• KSBB Journal
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• v.30 no.5
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• pp.239-244
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• 2015

Bacterial vaginosis (BV) is caused by microbial imbalance of the vaginal ecosystem and overgrowth of anaerobic bacteria. The antibiotic treatment often results in very high recurrence of BV because it disturbs the vaginal ecosystem. The high recurrence rates suggest a need for alternative therapeutic methods and probiotics are being recognized as alternative or additional treatment method for BV. The purpose of this study was to investigate how human vaginal isolates of Lactobacillus spp. inhibit the BV-associated pathogen Gardnerella vaginalis. Results show that selected strains significantly reduced the viability of G. vaginalis. Among these selected strains KLB410 and KLB416 were further selected based on acid/bile tolerance and identified through 16S rRNA gene sequencing being Lactobacillus plantarum. Further studies are underway to demonstrate that the selected strain can be applied as potential probiotics for recovering vaginal ecosystem.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.63-74
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• 2022

Microbial dysbiosis in the gut is associated with human diseases, and variations in mucus alter gut microbiota. Therefore, we explored the effects of mucin on the gut microbiota using a community of 19 synthetic gut microbial species. Cultivation of these species in modified Gifu anaerobic medium (GAM) supplemented with mucin before synthetic community assembly facilitated substantial growth of the Bacteroides, Akkermansia, and Clostridium genera. The results of 16S rRNA microbial relative abundance profiling revealed more of the beneficial microbes Collinsella, Bifidobacterium, Ruminococcus, and Lactobacillus. This increased acetate levels in the community cultivated with, rather than without (control), mucin. We identified differences in predicted cell function and metabolism between microbes cultivated in GAM with and without mucin. Mucin not only changed the composition of the gut microbial community, but also modulated metabolic functions, indicating that it could help to modulate microbial changes associated with human diseases.

• Journal of Animal Science and Technology
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• v.66 no.5
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• pp.1079-1082
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• 2024

Treponema pedis, a fastidious anaerobic spirochete, is one of the main pathogens involved in the development and progression of bovine digital dermatitis (BDD), a lameness-causing hoof infection in cattle. Here, the complete genome sequencing of T. pedis GNW45 isolated from a dairy cow infected with BDD, was presented. Libraries for long and short reads were sequenced using PacBioRSII and Illimuna HiSeqXTen platforms, respectively. De-novo assembly was done using the long reads, producing a circular contig, by which the short reads were aligned to generate a more accurate genome sequence. The genome has a total size of 3,077,465 base pairs, with 36.84% guanine-cytosine content. A total of 2,749 protein-coding sequences, seven ribosomal RNA's, and 45 transfer RNA's were annotated. Functional analysis revealed genes associated with pathogenicity and survivability in the complex pathobiome of BDD. This study provided novel insights into the survival and pathogenic mechanisms of T. pedis GNW45.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1345-1352
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• 2016

The hindgut of horses is an anaerobic fermentative chamber for a complex and dynamic microbial population, which plays a critical role in health and energy requirements. Research on the gut microbiota of Mongolian horses has not been reported until now as far as we know. Mongolian horse is a major local breed in China. We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions from gut fecal material to characterize the gut microbiota of Mongolian horses and compare them to the microbiota in Thoroughbred horses. Fourteen Mongolian and 19 Thoroughbred horses were used in the study. A total of 593,678 sequence reads were obtained from 33 samples analyzed, which were found to belong to 16 phyla and 75 genera. The bacterial community compositions were similar for the two breeds. Firmicutes (56% in Mongolian horses and 53% in Thoroughbred horses) and Bacteroidetes (33% and 32% respectively) were the most abundant and predominant phyla followed by Spirochaete, Verrucomicrobia, Proteobacteria, and Fibrobacteres. Of these 16 phyla, five (Synergistetes, Planctomycetes, Proteobacteria, TM7, and Chloroflexi) were significantly different (p<0.05) between the two breeds. At the genus level, Treponema was the most abundant genus (43% in Mongolian horses vs 29% in Thoroughbred horses), followed by Ruminococcus, Roseburia, Pseudobutyrivibrio, and Anaeroplasma, which were detected in higher distribution proportion in Mongolian horses than in Thoroughbred horses. In contrast, Oscillibacter, Fibrobacter, Methanocorpusculum, and Succinivibrio levels were lower in Mongolian horses. Among 75 genera, 30 genera were significantly different (p<0.05) between the two breeds. We found that the environment was one of very important factors that influenced horse gut microbiota. These findings provide novel information about the gut microbiota of Mongolian horses and a foundation for future investigations of gut bacterial factors that may influence the development and progression of gastrointestinal disease in horses.

• Journal of Life Science
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• v.28 no.10
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• pp.1244-1253
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• 2018

Rumen microbiome consists of a wide variety of microorganisms, such as bacteria, archaea, protozoa, fungi, and viruses, that are in a symbiotic relationship in a strict anaerobic environment in the rumen. These rumen microbiome, a vital maker, play a significant role in feed fermentation within the rumen and produce different volatile fatty acids (VFAs). VFAs are essential for energy metabolism and protein synthesis of the host animal, even though emission of methane gas after feed fermentation is considered a negative indicator of loss of dietary energy of the host animal. To improve rumen microbial efficiency, a variety of approaches, such as feed formulation, the addition of natural feed additives, dietary feed-microbes, etc., have taken to increase ruminant performance. Recently with the application of high-throughput sequencing or next-generation sequencing technologies, especially for metagenomics and metatranscriptomics of rumen microbiomes, our understanding of rumen microbial diversity and function has significantly increased. The metaproteome and metabolome provide deeper insights into the complicated microbial network of the rumen ecosystem and its response to different ruminant diets to improve efficiency in animal production. This review summarized some recent advances of rumen microbiome techniques, especially "meta-omics," viz. metagenomic, metatranscriptomic, metaproteomic, and metabolomic techniques to increase feed fermentation and utilization in ruminants.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.176-182
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• 2009

Hydrogen producing bacterium, strain MeL 6-2 was isolated from the sludge of the factory areas in Anyang through the acclimation in basal salt medium (BSM) supplemented with 10 g/L of sucrose. Isolated strain MeL 6-2 was a facultative anaerobe which could grow in both aerobic and anaerobic environments. An aerobically grown pure culture isolated from enriched culture was analyzed by 16S rDNA sequencing and identified as Rhodopseudomonas sp. MeL 6-2. Effects of the concentrations of glucose and sucrose on the hydrogen production rate and the hydrogen production yield were investigated. When glucose in the range of 1~12 g/L was supplemented to the BSM, strain MeL 6-2 could grow without lag phase. An increased glucose concentration increased the specific hydrogen production rate linearly to $4.2\;mmol-H_2{\cdot}L^{-1}{\cdot}h^{-1}$ at 10 g/L, and $60\;mmol-H_2{\cdot}mg-DCW^{-1}{\cdot}h^{-1}$, but decreased slightly as the concentration increased to 12 g/L. The hydrogen production yield was maintained over a range from 2.6 to $3.1\;mol-H_2{\cdot}mol-glucose^{-1}$. When sucrose in the range of 1~12 g/L was supplemented to the BSM, strain MeL 6-2 could grow after ten hours. An increased sucrose concentration increased the specific hydrogen production rate and the hydrogen production yield to $163\;mmol-H_2{\cdot}mg-DCW^{-1}{\cdot}h^{-1}$ and to $4.5\;mol-H_2{\cdot}mol-sucrose^{-1}$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1205-1212
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• 2000

The effect of temperature on the sources of organic acids and sludge when phosphorus was biologically released was evaluated in this study. The sludge used in this study was obtained from sequencing batch reactor processing the swine wastewater. Temperature is one of the most important parameters influencing the phosphorus release. As a result, the rate of phosphorus released was increased as the temperatures were increased from 5 to $30^{\circ}C$ regardless of the sources of organic acids used. Under anaerobic conditions, as acetate, propionate, glucose, and domestic wastewater were used as the sources of organic acids, the corresponding activation energy($E_a$) values were 49.83, 55.82, 54.61, and 45.44 KJ/mol, respectively. Temperature coefficient($\theta$) values were 1.0676, 1.0826, 1.0748, and 1.0698, respectively. Therefore, the rate of phosphorus released was increased as temperature was increased, whereas, the effect, of the sources of organic acids and temperature on the activation energy and temperature coefficient values were minimal. When the sludge previously adapted to acetate as external organic source was used, the activation energy and temperature coefficient values were 44.94 KJ/mol and 1.0570 respectively. The effect of temperature was minimal. These values obtained from the sludge previously adapted to acetate were smaller than those from the sludge not previously adapted to the same organic acid. This suggest that the sludge previously adapted to acetate was less dependent on temperature than that not adapted to the acetate.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1485-1491
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• 2015

There are two treatment processes that are currently applied to ships are the biological treatment process using the activated sludge and the electrochemical treatment. However, neither of them are able to remove both nitrogen and phosphorus due to their limited ability to remove organic matters, which are main causes of the red tide. This study was conducted to identify the characteristics of nitrogen removal factors from manure wastewater by replacing the final settling tank in SBR (Sequencing Batch Reactor) process and applying immersion type hollow fiber membrane. SBR process is known to have an advantage of the least land requirement in special environment such as in ship and the immersion type hollow fiber membrane is more stable in water quality change. As the result, the average in the cases of DO (Dissolved Oxygen) is 2.9(0. 6~3.9) mg/L which was determined to be the denitrifying microorganism activity in anaerobic conditions. The average in the cases of ORP (Oxidation Reduction Potential) is 98.4~237.3 mV which was determined to be the termination of nitrification since the inflection point was formed on the ORP curve due to decrease in the stirring treatment after the aeration, same as in the cases of DO. Little or no variation in the pH was determined to have positive effect on the nitrification. T-N (Total Nitrigen) removal efficiencies of the finally treated water were 71.4%, 72.3% and 66.5% in relatively average figures, thus was not a distinct prominence. In being applied in ships in the future, the operating conditions and structure improvements are deemed necessary since the MEPC (Marine Environment Protection Committee). 227(64) ship sewage nitrogen is less than the standard of 20 Qi/Qe mg/L or the removal rate of 70%.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.329-334
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• 2009

Bacterial numbers, such as endospore-formers, and treatment efficiencies were investigated for Rotating Activated Bacillus Contactors (RABC) and other advanced wastewater treatment processes including anaerobic-anoxic-oxic (A2O), sequencing batch reactor (SBR) and biological aerated filter (BAF). Endospore-forming bacterial numbers in the RABC showed 129-fold higher levels than those of the existing advanced systems. RABC process demonstrated the highest bacterial numbers in its bioreactors (paired t-test, p<0.01). RBC biofilms and aeration tanks of the RABC system showed 131- and 476-fold higher than other existing advanced processes, respectively. Mean treatment efficiencies of the existing systems were 83.5% for chemical oxygen demand (COD), 59.1% for total nitrogen (TN) and 76.8% for total phosphorus (TP). However, RABC process removed 96.9% for COD, 96.9% for TN and 91.9% for TP for highly concentrated food wastewater (COD>1,500 mg/L, TN>150 mg/L, TP>50 mg/L). Treatment efficiency was significantly reduced when the numbers of Bacillus genus in the bioreactors decreased below $10^6CFU/mL$. The automated RABC (A-RABC), in which dissolved oxygen concentrations are automatically controlled, showed higher treatment efficiencies compared to the RABC process. The RABC system maintained sufficient bacterial numbers for the effective treatment of highly concentrated food wastewater. Moreover, final effluent was in agreement to water quality standards.