number of algal cells decreased as the waterflea population increased. However, the number of algal cells gradually increased again when waterflea population decreased partly due to the environmental resistance. From these results, it was believed that the ecological water treatment system could be used for removing the nitrogen and phosphorus from organic wastewater very effectively. Moreover, the waterflea cultured by this system as a final predator could be used as a good foodstuff for fishes.

• Journal of Navigation and Port Research
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• v.35 no.10
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• pp.817-822
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• 2011

Lab scale experiment study was carried out for biological treatment process development in cruise. SBR(Sequence Batch Reactor) process with BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. From the results it was suggested that SBR process with BM might be a suitable process for cruise sewage treatment in terms of decrease in odorous compounds, maintenance of useful microorganisms and creating special environmental conditions. By adding BM to SBR system, odor unit of sulfur compounds was about 20 times reduced.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.163-171
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• 1994

The effects of diesel oil on the microbial community in sandy loam soil were investigated, and the effects of bioremediation which was performed to enhance the removal of diesel oil from soil were also measured. The residual percentage of diesel oil was about 50% after 16 week incubation period. The bioremediation treatment increased the removal rate at 60~95%. When the soil was contaminated with diesel oil, the direct bacterial count, length of fungal hyphae, aerobic heterotroph and hydrocarbon degrader were increased by 2~3 orders of magnitude. The bioremediation further increased these numbers 10 to 100-fold. There were no difinite patterns of change in fluorescein diacetate hydrolysis activity in bioremediation-untreated soil, but about 10 times of increase of activity was observed in bioremediation-treated soil. Similar change was occurred in soil dehydrogenase activity.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.236-241
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• 2011

Soil microbial diversity was responsible for a strong effect on the chemical properties of orchard soils. This study evaluated a relationship between soil chemical properties and soil microbial diversities at 25 sites in orchard soils in Gyeongnam Province. The average nutrients in the orchard soils were 2.6 times for available phosphorous, 2.3 times for exchangeable potassium and 1.3 times for exchangeable calcium higher compared to recommend concentrations in the orchard soils. Contents of available phosphorous and organic matter in the inclined piedmont soils were higher than those in the other topographical soils (p<0.05). Populations of fungi and fluorescence Pseudomonas sp. in the silt loam soils were significantly higher than those in the sandy loam soils (p<0.05). In principal component analysis of chemical properties and microbial populations in the upland soils, our findings suggested that population of bacteria should be considered as potential factor responsible for the clear orchard soils differentiation. The soil organic matter was significantly negative correlation with population of bacteria whereas was positive correlation with population of fungi in orchard soils.