Characterization of extracellular beta-lactamases from penicillin G-resistant cells of Streptococcus thermophilus

Date

1998-07-01

Author

Chirica, LC
Güray, Nülüfer Tülün
Gültekin, Güzin Candan
Bozoglu, F

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

233
views

0
downloads

In this study, biochemical properties of two extracellular beta-lactamases produced by penicillin-resistant Streptococcus thermophilus cells were investigated. Both beta-lactamases showed specificity for penicillins but not for cephaloridins. The p-lactamases exhibited different affinities for penicillin G. The one with the higher molecular weight (F1) had a K(m) value of 3.44 mu M and a V(max), value of 8.33, mu mol/min/mg of protein, whereas the beta-lactamase with the lower molecular weight (FII) had a K(m) value of 4.76 mu M and a V(max) value of 3.13 mu mol/min/mg of protein. Both beta-lactamases were inhibited by iodine, copper sulfate, and iron sulfate but not by EDTA. The optimal pH ranged between 6 and 7. and the optimal temperatures were between 40 and 45 degrees C for both enzymes.

Subject Keywords

Food Science, Microbiology

URI

https://hdl.handle.net/11511/48947

Journal

JOURNAL OF FOOD PROTECTION

DOI

https://doi.org/10.4315/0362-028x-61.7.896

Collections

Department of Biology, Article

Suggestions

OpenMETU
Core

Evaluation of high hydrostatic pressure sensitivity of Staphylococcus aureus and Escherichia coli O157 : H7 by differential scanning calorimetry Alpas, Hami; BOZOGLU, F; KALETUNC, G (Elsevier BV, 2003-11-01) Differential scanning calorimetry (DSC) was used to evaluate the relative high hydrostatic pressure (HHP) resistances of bacterial strains from Staphylococcus aureus and Escherichia coli O157:H7 in vivo. The total apparent enthalpy change and thermal stability were two DSC parameters used to compare bacterial strains of untreated control and pressure-treated bacteria. DSC thermograms indicated that ribosomal denaturation appears to be a major factor in cell death by both thermal and high pressure treatments...
Characterization and functional analysis of a novel multicopper oxidase and associated polyketide biosynthesis gene cluster of aspergillus fumigatus Metin, Banu; Ögel, Zümrüt Begüm; Department of Food Engineering (2007) In this study, novel polyketide biosynthesis gene cluster of Aspergillus fumigatus was characterized and functionally analyzed. Analysis of the newly sequenced A. fumigatus genome for laccases, which are involved in melanin biosynthesis and detoxification in fungi, resulted in several putative laccase and multicopper oxidase gene sequences, one of which, Afu4g14490 (tpnJ), was selected for further characterization. The predicted amino acid sequence TpnJp showed 63% identity with the dihydrogeodin oxidase of...
High hydrostatic pressure induced inactivation kinetics of e. coli o157:h7 and s. aureus in carrot juice and analysis of cell volume change Pilavtepe, Mutlu; Alpas, Hami; Department of Food Engineering (2007) The main objective of this study was to determine the pressure induced inactivation mechanism of pressure-resistant Escherichia coli O157:H7 933 and Staphylococcus aureus 485 in a low acid food. Firstly, inactivation curves of pathogens were obtained at 200 to 400 MPa at 40ºC in peptone water and carrot juice. First-order and Weibull models were fitted and Weibull model described the inactivation curves of both pathogens more accurately than first-order model, revealing that food systems could exhibit eithe...
Investigation of cytocidal effect of K5 type yeast killer protein on sensitive microbial cells Sertkaya, Abdullah; İzgü, Kadri Fatih; Department of Biology (2005) Some yeasts secrete polypeptide toxins, which are lethal to other sensitive yeast cells, gram-positive pathogenic bacteria and pathogenic fungi. Therefore these are designated as killer toxins. Killer toxins are suggested as potent antimicrobial agents especially for the protection of fermentation process against contaminating yeasts, biological control of undesirable yeasts in the preservation of foods. Moreover they are promising antimicrobial agents in the medical field; due to immune system suppressing ...
Evaluation of hemicellulose as a coating material with gum arabic for food microencapsulation Tatar, Feyza; Tunc, Merve Tugce; DERVİŞOĞLU, MUHAMMET; Çekmecelioğlu, Deniz; KAHYAOĞLU, TALİP (Elsevier BV, 2014-03-01) In this study, hemicellulose-based coatings were assessed for use in microencapsulated fish oil. The fish oil emulsions were prepared using the solutions of gum arabic (GA), gum arabic-hemicellulose (GA-HC) and hemicellulose (HC) as the coating materials, amended with maltodextrin as a cheap filler material. The fish oil was then encapsulated with these emulsions using the spray drying method. The effects of the hemicelluloses on the emulsions and the formed microcapsules were evaluated by physical and chem...

Citation Formats

L. Chirica, N. T. Güray, G. C. Gültekin, and F. Bozoglu, “Characterization of extracellular beta-lactamases from penicillin G-resistant cells of Streptococcus thermophilus,” JOURNAL OF FOOD PROTECTION, pp. 896–898, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48947.