• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.655-668
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• 2021

The present study was conducted to investigate the effects of the supplementation of Achyranthes japonica extract (AJE) on overall performance levels with different nutrition concentrations in the diets of finishing pigs. Here, 140 finishing pigs with initial body weights of 50.18 ± 2.37 kg were used in a ten-week trial involving a 2 × 2 factorial design in two phases with the following factors: diet types with different nutrition concentrations (Positive control [PC] vs. Negative control [NC]) and 0 or 0.05% AJE supplementation to NC and PC diets. The PC diet was a basal diet, whereas the NC diet consisted of a 5% and 7% crude protein (CP) reduced basal diet during phase 1 (1 - 35 days) and phase 2 (36 - 70 days), respectively. A significant effect (p < 0.05) on the gain-to-feed ratio (G : F) was observed with interaction effects between the diets and AJE supplementation. However, during phase 1 and in all periods, the pigs fed the PC and NC diets with average daily feed intake (ADFI) tended to decrease compared to those fed diets with AJE. A significant effect (p = 0.0380) of E. coli was observed in pigs fed the PC and NC diets compared to AJE supplementation in phase 2 of the experiment. The backfat thickness (BFT) tended to decrease and the lean meat percentage (LMP) was significantly improved in phase 2 for pigs fed the PC and NC diets. In summary, BFT and LMP showed beneficial effects and fecal microbiota of E. coli counts were positively affected when pigs were fed diets with different nutrient concentrations.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.141-148
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• 2017

The oxidation ditch (OD) is one of the most widely used processes for treating municipal wastewater. However, the microbial communities in the OD systems have not been well characterized, and little information about the shift of bacterial community during the startup process of the OD systems is available. In this study, we investigated the bacterial community changes during the startup period (over 100 days) of a full-scale OD. The results showed that the bacterial community dramatically changed during the startup period. Similar to the activated sludge samples in other studies, Proteobacteria (accounting for 26.3%-48.4%) was the most dominant bacterial phylum in the OD system, but its relative abundance declined nearly 40% during the startup process. It was also found that Planctomycetes proliferated greatly (from 4.79% to 13.5%) and finally replaced Bacteroidetes as the second abundant phylum in the OD system. Specifically, some bacteria affiliated with genus Flavobacterium exhibited remarkable decreasing trends, whereas bacterial species belonging to the OD1 candidate division and Saprospiraceae family were found to increase during the startup process. Despite of the bacterial community shift, the organic matter, nitrogen, and phosphorus in the effluent were always in low concentrations, suggesting the functional redundancy of the bacterial community. Moreover, by comparing with the bacterial community in other municipal wastewater treatment bioreactors, some potentially novel bacterial species were found to be present in the OD system. Collectively, this study improved our understandings of the bacterial community structure and microbial ecology during the startup of a full-scale wastewater treatment bioreactor.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.384-397
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• 2018

The aim of this study is to screen the strains of Bacillus spp. possessing safety, probiotic activity, and so on, which can be utilized as probiotic resource for using the feed and supplement food of companion animal. About 300 isolates were isolated from traditional Korean sauces, four isolates that did not have or produce the six kinds of B. cereus type vomiting and diarrhea toxin genes, ${\beta}$-hemolytic, and three kinds of carcinogenic enzymes were selected. Antibiotic gene retention, cell surface hydrophobicity, antibiotic sensitivity, and glucose utilization were analyzed for four isolates, and finally SRCM 100731 was selected. SRCM 100731 was named as Bacillus amyloliquefaciens SRCM 100731 16S rRNA sequencing analysis, and carried out optimization of cell growth for industrial applications such as pet food and feed. The effects of 14 different components on cell growth were investigated and three significant positive factors, molasses, sodium chloride, and potassium chloride were selected as the main factors based on a Plackett-Burman design. In order to find out optimal concentration on each constituent, we carried out central composite design. The predicted optimized concentrations were 7% molasses, 1.1% sodium chloride, 0.5% potassium chloride. Finally, an overall about 7-fold increase in dry cell weight yield ($12.6625{\pm}0.0658g/L$) was achieved using the optimized medium compared with the non-optimized medium ($1.8273{\pm}0.0214g/L$). This research is expected to be highly utilized in the growing pet industry by establishing optimal cultivation conditions for industrial application as well as screening Bacillus amyloliquefaciens SRCM 100731 as probiotic resource for companion animal.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.05a
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• pp.10-16
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• 2003

Natural resource plants have been useful and helpful materials for human to against diseases and Prevention since ancient Egyptian and Roman times. However, according to recent survey, its habitat and indigenous are continuously decreased and almost extinct some valuable species, as Adonis vernalis, Digitalis lanata etc., especially in Eastern Europe and east Asian countries due to radical political and social reforms. ESCOP and FAO have already initiated to protect the endangered species for conservation, protection and propagation technology but it is not easy tasks without global concerning. Most natural resource plants have volatile components in essential oils and its consumption and demanding is increased every year, which contained certain compounds have no side effects and good properties for biological activities. Essential oils of natural resource plants are also well known for medical purposes, such as Central Nervous System (CNS, linalool), anticancer (d-limonene, perillyl alcohol, etc.), microbial and fungicidal activities (menthol, borneol, etc). Essential oil also used for natural therapy to prevent and increase immune systems instead of chemical synthesis drugs. With this, researchers of natural resource plants are ultimately faced to develop and optimal technology for increasing the Korean farmer's income by high added-value herbal products in present and future.

• Journal of Environmental Science International
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• v.30 no.8
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• pp.703-708
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• 2021

To improve the environmental management and resources, in this study, we aimed to investigate the effect of adding oyster shell powder to Hanwoo manure on its characteristics and microbial composition during the storage period. Additives were deposited on top of the manure surface at the rate of 0, 0.5, and 1% of oyster shell powder per 200 g of Hanwoo manure in a plastic container with three replicates; however, untreated manure litter served as the control. Manure characteristics (dry matter, organic matter and crude ash) and microbial composition (lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli) were evaluated at day 0, 2, 4, and 8. Manure characteristics exhibited an effect on dry matter, organic matter, and crude ash at day 2 and 8 (p<0.05), and not for day 0 and 4 (p>0.05). With the exception of yeast content at day 4 of storage, lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli exhibited no significant differences in all conditions during the storage period. Conclusively, addition of 1% oyster shell powder to Hanwoo manure resulted in slightly better manure characteristics; however, its microbial composition remained unchanged.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.231-237
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• 2019

Peroxymonosulfate (PMS) in combination with Cu(II) was examined to inactivate E. coli and MS2 coliphage in natural water. The combined system (i.e., the Cu(II)/PMS system) caused a synergistic inactivation of E. coli and MS2, in contrast with either Cu(II) or PMS alone. Increasing the concentration of PMS enhanced the inactivation of E. coli and MS2, but after a certain point, it decreased the efficacy of the microbial inactivation. In the Cu(II)/PMS system, adding reactive oxidant scavengers marginally affected the E. coli inactivation, but the inhibitory effects of copper-chelating agents were significant. Fluorescent assays indicated that the Cu(II)/PMS system greatly increased the level of reactive oxidants inside the E. coli cells. The sequential addition of Cu(II) and PMS inactivated more E. coli than did adding the two simultaneously; in particular, the inactivation efficacy was much higher when Cu(II) was added first. The observations from the study collectively showed that the microbial inactivation by the Cu(II)/PMS system could be attributed to the toxicity of Cu(I) as well as the intracellular oxidative stress induced by Cu(III) or radical species.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.839-846
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• 2016

Since oil leakage is one of the most common nonpoint pollution sources that contaminate soil in Korea, the capacity of soil microbial community for degrading petroleum hydrocarbons should be considered to assess the functional value of soil resource. However, conventional methods (e.g., microcosm experiments) to assess the remediation capacity of soil microbial community are costly and time-consuming to cover large area. The present study suggests a new approach to assess the toluene remediation capacity of soil microbial community using a microbial diversity index, which is a simpler detection method than measuring degradation rate. The results showed that Shannon index of microbial community were correlated with specific degradation rate ($V_{max}$), a degradation factor. Subsequently, a correlation equation was generated and applied to Michaelis-Menten kinetics. These results will be useful to conveniently assess the remediation capacity of soil microbial community and can be widely applied to diverse engineering fields including environment-friendly construction engineering fields.

• Journal of Ginseng Research
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• v.35 no.1
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• pp.1-11
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• 2011

Korean ginseng is a medicinally important perennial herb from the family Araliaceae. It has been cultivated for its highly valued medicinal properties for over 1,000 years in east Asian countries such as China, Korea, and Japan. Due to its longtime cultivation in shady areas, ginseng is frequently exposed to pathogenic infections. Plants protect themselves from microbial pathogens using an array of defense mechanisms, some of which are constitutively active, while others are activated upon pathogen invasion. These induced defense responses, controlled by defense-related genes, require tradeoffs in terms of plant fitness. We hypothesize that ginseng, as with other plants, possesses regulatory mechanisms that coordinate the activation of attacker-specific defenses in order to minimize fitness costs while attaining optimal resistance. Several classes of defense-related genes are induced by infection, wounds, irradiation, and other abiotic stresses. Both salicylates and jasmonates have been shown to cause such responses, although their specific roles and interactions in signaling and development are not fully understood in ginseng. This review summarizes possible defense-related genes in ginseng based on their expression patterns against biotic and abiotic stresses and describes their functional roles.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.521-532
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• 2021

Knowledge and better understanding of functions of the microbial community are pivotal for crop management. This study was conducted to study bacterial structures including Acidovorax species community structures and diversity from the watermelon cultivated soils in different regions of South Korea. In this study, soil samples were collected from watermelon cultivation areas from various places of South Korea and microbiome analysis was performed to analyze bacterial communities including Acidovorax species community. Next generation sequencing (NGS) was performed by extracting genomic DNA from 92 soil samples from 8 different provinces using a fast genomic DNA extraction kit. NGS data analysis results revealed that, total, 39,367 operational taxonomic unit (OTU), were obtained. NGS data results revealed that, most dominant phylum in all the soil samples was Proteobacteria (37.3%). In addition, most abundant genus was Acidobacterium (1.8%) in all the samples. In order to analyze species diversity among the collected soil samples, OTUs, community diversity, and Shannon index were measured. Shannon (9.297) and inverse Simpson (0.996) were found to have the highest diversity scores in the greenhouse soil sample of Gyeonggi-do province (GG4). Results from NGS sequencing suggest that, most of the soil samples consists of similar trend of bacterial community and diversity. Environmental factors play a key role in shaping the bacterial community and diversity. In order to address this statement, further correlation analysis between soil physical and chemical parameters with dominant bacterial community will be carried out to observe their interactions.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1808-1819
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• 2017

Knowledge on the functional characteristics and temporal variation of anaerobic bacterial populations is important for better understanding of the microbial process of two-stage anaerobic reactors. However, owing to the high diversity of anaerobic bacteria, close attention should be prioritized to the frequently abundant bacteria that were defined as core bacteria and putatively functionally important. In this study, using MiSeq sequencing technology, the core bacterial community of 98 operational taxonomic units (OTUs) was determined in a two-stage upflow blanket filter reactor treating pharmaceutical wastewater. The core bacterial community accounted for 61.66% of the total sequences and accurately predicted the sample location in the principal coordinates analysis scatter plot as the total bacterial OTUs did. The core bacterial community in the first-stage (FS) and second-stage (SS) reactors were generally distinct, in that the FS core bacterial community was indicated to be more related to a higher-level fermentation process, and the SS core bacterial community contained more microbes in syntrophic cooperation with methanogens. Moreover, the different responses of the FS and SS core bacterial communities to the temperature shock and influent disturbance caused by solid contamination were fully investigated. Co-occurring analysis at the Order level implied that Bacteroidales, Selenomonadales, Anaerolineales, Syneristales, and Thermotogales might play key roles in anaerobic digestion due to their high abundance and tight correlation with other microbes. These findings advance our knowledge about the core bacterial community and its temporal variability for future comparative research and improvement of the two-stage anaerobic system operation.