Purification, Biochemical Characterization and Decolorization Efficiency of Laccases from Peach and Cherry Cultures of Pleutorus eryngii: A Comparative Study.

BACKGROUND: Laccases (Lacs) are used potentially in industrial and biotechnological applications such as decolorization of dyes, degradation of industrial effluents, delignification, etc. thanks to their large varieties of substrate specificities and excellent catalytic efficiencies. The efficient utilizations of Lacs in these applications mostly depend on the identifying their biochemical properties. OBJECTIVE: The goal of this research is to investigate the purification, biochemical characterization and decolorization efficiencies of Lacs. METHODS: Pleurotus eryngii was incubated on peach (PC) and cherry (CC) wastes under optimized solid state fermentation conditions. Then, the enzymes extracts were purified by ammonium sulfate precipitation, anion exchange chromatography, gel filtration, respectively. Lacs fractions were subjected to electrophoretic analyses as well as their structural and kinetic characteristics. Also, the effects of selected chemical agents on purified Lacs activities and determination of decolorization efficiencies were studied. RESULTS: As the results of purification processes of Lacs from both cultures, 3.94-fold purification was obtained for PC, while it was 5.34 for CC. The electrophoretic results of purified Lacs illustrated the single bands of protein (30±1 kDa) in accordance with the results after gel filtration. The Km values of Lacs from PC and CC were respectively detected as 1.1381 and 0.329 mM for ABTS. The selected agents partially/completely inhibited Lac activities. The highest decolorization efficiencies of purified Lacs from PC and CC were separately obtained as 53 and 11.8%. CONCLUSION: The results clearly indicated that the performances of Lacs from both cultures in decolorization application are different from each other depending their activities, biochemical and kinetic characteristics.

Extracellular ligninolytic enzymes production by Pleurotus eryngii on agroindustrial wastes.

Pleurotus eryngii (DC.) Gillet (MCC58) was investigated for its ligninolytic ability to produce laccase (Lac), manganese peroxidase (MnP), aryl alcohol oxidase (AAO), and lignin peroxidase (LiP) enzymes through solid-state fermentation using apricot and pomegranate agroindustrial wastes. The reducing sugar, protein, lignin, and cellulose levels in these were studied. Also, the production of these ligninolytic enzymes was researched over the growth of the microorganism throughout 20 days, and the reducing sugar, protein, and nitrogen levels were recorded during the stationary cultivation at 28 ± 0.5°C. The highest Lac activity was obtained as 1618.5 ± 25 U/L on day 12 of cultivation using apricot. The highest MnP activity was attained as 570.82 ± 15 U/L on day 17 in pomegranate culture and about the same as apricot culture. There were low LiP activities in both cultures. The maximum LiP value detected was 16.13 ± 0.8 U/L in apricot cultures. In addition, AAO activities in both cultures showed similar trends up to day 17 of cultivation, with the highest AAO activity determined as 105.99 ± 6.3 U/L on day 10 in apricot cultures. Decolorization of the azo dye methyl orange was also achieved with produced ligninolytic enzymes by P. eryngii using apricot and pomegranate wastes.

Production of ligninolytic enzymes by solid-state fermentation using Pleurotus eryngii.

Pleurotus eryngii (DC.) Gillet (MCC58) was investigated for its ability to produce various ligninolytic enzymes such as laccase (Lac), manganese peroxidase (MnP), aryl alcohol oxidase (AAO), and lignin peroxidase (LiP) by solid-state fermentation (SSF), which was carried out using a support substrate from the fruit juice industry. The chemical content of grape waste from this industry was studied. Also, the production patterns of these extracellular enzymes were researched during the growth of the organism for a period of 20 days and the protein, reducing sugar, and nitrogen levels were monitored during the stationary cultivation. The highest Lac activity was obtained as 2247.62 ± 75 U/L on day 10 in the presence of 750 µM Mn²âº, while the highest MnP activity was attained as 2198.44 ± 65 U/L on day 15 in the presence of 500 µM Mn²âº. Decolorization of methyl orange and reactive red 2 azo dyes was also achieved with ligninolytic enzymes, produced in SSF of P. eryngii.

Manganese peroxidase production by immobilized Phanerochaete chrysosporium BKM-F-1767 in a cell bioreactor.

Manganese-dependent peroxidase (MnP) production was performed in an immobilized cell bioreactor in which Phanerochaete chrysosporium BKM-F-1767 was immobilized on polystyrene foam. The immobilized cell culture yielded significantly greater MnP activity than the conventional stationary liquid culture. Cultivation was carried out in batch mode; the effect of glucose concentration was investigated and growth kinetics parameters were found as, micromax=0.59 day(-1), Ks=0.33 g/L and Kss=14.5. Batch operation led to maximum MnP (770.82 U/L) in the culture medium containing 0.05% Tween 80, 10 g/L glucose, and 174 microM Mn2+ at 37 degrees C and pH 4.5. Enzyme productivity was obtained as 110.12 U/day/L.

Enhanced production of manganese peroxidase by Phanerochaete chrysosporium

Production of manganese-dependent peroxidase (MnP) by the white-rot fungus Phanerochaete chrysosporium BKM-F-1767 (ATCC 24725) was monitored during growth in different media and growth conditions. The effect of some activators of MnP production, Mn2+, Tween 80, phenylmethylsulphonylfloride (PMSF), oxygen, temperature, pH, glycerol and nitrogen was studied. Supplementing the cultures with Tween 80 (0.05 percent, v/v) and Mn2+ (174 µM) resulted a maximum MnP activity of 356 U/L which was approximately two times higher than that obtained in the control culture (without Tween 80). Decolourisation of Direct Blue 15 and Direct Green 6 (50 mg/L) was also achieved with MnP.

In vitro antioxidant properties of Cucurbita pepo L. male and female flowers extracts.

Total antioxidant capacities, 2,2-diphenyl-1-picrylhydrazyl (DPPH.), hydroxyl (HO.), scavenging activities, and total phenolic values were determined in extracts of Cucurbita pepo L. female and male flowers. Powdered C. pepo L. samples were extracted in aqueous ethyl acetate (EA: W1, 17:3), ethanol (E), and water (W) by agitating in magnetic stirrer for 80 degrees C, 15 min and also by in aqueous ethyl acetate (EA: W2, 17:3) at 25 degrees C, 15 min. DPPH., HO. scavenging capacities and total phenolic values of C. pepo L. female and male were higher in EA:W2 than in other extracts. In addition, all determined antioxidant capacities of female were significantly higher than male.

A novel carrier for Phanerochaete chrysosporium immobilization.

Phanerochaete chrysosporium BKMF-1767 cells were immobilized on different carriers. The optimum carrier according to adsorbed P. chrysosporium cells number (86.38%) was determined to be polystyrene foam, a novel carrier. The conditions for the immobilization of cells on polystyrene foam were optimized and determined as 50 rpm, 37 degrees C, and 2h. The results show that the adsorption of P. chrysosporium on polystyrene foam follows the Langmuir adsorption isotherm. High manganese peroxidase activity (421 U/L) and dry mass (4.7 g/L) were recovered from the batch mode polystyrene foam solid state fermentation system.