• Title/Summary/Keyword: Total microbial number

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Differential Selection by Nematodes of an Introduced Biocontrol Fungus vs. Indigenous Fungi in Nonsterile Soil

  • Kim, Tae Gwan;Knudsen, Guy R.
    • Journal of Microbiology and Biotechnology
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    • v.28 no.5
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    • pp.831-838
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    • 2018
  • Trophic interactions of introduced biocontrol fungi with soil animals can be a key determinant in the fungal proliferation and activity. This study investigated the trophic interaction of an introduced biocontrol fungus with soil nematodes. The biocontrol fungus Trichoderma harzianum ThzID1-M3 and the fungivorous nematode Aphelenchoides sp. (10 per gram of soil) were added to nonsterile soil, and microbial populations were monitored for 40 days. Similar results were obtained when the experiment was duplicated. ThzID1-M3 stimulated the population growth of indigenous nematodes (p < 0.05), regardless of whether Aphelenchoides sp. was added. Without ThzID1-M3, indigenous nematodes did not increase in number and the added Aphelenchoides sp. nematodes almost disappeared by day 10. With ThzID1-M3, population growth of nematodes was rapid between 5 and 10 days after treatment. ThzID1-M3 biomass peaked on day 5, dropped at day 10, and then almost disappeared at day 20, which was not influenced by the addition of nematodes. In contrast, a large quantity of ThzID1-M3 hyphae were present in a heat-treated soil in which nematodes were eliminated. Total fungal biomass in all treatments peaked on day 5 and subsequently decreased. Addition of nematodes increased the total fungal biomass (p < 0.05), but ThzID1-M3 addition did not affect the fungal biomass. Hyphae of total fungi when homogenously distributed did not support the nematode population growth; however, hyphae of the introduced fungus did when densely localized. The results suggest that soil fungivorous nematodes are an important constraint on the hyphal proliferation of fungal agents introduced into natural soils.

Effect of Blanching Treatment on Quality Characteristics and Antioxidant Activity of Beetroots (블랜칭 처리가 비트의 품질특성과 항산화 활성에 미치는 영향)

  • Hae Yeon Choi;Soo Bin Kim;Eun Seong Go;Ji Hye Chu;Hee-Kyung Jeon;Jin Hee Choi
    • Journal of the Korean Society of Food Culture
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    • v.38 no.6
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    • pp.434-441
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    • 2023
  • This study investigated quality characteristics and antioxidant activity of beetroots after blanching. Beetroots were blanched in distilled water, 2% NaCl water, and 2% citric acid water at 100℃ for 3 minutes (the blanched group). The moisture content was highest in the control (CON) at 91.30% (p<0.05), and cooking loss was lowest in the water-blanched beetroot (BW) at 5.39% (p<0.01). Chromaticity decreased after blanching compared to CON (p<0.001). Total polyphenol contents (TPC) and total flavonoid contents (TFC) decreased after blanching, and as a result of comparing the True retention (TR) of the blanching treatment group, BW had the highest with TPC TR 91.22% and TFC TR 70.51%. DPPH and ABTS+radical scavenging activities were highest in the CON, and in the blanching group BW was highest scavenging activity. The total number of microorganisms in the CON group was 2.97 log CFU/g, whereas no microorganisms were detected in the blanched groups. Therefore, this study, blanching in water without additives is the most appropriate method for preserving physiologically active substances and nutrients in beetroots and inhibiting microbial growth.

Distributions and heterotrophic actibities of bacteria in Lake Paro (파로호 수중생태계에서의 미생물 분포 및 활성도)

  • 안태석;이동훈
    • Korean Journal of Microbiology
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    • v.26 no.3
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    • pp.230-236
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    • 1988
  • The distributions of bacterial numbers and activities were studied bimonthly in 1987, at 3 sites in Lade Paro for elucidating the changes by disturbance of aquatic ecosystem. The total bacterial number was $0.3\times 10^{5}-13.1\times ^{5}$ cells/ml. The geterotrophic bacterial number had the variance from $1.9\times 10^{3}$ CFUs/ml to $3.1\times 10^{4}$CFUs/ml and the variation trend was similar to that of the total bacterial number. The proportions of alpha-glucosidase or beta-glucosidase releasing bacteria showed temporal changes rather than spatial changes. The proportions of phosphatase releasing bacteria had the maximum values, 22.7-83.0%, in July. The electron transpory system activity revealed the variation from $480{\mu}gO_{2}$/l/day to $1696{\mu}gO_{2}$/l/day and hagher values at upper stream and in summer. The degradation fraction by phosphatase was 0.4-9.1%/h and increased with temperature. The maximum value of heterotrophic activity was 8.2%/h in summer. Eventhough the distributions of total bacteria and heterotrophic bacteria were affected by the water disturbance but microbial activities and proportions of the specific enzume releasing bacteria were not affected.

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Mulching Materials as Yield Booster for Sustainable Mungbean Production

  • Kim Hee-Jung;Lee Ho-Yong
    • Korean Journal of Environmental Biology
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    • v.23 no.4
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    • pp.383-389
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    • 2005
  • The effect of different mulching materials on mungbean production was studied. The general objective was to assess the ecological effects of mulching materials in sustainable mungbean production. Specifically, the study aimed to determine the effects of different mulching materials on the chemical, physical and biological soil properties, on weed control and yield, and to identify mulching materials that are environmentally friendly in mungbean production. The experiment was conducted at the Fruit and Vegetables Seeds Center, Science City of $Mu/tilde{n}oz$, Nueva Ecija, Philippines from May to July 2004. The initial soil chemical properties were: pH of 6.4, 2.0 percent organic matter content, 0.10 percent total nitrogen, 22 ppm phosphorus, and 370 ppm available potassium. The soil microbial loads were $8\times10^4\;CFU\;g^{-1}$ for bacteria and $14\times10^4\;CFU\;g^{-1}$ for fungi. Mushroom spent mulch increased soil organic matter with an average of 3.13 percent, nitrogen with an average of 0.16 percent and the highest number of bacterial count with $3.4\times10^8\;CFU\;g^{-1}$. Use of mulch, except rice straw mulch, generally increased mungbean yield. The best mulching material for high yield production of mungbean was black polyethylene plastic film, although environmentally unfriendly.

Denaturing Gradient Gel Electrophoresis Analysis of Bacterial Populations in 5-Stage Biological Nutrient Removal Process with Step Feed System for Wastewater Treatment

  • Lee, Soo-Youn;Kim, Hyeon-Guk;Park, Jong-Bok;Park, Yong-Keun
    • Journal of Microbiology
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    • v.42 no.1
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    • pp.1-8
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    • 2004
  • Changes in the bacterial populations of a 5-stage biological nutrient removal (BNR) process, with a step feed system for wastewater treatment, were monitored by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA fragments. DGGE analysis indicated seasonal community changes were observed, however, community profiles of the total bacteria of each reactor showed only minor differences in the samples obtained from the same season. The number of major bands was higher in the summer samples, and decreased during the winter period, indicating that the microbial community structure became simpler at low temperatures. Since the nitrogen and phosphate removal efficiencies were highly maintained throughout the winter operation period, the bacteria which still remaining in the winter sample can be considered important, playing a key role in the present 5-stage BNR sludge. The prominent DGGE bands were excised, and sequenced to gain insight into the identities of the predominant bacterial populations present, and most were found to not be closely related to previously characterized bacteria. These data suggest the importance of culture-independent methods for the quality control of wastewater treatment.

Efficient Storage of Gorosoe(Acer mono Max.) Sap by Gamma Irradiation (감마선 조사에 의한 고로쇠 수액의 효율적인 저장방법)

  • Seo, Sang-Tae;Oh, Hye-Young;Kang, Ha-Young
    • The Korean Journal of Food And Nutrition
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    • v.23 no.1
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    • pp.84-87
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    • 2010
  • Effects of gamma irradiation on microbiological changes of Gorosoe sap were characterized during a post-irradiation storage at $4^{\circ}C$. The aseptically collected sap was irradiated and stored at $4^{\circ}C$ for 0 to 60 days and analysed for standard plate counts and 16S rDNA. There were significant differences in the total number of colony forming units(CFUs) of bacteria between irradiated and non-irradiated control sap. Bacteria of non-irradiated sap were present at levels of $1.5{\times}10^4{\sim}2.3{\times}10^8\;CFU/m{\ell}$, whereas no viable microbial cells were detected in sap after 10 kGy of irradiation during storage. According to the 16S rDNA sequence analysis, bacterial community structures decrease with time and the most abundant strain was Pseudomonas species. Our results suggested that gamma irradiation can be used to enhance the shelf-life of Gorosoe sap.

Comparison of Endophytic Microbial Community in Kiwifruit Plant Cultivars

  • Cho, Gyeongjun;Kim, Min-jung;Kwon, Youngho;Kwak, Youn-Sig
    • The Plant Pathology Journal
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    • v.34 no.4
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    • pp.341-346
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    • 2018
  • The microbiome makes a significant contribution to plant health and endophytes may generate positive effects for the host. However, there is a limited knowledge available concerning the kiwifruit endophyte. Therefore, we discuss endophyte microbiome community structures among the kiwifruit cultivars. Total reads numbered 17620 in cv. Hayward, 11515 in cv. Haegeum and 13613 in cv. Jecygold. The number of OTUs was follows: 112 in cv. Hageum; and 87 in cvs. Hayward and Jecygold. Most of the identified OTUs were phylum Proteobacteria and it emerged that Actinobacteria, Firmicute and Bacteroidetes were mainly present. While the largest difference in Proteobacteria content is between cv. Haegeum and cv. Jecygold, they shared more OTUs than cv. Hayward. As well, this study revealed the presence of remarkably dominated OTU of Pseudomonas spp. in kiwifruit sap regardless of cultivars. To the best of our knowledge, this study is the first tone to investigate the kiwifruit endophyte-microbiome community.

Beneficial Effects of Lactic Acid Bacteria Inoculation on Oat Based Silage in South Korea

  • Ilavenil, Soundharrajan;Srigopalram, Srisesharam;Park, Hyung Soo;Kim, Won Ho;Lee, Kyung Dong;Choi, Ki Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.35 no.3
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    • pp.207-211
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    • 2015
  • The objective of the study was to measure the beneficial effects of lactic acid bacteria (LAB) inoculation on the nutritive value of oat silage collected from thirteen regions in the Republic of Korea. The contents of crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF) and crude ash (CA) were slightly lower in LAB inoculated silage when compared with the control silage, whereas inoculation of LAB resulted in increased total digestible nutrient (TDN). Higher number of LAB, but lower count of yeast and fungi indicated the effectiveness of the LAB inoculation on oat silage fermentation. LAB inoculation resulted in low pH silage, which may prevent undesirable microbial growth. The LAB inoculation promoted lactic acid dominant fermentation with marginal levels of acetic acid and butyric acid in oat silage. These data suggest that the LAB inoculation may preserve oat silage at better quality for ruminant animal production.

Can Coffee Shops That Have Become the Red Ocean Win with ESG?

  • KWAK, Min-Kyu;CHA, Seong-Soo
    • Journal of Distribution Science
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    • v.20 no.3
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    • pp.83-93
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    • 2022
  • Purpose: This study aims to investigate the relationship between ESG activities (Environment, Social, Governance) of coffee shops and their brand image, purchase intention. Research design, data and methodology: To test the hypothesis, a survey was conducted for about one month from May to June, 2021, and a total of 311 people responded to the survey, and the responses from 311 copies were used for the analysis. Validity and reliability analysis were performed, and the relationship between latent variables was empirically analyzed using the structural equation modelling. Results: The results of the study are as follows. First, among the ESG activities of coffee shops, the environmental and social sectors had a significant positive (+) effect on the brand image, but the governance aspect showed no significant effect on the brand image. Second, it was found that the symbolic image and the empirical image had a significant positive (+) effect on the purchase intention, but the functional image did not have a significant effect on the purchase intention. Conclusions: The results of this study suggest that as the number of coffee shops and the heated competition are increasing, it is possible to build a differentiated brand image through ESG activities rather than relying on the functions and services of competing products.

Blending Three Probiotics Alleviates Loperamide-Induced Constipation in Sprague-Dawley (SD)-Rats

  • Ye-Ji Jang;Jin Seok Moon;Ji Eun Kim;Dayoung Kim;Han Sol Choi;Ikhoon Oh
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.119-131
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    • 2024
  • BIOVITA 3 bacterial species (BIOVITA 3), a probiotic blend powder containing Clostridium butyricum IDCC 1301, Weizmannia coagulans IDCC 1201, and Bacillus subtilis IDCC 1101, has been used as a food ingredient for gut health. However, its efficacy in improving constipation has not been reported. Therefore, we aimed to investigate the functional effects of oral administration of BIOVITA 3 as well as its component strains alone (at 1.0×109 CFU/day) in Sprague-Dawley (SD) rats with loperamide-induced constipation. The study included fecal analysis, gastrointestinal transit ratio, histopathological analysis, short chain fatty acids (SCFAs), and metagenome analysis. As results, the BIOVITA 3 group showed significant improvements in fecal number, water content, gastrointestinal transit ratio, and thickening of the mucosal layer. In the SCFAs analysis, all probiotic-treated groups showed an increase in total SCFAs compared to the loperamide-constipated group. Changes in microbial abundance and the diversity index of three groups (normal, constipated, and BIOVITA 3) were also defined. Of these, the BIOVITA 3 showed a significant improvement in loperamide-constipated SD-rats. This study suggests the possibility that BIOVITA 3 can be applied as an ingredient in functional foods to relieve constipation.