17 research outputs found

    An RNA-Sequencing Study of the Genes and Metabolic Pathways Involved in <i>Aspergillus niger</i> Weathering of Potassium Feldspar

    No full text
    <div><p>Microbial transformation of potassium feldspar to produce organic composite potassium fertilizer is recognized to be an important method of effective use of the huge reserves of low grade K<sup>+</sup>-bearing rock in China. The mechanism underlying microbial weathering of silicate minerals is still unclear, and this is an obstacle to practical methods of application. To thoroughly understand the molecular mechanism responsible for the weathering of potassium feldspar by <i>Aspergillus niger</i> at a molecular level, high-throughput RNA-sequencing (RNA-seq) and treatment with different potassium sources (cultured in Czapek medium with soluble K<sup>+</sup> or potassium feldspar) were used to investigate the differentially expressed genes of <i>A</i>. <i>niger</i> associated with potassium feldspar weathering and the related metabolic pathways. A series of differentially expressed genes related to the synthesis and transportation of organic acids, polysaccharides, and proteins (enzymes) were found to be closely associated with the K<sup>+</sup> released from minerals through bioinformatic analysis. In addition, 12 genes that showed apparent expression differences by RNA-seq analysis and are relevant to organic acid synthesis, protein modification, maintenance of cellular homeostasis, and material transportation, were selected to be further verified using RT-qPCR. Compared to the fungal samples cultured with soluble K<sup>+</sup>, those with potassium feldspar have certain genes that are more up-regulated, such as the genes for Na<sup>+</sup>,K<sup>+</sup>-ATPase (447.6 multiples), cystathionine beta-synthase (5.6 multiples), cysteine synthase (9 multiples), and glutathione synthase (3.5 multiples). The analysis indicates that <i>A. niger</i> weathering of potassium feldspar is due to the synergistic effect of many factors including the up-regulation of certain genes and activation of related metabolite pathways. The research improves our understanding of the mechanisms of microbial weathering of silicate minerals.</p></div

    Analysis of variance for the concentrations of water-soluble and nitric acid-extractable K, Al, Fe and Ca of the samples.

    No full text
    <p>Analysis of variance for the concentrations of water-soluble and nitric acid-extractable K, Al, Fe and Ca of the samples.</p

    Post hoc tests for analyzing the concentrations of water-soluble and nitric acid-extractable K, Al, Fe and Ca of the samples.

    No full text
    <p>Post hoc tests for analyzing the concentrations of water-soluble and nitric acid-extractable K, Al, Fe and Ca of the samples.</p

    Neighbour-joining tree of 16SRNA gene sequences depicting the phylogenetic relationships of clones from the PBRP samples after having been processed by the earthworms in ten days.

    No full text
    <p>The scale bars represent a 5% sequence divergence and percentages of 1000 bootstrap resamplings are shown at the nodes. Species names and OTUs' numbers are followed by their GenBank accession numbers their proportion in all clones of the library, respectively.</p

    Neighbour-joining tree of 16SRNA gene sequences depicting the phylogenetic relationships of clones from the gut contents of the earthworms fed with PBRP for ten days.

    No full text
    <p>The scale bars represent a 5% sequence divergence and percentages of 1000 bootstrap resamplings are shown at the nodes. Species names and OTUs' numbers are followed by their GenBank accession numbers their proportion in all clones of the library, respectively.</p

    The number of shared OTUs between the five samples.

    No full text
    <p>The number of shared OTUs between the five samples.</p

    UniFrac unweighted principal coordinate analyses (PCA) (a) and weighted PCA (b) for the five samples.

    No full text
    <p>UniFrac unweighted principal coordinate analyses (PCA) (a) and weighted PCA (b) for the five samples.</p

    Hierarchical clustering of the five samples with weighted and unweighted UniFrac.

    No full text
    <p>The percentage support for nodes supported at least 70% of the time with sequence jackknifing is indicated.</p

    Neighbour-joining tree of 16SRNA gene sequences depicting the phylogenetic relationships of clones from the gut contents of the earthworms fed with soil for ten days.

    No full text
    <p>The scale bars represent a 5% sequence divergence and percentages of 1000 bootstrap resamplings are shown at the nodes. Species names and OTUs' numbers are followed by their GenBank accession numbers their proportion in all clones of the library, respectively.</p

    Neighbour-joining tree of 16SRNA gene sequences depicting the phylogenetic relationships of clones from the soil samples after having been processed by the earthworms in ten days.

    No full text
    <p>The scale bars represent a 5% sequence divergence and percentages of 1000 bootstrap resamplings are shown at the nodes. Species names and OTUs' numbers are followed by their GenBank accession numbers their proportion in all clones of the library, respectively.</p
    corecore