Trichloroethylene oxidation by the membrane-associated methane monooxygenase in type I, type II and type X methanotrophs

DiSpirito, Alan A.; Gulledge, Jay; Shiemke, Andrew K.; Murrell, J. Colin; Lidstrom, Mary E.; Krema, Cinder L.

doi:10.1007/bf00124489

Cited by 118 publications

(109 citation statements)

References 54 publications

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“…The 26 kDa subunit apparently contains the active site, as it binds the suicide inhibitor acetylene (Prior & Dalton, 1985b;DiSpirito et a/., 1992). Hybridization studies have suggested that methanotrophs contain multiple copies of genes encoding the 45 and 26 kDa subunits (pmoB1 and pmoAl, respectively) (Semrau et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Role of multiple gene copies in particulate methane monooxygenase activity in the methane-oxidizing bacterium Methylococcus capsulatus Bath

et al. 1999

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Genes for the subunits of particulate methane monooxygenase, PmoABC, have been sequenced from the y-proteobacterial methanotroph Methylococcus capsulatus Bath. M. capsulatus Bath contains two complete copies of pmoCAB, as well as a third copy of pmoC. The two pmoCAB regions were almost identical a t the nucleotide sequence level, differing in only 13 positions in 3183 bp. A t the amino acid level, each translated gene product contained only one differing residue in each copy. However, the pmOC3 sequence was more divergent from the two other pmoC copies a t both the far N-terminus and far C-terminus. Chromosomal insertion mutations were generated in all seven genes. Null mutants could not be obtained for pmOC3, suggesting that it may play an essential role in growth on methane. Null mutants were obtained for pmoCl, pmoC2, pmoAl, pmoA2, pmoBl and pmoB2. All of these mutants grew on methane, demonstrating that both gene copies were functional. Copy 1 mutants showed about two-thirds of the wild-type whole-cell methane oxidation rate, while copy 2 mutants showed only about one-third of the wildtype rate, indicating that both gene copies were necessary for wild-type particulate methane monooxygenase activity. It was not possible to obtain double null mutants that were defective in both pmo copies, which may indicate that some expression of pMMO is important for growth.

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Section: Introductionmentioning

confidence: 99%

Role of multiple gene copies in particulate methane monooxygenase activity in the methane-oxidizing bacterium Methylococcus capsulatus Bath

et al. 1999

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“…Methane is efficient at absorbing and re-emitting infrared radiation, and its accumulation contributes to global warming (Topp & Hanson, 1991). Methanotrophs are also of interest due to their ability to degrade some environmental contaminants, like the common solvent trichloroethylene (DiSpirito et al, 1992 ;Tsien et al, 1989). Methane-oxidizing bacteria have historically been divided into two groups, the type I and the type II methanotrophs, based primarily on their biochemistry, morphological features and phylogenetic placement (Hanson & Hanson, 1996).…”

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confidence: 99%

Methylosarcina fibrata gen. nov., sp. nov. and Methylosarcina quisquiliarum sp.nov., novel type 1 methanotrophs.

Wise¹,

McArthur²,

Shimkets³

2001

International Journal of Systematic and Evolutionary Microbiology

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Two novel species of obligate methane-oxidizing bacteria, isolated from landfill soil, were characterized. Both strains were unusual in that some members of the population grew in irregularly shaped, refractile cell packets that resembled sarcina-like clusters. Electron microscopy revealed that the cell packets were covered with a slime layer and the cells contained many large granular inclusion bodies. The individual cells of each strain were sometimes motile and had differing morphologies. Isolate AML-C10 T was always coccoidal in shape, and the cells were covered with extracellular fibrils. Isolate AML-D4 T was pleomorphic, changing from rod to coccal form, sometimes exhibiting an unusual fusiform morphology. AML-D4T lacked the extensive fibrillar matrix observed with AML-C10 T . Both strains utilized only methane and methanol as carbon sources. In stationary phase, the cells of each strain swelled in size and formed cysts. Aside from morphological differences, strains could also be distinguished from each other by cellular protein patterns, as well as by temperature and pH tolerances. 16S rDNA phylogenetic analysis showed that these are type I methanotrophs (family : Methylococcaceae) most closely related to the Methylobacter/Methylomicrobium clade, although they form a monophyletic grouping supported by moderately high bootstrap values. By 16S rDNA database searches, the most similar species to both isolates were Methylobacter spp. However, partial particulate methane monooxygenase sequence analysis suggested that these bacteria might be more closely related to Methylomicrobium than Methylobacter. Furthermore, cellular fatty acid profiles of the strains more closely resemble those of Methylomicrobium, although the absence of significant levels of 16 :1ω5c argues for the uniqueness of these two strains. On the basis of the results described here, it is proposed that a new genus should be created, Methylosarcina gen. nov., harbouring two species, Methylosarcina fibrata sp. nov. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA and partial pmoA sequence of AML-C10T and AML-D4 T are AF177296 and AF177325, and AF177297 and AF177326, respectively. methanotrophs, play a key role in the global consumption of methane (Hanson, 1998 ;King, 1992). Methane is efficient at absorbing and re-emitting infrared radiation, and its accumulation contributes to global warming (Topp & Hanson, 1991). Methanotrophs are also of interest due to their ability to degrade some environmental contaminants, like the common solvent trichloroethylene (DiSpirito et al., 1992 ;Tsien et al., 1989). Methane-oxidizing bacteria have historically been divided into two groups, the type I and the type II methanotrophs, based primarily on their biochemistry, morphological features and phylogenetic placement (Hanson & Hanson, 1996). 16S rRNA sequence analysis of the type I (or group I) methanotrophs shows them to form a coherent cluster within the γ-subclass of the Proteobacteria (Bowman et al., 1995). These bacteria utilize the ribulose monopho...

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“…As a pollutant, it has been found in underground aquifers, many surface waters and soils as a result of its use and improper disposal (ATSDR 2003). In aerobic conditions TCE disappearance was related to the cometabolic activity of local microflora: methanotrophs using either type of methane monooxygenase (DiSpirito et al 1991) or aromatic-degraders expressing enzymes such as toluene monooxygenase (Shields et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Dual augmentation for aerobic bioremediation of MTBE and TCE pollution in heavy metal-contaminated soil

et al. 2008

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In this work we isolated from soil and characterized several bacterial strains capable of either resisting high concentrations of heavy metals (Cd 2? or Hg 2? or Pb 2? ) or degrading the common soil and groundwater pollutants MTBE (methyl-tertbutyl ether) or TCE (trichloroethylene). We then used soil microcosms exposed to MTBE (50 mg/l) or TCE (50 mg/l) in the presence of one heavy metal (Cd 10 ppm or Hg 5 ppm or Pb 50 or 100 ppm) and two bacterial isolates at a time, a degrader plus a metalresistant strain. Some of these two-membered consortia showed degradation efficiencies well higher (49-182% higher) than those expected under the conditions employed, demonstrating the occurrence of a synergetic relationship between the strains used. Our results show the efficacy of the dual augmentation strategy for MTBE and TCE bioremediation in the presence of heavy metals.

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Trichloroethylene oxidation by the membrane-associated methane monooxygenase in type I, type II and type X methanotrophs

Cited by 118 publications

References 54 publications

Role of multiple gene copies in particulate methane monooxygenase activity in the methane-oxidizing bacterium Methylococcus capsulatus Bath

Role of multiple gene copies in particulate methane monooxygenase activity in the methane-oxidizing bacterium Methylococcus capsulatus Bath

Methylosarcina fibrata gen. nov., sp. nov. and Methylosarcina quisquiliarum sp.nov., novel type 1 methanotrophs.

Dual augmentation for aerobic bioremediation of MTBE and TCE pollution in heavy metal-contaminated soil

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