The invasive insect pest, red palm weevil (RPW), Rhynchophorus ferrugineus, poses a significant threat to date production, causing substantial economic damage. If uncontrolled, RPW leads the severely infested host tre...The invasive insect pest, red palm weevil (RPW), Rhynchophorus ferrugineus, poses a significant threat to date production, causing substantial economic damage. If uncontrolled, RPW leads the severely infested host tree to collapse and eventually die. The symbiotic associations with microorganisms and RPW in their gut may help their host insects’ establishment, development, nutrition assimilation, and survival. The objective of this research was the molecular characterization of the microbiome of RPW. In this study, the microbiome was compared among different tissues in females and males of RPW of three different morphs and larvae collected from date palm plantations in the Kingdom of Bahrain. A 251-bp segment of bacterial 16S rRNA was amplified by PCR, sequenced, and processed using the bioinformatics platform QIIME2. One ASV, corresponding to the obligate weevil symbiont Nardonella, predominated in adult female samples, constituting 56 ± 7% of total reads, but was less dominant in male samples (12 ± 3%) and larval samples (2.6 ± 1.9%). For females, samples that included reproductive tissues were almost entirely composed of Nardonella (88% - 99%). When Nardonella was excluded from analyses, there were no differences between adult females and adult males, but larval samples were more species-rich and differed in microbial composition from adults. There were no consistent differences in the microbiomes among morphs. Several specimens showed evidence of infection with host-specific strains of Spiroplasma-like members of the Entomoplasmatales, which are often pathogens or vertically transmitted symbionts. Such close microbial associates deserve additional attention as potential routes to control this destructive date palm pest.展开更多
The Maochang bauxite in Guizhou Province is one of the important aluminum ore deposits in southwestern China. Ferruginous spherules, measuring about a few microns across, were found in the transitional layer of the de...The Maochang bauxite in Guizhou Province is one of the important aluminum ore deposits in southwestern China. Ferruginous spherules, measuring about a few microns across, were found in the transitional layer of the deposit. The EDS and XRD results show that the microspherules are composed mostly of iron （hydr）oxide minerals （goethite） with only weak presence of aluminum and silicon. Occasionally, some pyrite micrograins with dissolved surface are found associated with goethite within the spherules. It is thus suggested that microspherules are linked to pyrite oxidization. It is also thought that microbial activities contribute not only to pyrite oxidization, but also to ball-like assemblage of the iron （hydr）oxides. The mechanism of the formation of ferruginous microspherules is also believed to be important in studying geomicrobiology of bauxite.展开更多
The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separa...The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separation process were studied using X-ray and laser diffraction methods. The results revealed the relationship between variations in the mean particle size of activated powders and the milling time. The crystallite size, microstrain, lattice parameters and unit cell volumes were determined for different milling times in powder samples of quartz, hematite, dolomite, and magnetite from the beneficiation tailings. The main trends in the variation of the crystallite size of quartz, hematite, dolomite, and magnetite as a function mean particle size of powder samples were revealed. Changes in the particle shape as a function of the activation time was also investigated.展开更多
Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), in...Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.展开更多
Abstract The use of microbial technologies in agriculture is rapidly expanding with the discovery of new bacterial strains effective in improving plant growth. In this study, we tested and highlighted the efficacy of ...Abstract The use of microbial technologies in agriculture is rapidly expanding with the discovery of new bacterial strains effective in improving plant growth. In this study, we tested and highlighted the efficacy of PGPR (Plant Growth Promoting Rhizobacteria) alone or in a consortium on maize growth. For this purpose, a greenhouse experiment was carried out in pots containing sterilized ferruginous soil for 30 days. The corn seeds of the EVDT 97 SRT C1 variety were inoculated with bacterial suspensions of concentration 108 UFC/ml. The experimental device was a random block of 16 three-repeat treatments. The incidence of PGPR inoculated strains is assessed on the biomass growth and yield parameters of maize. At the end of the trial, the results showed that inoculation stimulated plant growth and development and resulted in a significant increase in the height, diameter at the collar, leaf surface and dry weight of aerial biomass. 20.15%, 21%, 32.77% and 37.73% respectively compared to controls, especially in corn plants inoculated with B. thurengiensis;B.thurengiensis B.panthethonicus- S.marcescens et Pseudomonas cichorii- Pseudomonas. putida- Pseudomonas syringae. These results show the potential of using these rhizobacteria as biological inoculants to improve maize productivity in Benin.展开更多
文摘The invasive insect pest, red palm weevil (RPW), Rhynchophorus ferrugineus, poses a significant threat to date production, causing substantial economic damage. If uncontrolled, RPW leads the severely infested host tree to collapse and eventually die. The symbiotic associations with microorganisms and RPW in their gut may help their host insects’ establishment, development, nutrition assimilation, and survival. The objective of this research was the molecular characterization of the microbiome of RPW. In this study, the microbiome was compared among different tissues in females and males of RPW of three different morphs and larvae collected from date palm plantations in the Kingdom of Bahrain. A 251-bp segment of bacterial 16S rRNA was amplified by PCR, sequenced, and processed using the bioinformatics platform QIIME2. One ASV, corresponding to the obligate weevil symbiont Nardonella, predominated in adult female samples, constituting 56 ± 7% of total reads, but was less dominant in male samples (12 ± 3%) and larval samples (2.6 ± 1.9%). For females, samples that included reproductive tissues were almost entirely composed of Nardonella (88% - 99%). When Nardonella was excluded from analyses, there were no differences between adult females and adult males, but larval samples were more species-rich and differed in microbial composition from adults. There were no consistent differences in the microbiomes among morphs. Several specimens showed evidence of infection with host-specific strains of Spiroplasma-like members of the Entomoplasmatales, which are often pathogens or vertically transmitted symbionts. Such close microbial associates deserve additional attention as potential routes to control this destructive date palm pest.
文摘The Maochang bauxite in Guizhou Province is one of the important aluminum ore deposits in southwestern China. Ferruginous spherules, measuring about a few microns across, were found in the transitional layer of the deposit. The EDS and XRD results show that the microspherules are composed mostly of iron （hydr）oxide minerals （goethite） with only weak presence of aluminum and silicon. Occasionally, some pyrite micrograins with dissolved surface are found associated with goethite within the spherules. It is thus suggested that microspherules are linked to pyrite oxidization. It is also thought that microbial activities contribute not only to pyrite oxidization, but also to ball-like assemblage of the iron （hydr）oxides. The mechanism of the formation of ferruginous microspherules is also believed to be important in studying geomicrobiology of bauxite.
文摘The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separation process were studied using X-ray and laser diffraction methods. The results revealed the relationship between variations in the mean particle size of activated powders and the milling time. The crystallite size, microstrain, lattice parameters and unit cell volumes were determined for different milling times in powder samples of quartz, hematite, dolomite, and magnetite from the beneficiation tailings. The main trends in the variation of the crystallite size of quartz, hematite, dolomite, and magnetite as a function mean particle size of powder samples were revealed. Changes in the particle shape as a function of the activation time was also investigated.
基金financially supported by the Interdisciplinary Programs in Education and the Projects in Research Development, Kyushu University
文摘Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.
基金the West Africa Agricultural Productivity Program(WAAPP/PPAAO),the“Centre National de Specialisationsur le Mais(CNS-Mais)”and the“Fond National pour la Recherche Scientifique et de l’Innovation Technologique(FNRSIT)”of the Benin government for funding this project.
文摘Abstract The use of microbial technologies in agriculture is rapidly expanding with the discovery of new bacterial strains effective in improving plant growth. In this study, we tested and highlighted the efficacy of PGPR (Plant Growth Promoting Rhizobacteria) alone or in a consortium on maize growth. For this purpose, a greenhouse experiment was carried out in pots containing sterilized ferruginous soil for 30 days. The corn seeds of the EVDT 97 SRT C1 variety were inoculated with bacterial suspensions of concentration 108 UFC/ml. The experimental device was a random block of 16 three-repeat treatments. The incidence of PGPR inoculated strains is assessed on the biomass growth and yield parameters of maize. At the end of the trial, the results showed that inoculation stimulated plant growth and development and resulted in a significant increase in the height, diameter at the collar, leaf surface and dry weight of aerial biomass. 20.15%, 21%, 32.77% and 37.73% respectively compared to controls, especially in corn plants inoculated with B. thurengiensis;B.thurengiensis B.panthethonicus- S.marcescens et Pseudomonas cichorii- Pseudomonas. putida- Pseudomonas syringae. These results show the potential of using these rhizobacteria as biological inoculants to improve maize productivity in Benin.
