01968nas a2200229   4500008004100000022001400041245019500055210006900250260007900319300001400398490000800412520102600420653002001446653001001466653002101476653003001497653001201527100002201539700002601561700002101587856013001608       2013                        eng d  a0273-228900aCrystalline xylitol production by a novel yeast, pichia caribbica (HQ222812), and its application for quorum sensing inhibition in gram-negative marker strain chromobacterium violaceum CV0260 aCrystalline xylitol production by a novel yeast pichia caribbica  a999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USAbHUMANA PRESS INCcMAR  a1753-17630 v1693 a<p>Xylitol, a sugar alcohol, is fast gaining ground over other artificial sugar substitutes owing to its advantageous properties. Xylitol is a safer alternative for diabetics because of insulin-independent metabolism. It has beneficial properties suitable to form an important part of odontological formulations. Conventional commercial production of xylitol involves harsh chemical method operating at high temperature and pressure. Thus, microbial production of xylitol is preferred over chemical method, and yeasts have been extensively exploited for this purpose. In the present manuscript, quantitative production of xylitol from d-xylose with the yield of 0.852 gm/gm and volumetric productivity of 1.83 gm/l/h in crystalline form, using novel yeast Pichia caribbica is reported. Also, a mild, safe procedure for product extraction is described. The ability of xylitol to act as a quorum sensing antagonist in gram-negative marker strain Chromobacterium violaceum CV026 has been demonstrated for the first time.</p>10aCrystallization10aCV02610aPichia caribbica10aQuorum sensing antagonist10axylitol1 aMukherji, Ruchira1 aJoshi-Navare, Kasturi1 aPrabhune, Asmita  uhttps://library.ncl.res.in/content/crystalline-xylitol-production-novel-yeast-pichia-caribbica-hq222812-and-its-application-002274nas a2200241   4500008004100000022001400041245014400055210006900199260007900268300000800347490000700355520135400362653002901716653001001745653001001755653002101765100002201786700002901808700002601837700001901863700002101882856012901903       2014                        eng d  a0141-022900aNew role for penicillin acylases: degradation of acyl homoserine lactone quorum sensing signals by Kluyvera citrophila penicillin G acylase0 aNew role for penicillin acylases degradation of acyl homoserine   a360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USAbELSEVIER SCIENCE INCcMAR  a1-70 v563 a<p>Use of penicillin acylases for the production of semi-synthetic penicillins is well-known. Escherichia coli penicillin G acylase (EcPGA) has been extensively used for this purpose; however, Kluyvera citrophila penicillin G acylase (KcPGA) is assumed to be a better substitute, owing to its increased resilience to extreme pH conditions and ease of immobilization. In the present article we report a new dimension for the amidase activity of KcPGA by demonstrating its ability to cleave bacterial quorum sensing signal molecules, acyl homoserine lactones (AHL) with acyl chain length of 6-8 with or without oxo-substitution at third carbon position. Initial evidence of AHL degrading capability of KcPGA was obtained using CV026 based bioassay method. Kinetic studies performed at pH 8.0 and 50 degrees C revealed 3-oxo-C6 HSL to be the best substrate for the enzyme with V-max and K-m values of 21.37+0.85 mM/h/mg of protein and 0.1+0.01 mM, respectively. C6 HSL was found to be the second best substrate with V-max. and K-m value of 10.06+0.27 mM/h/mg of protein and 0.28+0.02 mM, respectively. Molecular modeling and docking studies performed on the active site of the enzyme support these findings by showing the fitting of AHLs perfectly within the hydrophobic pocket of the enzyme active site. (c) 2013 Elsevier Inc. All rights reserved.</p>10aAcyl homoserine lactones10aCV02610aKcPGA10aQuorum quenching1 aMukherji, Ruchira1 aVarshney, Nishant, Kumar1 aPanigrahi, Priyabrata1 aSuresh, C., G.1 aPrabhune, Asmita  uhttps://library.ncl.res.in/content/new-role-penicillin-acylases-degradation-acyl-homoserine-lactone-quorum-sensing-signals-001909nas a2200217   4500008004100000022001400041245016500055210006900220260007900289300001200368490000800380520103200388653001601420653002401436653001001460653002101470653003101491100002201522700002101544856012601565       2015                        eng d  a0273-228900aPossible correlation between bile salt hydrolysis and ahl deamidation: staphylococcus epidermidis RM1, a potent quorum quencher and bile salt hydrolase producer0 aPossible correlation between bile salt hydrolysis and ahl deamid  a999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USAbHUMANA PRESS INCcMAY  a140-1500 v1763 a<p>The aim of the present work was to isolate a bile salt hydrolase (BSH) producer from fermented soy curd and explore the ability of the BSH produced to cleave bacterial quorum sensing signals. Bacterial isolates with possible ability to deconjugate bile salts were enriched and isolated on De Man, Rogosa and Sharpe (MRS) medium containing 0.2 % bile salts. BSH-producing positive isolate with orange-pink-pigmented colonies was isolated and was identified as a strain of Staphylococcus epidermidis using biochemical and phylogenetic tools. S. epidermidis RM1 was shown to possess both potent BSH and N-acyl homoserine lactone (AHL) cleavage activity. Genetic basis of this dual-enzyme activity was explored by means of specific primers designed using S. epidermidis ATCC 12228 genome as template. It was observed that a single enzyme was not responsible for both the activity. Two different genetic elements corresponding to each of the enzymatic activity were successfully amplified from the genomic DNA of the isolate.</p>10aAHL acylase10aBile salt hydrolase10aCV02610aQuorum quenching10aStaphylococcus epidermidis1 aMukherji, Ruchira1 aPrabhune, Asmita  uhttps://library.ncl.res.in/content/possible-correlation-between-bile-salt-hydrolysis-and-ahl-deamidation-staphylococcus-0