New chromogenic substrates for feruloyl esterases.

Indolyl and nitrophenyl 5-O-hydroxycinnamoyl-alpha-L-arabinofuranosides were prepared by chemo-enzymatic syntheses. These probes were designed as substrates to be used in assays of feruloyl esterase activity (EC 3.1.

FOLy: an integrated database for the classification and functional annotation of fungal oxidoreductases potentially involved in the degradation of lignin and related aromatic compounds.

The breakdown of lignin by fungi is a key step during carbon recycling in terrestrial ecosystems. This process is of great interest for green and white biotechnological applications. Given the importance of these enzymatic processes, we have classified the enzymes potentially involved in lignin catabolism into sequence-based families and integrated them in a newly developed database, designated Fungal Oxidative Lignin enzymes (FOLy).

Gene overexpression and biochemical characterization of the biotechnologically relevant chlorogenic acid hydrolase from Aspergillus niger.

The full-length gene that encodes the chlorogenic acid hydrolase from Aspergillus niger CIRM BRFM 131 was cloned by PCR based on the genome of the strain A. niger CBS 513.88.

Chromogenic substrates for feruloyl esterases.

Chromogenic mono- and diferuloyl-butanetriol analogs were prepared by chemical syntheses and their efficiency was evaluated as substrates for feruloyl esterases from Aspergillus niger.

Exploration of members of Aspergillus sections Nigri, Flavi, and Terrei for feruloyl esterase production.

The ability of members of Aspergillus sections Nigri, Flavi, and Terrei to produce feruloyl esterases was studied according to their substrate specificity against synthetic methyl esters of hydroxycinnamic acids. Type A feruloyl esterases (FAEA), induced during growth on cereal-derived products, show a preference for the phenolic moiety of substrates that contain methoxy substitutions, as found in methyl sinapinate, whereas type B feruloyl esterases (FAEB) show a preference for the phenolic moiety of substrates that contain hydroxyl substitutions, as occurs in methyl caffeate. All the strains of Aspergillus section Nigri (e.

Tracking the connection between evolutionary and functional shifts using the fungal lipase/feruloyl esterase A family.

Background: There have been many claims of adaptive molecular evolution, but what role does positive selection play in functional divergence? The aim of this study was to test the relationship between evolutionary and functional shifts with special emphasis on the role of the environment. For this purpose, we studied the fungal lipase/feruloyl esterase A family, whose functional diversification makes it a very promising candidate.

Results: The results suggested functional shift following a duplication event where neofunctionalisation of feruloyl esterase A had occurred with conservation of the ancestral lipase function.

Respective importance of protein folding and glycosylation in the thermal stability of recombinant feruloyl esterase A.

The thermal stability of four molecular forms (native, refolded, glycosylated, non-glycosylated) of feruloyl esterase A (FAEA) was studied. From the most to the least thermo-resistant, the four molecular species ranked as follows: (i) glycosylated form produced native, (ii) non-glycosylated form produced native, (iii) non-glycosylated form produced as inclusion bodies and refolded, and (iv) glycosylated form produced native chemically denatured and then refolded. On the basis of these results and of crystal structure data, we discuss the respective importance of protein folding and glycosylation in the thermal stability of recombinant FAEA.

Feruloyl esterases as a tool for the release of phenolic compounds from agro-industrial by-products.

Agro-industrial by-products are a potential source of added-value phenolic acids with promising applications in the food and pharmaceutical industries. Here two purified feruloyl esterases from Aspergillus niger, FAEA and FAEB were tested for their ability to release phenolic acids such as caffeic acid, p-coumaric acid and ferulic acid from coffee pulp, apple marc and wheat straw. Their hydrolysis activity was evaluated and compared with their action on maize bran and sugar beet pulp.

Comparison of different fungal enzymes for bleaching high-quality paper pulps.

Wild and recombinant hydrolases and oxidoreductases with a potential interest for environmentally sound bleaching of high-quality paper pulp (from flax) were incorporated into a totally chlorine free (TCF) sequence that also included a peroxide stage. The ability of feruloyl esterase (from Aspergillus niger) and Mn2+-oxidizing peroxidases (from Phanerochaete chrysosporium and Pleurotus eryngii) to decrease the final lignin content of flax pulp was shown. Laccase from Pycnoporus cinnabarinus (without mediator) also caused a slight improvement of pulp brightness that was increased in the presence of aryl-alcohol oxidase.

Purification and characterization of a chlorogenic acid hydrolase from Aspergillus niger catalysing the hydrolysis of chlorogenic acid.

Among 15 Aspergillus strains, Aspergillus niger BRFM 131 was selected for its high chlorogenic acid hydrolase activity. The enzyme was purified and characterized with respect to its physico-chemical and kinetic properties. Four chromatographic steps were necessary to purify the protein to homogeneity with a recovery of 2%.

Homologous expression of the feruloyl esterase B gene from Aspergillus niger and characterization of the recombinant enzyme.

The faeB gene encoding the feruloyl esterase B (FAEB) was isolated from Aspergillus niger BRFM131 genomic DNA. The faeB gene, with additional sequence coding for a C-terminal histidine tag, was inserted into an expression vector under the control of the gpd promoter and trpC terminator and expressed in a protease deficient A. niger strain.

A biotechnological process involving filamentous fungi to produce natural crystalline vanillin from maize bran.

A new process involving the filamentous fungi Aspergillus niger and Pycnoporus cinnabarinus has been designed for the release of ferulic acid by enzymic degradation of a cheap and natural agricultural byproduct (autoclaved maize bran) and its biotransformation into vanillic acid and/or vanillin with a limited number of steps. On the one hand, the potentialities of A. niger I-1472 to produce high levels of polysaccharide-degrading enzymes including feruloyl esterases and to transform ferulic acid into vanillic acid were successfully combined for the release of free ferulic acid from autoclaved maize bran.