• Title/Summary/Keyword: Soil microbiology

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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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    • v.30 no.11
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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.

Bacillus subtilis as a Tool for Screening Soil Metagenomic Libraries for Antimicrobial Activities

  • Biver, Sophie;Steels, Sebastien;Portetelle, Daniel;Vandenbol, Micheline
    • Journal of Microbiology and Biotechnology
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    • v.23 no.6
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    • pp.850-855
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    • 2013
  • Finding new antimicrobial activities by functional metagenomics has been shown to depend on the heterologous host used to express the foreign DNA. Therefore, efforts are devoted to developing new tools for constructing metagenomic libraries in shuttle vectors replicatable in phylogenetically distinct hosts. Here we evaluated the use of the Escherichia coli-Bacillus subtilis shuttle vector pHT01 to construct a forest-soil metagenomic library. This library was screened in both hosts for antimicrobial activities against four opportunistic bacteria: Proteus vulgaris, Bacillus cereus, Staphylococcus epidermidis, and Micrococcus luteus. A new antibacterial activity against B. cereus was found upon screening in B. subtilis. The new antimicrobial agent, sensitive to proteinase K, was not active when the corresponding DNA fragment was expressed in E. coli. Our results validate the use of pHT01 as a shuttle vector and B. subtilis as a host to isolate new activities by functional metagenomics.

Investigation of Possible Horizontal Gene Transfer from Transgenic Rice to Soil Microorganisms in Paddy Rice Field

  • Kim, Sung-Eun;Moon, Jae-Sun;Kim, Jung-Kyu;Choi, Won-Sik;Lee, Sang-Han;Kim, Sung-Uk
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.187-192
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    • 2010
  • In order to monitor the possibility of horizontal gene transfer between transgenic rice and microorganisms in a paddy rice field, the gene flow from a bifunctional fusion (TPSP) rice containing trehalose-6-phosphate synthase and phosphatase to microorganisms in soils was investigated. The soil samples collected from the paddy rice field during June 2004 to March 2006 were investigated by multiplex PCR, Southern hybridization, and amplified fragment length polymorphism (AFLP). The TPSP gene from soil genomic DNAs was not detected by PCR. Soil genomic DNAs did not show homologies on the Southern blotting data, indicating that gene transfer did not occur during the last two years in the paddy rice field. In addition, the AFLP band patterns produced by soil genomic DNAs from both transgenic and non-transgenic rice fields appeared similar to each other when analyzed by the NTSYSpc program. Thus, these data suggest that transgenic rice does not give a significant impact on the communities of soil microorganisms, although long-term observation may be needed.

Influence of Allyl Isothiocyanate on the Soil Microbial Community Structure and Composition during Pepper Cultivation

  • Gao, Jingxia;Pei, Hongxia;Xie, Hua
    • Journal of Microbiology and Biotechnology
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    • v.31 no.7
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    • pp.978-989
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    • 2021
  • Allyl isothiocyanate (AITC), as a fumigant, plays an important role in soil control of nematodes, soil-borne pathogens, and weeds, but its effects on soil microorganisms are unclear. In this study, the effects of AITC on microbial diversity and community composition of Capsicum annuum L. soil were investigated through Illumina high-throughput sequencing. The results showed that microbial diversity and community structure were significantly influenced by AITC. AITC reduced the diversity of soil bacteria, stimulated the diversity of the soil fungal community, and significantly changed the structure of fungal community. AITC decreased the relative abundance of dominant bacteria Planctomycetes, Acinetobacter, Pseudodeganella, and RB41, but increased that of Lysobacter, Sphingomonas, Pseudomonas, Luteimonas, Pseudoxanthomonas, and Bacillus at the genera level, while for fungi, Trichoderma, Neurospora, and Lasiodiplodia decreased significantly and Aspergillus, Cladosporium, Fusarium, Penicillium, and Saccharomyces were higher than the control. The correlation analysis suggested cellulase had a significant correlation with fungal operational taxonomic units and there was a significant correlation between cellulase and fungal diversity, while catalase, cellulose, sucrase, and urease were the major contributors in the shift of the community structure. Our results will provide useful information for the use of AITC in the assessment of environmental and ecological security.

Screening of Microorganisms having Antiviral Activity against HIV Virus from Soil (토양으로부터 HIV 바이러스에 항바이러스 활성을 나타내는 미생물의 탐색)

  • 김성욱;이상한;정태숙;문석식;이종교;이항우;이원영;복성해
    • Microbiology and Biotechnology Letters
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    • v.21 no.5
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    • pp.399-405
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    • 1993
  • For screening of the antiviral agent from soil, about 520 strains of microorganisms were evaluated for their antiviral activity, About 6.9% of strains showed more than 95% antiviral activity against Herpes Simples Virus (HSV)-1. Two strains among 30 strains active against HSV-1 virus showed a quite strong activity against human immunodeficiency virus.

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