THE ISOLATION AND CHARACTERIZATION OF METHANOMONAS METHANOOXIDANS BROWN AND STRAWINSKI

1964 ◽  
Vol 10 (5) ◽  
pp. 791-799 ◽  
Author(s):  
L. R. Brown ◽  
R. J. Strawinski ◽  
C. S. McCleskey
Keyword(s):  
Formic Acid ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Energy Sources ◽  
Resting Cells ◽  
Gram Negative ◽  
Oxidation Of Methane ◽  
Isolation And Characterization ◽  
Trapping Agent

Procedures for the isolation and characterization of Metkanomonas methanooxidans Brown and Strawinski are described. Isolates from varied sources are alike in cellular morphology, inasmuch as they form only microcolonies, and in their dependence on methane or methanol as carbon and energy sources for growth. Both organic and inorganic nitrogen sources are used. The organism is a Gram negative non-sporeforming rod, 1.5 to 3.0 μ by 1.0 μ in size, and motile by means of a single polar flagellum. In growing cultures the oxygen/methane ratio was approximately 1.1 and in resting cells 1.7. The R.Q. for methane with resting cells was 0.43. Resting cells were unable to oxidize organic compounds other than methane, methanol, formaldehyde, and formate. Formic acid was detected in test solutions after cell suspensions had metabolized methane, methanol, and formaldehyde. Using sodium sulphite as trapping agent for formaldehyde, it was found that 60 to 70% of the methane or methanol consumed was converted to formaldehyde. In the presence of iodoacetate, 70% of the methane consumed was present terminally as methanol. Thus it was shown that methanol, formaldehyde, and formic acid are sequential intermediates in the oxidation of methane by these organisms.

scholarly journals Isolation and Characterization of Pb Resistant Bacteria from Cilalay Lake, Indonesia

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Kesi Kurnia ◽  
Nina Hermayani Sadi ◽  
Syafitri Jumianto
Keyword(s):  
Heterotrophic Bacteria ◽  
Water Environment ◽  
Resistant Bacteria ◽  
Bacterial Isolates ◽  
Gram Negative ◽  
Isolation And Characterization ◽  
Agar Media ◽  
Physical And Chemical ◽  
Standard Disk

<span>Pollution of water environment with heavy metals is becoming one of the most severe environmental and human health hazards. Lead (Pb) is a major pollutant and highly toxic to human, animals, plants, and microbes. </span><span lang="IN">Toxic metals are difficult to remove from the environment, since they cannot be chemically or biologically degraded and are ultimately indestructible. Biological approaches based on metal-resistant microorganisms have received a great deal of attention as alternative remediation processes. </span><span>This study aim to isolat</span><span lang="IN">e</span><span> and characterize Pb resistant of heterotrophic bacteria in Cilalay Lake, </span><span lang="IN">West Java, </span><span>Indonesia. The water samples were collected </span><span lang="IN">along</span><span> three points around Cilalay Lake. </span><span lang="IN">Water physical and chemical </span><span>determination was performed using the Water Quality Checker</span><span lang="IN">. </span><span>The bacterial isolates were screened on T</span><span lang="IN">r</span><span>ipton</span><span lang="IN">e</span><span> Glucose Yeast (TGY) agar plates. </span><span lang="IN">Afterwards s</span><span>elected isolates were grown on Nutrient Agar media 50% </span><span lang="IN">with </span><span>supplemented Pb 100 ppm by the standard disk. Population of resistant bacteria was counted. The result from metal resistant bacteria indicated that all isolates w</span><span lang="IN">ere</span><span> resistant. The most abundant type of resistant </span><span lang="IN">bacteria </span><span>to lead was Gram negative more than Gram positive. Identified have metal resistant bacteria could be useful for the bioremediation of heavy metal contaminated sewage and waste water</span>

Isolation and characterization of the peptidoglycans from selected Gram-positive and Gram-negative periodontal pathogens

1985 ◽  
Vol 31 (2) ◽  
pp. 154-160 ◽  
Author(s):  
M. R. Barnard ◽  
S. C. Holt
Keyword(s):  
Electron Microscopy ◽  
Diaminopimelic Acid ◽  
Muramic Acid ◽  
Periodontal Pathogens ◽  
Gram Positive ◽  
Gram Negative ◽  
Isolation And Characterization ◽  
Bacteroides Gingivalis ◽  
Scanning Electron

The peptidoglycans from several Gram-negative and Gram-positive periodontal pathogens were isolated, purified, and characterized both morphologically and chemically. In addition, the effects of the mureolytic enzymes, lysozyme, M-1 N-acetyl-muramidase, and the AM-3 endopeptidase, on the peptidoglycans were examined. These enzymes were found to be highly effective in the degradation of the purified peptidoglycans; however, a Bacteroides capillus peptidoglycan–protein complex exhibited a greater resistance to these enzymes. Morphologically, the peptidoglycans consisted of large saccular sheets which, when viewed by scanning electron microscopy, contained numerous holes and tears. Chemically, the peptidoglycans consisted of muramic acid, glucosamine, alanine, glutamic acid, and meso-diaminopimelic acid (DAP). One Bacteroides species, Bacteroides gingivalis strain W, contained glycine and LL-DAP, suggestive of an indirectly cross-linked A3γ peptidoglycan.

scholarly journals A recently evolved diflavin-containing monomeric nitrate reductase is responsible for highly efficient bacterial nitrate assimilation

2020 ◽  
Vol 295 (15) ◽  
pp. 5051-5066 ◽  
Author(s):  
Wei Tan ◽  
Tian-Hua Liao ◽  
Jin Wang ◽  
Yu Ye ◽  
Yu-Chen Wei ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Biochemical Characterization ◽  
Catalytic Domain ◽  
Inorganic Nitrogen ◽  
Nitrate Assimilation ◽  
Nitrogen Sources ◽  
Electron Transfer Mechanism ◽  
Cofactor Binding ◽  
Environmental Mycobacteria

Nitrate is one of the major inorganic nitrogen sources for microbes. Many bacterial and archaeal lineages have the capacity to express assimilatory nitrate reductase (NAS), which catalyzes the rate-limiting reduction of nitrate to nitrite. Although a nitrate assimilatory pathway in mycobacteria has been proposed and validated physiologically and genetically, the putative NAS enzyme has yet to be identified. Here, we report the characterization of a novel NAS encoded by Mycolicibacterium smegmatis Msmeg_4206, designated NasN, which differs from the canonical NASs in its structure, electron transfer mechanism, enzymatic properties, and phylogenetic distribution. Using sequence analysis and biochemical characterization, we found that NasN is an NADPH-dependent, diflavin-containing monomeric enzyme composed of a canonical molybdopterin cofactor-binding catalytic domain and an FMN–FAD/NAD-binding, electron-receiving/transferring domain, making it unique among all previously reported hetero-oligomeric NASs. Genetic studies revealed that NasN is essential for aerobic M. smegmatis growth on nitrate as the sole nitrogen source and that the global transcriptional regulator GlnR regulates nasN expression. Moreover, unlike the NADH-dependent heterodimeric NAS enzyme, NasN efficiently supports bacterial growth under nitrate-limiting conditions, likely due to its significantly greater catalytic activity and oxygen tolerance. Results from a phylogenetic analysis suggested that the nasN gene is more recently evolved than those encoding other NASs and that its distribution is limited mainly to Actinobacteria and Proteobacteria. We observed that among mycobacterial species, most fast-growing environmental mycobacteria carry nasN, but that it is largely lacking in slow-growing pathogenic mycobacteria because of multiple independent genomic deletion events along their evolution.

Isolierung und Charakterisierung Antipyrin-abbauender Bakterien / Isolation and Characterization of Antipyrine-degrading Bacteria

1978 ◽  
Vol 33 (1-2) ◽  
pp. 120-123 ◽  
Author(s):  
Hartmut Blecher ◽  
Renate Blecher ◽  
Rudolf Müller ◽  
Franz Lingens
Keyword(s):  
Sole Source ◽  
Resting Cells ◽  
Determinative Bacteriology ◽  
Isolation And Characterization ◽  
Degrading Bacteria ◽  
Different Strains

Abstract Five different strains of bacteria ultilizing antipyrine as sole source of carbon were isolated from soil. It was shown by morphological and physiological examinations, that the new isolates are closely related to strains selected with the herbicide chloridazon. A ll of these bacteria are charac­ terized by special features and cannot be classified according to Bergey’s Manual of Determinative Bacteriology.Part of the strains which were selected with antipyrine not only grow with antipyrine but also with chloridazon. The others cannot be grown on chloridazon. However, resting cells of the latter group convert chloridazon to its catechol derivative (5-amino-4-chloro-2 (2,3-dihydroxyphenyl) -3 (2H)-pyridazinone). In these bacteria a catechol-2,3-dioxygenase (catechol: oxygen 2,3-oxido-reductase, EC 1.13.11.2) was found which readily catalyzes the cleavage of the catechol derivative of antipyrine (2,3-dimethyl-l-(2,3-dihydroxyphenyl)-pyrazolone (5)). The enzyme shows only slight activity with the corresponding derivative of chloridazon.

scholarly journals Functional Characterization of pGKT2, a 182-Kilobase Plasmid Containing the xplAB Genes, Which Are Involved in the Degradation of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine by Gordonia sp. Strain KTR9

2010 ◽  
Vol 76 (19) ◽  
pp. 6329-6337 ◽  
Author(s):  
Karl J. Indest ◽  
Carina M. Jung ◽  
Hao-Ping Chen ◽  
Dawn Hancock ◽  
Christine Florizone ◽  
...  
Keyword(s):  
Amino Acid Sequence Identity ◽  
Inorganic Nitrogen ◽  
Cytochromes P450 ◽  
Functional Characterization ◽  
Protein A ◽  
Nitrogen Sources ◽  
Pcr Analysis ◽  
Bacterial Cells ◽  
Glutamine Synthase

ABSTRACT Several microorganisms have been isolated that can transform hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a cyclic nitramine explosive. To better characterize the microbial genes that facilitate this transformation, we sequenced and annotated a 182-kb plasmid, pGKT2, from the RDX-degrading strain Gordonia sp. KTR9. This plasmid carries xplA, encoding a protein sharing up to 99% amino acid sequence identity with characterized RDX-degrading cytochromes P450. Other genes that cluster with xplA are predicted to encode a glutamine synthase-XplB fusion protein, a second cytochrome P450, Cyp151C, and XplR, a GntR-type regulator. Rhodococcus jostii RHA1 expressing xplA from KTR9 degraded RDX but did not utilize RDX as a nitrogen source. Moreover, an Escherichia coli strain producing XplA degraded RDX but a strain producing Cyp151C did not. KTR9 strains cured of pGKT2 did not transform RDX. Physiological studies examining the effects of exogenous nitrogen sources on RDX degradation in strain KTR9 revealed that ammonium, nitrite, and nitrate each inhibited RDX degradation by up to 79%. Quantitative real-time PCR analysis of glnA-xplB, xplA, and xplR showed that transcript levels were 3.7-fold higher during growth on RDX than during growth on ammonium and that this upregulation was repressed in the presence of various inorganic nitrogen sources. Overall, the results indicate that RDX degradation by KTR9 is integrated with central nitrogen metabolism and that the uptake of RDX by bacterial cells does not require a dedicated transporter.

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