ABSTRACT
We developed an electrical modulation method for attachment and detachment of microorganisms. Living microorganisms suspended in non-nutritive media such as PBSâ» and artificial seawater were attracted by and selectively attached to indium tin oxide (ITO)/glass electrode regions to which a negative potential was applied. The microorganisms suspended in LB medium and glucose solution were not attracted to the ITO electrode. Dead microorganisms were not attracted to the ITO electrode. The living microorganisms were retrieved after detachment from the ITO electrode by application of a high-frequency triangular wave potential. When we applied this method to separate microorganisms from deep-sea sediment, bacteria belonging to 19 phyla and 23 classes were collected without undesirable high molecular weight contaminants such as humic acids. At the phylum and class level, respectively, 95 and 87 % of the phylotypes among electrically retrieved bacteria were common to the gene clones from the direct sediment DNA extraction. This technique is a novel useful method to prepare bacterial cells in a single population or a community for metagenomic analyses.
Subject(s)
Bacteria/metabolism , Electrodes/microbiology , Geologic Sediments/microbiology , Metagenomics/methods , Seawater/microbiology , Soil Microbiology , Tin Compounds/metabolism , Bacteria/genetics , Bacteria/ultrastructure , Base Sequence , Computational Biology , DNA Primers/genetics , Electromagnetic Fields , Japan , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Molecular Sequence Data , Phylogeny , Sequence Analysis, DNA , Species SpecificityABSTRACT
PURPOSE OF WORK: To explore a novel glycolipid, we performed biochemical reactions using a recombinant α-glucosidase from Geobacillus sp. which shows excellent transglycosylation reaction to hydroxyl groups in a variety of compounds. Two different glycolipids (GL-1 and GL-2) were prepared from ricinoleic acid using a recombinant α-glucosidase from Geobacillus sp. The molecular structure of GL-1 was confirmed as 12-O-α-D-glucopyranosyl-9-hexadecenoic acid by 1D and 2D NMR analyses. According to MALDI-TOF/MS, GL-1 and GL-2 showed single major peaks at m/z 483.82 and 645.97, respectively. The peaks corresponded to the [M + Na](+) ions of the glycolipids. GL-2 was estimated as 12-O-α-D-glucopyranosyl-(4'-O-α-glucopyranosyl)-9-hexadecenoic acid. Light polarization microscopy revealed that GL-2 easily formed self-assembled vesicles in aqueous solution.
