Plant growth promoting pseudomonads play an important role in disease suppression and there is considerable interest in development of bio-marker genes that can be used to monitor these bacteria in agricultural soils....Plant growth promoting pseudomonads play an important role in disease suppression and there is considerable interest in development of bio-marker genes that can be used to monitor these bacteria in agricultural soils. Here, we report the application ofa PCR primer sets targeting genes encoding the main antibiotic groups. Distribution of the genes was variably distributed across type strains of 28 species with no phylogenetic groupingfor the detected antibioticsgenes, phlD for 2,4-diacetylphloroglucinol (2,4-DAPG) and phzCD for phenazine-1-carboxylic acid or hcnBC for hydrogen cyanide production. Analysis of field soils showed that primer sets for phlD and phzCD detected these genes in a fallowed neutral pH soil following wheat production, but that the copy numbers were below the detection limits in bulk soils having an acidic pH. In contrast, PCR products for the phzCD, pltc and hcnBc genes were detectable in mature root zones following plantingwith wheat. The ability to rapidly characterize populations of antibiotics producers using specific primer sets will improve our ability to assess the impacts of management practices on the functional traits of Pseudomonas spp. populations in agricultural soils.展开更多
The abundance and diversity of archaeal assemblages were analyzed in soils collected from Gyorae Gotjawal forest, Jeju, Korea. Gotjawal soil refers to soil derived from a lava-formed forest, characterized by high orga...The abundance and diversity of archaeal assemblages were analyzed in soils collected from Gyorae Gotjawal forest, Jeju, Korea. Gotjawal soil refers to soil derived from a lava-formed forest, characterized by high organic matter content, fertility, and poor rocky soil. Using domain-specific primers, archaeal 16S rRNA gene sequences were PCR amplified for clone library construction, and a total of 185 archaeal clones were examined. The archaeal clones were affiliated with the phyla Thaumarchaeota (96.2%) and Euryarchaeota (3.8%). The most abundant thaumarchaeal group (90.3% of the clones) was the group I.1b clade, which includes soil ammonia-oxidizing archaea. The unique characteristics of Gotjawal soil, including basalt morphology, vegetation, and groundwater aquifer penetration, may be reflected in the archaeal community composition. Further study is necessary to understand the unique factors of Gotjawal soils that influence archaeal abundance, composition, and diversity.展开更多
Protein expression patterns in the polychlorinated biphenyl (PCB)-degrading Rhodococcussp. strain ACS were examined following growth on two substrates capable of inducing the enantioselective biotransformation of PCBs...Protein expression patterns in the polychlorinated biphenyl (PCB)-degrading Rhodococcussp. strain ACS were examined following growth on two substrates capable of inducing the enantioselective biotransformation of PCBs via different degradation pathways. Eleven inducible proteins were identified by SDS-PAGE and characterized by LC-MS/MS. Four of the peptides, a spore coat protein, an extracellular serine protease, a spoVP, and a molecular chaperonin from Bacillus subtilis, were identified as being unique to biphenyl-induced cells, whereas anextracellular serine protease from B. subtilis was identified as being unique to carvone-induced cells. None of the peptides identified had sequences that corresponded to known dioxygenases or other PCB-degrading enzymes of this Gram- positive bacterium, suggesting that the identified induced proteins may be involved in either PCB degradation or adaptive responses that protect cells from toxicity.展开更多
The microbial community structure in various microaggregates in a loamy sand soil was investigated. The microaggregates were separated into outer and inner aggregates using a series of soil washes. Further physical fr...The microbial community structure in various microaggregates in a loamy sand soil was investigated. The microaggregates were separated into outer and inner aggregates using a series of soil washes. Further physical fractionation of inner aggregates was achieved by separation into coarse and fine sand as macroaggregate fractions, coarse and fine silt as microaggregate fractions, and clay. Research on microbial communities and soil microaggregates can aid in our understanding of soil microhabitats and microorganisms in soil structures, with applications that may contribute to increasing crop production and maintaining sustainable agriculture. In order to study the microbial community structure of aggregates, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was performed using 16S rRNA genes. The PCR-DGGE of the Bacteria Actinomycetes and Archaea showed divergent results between the different aggregate fractions. The results showed that the bacterial community structure was highly similar between bulk soil and clay;the inner aggregate community structure of Actinomycetes was closely related between coarse and fine sand and coarse silt, and the Archaea community structure of outer and inner aggregates was more similar than that of total bacteria or Actinomycetes.展开更多
High rigidity twenty-high Sendzimir mills （ZRMs） are widely used for rolling stainless steels, silicon sheets, etc. A ZRM uses a small diameter work roll to produce massive rolling forces. Since a work roll with a s...High rigidity twenty-high Sendzimir mills （ZRMs） are widely used for rolling stainless steels, silicon sheets, etc. A ZRM uses a small diameter work roll to produce massive rolling forces. Since a work roll with a small diameter can be bent easily, strips often have complex shapes with mixed quarter and deep edge waves in the shape of plates. In order to solve this problem, fuzzy neural network controls are generally used for shape： recognition in ZRM control systems. Among various neural network types, the multi-layer perceptron （MLP） is typically used in current ZRMs. However, an MLP causes the loss of a large amount of shape recognition data. To improve the shape recognition per- formance of ZRM control systems, echo state networks （ESNs） are proposed to be used. Through simulation re- sults, it is found that shape recognition performance could be improved using the proposed ESN method.展开更多
文摘Plant growth promoting pseudomonads play an important role in disease suppression and there is considerable interest in development of bio-marker genes that can be used to monitor these bacteria in agricultural soils. Here, we report the application ofa PCR primer sets targeting genes encoding the main antibiotic groups. Distribution of the genes was variably distributed across type strains of 28 species with no phylogenetic groupingfor the detected antibioticsgenes, phlD for 2,4-diacetylphloroglucinol (2,4-DAPG) and phzCD for phenazine-1-carboxylic acid or hcnBC for hydrogen cyanide production. Analysis of field soils showed that primer sets for phlD and phzCD detected these genes in a fallowed neutral pH soil following wheat production, but that the copy numbers were below the detection limits in bulk soils having an acidic pH. In contrast, PCR products for the phzCD, pltc and hcnBc genes were detectable in mature root zones following plantingwith wheat. The ability to rapidly characterize populations of antibiotics producers using specific primer sets will improve our ability to assess the impacts of management practices on the functional traits of Pseudomonas spp. populations in agricultural soils.
文摘The abundance and diversity of archaeal assemblages were analyzed in soils collected from Gyorae Gotjawal forest, Jeju, Korea. Gotjawal soil refers to soil derived from a lava-formed forest, characterized by high organic matter content, fertility, and poor rocky soil. Using domain-specific primers, archaeal 16S rRNA gene sequences were PCR amplified for clone library construction, and a total of 185 archaeal clones were examined. The archaeal clones were affiliated with the phyla Thaumarchaeota (96.2%) and Euryarchaeota (3.8%). The most abundant thaumarchaeal group (90.3% of the clones) was the group I.1b clade, which includes soil ammonia-oxidizing archaea. The unique characteristics of Gotjawal soil, including basalt morphology, vegetation, and groundwater aquifer penetration, may be reflected in the archaeal community composition. Further study is necessary to understand the unique factors of Gotjawal soils that influence archaeal abundance, composition, and diversity.
文摘Protein expression patterns in the polychlorinated biphenyl (PCB)-degrading Rhodococcussp. strain ACS were examined following growth on two substrates capable of inducing the enantioselective biotransformation of PCBs via different degradation pathways. Eleven inducible proteins were identified by SDS-PAGE and characterized by LC-MS/MS. Four of the peptides, a spore coat protein, an extracellular serine protease, a spoVP, and a molecular chaperonin from Bacillus subtilis, were identified as being unique to biphenyl-induced cells, whereas anextracellular serine protease from B. subtilis was identified as being unique to carvone-induced cells. None of the peptides identified had sequences that corresponded to known dioxygenases or other PCB-degrading enzymes of this Gram- positive bacterium, suggesting that the identified induced proteins may be involved in either PCB degradation or adaptive responses that protect cells from toxicity.
文摘The microbial community structure in various microaggregates in a loamy sand soil was investigated. The microaggregates were separated into outer and inner aggregates using a series of soil washes. Further physical fractionation of inner aggregates was achieved by separation into coarse and fine sand as macroaggregate fractions, coarse and fine silt as microaggregate fractions, and clay. Research on microbial communities and soil microaggregates can aid in our understanding of soil microhabitats and microorganisms in soil structures, with applications that may contribute to increasing crop production and maintaining sustainable agriculture. In order to study the microbial community structure of aggregates, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was performed using 16S rRNA genes. The PCR-DGGE of the Bacteria Actinomycetes and Archaea showed divergent results between the different aggregate fractions. The results showed that the bacterial community structure was highly similar between bulk soil and clay;the inner aggregate community structure of Actinomycetes was closely related between coarse and fine sand and coarse silt, and the Archaea community structure of outer and inner aggregates was more similar than that of total bacteria or Actinomycetes.
基金Sponsored by Korea Science and Engineering Foundation(KOSEF)Funded by Korea Government(MEST)(2010-0022521)
文摘High rigidity twenty-high Sendzimir mills （ZRMs） are widely used for rolling stainless steels, silicon sheets, etc. A ZRM uses a small diameter work roll to produce massive rolling forces. Since a work roll with a small diameter can be bent easily, strips often have complex shapes with mixed quarter and deep edge waves in the shape of plates. In order to solve this problem, fuzzy neural network controls are generally used for shape： recognition in ZRM control systems. Among various neural network types, the multi-layer perceptron （MLP） is typically used in current ZRMs. However, an MLP causes the loss of a large amount of shape recognition data. To improve the shape recognition per- formance of ZRM control systems, echo state networks （ESNs） are proposed to be used. Through simulation re- sults, it is found that shape recognition performance could be improved using the proposed ESN method.
