02078nas a2200253   4500008004100000022001400041245019000055210006900245260007900314300001200393490000800405520106000413653002801473653002501501653002401526653002101550653002701571100001601598700001801614700001901632700002101651700002001672856013201692       2009                        eng d  a0273-228900aEffect of cultural conditions and media constituents on production of penicillin V acylase and CTAB treatment to enhance whole-cell enzyme activity of rhodotorula aurantiaca (NCIM 3425)0 aEffect of cultural conditions and media constituents on producti  a999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USAbHUMANA PRESS INCcJUN  a463-4720 v1573 a<p>Penicillin V acylase (PVA) is a pharmaceutically important enzyme as it plays a vital role in the manufacture of semi-synthetic beta-lactam antibiotics. Rhodotorula aurantiaca (NCIM 3425) produced high levels of intracellular penicillin V acylase after 18 h at pH 8.0 and temperature 27 degrees C. Fructose was the best carbon source for PVA production, whereas tryptone was the best nitrogen source to produce the enzyme up to 170 and 1,088 IU/l of culture, respectively. Additionally, the cell-bound PVA activity was enhanced on treatment with cationic detergent. Whole-cell activity was found to be doubled (204%) on treatment of 0.01 g dry weight of cells with 50 mu g/ml solution of N-cetyl-N,N,N-trimethylammoniumbromide at pH 8.0 for 1 h at room temperature. Atomic force microscopy images of permeabilized cells show perturbation in the cell wall and offer first-ever visual illustration of surface structure modifications that occur during permeabilization of R. aurantiaca cells leading to enhancement in activity of intracellular enzyme.</p>10aAtomic force microscopy10aIntracellular enzyme10aPenicillin Vacylase10aPermeabilization10aRhodotorula aurantiaca1 aKumar, Atul1 aSingh, Sanjay1 aPoddar, Pankaj1 aPrabhune, Asmita1 aPundle, Archana  uhttps://library.ncl.res.in/content/effect-cultural-conditions-and-media-constituents-production-penicillin-v-acylase-and-ctab-002535nas a2200265   4500008004100000022001400041245013800055210006900193260000800262300001400270490000800284520159300292653003701885653001801922653001701940653002401957653002101981100002902002700002202031700002602053700002402079700001402103700002002117856013202137       2017                        eng d  a0175-759800aPenicillin V acylases from gram-negative bacteria degrade N-acylhomoserine lactones and attenuate virulence in Pseudomonas aeruginosa0 aPenicillin V acylases from gramnegative bacteria degrade Nacylho  cMAR  a2383-23950 v1013 a<p>Virulence pathways in gram-negative pathogenic bacteria are regulated by quorum sensing mechanisms, through the production and sensing of N-acylhomoserine lactone (AHL) signal molecules. Enzymatic degradation of AHLs leading to attenuation of virulence (quorum quenching) could pave the way for the development of new antibacterials. Penicillin V acylases (PVAs) belong to the Ntn hydrolase superfamily, together with AHL acylases. PVAs are exploited widely in the pharmaceutical industry, but their role in the natural physiology of their native microbes is not clearly understood. This report details the characterization of AHL degradation activity by homotetrameric PVAs from two gram-negative plant pathogenic bacteria, Pectobacterium atrosepticum (PaPVA) and Agrobacterium tumefaciens (AtPVA). Both the PVAs exhibited substrate specificity for degrading long-chain AHLs. Exogenous addition of these enzymes into Pseudomonas aeruginosa greatly diminished the production of elastase and pyocyanin and biofilm formation and increased the survival rate in an insect model of acute infection. Subtle structural differences in the PVA active site that regulate specificity for acyl chain length have been characterized, which could reflect the evolution of AHL-degrading acylases in relation to the environment of the bacteria that produce them and also provide strategies for enzyme engineering. The potential for using these enzymes as therapeutic agents in clinical applications and a few ideas about their possible significance in microbial physiology have also been discussed.</p>10aN-acylhomoserine lactone acylase10aNtn hydrolase10apathogenesis10aPenicillin Vacylase10aQuorum quenching1 aSunder, Avinash, Vellore1 aUtari, Putri, Dwi1 aRamasamy, Sureshkumar1 avan Merkerk, Ronald1 aQuax, Wim1 aPundle, Archana  uhttps://library.ncl.res.in/content/penicillin-v-acylases-gram-negative-bacteria-degrade-n-acylhomoserine-lactones-and-attenuate