• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.32-40
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• 2014

Methane oxidation and the production potentials of ground soil (soil A) and garden soil (soil B, C, & D) in an urban school were evaluated, and the methanotrophic and methanogen communities in the soil samples were quantified using quantitative realtime PCR. The methanotrophic community in the raw soil A sample possessed a $6.1{\times}10^3$ gene copy number/g dry weight soil, whereas those in the raw soils B~D samples were $1.6-1.9{\times}10^5$ gene copy numbers/g dry weight soil. Serum bottles added with the soil samples were enriched with methane gas, and then evaluated for their methane oxidation potential. The soil A sample had a longer induction phase for methane oxidation than the other soils. However, soil A showed a similar methane oxidation potential with soils B~D after the induction phase. The methanotrophic community in the enriched soil A sample was increased by up to $2.3{\times}10^7$ gene copy numbers/g dry weight soil, which had no significantly difference compared with those in soils B~D ($1.2-2.8{\times}10^8$ gene copy numbers/g dry weight soil). Methane production showed a similar tendency to methane oxidation. The methanogens community in raw soil A ($1.7{\times}10^5$ gene copy number/g dry weight soil) was much less than those in raw soils B~D ($1.3-3.4{\times}10^7$ gene copy numbers/g dry weight soil). However, after methane gas was produced by adding starch to the soils, soil samples A~D showed $10^7$ gene copy numbers/g dry weight soil in methanogens communities. The results indicate that methanotrophic and methanogenic bacteria have coexisted in this urban school's soils. Moreover, under appropriate conditions for methane oxidation and production, methanotrophic bacteria and methanogens are increased and they have the potential for methane oxidation and production.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.353-359
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• 2013

The objectives of this study were to investigate effectiveness of the Compressed Air Jet (CAJ) System for cleaning up shorelines contaminated with crude oils and to examine effects of the system on total petroleum hydrocarbon (TPH) removal and microbial community changes before and after remediation of the oil-contaminated shorelines. These data will lead to better understanding of optimized remediation process. About 66% of TPH reduction was observed when the contaminated site was treated with the CAJ System 2, 3, 4, and 5 times. This treatment system was more efficient than the seawater pumping system under similar treatment conditions (by 40%). By the way, little oil degrader communities were observed despite a potential function of the air jet system to stimulate aerobic oil degraders. The apparent low population density of the oil degraders might be as a result of low concentration of TPH as a carbon source and limiting nutrients such as nitrogen and phosphorus. It was proposed that the CAJ System would contribute significantly to removal of residual oils on the shorelines in combination with addition of these limiting nutrients.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.321-325
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• 2011

The mutant strain M6 derived from Acetobacter sp. A9, which produces high levels of the bacterial cellulose derived by random mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine or UV treatment, was selected by a Hestrin and Schramm medium (HSB) plate assay. The characterization of the cellulose production was studied in flask culture to improve the productivity of bacterial cellulose by $Acetobacter$ sp. A9 and mutant strain M6. The yield of cellulose production was superior to mutant M6 than $Acetobacter$ sp. A9. Cellulose was produced 0.12 g $L^{-1}$ by $Acetobacter$ sp. A9 at HS medium and the mutant M6 produced the cellulose 6.95 g $L^{-1}$at HS medium. Strain M6 produced less amount of gluconic acid than A9, thus showing that cellulose production is negatively relted with the gluconic acid production.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.208-215
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• 2005

This study was accomplished in order to collect fundamental data on microbial roles in recycling process of reed rhizosphere. Sunchon bay, which is considered as one of the marsh and mud environments severely affected by human activities such agriculture and fisheries, was selected as a model place. In our initial efforts, two bacterial consortia were obtained by enrichment culture using PAH mixtures containing anthracene, naphthalene, phenanthrene and pyrene as the sources of carbon and energy, and four pure bacteria capable of rapid degradation of PAH were isolated from them. Four strains designated as SCB1, SCB2, SCB6, and SCB7 revealed by morphological, physiological and molecular analyses were identified as Burkholderia anthina, Alcaligenes sp., Achromobacter xylosoxidans., and Pseudomonas putida, respectively with over $99{\%}$ confidence. Notably, Burkholderia anthina SCB1 and Alcaligenes sp. SCB2 were found to utilize anthracene and pyrene more quickly than naphthalene and phenanthrene, whereas Achromobacter xylosoxidans SCB6 and Pseudomonas putida SCB7 exhibited similar growth and degradation patterns except for pyrene. These facts suggest that the rhizosphere microorganisms capable of PAH degradation might be used to clean up the contamination sites with polycyclic aromatic hydrocarbons.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.38-45
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• 2013

In this study, euryhaline marine microorganism, Bacillus sp. strain EBW4 isolated from polychaete (Perinereis aibuhitensis) of Suncheon Bay was physiologically, biochemically and genetically characterized. Based on 16S rRNA sequence, EBW14 was found to share 98.25% similarity with Bacillus hemicentroti $JSM076093^T$, 97.96% similarity with Bacillus hwajinponensis SW-$72^T$ and 96.28% similarity with B. algicoa $KMM3737^T$, respectively. The temperature range for the growth of strain EBW4 was $4-40^{\circ}C$, NaCl concentration range 0-17% and pH range pH 5-9, revealing that EBW4 was euryhaline bacterium. Major fatty acids in strain EBW4 were composed of anteiso $C_{15:0}$ (48.2%), iso $C_{16:0}$ (12.1%), anteiso $C_{17:0}$ (11.6%) and iso $C_{14:0}$ (9.4%). EBW4 was found to have DNase, amylase, protease and lipase for the degradation of macromolecules such as DNA, carbohydrates, proteins, lipids, etc. The enzyme activities of alkaline phosphatase, esterase (C4), leucine arylamidase and ${\alpha}$-chymotrypsin were also found in strain EBW4. Analysis of the biodegradation ability of EBW4 for organic hydrocarbons under different salinity conditions using synthetic water waste revealed that EBW4 exhibited the ability to degrade organic hydrocarbons very quickly, suggesting strain EBW4 may be a good candidate for the application to various industries.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.27-35
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• 2003

No currently available methods to monitor pathogenic protozoa, Cryptosporidium and Giardia in environmental water come close to acceptable sensitivity, specificity and reproducibility, and so it has to be accompanied by thorough quality control and performance evaluation to credibly predict the distribution of them. We collected surface water samples from the Han River and spiked our prepared (oo)cysts, determined Matrix Spike recoveries using USEPA Method 1623 and considered what factors influence MS recovery and validity. As a result, average 46% of spiked oocysts and 60% of spike cysts were recovered, but repetitive sampling and statistical approach seemed to be necessary to determine the environmental pollution level of two protozoa as their variation coefficients was so much as 35oio and 26%. And MS recoveries with two acid dissociations during immunomagnetic separation were improved more 10% than that with one dissociations and the use of spiked suspension enumerated by flow cytometry instead of manual preparation enhanced the validity and reliability in spiking tests. Because fluorescence characteristics of (oo)cysts stained on well slides with FITC-labeled monoclonal antibodies and DAPI was not always same, well Elides from spiked field samples were helpful to evaluate the performance of staining. We found many (oo)cyst-like objects with typical fluorescence, not (co)cysts, from the Han River water samples, and then it was concluded that nuclei staining by DAPI (4',6-diamidino-2-phenylindole) and examination by Differential Interference Contrast Microscope should be critical for valid identification.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.248-252
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• 1999

The PI-oduction of virulence factors such as cholera toxin, heinolysin and hemagglutinin in V cliolerae non-01 and non-0139 were examined. Among 65 strains isolated from environmental and clinical blood sources, 29 (14.6%) strains produced hemolysin only, 35(53.9%) sh.ains produced both hemolysin and hemagglutinin. From one 037 slrain isolated from environmenl, cholera toxin, ctx gene, hemolysin, and hemagglutinin were detected. All of the strains isolated from clinical and environmental sources showed hemolytic activity against human 0 group e~ythrocytes. In inhibition patterns of heinagglotination, 5 of 18 clinical strains (27.8%) were inhibited by less than 1% mannose and galactose, while, among the 47 environmental isolates. hose paltems by less than 1% mannose and galactose 55.4% wel-e inhibited. Thel-ehre, exohamagglutinin positive rate was high in clinical blood isolates but in environnlental sources, the rate was almost similar lo ihe rate or endohemagglutinin positive. These results indicaled that V cholerae non-01 and non-0139 produced various virnlence factors such as cholera toxin, hemolysin, and hemagglutinin but not a single factor. Further studies are need for epidemiological or bacteriological shtdies of V cholerae 037 isolated from environment.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.112-118
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• 2009

Ammonia-oxidizing bacteria (AOB) are chemolithoautotrophs that play a key role in nitrogen removal from advanced wastewater treatment processes. Various AOB species inhabit and their community compositions vary over time in the wastewater treatment bioreactors. In this study, a hypothesis that operational and environmental conditions affect both the community compositions and the diversity of AOB in the bioreactors was proposed. To verify the hypothesis, the clone libraries based on ammonia monooxygenase subunit A were constructed using activated sludge samples from aerobic bioreactors at the Pohang, the Palo Alto, the Nine Springs, and the Marshall wastewater treatment plants (WWTPs). In those bioreactors, AOB within the Nitrosomonas europaea, N. oligotropha, N.-like, and Nitrosospira lineages were commonly found, while AOB within the N. communis, N. marina, and N. cryotolerans lineages were rarely detected in the samples. The AOB community structures were different in the bioreactors: AOB within the N. oligotropha lineage were the major microorganisms in the Pohang, the Palo Alto, and the Marshall WWTPs, while AOB within the N. europaea lineage were dominant in the Nine Springs WWTP. The correlations between the AOB community compositions of the wastewater treatment bioreactors and their operational (HRT, SRT, and MLSS) and environmental conditions (temperature, pH, COD, $NH_3$, and $NO_3{^-}$) were evaluated using a multivariate statistical analysis called the Redundancy Analysis (RDA). As a result, COD and $NO_3{^-}$ concentrations in the bioreactors were the statistically significant variables influencing the AOB community structures in the wastewater treatment bioreactors.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.32-40
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• 2009

To understand contribution of thermophilic microorganisms in decomposition of litter deposits on shore of lakes, we surveyed a lakeshore litter deposit for bacteria growing at $60^{\circ}C$. Ten thermophilic isolates were selected for in-depth characterization, based on their high capacity to degrade high molecular weight organic compounds. Based on phylogenetic analysis on their 16S rRNA gene sequences, all isolates were identified as Geobacillus. The optimal growth temperature and pH of the strains ranged $55{\sim}60^{\circ}C$ and 6.0${\sim}$8.0, respectively. Salinity was inhibitory to the growth of the isolates, showing marked decrease of growth rates at 3% salinity. Based on activities of hydrolytic enzymes and profiles of carbohydrate utilization (determined by API 50 CHB kit), three G. stearothermophilus strains showed patterns clearly distinctive from other isolates. Two G. kaustophilus strains also demonstrated distinctiveness in their metabolic pattern and ecological parameters. However, ecological and metabolic profiles of the other five isolates were more variable and showed some degree of digression from their phylogenetic classification. Therefore, it could be concluded that endospore-forming thermophilic bacteria in lakeshore litter deposits contribute to degradation of organic materials with diverse ecological niches while having successions similar to microbial flora in compost. We propose that the thermophilic isolates and/or their thermo-tolerant enzymes can be applied to industrial processes as appropriate mixtures.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.49-55
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• 2008

White Spot Syndrome Virus (WSSV) is one of the most virulent viral agents in the penaeid shrimp culture industry. In this study, WSSV in a Fenneropenaeus chinensis shrimp farm and an adjacent seawater were concentrated using a membrane filtration and quantified using the quantitative real-time PCR (QRT-PCR) method with newly designed primers and Taqman probe. Sensitivity of primers and probe was proven by WSSV standard curve assay in QRT-PCR. In order to demonstrate the relationship between WSSV and environmental parameters, physicochemical and biological parameters of the farm and influent seawaters were monitored from June to September, 2007. The abundance of WSSV ranged 3,814-121,546 copies per 1 liter of seawater, which was correlated with fecal enterococci ($r^2=0.9$, p=0.02), chlorophyll ${\alpha}$ ($r^2=0.8$, p=0.03) and $BOD_5$ ($r^2=0.8$, p=0.07). Subsequently, it is concluded that the QRT-PCR method using Taqman probe established in this study was efficient to clarify the quantification of WSSV in seawaters. Statistical analyses of environmental parameters obtained in this study also showed that the abundance of WSSV was correlated with several biological parameters rather than physicochemical parameters.