Use of bacteriophage for the selective isolation of thermophilic actinomycetes from composted eucalyptus bark

1993 ◽  
Vol 39 (1) ◽  
pp. 46-51 ◽  
Author(s):  
D. I. Kurtböke ◽  
N. E. Murphy ◽  
K. Sivasithamparam
Keyword(s):  
Thermophilic Bacteria ◽  
Casein Hydrolysate ◽  
Test Material ◽  
Selective Isolation ◽  
Thermophilic Actinomycetes ◽  
Streptomyces Spp ◽  
Saccharopolyspora Rectivirgula ◽  
Eucalyptus Bark

A method was developed to reduce the numbers of thermophilic bacteria on isolation plates, which in turn facilitated the detection and isolation of thermophilic actinomycetes. The method involves exposing the test material to bacteriophage suspensions prior to inoculation on isolation plates. This method was applied to composted eucalyptus bark samples, which were then inoculated on R8 and 1/2 TSA + 0.2% casein hydrolysate agar plates. The phage susceptibility of thermophilic bacteria provided a selective means of reducing their numbers on isolation plates and hence increased the numbers of Thermomonospora, Saccharopolyspora rectivirgula, and thermophilic Streptomyces spp. on these media in comparison with the numbers recorded from control plates.Key words: bacteriophage, thermophilic bacteria, thermophilic actinomycetes, composted eucalyptus bark.

scholarly journals Identification of Poly(cis-1,4-Isoprene) Degradation Intermediates during Growth of Moderately Thermophilic Actinomycetes on Rubber and Cloning of a Functional lcp Homologue from Nocardia farcinica Strain E1

2006 ◽  
Vol 72 (5) ◽  
pp. 3375-3382 ◽  
Author(s):  
Ebaid M. A. Ibrahim ◽  
Matthias Arensk�tter ◽  
Heinrich Luftmann ◽  
Alexander Steinb�chel
Keyword(s):  
Thermophilic Bacteria ◽  
Natural Rubber Latex ◽  
Gel Permeation Chromatography ◽  
Mycolic Acid ◽  
Rrna Gene ◽  
Ionization Mass ◽  
Thermophilic Actinomycetes ◽  
Moderately Thermophilic ◽  
Nocardia Farcinica ◽  
Different Strains

ABSTRACT The enrichment and isolation of thermophilic bacteria capable of rubber [poly(cis-1,4-isoprene)] degradation revealed eight different strains exhibiting both currently known strategies used by rubber-degrading mesophilic bacteria. Taxonomic characterization of these isolates by 16S rRNA gene sequence analysis demonstrated closest relationships to Actinomadura nitritigenes, Nocardia farcinica, and Thermomonospora curvata. While strains related to N. farcinica exhibited adhesive growth as described for mycolic acid-containing actinomycetes belonging to the genus Gordonia, strains related to A. nitritigenes and T. curvata formed translucent halos on natural rubber latex agar as described for several mycelium-forming actinomycetes. For all strains, optimum growth rates were observed at 50�C. The capability of rubber degradation was confirmed by mineralization experiments and by gel permeation chromatography (GPC). Intermediates resulting from early degradation steps were purified by preparative GPC, and their analysis by infrared spectroscopy revealed the occurrence of carbonyl carbon atoms. Staining with Schiff's reagent also revealed the presence of aldehyde groups in the intermediates. Bifunctional isoprenoid species terminated with a keto and aldehyde function were found by matrix-assisted laser desorption ionization-time-of-flight and electrospray ionization mass spectrometry analyses. Evidence was obtained that biodegradation of poly(cis-1,4-isoprene) is initiated by endocleavage, rather than by exocleavage. A gene (lcp) coding for a protein with high homology to Lcp (latex-clearing protein) from Streptomyces sp. strain K30 was identified in Nocardia farcinica E1. Streptomyces lividans TK23 expressing this Lcp homologue was able to cleave synthetic poly(cis-1,4-isoprene), confirming its involvement in initial polymer cleavage.

Electro-membrane filtration for the selective isolation of bioactive peptides from an ?s2-casein hydrolysate

2002 ◽  
Vol 80 (6) ◽  
pp. 599-609 ◽  
Author(s):  
Gerrald Bargeman ◽  
Joukje Houwing ◽  
Isidra Recio ◽  
Geert-Henk Koops ◽  
Caroline van der Horst
Keyword(s):  
Membrane Filtration ◽  
Bioactive Peptides ◽  
Casein Hydrolysate ◽  
Selective Isolation

Modern methods for species identification of thermophilic bacteria of Campylobacter species

2021 ◽  
Vol 1 (11) ◽  
pp. 27-34
Author(s):  
Svetlana A. Makavchik ◽  
◽  
Lubov I. Smirnova ◽  
Aleksandr A. Sukhinin ◽  
Vladimir A. Kuzmin ◽  
...  
Keyword(s):  
Thermophilic Bacteria ◽  
Test Material ◽  
Clinical Samples ◽  
Biological Method ◽  
Chain Reactions ◽  
Defibrinated Horse Blood ◽  
Study Results ◽  
Bacteriological Method ◽  
Causative Agents ◽  
Campylobacter Species

Emergent thermophilic Campylobacter hepaticus is the causative agent of Spotty Liver Disease (SLD) in laying hens. C. hepaticus is difficult to cultivate because commercial media for the isolation and cultivation of Campylobacter contain cefoperazone, which inhibits many isolates of the C. hepaticus species. Campylobacter was isolated using modified Preston broth, incubated at 37 °C under microaerophilic conditions for 7 days and then subcultured onto selective Preston agar, erythritol agar with Oxoid selective additives and 5–7% defibrinated horse blood. Commercial test systems (API Campy) were used for identification. The use of the classical bacteriological diagnostic method, which is considered the 'gold' standard, is limited due to the difficulties of cultivation. The identification of new Campylobacter species requires revision of phenotypic identification algorithms. Specific primers for the identification of new Campylobacter species also need to be developed. In our studies, using the KAM-BAC kit, we detected Campylobacter jejuni DNA in clinically healthy birds. Consequently, the carriage of Campylobacter is massive. 30 samples of test material were examined using the molecular-biological method, and 60 samples using the bacteriological method. Analyzing the results of Campylobacter detection, it should be noted that thermophilic Campylobacteria were isolated from 60 clinical samples by the bacteriological method in 5,0% (3 Campylobacter cultures), and from 30 samples by the molecular-biological method in 27,0% (8 positive samples). Based on the analysis of the study results, it is necessary to conduct an in-depth study of the natural sources of Campylobacter hepaticus distribution, virulence factors, pathogenesis and mechanisms of infections caused by these emergent pathogens. The most promising research in the study of the causative agents of Campylobacteriosis in birds will be based on the application of innovative genomic technologies based on multiplex polymerase chain reactions and genome sequencing of Campylobacter hepaticus.

Phospholipid N -methyltransferases produce various methylated phosphatidylethanolamine derivatives in thermophilic bacteria

2021 ◽  
Author(s):  
Julia Kleetz ◽  
Leon Welter ◽  
Ann-Sophie Mizza ◽  
Meriyem Aktas ◽  
Franz Narberhaus
Keyword(s):  
Electrostatic Interactions ◽  
Thermophilic Bacteria ◽  
Critical Role ◽  
Active Form ◽  
Functional Characteristics ◽  
Thermophilic Actinomycetes ◽  
Membrane Recruitment ◽  
Bacterial Membranes ◽  
Mesophilic Bacteria ◽  
Cytoplasmic Proteins

One of the most common pathways for the biosynthesis of the phospholipid phosphatidylcholine (PC) in bacteria is the successive three-fold N -methylation of phosphatidylethanolamine (PE) catalyzed by phospholipid N -methyltransferases (Pmts). Pmts with different activities have been described in a number of mesophilic bacteria. In the present study, we identified and characterized the substrate and product spectrum of four Pmts from thermophilic bacteria. Three of these enzymes were purified in an active form. The Pmts from Melghirimyces thermohalophilus , Thermochromogena staphylospora and Thermobifida fusca produce monomethyl-PE (MMPE) and dimethyl-PE (DMPE). T. fusca encodes two Pmt candidates, one is mutationally inactivated and the other is responsible for the accumulation of large amounts of MMPE. The Pmt enzyme from Rubellimicrobium thermophilum catalyzes all three methylation reactions to synthesize PC. Moreover, we show that PE, previously reported to be absent in R. thermophilum , is in fact produced and serves as precursor for the methylation pathway. In an alternative route, the strain is able to produce PC by the PC synthase pathway when choline is available. The activity of all purified thermophilic Pmt enzymes was stimulated by anionic lipids suggesting membrane recruitment of these cytoplasmic proteins via electrostatic interactions. Our study provides novel insights into the functional characteristics of phospholipid N -methyltransferases in a previously unexplored set of thermophilic environmental bacteria. Importance In recent years, the presence of phosphatidylcholine (PC) in bacterial membranes has gained increasing attention, partly due to its critical role in the interaction with eukaryotic hosts. PC biosynthesis via a three-step methylation of phosphatidylethanolamine, catalyzed by phospholipid N -methyltransferases (Pmts), has been described in a range of mesophilic bacteria. Here, we expand our knowledge on bacterial PC formation by the identification, purification and characterization of Pmts from phylogenetically diverse thermophilic bacteria, and thereby provide insights into the functional characteristics of Pmt enzymes in thermophilic actinomycetes and proteobacteria.

Electron microscopic assays of restriction endonuclease cutting, exonuclease digestion, and hybridization

1984 ◽  
Vol 42 ◽  
pp. 686-687
Author(s):  
Mark Hannibal ◽  
Jacob Varkey ◽  
Michael Beer
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Restriction Endonuclease ◽  
Double Helix ◽  
Test Material ◽  
Electron Microscopic ◽  
Exonuclease Iii ◽  
Dna Molecule ◽  
Linear Molecules ◽  
Exonuclease Digestion

Workman and Langmore have recently proposed a procedure for isolating particular chromatin fragments. The method requires restriction endonuclease cutting of the chromatin and a probe, their digestion with two exonucleases which leave complimentary single strand termini and low temperature hybridization of these. We here report simple electron microscopic monitoring of the four reactions involved.Our test material was ϕX-174 RF DNA which is cut once by restriction endonuclease Xho I. The conversion of circles to linear molecules was followed in Kleinschmidt spreads. Plate I shows a circular and a linear DNA molecule. The rate of cutting is shown in Figure 1.After completion of the endonuclease cutting, one portion of the DNA was treated with exonuclease III, an enzyme known to digest the 3' terminals of double helical DNA. Aliquots when examined in the electron microscope reveal a decreasing length of double helix and increasing bushes at the ends.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Comparison of Lead, Copper and Aluminium as Gamma Radiation Shielding Material through Experimental Measurements and Simulation Using MCNP Version 4c

2018 ◽  
Vol 9 (08) ◽  
pp. 20193-20206 ◽  
Author(s):  
Md. Akhlak Bin Aziz ◽  
Md. Faisal Rahman ◽  
Md. Mahidul Haque Prodhan
Keyword(s):  
Gamma Radiation ◽  
Sodium Iodide ◽  
Experimental Approach ◽  
Radiation Shielding ◽  
Test Material ◽  
Simulation Techniques ◽  
Radiation Sources ◽  
Simulation Monte Carlo ◽  
Shielding Material ◽  
Code Version

The paper compares  Lead, Copper and Aluminium as gamma radiation shielding material using both experimental and simulation techniques. Cs- 137 (662KeV), Na-22 (511KeV) and Na- 22(1274KeV) were used as gamma radiation sources and a sodium iodide (NaI) detector was used to detect the radiation. Variations were noted for detected gamma count rates by changing shielding material thickness. In the experimental approach, thickness was varied by placing sheets of a particular test material one by one. For simulation, Monte Carlo n- Particle (MCNP) code version 4c was used and the geometry of the whole experimental setup was plotted in it. The results were then compared for each test material and it was found that lead is the best shielding material for gamma radiation followed by copper and aluminium.

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