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Journal of Food Protection Mar 2007The outgrowth of Clostridium spp. spores causes spoilage in processed cheese products due to gas and off-odor formation. The present study focuses on the response of...
The outgrowth of Clostridium spp. spores causes spoilage in processed cheese products due to gas and off-odor formation. The present study focuses on the response of spores of Clostridium sporogenes and Clostridium cochlearium at 25 degrees C to polyphosphate, both alone and in combination with heat treatment. The two strains used were isolated from spoiled cheese spread. The addition of 1.5% polyphosphate but not 0.75% polyphosphate totally inhibited the growth of C. sporogenes SIK4.3; in contrast, 0.75% polyphosphate was sufficient to totally inhibit C. cochlearium CCUG 45978. The highest polyphosphate concentration tested (1.5%) was sporicidal for C. sporogenes SIK4.3 but not for C. cochlearium CCUG 45978. When 0.75% polyphosphate Bekaplus FS was combined with a holding time of 5 min at 98 degrees C, no survival or growth of C. sporogenes SIK4.3 was detected; however, the same effect was not achieved through heating alone or through application of polyphosphate alone. C. cochlearium CCUG 45978 was more heat tolerant, as shown by higher D-values. In conclusion, the results strongly suggest that polyphosphate Bekaplus FS has the potential to restrict the growth of C. sporogenes and C. cochlearium in cheese spread stored at ambient storage temperature. Experiments with cheese are needed in order to verify this effect.
Topics: Cheese; Clostridium; Colony Count, Microbial; Consumer Product Safety; Dose-Response Relationship, Drug; Food Contamination; Food Preservation; Hot Temperature; Humans; Polyphosphates; Species Specificity; Spores, Bacterial; Time Factors
PubMed: 17388069
DOI: 10.4315/0362-028x-70.3.744 -
Journal of Bacteriology Sep 2000The corrinoids from the obligate anaerobe Clostridium cochlearium were extracted as a mixture of Co(beta)-cyano derivatives. From 50 g of frozen cells, approximately 2...
The corrinoids from the obligate anaerobe Clostridium cochlearium were extracted as a mixture of Co(beta)-cyano derivatives. From 50 g of frozen cells, approximately 2 mg (1.5 micromol) of B(12) derivatives was obtained as a crystalline sample. Analysis of the corrinoid sample of C. cochlearium by a combination of high-pressure liquid chromatography and UV-Vis absorbance spectroscopy revealed the presence of three cyano corrinoids in a ratio of about 3:1:1. The spectroscopic data acquired for the sample indicated the main components to be pseudovitamin B(12) (Co(beta)-cyano-7"-adeninylcobamide) (60%) and factor A (Co(beta)-cyano-7"-[2-methyl]adeninylcobamide) (20%). Authentic pseudovitamin B(12) was prepared by guided biosynthesis from cobinamide and adenine. Both pseudovitamin B(12) and its homologue, factor A, were subjected to complete spectroscopic analysis by UV-Vis, circular dichroism, mass spectrometry, and by one- and two-dimensional (1)H, (13)C-, and (15)N nuclear magnetic resonance (NMR) spectroscopy. The third component was indicated by the mass spectra to be an isomer of factor A and is likely (according to NMR) to be 7"-[N(6)-methyl]-adeninylcobamide, a previously unknown corrinoid. C. cochlearium thus biosynthesizes as its native "complete" B(12) cofactors the 7"-adeninylcobamides and two homologous corrinoids, in which the nucleotide base is a methylated adenine.
Topics: Circular Dichroism; Clostridium; Cobamides; Corrinoids; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Porphyrins; Spectrophotometry, Ultraviolet; Vitamin B 12
PubMed: 10940017
DOI: 10.1128/JB.182.17.4773-4782.2000 -
Journal of Food Protection Aug 2006Of 42 spoiled cheese spread products, 35 were found to harbor Clostridium spp. Typical signs of spoilage were gas production and off-odor. The identity was determined...
Of 42 spoiled cheese spread products, 35 were found to harbor Clostridium spp. Typical signs of spoilage were gas production and off-odor. The identity was determined for about half of the isolates (n = 124) by Analytab Products (API), Biolog, the RiboPrinter System, 16S rDNA sequencing, cellular fatty acid analysis, or some combination of these. The majority of isolates were identified as Clostridium sporogenes (in 33% of products), but Clostridium cochlearium (in 12% of products) and Clostridium tyrobutyricum (in 2% of products) were also retrieved. Similarity analysis of the riboprint patterns for 21 isolates resulted in the identification of 10 ribogroups. A high degree of relatedness was observed between isolates of C. sporogenes originating from products produced 3 years apart, indicating a common and, over time, persistent source of infection. The spoilage potential of 11 well-characterized isolates and two culture collection strains was analyzed by inoculating shrimp cheese spread with single cultures and then storing them at 37 degrees C. Tubes inoculated with C. tyrobutyricum did not show any visible signs of growth (e.g., coagulation, discoloration, gas formation) in the cheese spread. After 2 weeks of incubation, tubes inoculated with C. cochlearium or C. sporogenes showed gas-holes, syneresis with separation of coagulated casein and liquid, and a change in color of the cheese. The amount of CO2 produced by C. cochlearium strains was approximately one-third that produced by the majority of C. sporogenes strains. To our knowledge, this is the first study to isolate and identify C. cochlearium as a spoilage organism in cheese spread.
Topics: Cheese; Clostridium; Consumer Product Safety; Food Contamination; Food Microbiology; Humans; Phylogeny; Ribotyping
PubMed: 16924914
DOI: 10.4315/0362-028x-69.8.1887 -
European Journal of Biochemistry Apr 1992Both components, E and S, of the adenosylcobalamin-(coenzyme B12)-dependent glutamate mutase from Clostridium cochlearium were purified. Component S (16 kDa) must be... (Comparative Study)
Comparative Study
Both components, E and S, of the adenosylcobalamin-(coenzyme B12)-dependent glutamate mutase from Clostridium cochlearium were purified. Component S (16 kDa) must be added to component E to obtain activity, although the latter contains substoichiometric amounts of component S besides the major 50-kDa subunit. The enzyme proved to be very similar to that of C. tetanomorphum as described by Barker et al. [Barker, H. A., Rooze, V., Suzuki, F. & Iodice, A. A. (1964) J. Biol. Chem. 239, 3260-3266] but component E of C. cochlearium was more stable and led to the first pure preparation. The pink component E showed a cobamide-like absorbance spectrum with a characteristic maximum at 470 nm indicating the presence of a cob(II)amide, probably Co alpha-[alpha-(aden-9-yl)]-cob(II)amide. A typical cob(II)amide signal at g = 2.23 with hyperfine and superhyperfine splitting was observed by EPR spectroscopy. A cobamide content of about 0.43 mol/mol 50-kDa subunit was determined by cyanolysis. Substitution of the migrating hydrogen at C-4 of glutamate by fluorine yielded the potent competitive inhibitor (2S,4S)-4-fluoroglutamate (Ki = 70 microM). (2R,3RS)-3-Fluoroglutamate (Ki = 600 microM) was also inhibitory. The competitive inhibition by 2-methyleneglutarate (Ki = 400 microM) and (S)-3-methylitaconate (Ki = 100 microM) but not by (RS)-2-methylglutarate suggested the transient formation of an sp2 center during catalysis. However, the presence of an N-terminal pyruvoyl residue was excluded and no evidence for the participation of another electrophilic center in the reaction was obtained.
Topics: Amino Acid Isomerases; Amino Acid Sequence; Bacterial Proteins; Chromatography, Gel; Chromatography, Ion Exchange; Clostridium; Cobamides; Electron Spin Resonance Spectroscopy; Electrophoresis, Polyacrylamide Gel; Glutamates; Intramolecular Transferases; Kinetics; Molecular Sequence Data; Protein Conformation; Spectrophotometry; Structure-Activity Relationship
PubMed: 1315276
DOI: 10.1111/j.1432-1033.1992.tb16840.x -
MBio Dec 2018is the causative agent of the deadly infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the...
is the causative agent of the deadly infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the mechanism of resistance is currently unknown. We discovered that encodes class D β-lactamases, i.e., CDDs, which are intrinsic to this species. We studied two CDD enzymes, CDD-1 and CDD-2, and showed that they display broad-spectrum, high catalytic efficiency against various β-lactam antibiotics, including penicillins and expanded-spectrum cephalosporins. We demonstrated that the genes are poorly expressed under the control of their own promoters and contribute only partially to the observed resistance to β-lactams. However, when the gene was expressed under the control of efficient promoters in the antibiotic-sensitive strain, it produced high-level resistance to β-lactams. Taken together, the results determined in this work demonstrate the existence in of intrinsic class D β-lactamases which constitute a reservoir of highly potent enzymes capable of conferring broad-spectrum, clinically relevant levels of resistance to β-lactam antibiotics. This discovery is a significant contribution to elucidation of the mechanism(s) of resistance of the clinically important pathogen to β-lactam antibiotics. is a spore-forming anaerobic bacterium which causes infection of the large intestine with high mortality rates. The infection is difficult to prevent and treat, as the pathogen is resistant to many antimicrobial agents. Prolonged use of β-lactam antibiotics for treatment of various infectious diseases triggers the infection, as these drugs suppress the abundance of protective gut bacteria, allowing the resistant bacteria to multiply. While resistance of to β-lactam antibiotics plays the major role in the development of the disease, the mechanism of resistance is unknown. The significance of our research is in the discovery in of β-lactamases, enzymes that destroy β-lactam antibiotics. These findings ultimately can help to combat deadly infections.
Topics: Anti-Bacterial Agents; Clostridioides difficile; beta-Lactam Resistance; beta-Lactamases; beta-Lactams
PubMed: 30563905
DOI: 10.1128/mBio.01803-18 -
European Journal of Biochemistry Jul 1999Glutamate mutase (Glm) is an adenosylcobamide-dependent enzyme that catalyzes the reversible rearrangement of (2S)-glutamate to (2S, 3S)-3-methylaspartate. The active...
Glutamate mutase (Glm) is an adenosylcobamide-dependent enzyme that catalyzes the reversible rearrangement of (2S)-glutamate to (2S, 3S)-3-methylaspartate. The active enzyme from Clostridium cochlearium consists of two subunits (of 53.6 and 14.8 kDa) as an alpha2beta2 tetramer, whose assembly is mediated by coenzyme B12. The smaller of the protein components, GlmS, has been suggested to be the B12-binding subunit. Here we report the solution structure of GlmS, determined from a heteronuclear NMR-study, and the analysis of important dynamical aspects of this apoenzyme subunit. The global fold and dynamic behavior of GlmS in solution are similar to those of the corresponding subunit MutS from C. tetanomorphum, which has previously been investigated using NMR-spectroscopy. Both solution structures of the two Glm B12-binding subunits share striking similarities with that determined by crystallography for the B12-binding domain of methylmalonyl CoA mutase (Mcm) from Propionibacterium shermanii, which is B12 bound. In the crystal structure a conserved histidine residue was found to be coordinated to cobalt, displacing the endogenous axial ligand of the cobamide. However, in GlmS and MutS the sequence motif, Asp-x-His-x-x-Gly, which includes the cobalt-coordinating histidine residue, and a predicted alpha-helical region following the motif, are present as an unstructured and highly mobile loop. In the absence of coenzyme, the B12-binding site apparently is only partially formed. By comparing the crystal structure of Mcm with the solution structures of B12-free GlmS and MutS, a consistent picture on the mechanism of B12 binding has been obtained. Important elements of the binding site only become structured upon binding B12; these include the cobalt-coordinating histidine residue, and an alpha helix that forms one side of the cleft accommodating the nucleotide 'tail' of the coenzyme.
Topics: Amino Acid Sequence; Catalytic Domain; Clostridium; Cobamides; Hydrogen; Intramolecular Transferases; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Sequence Data; Protein Conformation; Protein Structure, Tertiary; Sequence Homology, Amino Acid; Thermodynamics
PubMed: 10429202
DOI: 10.1046/j.1432-1327.1999.00482.x -
Journal of Bacteriology Nov 1968
Topics: Clostridium; Cytoplasm; Spores
PubMed: 5726313
DOI: 10.1128/jb.96.5.1859-1862.1968 -
Microbiology Resource Announcements Jun 2020We report the draft genome sequence of a new strain, AGROS13, which was isolated from a sheep dairy farm environment in New Zealand. The genome is 2.7 Mbp, with a GC...
We report the draft genome sequence of a new strain, AGROS13, which was isolated from a sheep dairy farm environment in New Zealand. The genome is 2.7 Mbp, with a GC content of 28.2%. The genome sequence was found to be closely related to that of ATCC 17787. The new strain harbors a biosynthetic gene cluster coding for an unknown sactipeptide.
PubMed: 32586862
DOI: 10.1128/MRA.00593-20 -
Applied and Environmental Microbiology Dec 1980A strain of Clostridium cochlearium having methylmercury-decomposing ability was isolated. The ability was cured by the treatment with acridine dye and recovered by the...
A strain of Clostridium cochlearium having methylmercury-decomposing ability was isolated. The ability was cured by the treatment with acridine dye and recovered by the conjugation of the cured strain with the parent strain. The cured strain then showed the activity to methylate mercuric ion as previously reported (M. Yamada and K. Tonomura, J. Ferment. Technol. 50:159-166, 1971). These results and the agarose gel electrophoretic pattern of the deoxyribonucleic acids from the lysates indicate a possible role of plasmids in controlling the mercury biotransformation of the two opposite directions in a single bacterial strain: methylation in the absence of the plasmid and demethylation in the presence of it. A possible mechanism for mercury resistance involving hydrogen sulfide is discussed.
Topics: Biotransformation; Clostridium; Hydrogen Sulfide; Mercury; Methylation; Methylmercury Compounds; Plasmids; Vitamin B 12
PubMed: 7458307
DOI: 10.1128/aem.40.6.1007-1011.1980 -
Journal of Bacteriology Nov 1969The fine structure of Clostridium cochlearium was examined by use of thin sections, negative stains, and carbon replicas. Particular attention was given to details of...
The fine structure of Clostridium cochlearium was examined by use of thin sections, negative stains, and carbon replicas. Particular attention was given to details of the sporulation process and to fine structure of the spores. Spore coat formation was well advanced before the first evidence of cortex formation was noted. Three distinct spore coats were detected, the outermost of which was composed of seven layers. In addition, the spores possessed tubular appendages of variable length attached to one end of the spore. These differed in a number of respects from those described for other clostridia.
Topics: Clostridium; Microscopy, Electron; Spores
PubMed: 5354956
DOI: 10.1128/jb.100.2.994-1001.1969