Craig B. Faulds
Aix-Marseille University
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Featured researches published by Craig B. Faulds.
FEBS Letters | 2000
Andrea J. Day; F. Javier Cañada; Juan C Dı́az; Paul A. Kroon; Russell Mclauchlan; Craig B. Faulds; Geoff W. Plumb; Michael R.A. Morgan; Gary Williamson
Lactase phlorizin hydrolase (LPH; EC 3.2.1.62) is a membrane‐bound, family 1 β‐glycosidase found on the brush border of the mammalian small intestine. LPH, purified from sheep small intestine, was capable of hydrolysing a range of flavonol and isoflavone glycosides. The catalytic efficiency (k cat/K m) for the hydrolysis of quercetin‐4′‐glucoside, quercetin‐3‐glucoside, genistein‐7‐glucoside and daidzein‐7‐glucoside was 170, 137, 77 and 14 (mM−1 s−1) respectively. The majority of the activity occurred at the lactase and not phlorizin hydrolase site. The ability of LPH to deglycosylate dietary (iso)flavonoid glycosides suggests a possible role for this enzyme in the metabolism of these biologically active compounds.
Applied Microbiology and Biotechnology | 2004
Valerie F. Crepin; Craig B. Faulds; Ian F. Connerton
Abstract Feruloyl esterases have potential uses over a broad range of applications in the agri-food industries. In recent years, the number of microbial feruloyl esterase activities reported has increased and, in parallel, even more related protein sequences may be discerned in the growing genome databases. Based on substrate utilisation data and supported by primary sequence identity, four sub-classes have been characterised and termed type-A, B, C and D. The proposed sub-classification scheme is discussed in terms of the evolutionary relationships existing between carbohydrate esterases.
Microbiology | 1998
Gary Williamson; Paul A. Kroon; Craig B. Faulds
Plants employ an impressive number of ingenious ways to protect themselves from disease. Probably the most important protection against invading micro-organisms is the erection of a tough physical barrier, the plant cell wall, which protects the delicate interior of the plant cell. Pore sizes in the plant cell wall are too small even to allow passage of viruses, and so microbes which infect by penetration must enter either through opportunistic breaks in the wall or by enzymic dissolution (Brett & Waldron, 1990). Plant-saprophytic and -pathogenic micro-organisms produce a range of enzymes to degrade plant cell walls in order to use the cell contents as nutrients or to digest and utilize the polysaccharides in the plant cell wall. This enzyme tool kit has evolved in some micro-organisms to unlock even the most recalcitrant plant cell walls, given time and suitable conditions.
Journal of Applied Microbiology | 2001
D. Couteau; Anne L. McCartney; Glen R. Gibson; Gary Williamson; Craig B. Faulds
D. COUTEAU, A.L. McCARTNEY, G.R. GIBSON, G. WILLIAMSON AND C.B. FAULDS. 2001.
Microbiology | 1994
Craig B. Faulds; Gary Williamson
An inducible ferulic acid esterase (FAE-III) has been isolated, purified and partially characterized from Aspergillus niger after growth on oat spelt xylan. The purification procedure utilized ammonium sulphate precipitation, hydrophobic interaction and anion-exchange chromatography. The purified enzyme appeared almost pure by SDS-PAGE, with an apparent M r of 36000. A single band, corresponding to a pl of 3·3 was observed on isoelectric focusing. With methyl ferulate as substrate, the enzyme had a specific activity of 67 IU (mg protein)-1, pH and temperature optima of 5 and 55–60 °C, respectively, and a Km of 2·08 mM and a V max of 175 μmol min-1 (mg protein)-1. The enzyme was also active upon methyl sinapinate, methyl-3,4-dimethoxy cinnamate and methyl p-coumarate, but not benzoic acid methyl esters or methyl caffeate. Similarly, Streptomyces olivochromogenes FAE showed activity against methyl ferulate, methyl sinapinate and methyl p-coumarate, but at a level 420-fold less (on methyl ferulate) than the A. niger esterase. No activity was detected against the benzoate methyl esters. For both enzymes, this shows the necessity for C-3 on the phenol ring to be methoxylated and the aliphatic region of the substrate to be unsaturated. The specific activity of FAE-III on destarched wheat bran was 31 U (mg protein)-1 in the presence of Trichoderma viride xylanase and 3 U (mg protein)-1 in the absence. Apparent pH dependent binding of A. niger FAE-III to microcrystalline cellulose was also demonstrated.
Applied Microbiology and Biotechnology | 1995
Craig B. Faulds; Gary Williamson
Ferulic acid was efficiently released from a wheat bran preparation by a ferulic acid esterase from Aspergillus niger (FAE-III) when incubated together with a Trichoderma viride xylanase (a maximum of 95% total ferulic acid released after 5 h incubation). FAE-III by itself could release ferulic acid but at a level almost 24-fold lower than that obtained in the presence of the xylanase (2 U). Release of ferulic acid was proportional to the FAE-III concentration between 0.1 U and 1.3 U, but the presence of low levels of xylanase (0.1 U) increased the amount of ferulic acid released 6-fold. Total sugar release was not influenced by the action of FAE-III on the wheat bran, but the rate of release of the apparent end-products of xylanase action (xylose and xylobiose) was elevated by the presence of the esterase. The results show that FAE-III and the xylanase act together to break down feruloylated plant cell-wall polysaccharides to give a high yield of ferulic acid.
Journal of Applied Microbiology | 2007
Giuseppina Mandalari; Richard N. Bennett; Giuseppe Bisignano; Domenico Trombetta; Antonella Saija; Craig B. Faulds; Michael J. Gasson; Arjan Narbad
Aims: To evaluate the antimicrobial properties of flavonoid‐rich fractions derived from bergamot peel, a byproduct from the Citrus fruit processing industry and the influence of enzymatic deglycosylation on their activity against different bacteria and yeast.
Carbohydrate Research | 1994
Ian J. Colquhoun; Marie-Christine Ralet; Jean-François Thibault; Craig B. Faulds; Gary Williamson
1D NMR (1H and 13C) and 2D NMR spectroscopy have been used to determine the structure of feruloylated oligosaccharides obtained by enzymic degradation or mild acid hydrolysis of sugar-beet pulp. Feruloylated oligosaccharides derived from pectic neutral side-chains containing arabinose or galactose residues were identified. In the feruloylated arabinose oligosaccharides, feruloyl groups were linked to O-2 of L-Ara f residues. The structure of the feruloylated arabinose disaccharide was identified as O-[2-O-(transferuloyl)-alpha-L-Ara f]-(1-->5)-L-Ara f and that of the feruloylated arabinose trisaccharide as O-alpha-L-Ara f-(1-->3)-O-[2-O-(trans-feruloyl)-alpha-L-Ara f]-(1-->5)-L- Ara f. The structure of the feruloylated galactose disaccharide was identified as O-[6-O-(trans-feruloyl) -beta-D-Gal p]-(1-->4)-D-Gal p. From our results, we suggest that the feruloyl groups present in sugar-beet pulp are linked to the arabinofuranosyl residues of the main core of alpha-(1-->5)-linked arabinan chains and to the galactopyranosyl residues of the main core of beta-(1-->4)-linked type I galactan chains.
Carbohydrate Research | 1994
Marie-Christine Ralet; Craig B. Faulds; Gary Williamson; Jean-François Thibault
The activity of two forms of ferulic acid esterase (FAE) from Aspergillus niger on a synthetic feruloylated substrate (methyl ferulate) and on 11 different feruloylated oligosaccharides from sugar-beet pulp and wheat bran was determined. The enzymes exhibited different specificities for the various feruloylated substrates and were more active on certain substrates of cell-wall origin than on methyl ferulate. Both enzymes preferred the arabinose residue to which ferulic acid is attached in the furanose form. FAE-I had no clear preference for the type of linkage involved between the ferulic acid units and the oligosaccharide chain. In contrast, FAE-III had a clear requirement for ferulic acid to be attached to O-5 of the Ara f ring while no catalysis was observed when ferulic acid was attached to O-2. Both enzymes showed maximum activity on feruloylated trisaccharides. An increase in the length of the oligosaccharide chain did not preclude catalysis, but feruloylated oligosaccharides of a dp > 3 were hydrolysed at a reduced rate. Our results support the hypothesis that different kinds of ferulic acid esterases exist with different specificities for the oligosaccharide chain of the feruloylated substrates.
Plant Physiology | 2011
Jorge Rencoret; Ana Gutiérrez; Lidia Nieto; Jesús Jiménez-Barbero; Craig B. Faulds; Hoon Kim; John Ralph; Ángel T. Martínez; José C. del Río
Lignin changes during plant growth were investigated in a selected Eucalyptus globulus clone. The lignin composition and structure were studied in situ by a new procedure enabling the acquisition of two-dimensional nuclear magnetic resonance (2D-NMR) spectra on wood gels formed in the NMR tube as well as by analytical pyrolysis-gas chromatography-mass spectrometry. In addition, milled-wood lignins were isolated and analyzed by 2D-NMR, pyrolysis-gas chromatography-mass spectrometry, and thioacidolysis. The data indicated that p-hydroxyphenyl and guaiacyl units are deposited at the earlier stages, whereas the woods are enriched in syringyl (S) lignin during late lignification. Wood 2D-NMR showed that β-O-4′ and resinol linkages were predominant in the eucalypt lignin, whereas other substructures were present in much lower amounts. Interestingly, open β-1′ structures could be detected in the isolated lignins. Phenylcoumarans and cinnamyl end groups were depleted with age, spirodienone abundance increased, and the main substructures (β-O-4′ and resinols) were scarcely modified. Thioacidolysis revealed a higher predominance of S units in the ether-linked lignin than in the total lignin and, in agreement with NMR, also indicated that resinols are the most important nonether linkages. Dimer analysis showed that most of the resinol-type structures comprised two S units (syringaresinol), the crossed guaiacyl-S resinol appearing as a minor substructure and pinoresinol being totally absent. Changes in hemicelluloses were also shown by the 2D-NMR spectra of the wood gels without polysaccharide isolation. These include decreases of methyl galacturonosyl, arabinosyl, and galactosyl (anomeric) signals, assigned to pectin and related neutral polysaccharides, and increases of xylosyl (which are approximately 50% acetylated) and 4-O-methylglucuronosyl signals.