Ellagic acid from acorn fringe by enzymatic hydrolysis and combined effects of operational variables and enzymes on yield of the production

Evaluation of brilliant green decolorization by LiP purified from a novel Penicillium chrysogenum isolated from Similipal forest soil, Odisha

Lignin peroxidase (LiP) is a haem-containing microbial ligninolytic enzyme that has gained much attention for its potential application to degrade industrial effluents. In the current study, seven fungi (SLF1-7) showing ligninolytic activity were isolated from Similipal forest soil, and screened for LiP activity. SLF3 showed the highest LiP activity (3.351 U/mL.min) at un-optimized conditions and was identified as P. chrysogenum using 18S rRNA sequencing. The production of enzyme was optimized using Response Surface Methodology. LiP activity of P. chrysogenum was enhanced to 9.38 U.mL-1.min (2.79 folds) at pH 6, temperature 37.5 °C, substrate concentration 1.75%, and time 108 h. The LiP enzyme was purified by ammonium sulfate precipitation followed by dialysis and Sephadex G-100 column chromatography. The purified protein showed a single band of approximately 40 kDa by SDS-PAGE analysis. The purified LiP also showed the highest catalytic efficiency with Km of 0.316 M and Vmax of 147.059 U/mL.min. The purified LiP reduced brilliant green color (69.53 ± 0.003%) after 80 min of incubation at 37 °C and pH 6.0. It is apparent from the study that the strain P. chrysogenum has significant potential in degrading brilliant green, which can be explored for bioremediation applications of industrial dyes.

Production of a Fungal Punicalagin-Degrading Enzyme by Solid-State Fermentation: Studies of Purification and Characterization

The present work describes the purification of an enzyme capable of degrading punicalagin. The enzyme was produced by Aspergillus niger GH1 by solid-state fermentation, and the enzyme production was induced by using ellagitannins as the sole carbon source. The purification steps included the concentration by lyophilization, desalting, anionic exchange, and gel filtration chromatography. The enzyme kinetic constants were calculated by using punicalagin, methyl gallate, and sugar beet arabinans. The molecular mass of the protein was estimated by SDS-PAGE. The identified bands were excised and digested using trypsin, and the peptides were submitted to HPLC-MS/MS analysis. The docking analysis was conducted, and a 3D model was created. The purification fold increases 75 times compared with the cell-free extract. The obtained Km values were 0.053 mM, 0.53% and 6.66 mM for punicalagin, sugar beet arabinans and methyl gallate, respectively. The optimal pH and temperature for the reaction were 5 and 40 °C, respectively. The SDS-PAGE and native PAGE analysis revealed the presence of two bands identified as α-l-arabinofuranosidase. Both enzymes were capable of degrading punicalagin and releasing ellagic acid.

Inhibition profile of a series of phenolic acids on bovine lactoperoxidase enzyme

Lactoperoxidase (LPO) catalyzes the oxidation of numerous of organic and inorganic substrates by hydrogen peroxide. It has very vital activity in the innate immune system by decreasing or stopping the activation of the bacteria in milk and mucosal secretions. This study's purpose was to investigate in vitro effect of some phenolic acids (ellagic, gallic, ferulic, caffeic, quercetin, p-coumaric, syringic, catechol and epicatechin) on the purified LPO. This enzyme was purified from milk by using different methods such as Amberlite CG-50 resin, CM-Sephadex C-50 ion-exchange and Sephadex G-100 gel filtration chromatography. LPO was purified 28.7-fold with a yield of 20.03%. We found phenolic acids have inhibition effects on bovine LPO enzyme to different concentrations. Our study showed lower concentrations of caffeic acid, ferulic acid and quercetin exhibited much higher inhibitory effect on enzyme, so these three of them were clearly a more potent inhibitor than the others were. All of compounds were non-competitive inhibitors.

Carbonic anhydrase inhibitors: Inhibition of human erythrocyte isozymes I and II with a series of phenolic acids

The inhibitory effects of some phenolic acids on the cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes hCA I and hCA II were investigated. Ellagic acid, gallic acid, ferulic acid, caffeic acid, quercetin, p-coumaric acid, p-hydroxybenzoic acid, and syringic acid showed K(I) values in the range of 99-1061 microm for hCA I and of 105-758 microm against hCA II, respectively. Quercetin (for hCA I), p-coumaric acid (for hCA II), and gallic acid (for hCA II) exhibited competitive inhibitory effects with 4-nitrophenyl acetate as substrate. All of the other phenolic acids were found as non-competitive inhibitors with 4-nitrophenylacetate as substrate for hCA I and hCA II. The phenolic acids investigated here showed thus interesting hCA I and hCA II inhibitory effects and might be used as leads for generating enzyme inhibitors possibly targeting other CA isoforms which have not been yet assayed for their interactions with such agents.

Enrichment of phenolics and free radical scavenging property of wheat koji prepared with two filamentous fungi

In the present study, total phenolic content and antioxidant property of wheat (54% ethanolic extract) was drastically enhanced when fermented with two GRAS filamentous fungi, Aspergillus oryzae and Aspergillus awamori nakazawa. A. oryzae yielded significant (P<0.05) amounts of phenolic compounds, DPPH* (2,2-diphenyl-1-picrylhydrazyl) and ABTS*(+) [2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] scavenging properties on 4th day of incubation compared to A. awamori on 5th day of incubation. A linear correlation was observed between total phenolic contents and activities of three different carbohydrate hydrolyzing enzymes (alpha-amylase, beta-Glucosidase and xylanase) produced by A. oryzae. However, in case of A. awamori nakazawa, only two enzymes (xylanase and beta-glucosidase) were mainly responsible for the release of phenolics. This study demonstrated that fermented wheat grain is a better source of phytochemicals compared to non-fermented wheat. In addition, different carbohydrate cleaving enzymes are responsible for the improvement of phytochemical properties of fermented wheat.