Carboxydobacteria are a group of bacteria which are able to grow chemolithotrophically on carbon monoxide (CO) as the sole carbon and energy source under aerobic conditions (22,30 Microbiol. 1965Microbiol. , abstr. P108, 1965, and Actinoplanes, Microbispora, and Mycobacterium (4), have also been described.The facultatively chemolithotrophic bacterium Mycobacterium sp. strain JC1 (originally Acinetobacter sp. strain JC1 DSM 3803; reclassified by Song et al. [41]), is capable of growing aerobically not only on CO but also on methanol as a sole source of carbon and energy (8,39). This means that the bacterium is able to employ three distinct types of nutrition, chemoheterotrophy, chemolithotrophy, and methylotrophy, depending on substrate availability.Combined with these results, the facts that many mycobacterial species including Mycobacterium tuberculosis (10; GenBank accession no. AL123456), Mycobacterium avium (NCBI reference sequence [RefSeq] NC-002943), Mycobacterium bovis (NCBI RefSeq NC-002945), Mycobacterium leprae (9; GenBank accession no. AL450380), and Mycobacterium smegmatis (NCBI RefSeq NC-002974) have genes encoding amino acid sequences similar to those of Mycobacterium sp. strain JC1 CO dehydrogenase (CO-DH) (T. Song and Y. M. Kim, unpublished data), that Mycobacterium phlei is able to oxidize CO (4), and that Mycobacterium cuneatum (40), Mycobaterium gastri (18), and Mycobacterium ID-Y (36) are capable of growing on methanol raise the possibility that all known mycobacteria have an intrinsic ability to grow on CO and/or methanol as the sole carbon and energy source.In order to address this question, we examined several wellknown mycobacteria for the ability to grow on CO and/or methanol, and we found that all the mycobacteria tested grew well on each of these substrates as the sole source of carbon and energy, except that M. tuberculosis did not grow on methanol. We also present several enzymological backgrounds for the growth of the mycobacteria on CO and methanol. MATERIALS AND METHODSStrains and cultivation conditions. Mycobacterium sp. strain JC1 (DSM 3803) (3, 41), Mycobacterium flavescens (ATCC 14474), M. gastri (ATCC 15754), Mycobacterium neoaurum (ATCC 25795), Mycobacterium parafortuitum (ATCC 19686), Mycobacterium peregrinum (ATCC 14467), M. phlei (ATCC 11758), M. smegmatis mc 2 (ATCC 700084), M. tuberculosis H37Ra (ATCC 35835), and Mycobacterium vaccae (ATCC 15483) were used throughout this study. Cells were cultivated at 37°C under CO chemolithoautotrophy with a gas mixture of 30% CO-70% air in either standard mineral base (SMB) medium (SMB-CO) (21) or 0.47% (wt/vol) Middlebrook 7H9 medium (7H9-CO; Becton Dickinson, Cockeysville, Md.). For methylotrophic growth, cells were grown at 37°C in SMB medium supplemented with 1% (vol/vol) methanol (SMB-MeOH). For the methanol assimilation enzyme assay, Methylobacterium extorquens AM1 (NCIB 9133) and Methylobacillus sp. strain SK1 (DSM 8269) grown at 30°C in SMBMeOH were used as controls. Growth was measured with a spectrophotometer by determi...

Monitoring the migration of pore pressure, deformation, and saturation plumes with effective tools is important for the storage and utilization of fluids in underground reservoirs, such as geological stores of carbon dioxide (CO2) and natural gas. Such tools would also verify the security of the fluid contained reservoir‐caprock system. Utilizing the swelling strain attributed to pressure buildup and the adsorption of supercritical CO2 on clay minerals, we tracked the fluid plume in a natural clay‐rich Tako sandstone at the laboratory core scale. The strain was measured by a high‐resolution distributed fiber optic strain sensing (DFOSS) tool. The strain changes induced by CO2 adsorptions on clay minerals were significantly greater than those caused by pore pressure alone. The distribution of the swelling strain signals effectively captured the dynamic breakthrough of the CO2 plume from the high‐ to low‐permeability regions in the Tako sandstone. Besides revealing the in situ deformation state, the measured strain changes can track the movement of the CO2 plume as it enters the clay‐rich critical regions in the reservoir‐caprock system. The present findings and potential future applications of DFOSS in the field are expected to enhance the monitoring and management of underground fluid reservoirs.

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