Analysis of microstructural images of dry and water-saturated compacted bentonite samples observed with X-ray micro CT

Compacted bentonite, of which the major clay mineral is montmorillonite, is a candidate buffer material for geological disposal of high-level radioactive waste. In this study, a microfocus X-ray computed tomography (micro-CT, X-ray micro-scope), which enables non-destructive, three-dimensional observation of the interior microstructure of a sample with high resolution (several microns), examined compacted montmorillonite samples under dry and water-saturated states. The images thus obtained were analyzed by a computer code developed for this study to obtain the information on the size and shape of montmorillonite grains in the samples before and after the water saturation. From the results of the image analysis, it can be supposed that the outer montmorillonite sheets of grains swelled and formed a gel, whereas the inner montmorillonite sheets did not change significantly in the water-saturation process

Complete Genome Sequence of the Cesium-Accumulating Bacterium Rhodococcus qingshengii CS98, Isolated from Soil in Japan

Rhodococcus qingshengii CS98 is a bacterium isolated from soil in Japan that shows strong cesium-accumulating ability. The genome sequence of R. qingshengii CS98 was 6,726,107 bp in total length, G+C average content of 62.4% and comprised a circular chromosome (6,240,414 bp) and a linear plasmid (485,693 bp). The genome was predicted a total of 6,255 protein-coding sequences (CDSs), 59 tRNAs and 5 rRNA operons (5S/16S/23S). The complete genome sequence of R. qingshengii CS98 represents a valuable resource for future comparative genomic analysis and will help elucidate the genetic basis of bioremediation features