Search results for "phenolic"
showing 10 items of 200 documents
Mycophenolate mofetil for treatment of active inflammatory bowel disease. Clinical and immunological studies.
1998
The effect of explant cut and cytokinin type on micropropagation of fig (Ficus carica L.) 'Brown Turkey'
2017
This study was conducted to micropropagate 'Brown Turkey' fig, one of the most popular cultivars in California, USA for fresh and dried uses. Nodal segments cut lengthwise or not were cultured on Woody Plant Medium containing 0.3, 1.0 or 3.0 μM of N6 benzyladenine (BA) or kinetin in a 3 (concentrations) × 2 (cytokinins) × 2 (explant types) factorial experiment. 60% of explants became contaminated with various microbes when the standard protocol of washing shoots for 3 h under running tap water. Microbial contamination was nearly eliminated when the running water rinse and the use of an ascorbic acid dip were eliminated. Phenolic exudation was not a problem. Shoots grew longer with more leav…
Phenolic compounds and abscisic acid as potential markers for the floral origin of two Polish unifloral honeys
2012
The phenolic profiles of Polish honey samples from heather (Calluna vulgaris L.) and buckwheat (Fagopyrum esculentum L.) were determined. The phenolic components were isolated from honey samples using Amberlite-XAD-2 as a solid-phase extraction sorbent. For the determination of the composition of the honey extracts HPLC with photodiode array detector was applied. Identification and quantification of phenolics was performed by comparison of their retention times and UV spectra with those of standard solutions of pure reference substances and by using those references as external standards. From among 20 commercially available standards over 15 of them were identified as present in all analys…
The proteome and transcriptome analysis ofBacillus subtilis in response to salicylic acid
2007
Phenolic acids that are present in plant-soil ecosystems can be considered as toxins which induce specific stress responses in microorganisms. In this paper, we have analyzed the global response of the soil bacterium Bacillus subtilis to salicylic acid using proteomics and transcriptomics. The results demonstrate that salicylic acid caused predominantly the induction of the SigmaB-dependent general stress response in B. subtilis which is not related to the acidic conditions. Treatment of B. subtilis with growth-inhibitory concentrations of 4 mM salicylic acid caused protein damage in B. subtilis as reflected by the induction of the CtsR and Spx regulons. Both phenolic acid decarboxylases (p…
Phenolic Acid-Mediated Regulation of the padC Gene, Encoding the Phenolic Acid Decarboxylase of Bacillus subtilis
2008
ABSTRACT In Bacillus subtilis , several phenolic acids specifically induce expression of padC , encoding a phenolic acid decarboxylase that converts these antimicrobial compounds into vinyl derivatives. padC forms an operon with a putative coding sequence of unknown function, yveFG , and this coding sequence does not appear to be involved in the phenolic acid stress response (PASR). To identify putative regulators involved in the PASR, random transposon mutagenesis, combined with two different screens, was performed. PadR, a negative transcriptional regulator of padC expression, was identified. padR is not located in the vicinity of padC , and the expression of padR is low and appears const…
Expression in Escherichia coli of Native and Chimeric Phenolic Acid Decarboxylases with Modified Enzymatic Activities and Method for Screening Recomb…
2001
ABSTRACT Four bacterial phenolic acid decarboxylases (PAD) from Lactobacillus plantarum , Pediococcus pentosaceus , Bacillus subtilis , and Bacillus pumilus were expressed in Escherichia coli , and their activities on p -coumaric, ferulic, and caffeic acids were compared. Although these four enzymes displayed 61% amino acid sequence identity, they exhibit different activities for ferulic and caffeic acid metabolism. To elucidate the domain(s) that determines these differences, chimeric PAD proteins were constructed and expressed in E. coli by exchanging their individual carboxy-terminal portions. Analysis of the chimeric enzyme activities suggests that the C-terminal region may be involved …
Knockout of thep-Coumarate Decarboxylase Gene fromLactobacillus plantarumReveals the Existence of Two Other Inducible Enzymatic Activities Involved i…
2000
ABSTRACTLactobacillus plantarumNC8 contains apdcgene coding forp-coumaric acid decarboxylase activity (PDC). A food grade mutant, designated LPD1, in which the chromosomalpdcgene was replaced with the deletedpdcgene copy, was obtained by a two-step homologous recombination process using an unstable replicative vector. The LPD1 mutant strain remained able to weakly metabolizep-coumaric and ferulic acids into vinyl derivatives or into substituted phenyl propionic acids. We have shown thatL. plantarumhas a second acid phenol decarboxylase enzyme, better induced with ferulic acid than withp-coumaric acid, which also displays inducible acid phenol reductase activity that is mostly active when gl…
Kinetics and Intensity of the Expression of Genes Involved in the Stress Response Tightly Induced by Phenolic Acids in <i>Lactobacillus plantar…
2007
In <i>Lactobacillus plantarum</i>, PadR, the negative transcriptional regulator of <i>padA </i>encoding the phenolic acid decarboxylase, is divergently oriented from <i>padA. </i>Moreover, it forms an operonic structure with <i>usp1,</i> a genewhose products display homology with proteins belonging to the UspA family of universal stress proteins. PadR is inactivated by the addition of <i>p-</i>coumaric, ferulic or caffeic acid to the culture medium. In order to better characterize the stress response of this bacterium to phenolic acids, we report here the kinetics and quantitative expression by qRT-PCR of the 3 genes from the <i…
Ultrasound-assisted green solvent extraction of high-added value compounds from microalgae Nannochloropsis spp.
2015
Abstract The aim of this work was to investigate ultrasound (US)-assisted green solvent extraction of valuable compounds from the microalgae Nannochloropsis spp. Individual green solvents (water, ethanol (EtOH), dimethyl sulfoxide (DMSO)) and binary mixture of solvents (water-DMSO and water-EtOH) were used for the extraction procedures. Maximum total phenolic compounds yield ( Y p ≈ 0.33) was obtained after US pre-treatment ( W = 400 W, 15 min), being almost 5-folds higher compared to that found for the untreated samples and aqueous extraction ( Y p ≈ 0.06). The highest yield of total chlorophylls ( Y c ≈ 0.043) was obtained after US ( W = 400 W, 7.5 min), being more than 9-folds highe…
Field non-destructive determination of nectarine quality under deficit irrigation
2021
This study investigated the effects of deficit irrigation (DI) at different fruit growth stages and tree orientation on fruit quality of ‘September Bright’ nectarines (Prunus persica L. Batsch). Control trees were fully irrigated throughout the entire fruit development period, whereas deficit irrigation was supplied at fruit growth stage I (cell division, DI-I), II (pit hardening, DI-II), IIIa (cell expansion, DI-IIIa) and IIIb (fruit maturation, DI-IIIb). Non-destructive measurements of fruit maturity and quality were carried out using portable devices based on near-infrared spectrometry and pigment fluorescence on west- and east-oriented trees of an Open Tatura system. Chlorophyll degrada…