• 제목/요약/키워드: community reaction

검색결과 229건 처리시간 0.081초

Effects of Short-Term Soil Tillage Management on Activity and Community Structure of Denitrifiers under Double-Cropping Rice Field

  • Tang, Haiming;Li, Chao;Cheng, Kaikai;Shi, Lihong;Wen, Li;Xiao, Xiaoping;Xu, Yilan;Li, Weiyan;Wang, Ke
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1688-1696
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    • 2020
  • Soil physical and chemical characteristics, soil potential denitrification rates (PDR), community composition and nirK-, nirS- and nosZ-encoding denitrifiers were studied by using MiSeq sequencing, quantitative polymerase chain reaction (qPCR), and terminal restriction fragment polymorphism (T-RFLP) technologies base on short-term (5-year) tillage field experiment. The experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue retention (NT), and rotary tillage with crop residue removed as control (RTO). The results indicated that soil organic carbon, total nitrogen and NH4+-N contents were increased with CT, RT and NT treatments. Compared with RTO treatment, the copies number of nirK, nirS and nosZ in paddy soil with CT, RT and NT treatments were significantly increased. The principal coordinate analysis indicated that tillage management and crop residue returning management were the most and the second important factors for the change of denitrifying bacteria community, respectively. Meanwhile, this study indicated that activity and community composition of denitrifiers with CT, RT and NT treatments were increased, compared with RTO treatment. This result showed that nirK, nirS and nosZ-type denitrifiers communities in crop residue applied soil had higher species diversity compared with crop residue removed soil, and denitrifying bacteria community composition were dominated by Gammaproteobacteria, Deltaproteobacteria, and Betaproteobacteria. Therefore, it is a beneficial practice to increase soil PDR level, abundance and community composition of nitrogen-functional soil microorganism by combined application of tillage with crop residue management.

유류오염대수층 고온공기분사공정시 제한효소다형성 미생물 군집 (Microbial Community in the TPH-Contaminated Aquifer for Hot Air Sparging using Terminal-Restriction Fragment Length Polymorphism)

  • 이준호;박갑성
    • 한국물환경학회지
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    • 제24권1호
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    • pp.19-29
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    • 2008
  • Hot air sparging is a groundwater remediation technique, in which organic contaminants volatilized into hot air from the saturated to vadose zone. In the laboratory diesel (10,000 mg TPH/kg) was spiked in contaminated saturated aquifer soil. The hot air ($34.9{\pm}2.7^{\circ}C$) was injected in intermittent (Q=1,500 mL/min, 10 minute injection and 10 minute idle) modes. We performed microcosm tests using the groundwater samples to assess TPH reductive remediation activity. For Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis of eubacterial communities in sludge of wastewater treatment plants and soil of experiment site, the 16S rDNA was amplified by Polymerase Chain Reaction (PCR) from the sludge and the soil. The obtained 16S rDNA fragments were digested with Msp I and separated by electrophoresis gel. We found various sequence types for hot air sparging experiment with sludge soil samples that were closely related to Bacillus (149 bp, Firmicutes), Methlobacterium (149 bp, Euryarchaeotes), Pseudomonas (492 bp, ${\gamma}$-Proteobacteria), etc., in the clone library. In this study we find that TPH-water was reduced to 78.9% of the initial value in this experiment aquifer. The results of the present study suggests that T-RFLP method may be applied as a useful tool for the monitoring in the TPH contaminated soil fate of microorganisms in natural microbial community.

Mitigating $CH_4$ Emissions in Semi-Aerobic Landfills: Impacts of Operating Conditions on Abundance and Community Structure of Methanotrophs in Cover Soils

  • Li, Huai;Chi, Zi-Fang;Lu, Wen-Jing;Wang, Hong-Tao
    • Journal of Microbiology and Biotechnology
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    • 제23권7호
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    • pp.993-1003
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    • 2013
  • Methanotrophs are the most important sink of $CH_4$, which is a more highly potent greenhouse gas than $CO_2$. Methanotrophic abundance and community diversity in cover soils from two typical semi-aerobic landfills (SALs) in China were detected using real-time polymerase chain reaction (real-time-PCR) and denaturing gradient gel electrophoresis (DGGE) based on 16S rRNA genes, respectively. Real time-PCR showed that Type I methanotrophs ranged from $1.07{\times}10^6$ to $2.34{\times}10^7$ copies/g soil and that of Type II methanotrophs from $1.51{\times}10^7$ to $1.83{\times}10^8$ copies/g soil. The ratio of Type II to Type I methanotrophic copy numbers ranged from 5.61 to 21.89, indicating that Type II methanotrophs dominated in SAL. DGGE revealed that Type I methanotrophs responded more sensitively to the environment, changing as the community structure varied with different soil types and locations. Methylobacter, Methylosarcina, and Methylomicrobium for Type I, and Methylocystis for Type II were most prevalent in the SAL cover layer. Abundant interflow $O_2$ with high $CH_4$ concentration in SALs is the reason for the higher population density of methanotrophs and the higher enrichment of Type II methanotrophs compared with anaerobic landfills and other ecosystems, which proved a conclusion that increasing the oxygen supply in a landfill cover layer would greatly improve $CH_4$ mitigation.

지역사회중심재활운동이 여성 슬관절염 환자의 신체기능에 미치는 효과 (The Efficacy of Community-Based Rehabilitation Exercise to Improve Physical Function in Old Women with Knee Arthritis)

  • 김수민;송주민
    • The Journal of Korean Physical Therapy
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    • 제22권1호
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    • pp.9-17
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    • 2010
  • Purpose: The purpose of this study was to compare the effects of Tai-Chi exercise (TCE) and resistance exercise (RE) when used as part of a community-based exercise program on improvement of physical function in elderly women with knee arthritis. Methods: Forty-seven women with knee arthritis participated in this study. They were assigned to one of two groups: the TCE group (n=22) or the RE group (n=25). Tai-Chi exercise and resistance exercise sessions were held for 1 hour per session, twice per week, for 8 consecutive weeks. At pre-treatment and post-treatment, subjects were tested using the following measurements: one-legged stand test (sec), a functional reach test (cm), a test of the strength of the knee extensor and flexor muscles, determination of the pathway of center of foot pressure and vertical ground reaction force for stance phase at pre and post treatment time points. An independent t-test and a ${\chi}^2$ were used to determine the significance of differences between group means using SPSS 12.0. Results: After 8 weeks of participation in the exercise programs, there were significant improvements for both groups in joint pain, difficulty of performing activity, muscle strength of knee extensor and flexor. Also, vertical ground reaction force increased at the loading response phase for both groups. The RE group was significantly different from TC group on the eyes-closed one-legged stand test (sec). Conclusion: Tai-Chi exercise and resistance exercise programs improve physical functioning and reduce pain and locomotion difficulties.

Adverse Events Following Immunizations in Infants Under 1 Year of Age in Lorestan Province, Western Iran

  • Anbari Khatereh;Ghanadi Koruosh;Toulabipour Alireza;Jamebozuorghi Daryuosh;Baharvand Parastoo
    • Journal of Preventive Medicine and Public Health
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    • 제56권2호
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    • pp.172-179
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    • 2023
  • Objectives: Vaccination is an important intervention for preventing disease and reducing disease severity. Universal vaccination programs have significantly reduced the incidence of many dangerous diseases among children worldwide. This study investigated the side effects after immunization in infants under 1 year of age in Lorestan Province, western Iran. Methods: This descriptive analytical study included data from all children <1 year old in Lorestan Province, Iran who were vaccinated according to the national schedule in 2020 and had an adverse event following immunization (AEFI). Data were extracted from 1084 forms on age, sex, birth weight, type of birth, AEFI type, vaccine type, and time of vaccination. Descriptive statistics (frequency, percentage) were calculated, and the chi-square test and Fisher exact test were used to assess differences in AEFIs according to the abovelisted variables. Results: The most frequent AEFIs were high fever (n=386, 35.6%), mild local reaction (n=341, 31.5%), and swelling and pain (n=121, 11.2%). The least common AEFIs were encephalitis (n=1, 0.1%), convulsion (n=2, 0.2%), and nodules (n=3, 0.3%). Girls and boys only showed significant differences in mild local reactions (p=0.044) and skin allergies (p=0.002). The incidence of lymphadenitis (p<0.001), severe local reaction (p<0.001), mild local reaction (p=0.007), fainting (p=0.032), swelling and pain (p=0.006), high fever (p=0.005), and nodules (p<0.001) showed significant differences based on age at vaccination. Conclusions: Immunization is a fundamental public health policy for controlling vaccine-preventable infectious diseases. Although vaccines such as the Bacillus Calmette-Guérin vaccine, oral poliovirus vaccine, and pentavalent vaccine are well-researched and reliable, AEFIs are inevitable.

인터넷 쇼핑몰 품절상황에서 경험하는 소비자의 반응에 관한 질적 연구 (Qualitative Study on the Response of Consumers Experiencing Products' Being Sold Out on the Internet Shopping Malls)

  • 김주현;이진화
    • 복식
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    • 제65권5호
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    • pp.74-87
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    • 2015
  • It is common for popular products to sell out, and be out of stock. The purpose of this study is to examine the responses of consumers who have experiences of shopping online, and finding their desired products unavailable from being sold out. In order to carry out the study, in-depth interviews were conducted with ten recruits who were recruited from the Internet community, Soul Dresser, which is part of the Korean web portal, Daum. First, the cognitive reaction of the interviewees showed both positive and negative responses when they found out that their desired product was sold out. However, in the case of emotional reaction, all of them showed negative reactions. Observations showed that consumers researched and found similar products including price when they realized that their desired products were not going to be re-stocked. And in cases of similar products not being available, the consumers looked to buy other types of products such as bags, shoes, and other accessories.

Impact of a Recombinant Biocontrol Bacterium, Pseudomonas fluorescens pc78, on Microbial Community in Tomato Rhizosphere

  • Kong, Hyun Gi;Kim, Nam Hee;Lee, Seung Yeup;Lee, Seon-Woo
    • The Plant Pathology Journal
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    • 제32권2호
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    • pp.136-144
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    • 2016
  • Pseudomonas fluorescens pc78 is an effective biocontrol agent for soil-borne fungal diseases. We previously constructed a P43-gfp tagged biocontrol bacteria P. fluorescens pc78-48 to investigate bacterial traits in natural ecosystem and the environmental risk of genetically modified biocontrol bacteria in tomato rhizosphere. Fluctuation of culturable bacteria profile, microbial community structure, and potential horizontal gene transfer was investigated over time after the bacteria treatment to the tomato rhizosphere. Tagged gene transfer to other organisms such as tomato plants and bacteria cultured on various media was examined by polymerase chain reaction, using gene specific primers. Transfer of chromosomally integrated P43-gfp from pc78 to other organisms was not apparent. Population and colony types of culturable bacteria were not significantly affected by the introduction of P. fluorescens pc78 or pc78-48 into tomato rhizosphere. Additionally, terminal restriction fragment length polymorphism profiles were investigated to estimate the influence on the microbial community structure in tomato rhizosphere between non-treated and pc78-48-treated samples. Interestingly, rhizosphere soil treated with strain pc78-48 exhibited a significantly different bacterial community structure compared to that of non-treated rhizosphere soil. Our results suggest that biocontrol bacteria treatment influences microbial community in tomato rhizosphere, while the chromosomally modified biocontrol bacteria may not pose any specific environmental risk in terms of gene transfer.

중·소하천에서 부착미생물군집의 성장에 따른 불소 제거 효과 평가 (Evaluation of Fluoride Removal Effect with Growth of Attached Microbial Community in Middle and Small Stream)

  • 김태경;류서영;박윤아;이종준;주광진;장광현;오종민
    • 환경영향평가
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    • 제27권6호
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    • pp.595-603
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    • 2018
  • 본 연구는 경기도 중소하천에서 하상의 부착미생물군집의 시간에 따른 생장 변화와 부착미생물군집의 성장에 따른 불소의 제거 효율을 파악하기 위해 수행하였다. 방류수가 유입되는 지점인 P1과 그 곳에서 약 2 km 유하한 하류 지점인 P2에서 12주 동안의 현장 모니터링을 실시하고, 조사 지점의 수질과 부착미생물군집의 생체량 분석을 진행하였다. 부착미생물군집의 성장량은 7차 조사 시점까지 증가하다 이후 탈리현상이 발생하는 것으로 관찰되었으며, 부착미생물군집의 성장에 영향을 미치는 요인으로는 유량, 유속, 영양물질(질소, 인) 등으로 조사되었다. 한편, 부착미생물군집 체내의 불소 함유량 또한 7차 조사 시기까지 증가하다 8차 시점부터 감소하는 경향을 보였다. 이는 부착미생물군집의 탈리현상에 의해 불소의 함유량 또한 감소하였음을 사사한다. 이를 통해 하천 관리의 방안으로서 부착미생물군집의 활용법에 대한 평가 및 관리에 기여할 수 있을 것으로 기대된다. 부착미생물군집을 활용한 기법의 적용 시에는 부착미생물군집의 성장에 영향을 미칠 수 있는 요인에 대한 기초 조사 및 탈리 시점에 따른 부착판 교체 방안 등이 포함되어야할 것으로 사료된다.

혐기성 SBR을 이용한 anammox 미생물 배양 및 fluorescence in situ hybridization (FISH)을 통 미생물 군집 분석

  • 한동우;윤호준;김동진
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.286-289
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    • 2001
  • Anaerobic ammonium oxidation with nitrite to $N_2$(anammox) is a recently discovered microbial reaction with interesting potential for nitrogen removal from wastewater. Here we investigated the microbial community structure in the sequencing batch reactor(SBR) with an anammox activity. The SBR was optimized for the enrichment of a very slowly growing microbial community and showed that possibility of anaerobic ammonium oxidation. Fluorescence in situ hybridization(FISH) analysis revealed that anaerobic ammonium oxidizers were Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis. Furthermore, Nitrosomol1as spp. of the ${\beta}$ -subclass of Proteobacteria was also present within the anaerobic SBR microorganisms.

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低位生産 草地에서 石灰施用이 植物群落의 生活型과 生態的 反應에 미치는 影響 (Influences of liming on life form and ecological behaviour of plant community in low productive grassland)

  • Park, Geun Je
    • The Korean Journal of Ecology
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    • 제15권3호
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    • pp.221-229
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    • 1992
  • This experiment was carried out to investigate the effect of liming on life form and ecological behaviour of stand in low productive grassland with acidified solil at dairy fram in yesan, chungnam province. The inferior plant community of low productive grassland was improved to the most desirable pasture association with herbage of 84% by liming. the life forms of association in low productive grassland were composed of hemicryptophytes of 49.4%, therophytes of 48.2%, geophytes of 2.2% and chamaephytes of 0.2% but by liming their life forms of hemicryptophytes increased greatly by 32.6%, on the other hand geophytes were much more decreased by 33.4%. The ecological behaviour of moisture figure and nitrogen figure were slightly increased and soil reaction figure was gradually decreased in low productive grassland by liming.

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