• Clinical and Experimental Pediatrics
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• v.56 no.9
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• pp.369-376
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• 2013

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to microbes is closely linked to the development of the early immune system and allergic diseases. The intestinal flora may contribute to allergic disease through its substantial effect on mucosal immunity. Based on findings that exposure to microbial flora early in life can change the Th1/Th2 balance, thus favoring a Th1 cell response, probiotics may be beneficial in preventing allergic diseases. However, evidence from clinical and basic research to prove the efficacy of probiotics in preventing allergy is lacking. To date, studies have yielded inconsistent findings on the usefulness of probiotics in allergic diseases. It is difficult to demonstrate an exact effect of probiotics on asthma, allergic rhinitis, and food allergy because of study limitations, such as different first supplementation period, duration, different strains, short follow-up period, and host factors. However, many studies have demonstrated a significant clinical improvement in atopic dermatitis with the use of probiotics. An accurate understanding of the development of human immunity, intestinal barrier function, intestinal microbiota, and systemic immunity is required to comprehend the effects of probiotics on allergic diseases.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.321-326
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• 2015

This study was performed to analyze the resident microbial flora and the effects of probiotic inoculation on the fermentation characteristics of whole grain naked barley (Hordeum Vulgare L.) with the goal of evaluating the possibility of utilization as fermented feedstuff. Naked barley grains were harvested 35 days after heading, and the microbial flora was analyzed using MALDI-TOF mass spectrometer. After inoculation of commercial microbes to the naked barley grain (BT), the pH and number of bacteria, such as aerobic bacteria, lactic acid bacteria, yeast and E. coli, were measured and compared with the non-inoculated control (BC). A total of 122 colonies was isolated from the naked barley grain and the most popular bacteria species was Staphylococcus xylosus (n = 30, 24.59%). The pH value decreased more rapidly in BT than in BC, and was significantly lower after 7 days of fermentation at $4.33{\pm}0.02$ and $4.83{\pm}0.01$, respectively. The number of aerobic bacteria, lactic acid bacteria and yeast showed an increasing trend within the first 7 days of fermentation, however, their numbers decreased at 28 and 42 days of fermentation. The population of lactic acid bacteria in BT was higher than in BC, but there was no significant different at 7 days of fermentation, with respective levels of $9.24{\pm}0.20$ and $9.01{\pm}0.10logCFU/g$ (p>0.05). The initial number of E. coli was very high in the naked barley grain but subsequently decreased significantly. After 7 days of fermentation, E. coli was not detected in either BT or BC samples. From these results, it appears that the fermentation of naked barley grain proceeded adequately after 7 days, and that fermentation contributes to the safety of naked barley grain during storage.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.131-137
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• 2013

The inhibitory effect of citrus peel extract, onion peel extract, calcium lactate and phosvitin on microbial growth was investigated in seasoned chicken breast meat during aerobic storage at $4^{\circ}C$, $10^{\circ}C$ and $20^{\circ}C$. Citrus peel and onion peel extract significantly improved (p<0.05) the microbial quality of the sample by reducing the initial counts of the microbial flora compared to control and other two treatments. Data clearly revealed that the counts of the total aerobic bacteria significantly increased with the increase in storage temperature. The shelf life of all samples stored under $20^{\circ}C$ was less than 6 days, while the shelf life of citrus and onion treatment can be extended more than 9 days at $4^{\circ}C$ and more than 6 days at $10^{\circ}C$ in aerobic storage condition. These results indicated that citrus and onion peel extracts are efficient treatment methods to prevent microbial spoilage of seasoned chicken products during storage at $4^{\circ}C$. However, there was an adverse effect of addition of citrus and onion peel extract on several sensory attributes which need to be improved by reformulation of seasoning.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.76-83
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• 1999

Studies were conducted during 2 months from May of 1997 to evaluate the effects of pig manure compost(PMC) on soil microbial flora. To do so, a field experiment of Chinese cabbage(Brassica campestris L.) was conducted in a randomized block design on a sandy loam soil and microbial floral characteristics in soils were analyzed. Treatments to control included the application of PMC at (A) $8Mg\;ha^{-1}$CM-8), (B) $29Mg\;ha^{-1}$(CM-2,9), and (C) $57Mg\;ha^{-1}$(CM-57), and of chemical fertilizer(D) at $320N-80P_2O_5-200K_2O\;kg\;ha^{-1}$(NPK). In each treatment, the rhizosphere and non-rhizosphere soils were tested for the analysis of microbial populations. The populations of bacteria, actinomycetes, and fungi increased in soils with the applications of PMC and chemical fertilizer, but that of Bacillus sp. decreased. However, the population of fluorescent Pseudomonas sp. was reduced in NPK plots only. With increasing application rates of PMC, the number of colony forming units(cfu) of bacteria (Pseudomonas sp. and actinomycetes) and fungi increased. in all PMC-treated plots, the population density peaked at early growth stage for bacteria(including Bacillus sp.), at late growth for fluorscent Pseudomonas sp., and at harvest for fungi and actinomycetes. The rhizosphere effect was greatest for fluorscent Pseudomonas sp. As the application rates of PMC increased, Total N, organic matter, available phosphate, and exchangeable -K, -Ca, and -Mg increased compared to control, but soil pH was lowered. In NPK plots, EC was 3.4-fold and exchangeable K was 5-fold higher than control.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.451-456
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• 2014

Organic amendment practices can influence diversity and activities of soil microorganisms. There is a need to investigate this impact compared with other types of materials. This study was carried out to evaluate the long term effects of chemical and organic fertilizer on soil microbial community in upland field. During the last 11 years green manure, rice straw compost, rapeseed cake, pig mature compost, NPK, and NPK + pig mature compost were treated in upland soil. Organic fertilizer treatment found with high bacterial colony forming units (CFUs) as compared to chemical and without fertilizer treatment. There was no significant difference in the actinomycetes and fungal population. The average well color development (AWCD) value was the highest in green manure and, the lowest in without fertilizer treatment. Analyses based on the denaturing gradient gel electrophoresis (DGGE) profile showed that rice straw compost and pig mature compost had a similar banding pattern while rapeseed cake, NPK, NPK + pig mature compost and without fertilizer treatment were clustered in another cluster and clearly distinguished from green manure treatment. Bacterial diversity can be highly increased by the application of organic fertilizer while chemical fertilizer had less impact. It can be concluded that green manure had a beneficial impact on soil microbial flora, while, the use of chemical fertilizer could affect the soil bacterial communities adversely.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1640-1650
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• 2020

Colorectal cancer (CRC) is the leading cause of common malignant neoplasm worldwide. Many studies have analyzed compositions of gut microbiota associated with various diseases such as inflammatory bowel diseases (IBD) and colon cancer. One of the most representative bacteria involved in CRC is enterotoxigenic Bacteroides fragilis (ETBF), a species belonging to phylum Bacteroidetes. We used ETBF colonized mice with azoxymethane (AOM)/dextran sulphate sodium (DSS) and zerumbone, a compound with anti-bacterial effect, to determine whether zerumbone could restore intestinal microbiota composition. Four experimental groups of mice were used: sham, ETBF colonized AOM/DSS group, ETBF colonized AOM/DSS group zerumbone 60 mg kg-1 (ETBF/AOM/DSS + Z (60)), and only zerumbone (60 mg kg^-1)-treated group. We performed reversible dye terminators-based analysis of 16S rRNA gene region V3-V4 for group comparison. Microbiota compositions of ETBF/AOM/DSS + Z (60) group and ETBF colonized AOM/DSS group not given zerumbone were significantly different. There were more Bacteroides in ETBF/AOM/DSS + Z (60) group than those in ETBF colonized AOM/DSS group, suggesting that B. fragilis could be a normal flora activated by zerumbone. In addition, based on linear discriminant analysis of effect size (LEfSe) analysis, microbial diversity decreased significantly in the ETBF colonized AOM/DSS group. However, after given zerumbone, the taxonomic relative abundance was increased. These findings suggest that zerumbone not only influenced the microbial diversity and richness, but also could be helpful for enhancing the balance of gut microbial composition. In this work, we demonstrate that zerumbone could restore the composition of intestinal microbiota.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.401-409
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• 2004

Two experiments were conducted to evaluate the effects of a complex Lactobacilli preparation on performance, resistance to E. coli infection and gut microbial flora of weaning pigs. In exp. 1, twelve pigs (7.65$\pm$1.10 kg BW), weaned at 28 d, were randomly allotted into 2 groups and placed in individual metabolic cages. During the first 7 d, one group of pigs was provided ad libitum access to water containing $10^5$ colony forming units (CFU) Lactobacilli per ml and the control group was provided tap water. The Lactobacilli preparation included Lactobacillus gasseri, L. reuteri, L. acidophilus and L. fermentum, which were isolated from the gastrointestinal (GI) tract mucosa of weaning pigs. On d 8, 20 ml of $10^8$ CFU/ml E. coli solution (serovars K99, K88 and 987P at the ratio of 1:1:1) was orally administered to each pig. Diarrhea scores and diarrhea incidence were recorded from d 7 to 14. On d 14, pigs were euthanized and digesta and mucosa from the stomach, duodenum, jejunum, ileum, cecum and colon were sampled using aseptic technique to determine microflora by culturing bacteria in selective medium. The results showed that Lactobacilli treatment significantly decreased E. coli and aerobe counts (p<0.01) but increased Lactobacilli and anaerobe counts (p<0.01) in digesta and mucosa of most sections of the GI tract. A 66 and 69.1% decrease in diarrhea index and diarrhea incidence, respectively, was observed in the Lactobacilli treated group. In exp. 2, Thirty-six crossbred Duroc$\times$Landrace$\times$Yorkshire piglets, weaned at 28$\pm$2 days, were selected and randomly allocated into 2 groups. There were 18 piglets in each group, 3 piglets in one pen and 6 replicates in each treatment with 3 pens of barrow and 3 pens of female piglet in each treatment. Piglets had ad libitum access to feed and water. The initial body weight of piglet was 7.65$\pm$1.09 kg. Dietary treatments included a non-medicated basal diet with Lactobacilli ($10^5$ CFU/g diet) or carbadox (60 mg/kg) as control. On d 21, six pigs per group (one pig per pen) were euthanized. Ileal digesta was collected to determine apparent amino acid digestibility. Microflora content was determined similarly to exp.1. The results showed that Lactobacilli treatment significantly improved average daily feed intake (ADFI) of pigs compared to carbadox (p<0.05) during the first 2 wks after weaning and average daily gain (ADG) and ADFI increased significantly (p<0.05) from d 8 to 14. Nitrogen and total phosphorus digestibility also increased (p<0.05). Bacterial counts were similar to exp. 1. The results indicate that the complex Lactobacilli preparation improved performance for 2 wks after weaning, enhanced resistance to E. coli infection, and improved microbial balance in the GI tract.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.111-116
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• 2012

In this study, we investigated the microbial flora changes in Gugija-Liriope tuber Makgeolli during fermentation and storage periods. We brewed Gugija-Liriope tuber Makgeolli for a week through twostage fermentations and stored the fermentation broth for a month at $4^{\circ}C$ or $20^{\circ}C$. We collected the samples periodically and analyzed microbial flora changes using viable cell counts and PCR-denaturing gradient gel electrophoresis (DGGE). Yeast viable cells were seen to have decreased to 13% of pre-storage levels after storage for 15 days at $20^{\circ}C$; however significant changes were not observed during storage at $4^{\circ}C$. Prolongation of storage time dramatically decreased the availability of viable cells. Yeast viable cell numbers had decreased to 38% of pre-storage levels at $4^{\circ}C$ and 4.8% at $20^{\circ}C$ after storage for 30 days. The results of the DGGE profile for yeast showed that Saccharomyces cerevisiae and Saccharomyces sp. were the predominant strains at the beginning of fermentation and throughout the whole period of storage. Viable cell counts for total bacteria had decreased to 36% of pre-storage levels after storage for 15 days but did not significantly change for the full 30 days of storage at $4^{\circ}C$. Similarly, viable cell counts for bacteria had decreased to 5% while viable cell numbers did not significantly change for the full 30 days at $20^{\circ}C$. Viable cell counts for lactic acid bacteria were performed and the results were similar to those for total bacteria. The results of the DGGE profile for bacteria showed that Weissella cibaria was the predominant strain at the beginning of fermentation. However it had disappeared by the end of fermentation, and Lactobacillus fermentum and Pediococcus acidilactici became the predominant species during storage.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.204-210
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• 1998

The experiment was conducted to obtain the basic data required to characterize and improve rhizosphere environment of salt-accumulated greenhouse(SAG) soils by comparing the soil properties and the microbial flora of such soils to those of unprotected arable upland(UAU) soils. Soils were sampled from greenhouses and unprotected upland fields around the country. Microbial propulation, biomass C content and soil chemical properties were of interest. Population density of fluorescent Pseudomonas was high in UAU soils, while those of pathogenic Fusarium sp. and fluorescent Pseudomonas were low in SAG soils. With increasing soil organic matter(OM) content, the population densities of Bacillus sp., fluorescent Pseudomonas sp., Enterobacteriaceae, and microbial biomass C content increased. As soil electrical conductivity(EC) increased higher than $5.1dS\;m^{-1}$, the ratios of bacteria to fungi(B/F) and actinomycetes to fungi(A/F) and the population density of fluorescent Pseudomonas decreased remarkably. The soil pH was positively related to the population density of aerobic bacteria, while it was negatively related to that of fungi. The soil OM content was significantly correlated to the population densities of actinomycetes($r=0.226^*$). Bacillus sp.($r=0.334^{**}$), Enterobacteriaceae($r=0.276^*$), and the microbial biomass C content($R=0.439^{**}$). The population density of actinomycetes was also significantly correlated with soil exchangeable Ca($r=0.334^{**}$) and Mg($r=0.352^{**}$).