• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.1
• /
• pp.9-17
• /
• 2008

The presence of thiosulfate oxidizing bacteria was examined in rhizosphere soils of 19 economically important plant species belonging to 10 different families. The results showed that the thiosulfate oxidizing bacteria were present in all the tested rhizosphere soils, and the total 32 thiosulfate oxidizing bacteria were recovered. Furthermore, the biochemical characterization revealed that 56% and 44% of the isolates belonged to the obligate chemolithoautotrophs and facultative heterotrophs, respectively. The isolates ATSR15P utilized 19.17 mM of thiosulfate and accumulated 11.65 mM of sulfate in the medium. Concurrently, the decrease in pH of the medium was observed. This study comprehensively demonstrates that the active sulfur oxidation is a ubiquitous phenomenon in the rhizosphere of crop plants in Korea.

• Journal of the Korean GEO-environmental Society
• /
• v.8 no.4
• /
• pp.41-45
• /
• 2007

It is very important that selection of packing media with large surface area, high limited back pressure in biofilter. The object of this study is the isolation of sulfur-oxidizing bacteria and the removal of hydrogen sulfide in biofilter by media. This investigation led to the following results: 1) we isolated Thiobacillus sp. IW. at an abandoned coal mine in Hwasun, Jeonnam Province. 2) The inorganic media showed better results than the organic media from experiments looking at removal characteristics and changes in pressure drop using various media. 3) Among the inorganic media, fibril and PU media showed best performance.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.907-910
• /
• 2008

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biochemical reaction originated from sulfur-oxidizing bacteria. To prevent biochemical corrosion of the sewage concrete, antibiotics which inhibit growth of sulfur-oxidizing bacteria have to be developed and applied necessarily. In this study, we are going to introduce technology which biochemical corrosion of sewage facilities concrete could be controlled effectively by antibiosis of antimicrobial concrete

• Journal of the Korea Concrete Institute
• /
• v.20 no.4
• /
• pp.495-502
• /
• 2008

To analyze the growth of SOB(Thiobacillus novellus) and biochemical corrosion of concrete, simulation test method and device were developed, and basic conditions for SOB growth were established. Two types of simulation tests were conducted according to a transplant method and a concentration of $H_2SO_4$. As a result, the SOB growth in distinct manners and antibiosis of specimen were observed. In the case of the specimens indirectly transplanted with SOB through culture solution submersion at a hydrogen sulfide level of 120 ppm, the rapid activation of SOB and the resulting sulfuric acid production were observed. However, SOB were shown to grow rapidly and then die out in a relative short period of time. Meanwhile, in the case of the specimens directly transplanted with SOB at a hydrogen sulfide level of 50 ppm, the long-term growth of SOB was possible, but the production of sulfuric acid by SOB did not progress. In the case of the antibiotic metal-mixed specimens, SOB with destroyed cell membranes and internal organizations were observed.

• Journal of the Korea Concrete Institute
• /
• v.18 no.3 s.93
• /
• pp.371-378
• /
• 2006

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete covered with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption, air permeability, carbonation, salt damage and chemical attack of concrete was improved remarkably by covering with it.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.2
• /
• pp.67-75
• /
• 2006

Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete spread with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption and air permeability of concrete was improved remarkably by spraying with it.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.2 no.2
• /
• pp.31-37
• /
• 1994

For a microbiological study of composting process, screening and assay method for biopolymer degrading enzymes and microorganisms were developed and for the study of the possibility of composting in anaerobic state, distribution of sulfate reducing bacteria which plays a final role in anaerobic degradation was investigated. Substrates used for the development of assay methods for biopolymer degradation are ${\beta}-glucan$, xylan, dextran, CMC(carboxy methly cellulose), casein, and collagen. These substrates were made insoluble by a cross-linking agent and linked with dye to make chromogenic substrates. ${\beta}-glucan$ and xylan substrates could substitute congo-red method for screening of polymer degrading microorganisms without damaging the colonies. Sulfate reducing bacteria contained in the sample sludge showed preference to lactic acid, propionic acid, butyric acid and formic acid and could use acetic acid and valeric acid.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.4
• /
• pp.180-187
• /
• 2005

Nine chemolithoautotrophic and 12 chemolithoheterotrophic sulfur oxidizing bacteria were isolated using enrichment technique in modified Starkey's medium. All isolates reduced pH of the growth medium through oxidation of elementai sulfur to sulfuric acid. Isolates utilized the thiosulfate as energy source except LCH. None of the isolates grew anaerobically and utilization of glucose was found only in chemolithoheterotrophic isolates SGA6 and JIG. In vitro sulfate production from elemental sulfur was found maximum for chemoiithoautotroph LCH ($43.2mg\;100\;mL^{-1}$) and least for chemolithoheterotroph JIG ($10.04mg\;100\;mL^{-1}$). The above tests suggested that all isolates belong to the member of Thiobacillus. For field inoculation of Thiobacillus, clay based pellet formulation was developed with the cell load of $2.5{\times}10^7cfu\;g^{-1}$ of pellet. It is easy to handle by the farmers and more likely to lead to successful farming.

• Journal of the Korea Concrete Institute
• /
• v.19 no.1
• /
• pp.113-120
• /
• 2007

In this study, researches for the development of antibiotics and antimicrobial concrete were conducted to reduce biochemical corrosion of sewage concrete. First of all, desired performance, such as watertightness, antibiosis, homogeneity, workability and harmlessness, was proposed and performance of antibiotics and antimicrobial concrete were evaluated by them. As results of this study, dispersibility and antibiosis of liquid antibiotics superior to powdery antibiotics. Antibiosis of antimicrobial concrete was verified, and amount of elution of harmful and effective ingredients was little. In workability, setting time of antimicrobial concrete was delayed. Compressive strength and resistance to carbonation of antimicrobial concrete were more increased than ordinary concrete. Also, as little pore volume and closed structure of antimicrobial concrete were observed, watertightness of it was verified. Finally artificial accelerating test for biochemical corrosion was proposed, and its suitability was experimentally proved.

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.4
• /
• pp.41-47
• /
• 2010

It has been continuously noted that many sewage treatment concrete structures have deteriorated due to sulfur-oxidizing bacteria. There have been many reports on approaches to protecting concrete from this bacteria corrosion. The purpose of this study is to evaluate the inhibition of growth of a sulfur-oxidizing bacterium by a antifungal agent such as $NiSO_4{\cdot}6H_2O$, and the characteristics of polymer cement mortar using nickel type antifungal agent. First, we developed antifungal agents using metal nickel and $NiSO_4{\cdot}6H_2O$ to inhibit the growth of thiobacillus novellus, which is the sulfur-oxidizing bacteria in concrete. Then, ordinary cement mortar and polymer cement mortar using nickel type antifungal agent with various polymer-cement ratios, and antifungal agent content were prepared, and were tested for the antifungal adding effect, compressive and flexural strengths, expansion and leaching of nickel ion. From the test results, it was confirmed that the adding of an antifungal agent has an inhibition effect on the growth of sulfur-oxidizing bacteria at antifungal agent contents of 20 mM or more. In addition, the strengths and expansion of polymer cement mortars are not significantly changed by the addition of an antifungal agent. Therefore, the nickel-type antifungal agent developed in this study can be used to improve the durability of reinforced concrete hume pipe in the construction industry.