• The Plant Pathology Journal
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• v.15 no.3
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• pp.162-167
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• 1999

Integration of microbial antagonists with fungicides was tried to control the gray mold caused by Botrytis cinerea on pepper in greenhouse conditions and to reduce fungicide uses. All of the selected bacterial antagonists, Bacillus amyloliquefaciens BL3, Paenibacillus polymyxa BL4, and Pseudomonas putida Cha94, completely inhibited the conidial germination of B. cinerea until 30 days after treatment. However, bacterial colonization of pepper phylloplane was poor in BL4, while the other bacterial isolates and the fungal antagonist Trichoderma harzianum TM colonized well on the phylloplane, maintaining the population density of 104-105 cfu/g until 15 days after microbial treatments. Out of 13 kinds of selected fungicides used for gray mold diseases, polyoxin B and BKF 1995 showed the most discriminatory activity on the fungal growth between B. cinerea and TM. TM grew readily on the media containing those fungicides, while B. cinerea showed poor or no mycelial growth on them. The selected fungicides and antagonists alone reduced incidence of gray mold on pepper, showing disease indices of about 2.4 to 3.0, while its was increased up to 4.2 in the untreated control. Alternate treatments with the antagonists and 2-fold diluted fungicides inhibited the disease incidence as much as the antagonists or fungicides alone, and reduced the secondary inoculum more than the single treatments. This suggests that integration of antagonists and fungicides may be an efficient way to reduce fungicide sprays with reliable control efficacy of the disease. However, there was not much difference in the early and mid-term disease progress among the treatments and the untreated control, probably due to extremely favorable environmental conditions for the disease development in this experiment.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.3
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• pp.194-210
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• 2022

Human milk contains a number of nutritional and bioactive molecules including microorganisms that constitute the so-called "Human Milk Microbiota (HMM)". Recent studies have shown that not only bacterial but also viral, fungal, and archaeal components are present in the HMM. Previous research has established, a "core" microbiome, consisting of Firmicutes (i.e., Streptococcus, Staphylococcus), Proteobacteria (i.e., Serratia, Pseudomonas, Ralstonia, Sphingomonas, Bradyrhizobium), and Actinobacteria (i.e., Propionibacterium, Corynebacterium). This review aims to summarize the main characteristics of HMM and the role it plays in shaping a child's health. We reviewed the most recent literature on the topic (2019-2021), using the PubMed database. The main sources of HMM origin were identified as the retrograde flow and the entero-mammary pathway. Several factors can influence its composition, such as maternal body mass index and diet, use of antibiotics, time and type of delivery, and mode of breastfeeding. The COVID-19 pandemic, by altering the mother-infant dyad and modifying many of our previous habits, has emerged as a new risk factor for the modification of HMM. HMM is an important contributor to gastrointestinal colonization in children and therefore, it is fundamental to avoid any form of perturbation in the HMM that can alter the microbial equilibrium, especially in the first 100 days of life. Microbial dysbiosis can be a trigger point for the development of necrotizing enterocolitis, especially in preterm infants, and for onset of chronic diseases, such as asthma and obesity, later in life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4826-4832
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• 2010

The study has been done for about two months through June 2 to July 30 of 2010. The study subjects are three herbal-pharmaceutical companies located in Seoul. Each of them purchased thirteen types of medicinal herbs, then the study did analysis for microbial contamination status of bacteria and fungi. Here, the study focuses on settling out fundamental data bases regarding the investigation standards of microbial contamination. As comparing the study results with contamination limits of bacteria and fungi which are represented by $10^7$ CFU/g and $10^4$ CFU/g in number respectively, the total percentage of fungi contamination which is 12.8% is higher than that of bacteria is only 7.7%. In the DNA homology analysis regarding 16S rRNA gene, 117 of colonization have been selected as study subjects. Including B. cereus composing of resistant spores, soil microbes account for approximately 96.6%. It indicates that it is important to establish collection and preservation systems in handling medicinal herbs. Also, it is critical to manage microbial contamination limits. In conclusion, the study proposes the needs to study on possible mingling of bacteria and fungi in manufacturing process, and microbial contamination status in medicinal herbs.

• Research in Plant Disease
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• v.23 no.3
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• pp.212-227
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• 2017

Pseudomonas chlororaphis O6, isolated from the roots of dryland, field-grown commercial wheat in the USA, enhances plant health and therefore it is used in agriculture as a biofertilizer and biocontrol agent. The metabolites produced by this pseudomonad stimulate plant growth through direct antagonism of pathogens and by inducing systemic resistance in the plant. Studies upon P. chlororaphis O6 identify the pathways through which defined bacterial metabolites generate protection against pathogenic microbes, insects, and nematodes. P. chlororaphis O6 also triggers plant resistance to drought and salinity stresses. The beneficial determinants are produced from bacterial cells as they form biofilms during root colonization. Molecular control these processes in P. chlororaphis O6 involves the global regulatory Gac/Rsm signaling cascade with cross-talk between other global regulatory pathways. The Gac/Rsm regulon allows for coordinate phasing of expression of the genes that encode these beneficial traits among a community of cells. This review provides insights on the Gac/Rsm regulon in expression of beneficial traits of the P. chlororaphis O6 which can contribute to help yield enhancement and quality in agricultural production.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1011-1021
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• 2005

Rhizobacteria are actively sought for the substitution of chemical fertilizers and pathogen control agents in environment-friendly sustainable agriculture. To be successfully commercialized in the current Korean market as agriculture biomaterials, microbial agents should exhibit both properties of plant growth promotion and pathogen control. That is, the organism must be a phytostimulator as well as a biocontrol agent. These criteria and the survival rate of a rhizobacterium, Bacillus amyloliquefaciens 7079, in the soil system were investigated to evaluate the suitability for future commercialization. B. amyloliquefaciens 7079-treated seedlings showed $22.8\%$ maximum increase in leaf-length growth, compared with water-treated controls, showing the phytostimulating property. The disease suppression rates of Phytophthora-blight of peppers and Fusarium-wilt of tomatoes by B. amyloliquefaciens 7079 were 1.5 and 2.2 times better, respectively, than by three popular chemical fungicides used in actual agricultural practices to control the respective pathogens. Survival of B. amyloliquefaciens 7079 on the rhizoplane and in the rhizosphere was favorable up to 50 days in the soil system employed. These positive properties show that B. amyloliquefaciens 7079 is likely to be a suitable candidate for commercialization to market as agricultural biomaterials.

• Biomedical Science Letters
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• v.20 no.1
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• pp.25-31
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• 2014

Atopic dermatitis (AD) is an inflammatory, relapsing, chronic skin disease and lesions in AD are frequently colonized with Staphylococcus aureus (S. aureus). Activation of T cells and IgE production by staphylococcal enterotoxins B (SEB) plays a crucial role in the pathogenesis of AD. Enterococcus faecalis (E. faecalis) is a nonpathogenic bacterium and produces the probiotic products that have been shown to have inhibitory effects on inflammatory responses. In present study, we carried out to assess the anti-inflammatory role of lyzed E. faecalis against the damaging effects of SEB on AD related immune responses. Furthermore, we attempted to determine whether the co-cultured lyzed E. faecalis can influence the colonization of S. aureus. As a result, we identified the effect of E. faecalis lysate as a potent therapeutic agent for atopic dermatitis (AD). E. faecalis lysate reduces the productions of total IgE and cytokines of AD-related immune cells in response to SEB stimulation. The proliferation of S. aureus was also inhibited by E. faecalis lysate. In conclusions, E. faecalis lysate may improve the skin-defense system disturbed by atopic condition, and may prevent subsequent secondary infection of S. aureus and development of AD.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.859-862
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• 2004

An isolate of Pseudomonas putida has been found to aggressively colonize root tips and induce plant resistance to Fusarium wilt. However, P. putida mutants lacking Fe-superoxide dismutase (SOD) or both FeSOD and MnSOD activities are less competitive in root tip colonization. In the current study, the growth of an FeSOD mutant was found to be more sensitive than that of the wild-type or a MnSOD mutant to oxidative stress imposed by paraquat treatment and culturing with the soil fungus Talaromyces flavus, which generates reactive oxygen species. Also, the loss of culturability with an aging stationary-phase culture was greater for a double SOD mutant than an FeSOD mutant, while no reduction in culturability was observed with the wild-type and a MnSOD mutant under the same protracted stationary-phase conditions. Accordingly, it was concluded that FeSOD activity is the major form of SOD in P. putida and plays an essential role in survival under stress conditions when increased oxidative stress is encountered.

• Environmental Engineering Research
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• v.19 no.3
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• pp.275-281
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• 2014

Aim of this study was to investigate biofilms attached in pipeline of water reuse from the MBR system treating sewage without chlorination in correlation to the outflow water quality. Two general pipe materials: polyvinyl chloride (PVC) and polyethylene (PE) were employed in the experiment. The peak growths were found at week 4 in both pipes. The maximum biofilms in PE pipe was $33mgVSS/cm^2$ with the growth rate of $4.75mgVSS/cm^2-d$ which was significant higher than that of PVC pipe. Biofilms examined by PCR-DGGE technique revealed five bacterial species in PE biofilms namely Sinorhizobium medicae WSM419, Sinorhizobium fredii NGR234, Geobacter sp. M18, Parachlamydia acanthamoebae UV-7, and Mycobacterium chubuense NBB4. The VSS concentrations in outflow had directly correlated to the biofilm attachment and detachment. High COD concentrations of outflow appeared during biofilm detaching phase. In summary, water quality of reuse water corresponded to the biofilms attachment and detachment in the pipeline.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.473-485
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• 2019

Kiwifruit (Actinidia spp.) is an economically important crop and a bacterial canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa), is the most destructive disease in kiwifruit production. Therefore, prevent and control of the disease is a critical issue in kiwifruit industry worldwide. Unfortunately, there is no reliable control methods have been developed. Recently, interest in disease control using microbial agents is growing. However, kiwifruit microbiota and their roles in the disease control is mainly remaining unknown. In this study, we secured bacterial libraries from kiwifruit ecospheres (rhizosphere, endospere, and phyllosphere) and screened reliable biocontrol strains against Psa. As the results, Streptomyces racemochromogenes W1SF4, Streptomyces sp. W3SF9 and S. parvulus KPB2 were selected as anti-Psa agents from the libraries. The strains showed forcible antibacterial activity as well as exceptional colonization ability on rhizosphere or phyllosphere of kiwifruit. Genome analyses of the strains suggested that the strains may produce several anti-Psa secondary metabolites. Our results will contribute to develop biocontrol strains against the kiwifruit canker pathogen and the disease management strategies.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1819-1826
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• 2020

Increasing evidence suggests a potential role of microbial colonization in the inception of chronic airway diseases. However, it is not clear whether the lung and gut microbiome dysbiosis is coincidental or a result of mutual interaction. In this study, we investigated the airway microbiome in interleukin 13 (IL-13)-rich lung environment and related alterations of the gut microbiome. IL-13-overexpressing transgenic (TG) mice presented enhanced eosinophilic inflammatory responses and mucus production, together with airway hyperresponsiveness and subepithelial fibrosis. While bronchoalveolar lavage fluid and cecum samples obtained from 10-week-old IL-13 TG mice and their C57BL/6 wild-type (WT) littermates showed no significant differences in alpha diversity of lung and gut microbiome, they presented altered beta diversity in both lung and gut microbiota in the IL-13 TG mice compared to the WT mice. Lung-specific IL-13 overexpression also altered the composition of the gut as well as the lung microbiome. In particular, IL-13 TG mice showed an increased proportion of Proteobacteria and Cyanobacteria and a decreased amount of Bacteroidetes in the lungs, and depletion of Firmicutes and Proteobacteria in the gut. The patterns of polymicrobial interaction within the lung microbiota were different between WT and IL-13 TG mice. For instance, in IL-13 TG mice, lung Mesorhizobium significantly affected the alpha diversity of both lung and gut microbiomes. In summary, chronic asthma-like pathologic changes can alter the lung microbiota and affect the gut microbiome. These findings suggest that the lung-gut microbial axis might actually work in asthma.