| 1. |
- Acevedo, F., et al.
(författare)
-
A practical culture technique for enhanced production of manganese peroxidase by Anthracophyllum discolor Sp4
- 2011
-
Ingår i: Brazilian archives of biology and technology. - 1516-8913 .- 1678-4324. ; 54:6, s. 1175-1186
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, different growth conditions of Anthracophyllum discolor Sp4 including the effect of agitation, additions of lignocellulosic support, inducer and surfactant were evaluated on the MnP production in Kirk medium using a culture system made up of the tubes containing the glass bead. The highest MnP production (1,354 U/L on day 13) was obtained when the medium was supplemented with wheat grain and 0.25 mM MnSO 4 as inducer, under static conditions at 30°C. Two isoenzymes were purified (35 and 38 kDa respectively). MnP presented a maximal activity in the pH range between 4.5 and 5.5, a relatively high temperature tolerance (50°C) and a high catalytic activity for 2,6-dimethoxyphenol and hydrogen peroxide.
|
|
| 2. |
|
|
| 3. |
- Pezoa, R., et al.
(författare)
-
Use of ionic liquids in the pretreatment of forest and agricultural residues for the production of bioethanol
- 2010
-
Ingår i: Cellulose Chemistry and Technology. - : Publishing House of the Romanian Academy. - 0576-9787. ; 44:4-6, s. 165-172
-
Tidskriftsartikel (refereegranskat)abstract
- Pretreatment of lignocellulosic materials is an important step to achieve higher amounts of simple sugars, mono- and disaccharides, for obtaining ethanol as a biofuel, via enzymatic hydrolysis. The study introduces a concept that utilizes ionic liquids (ILs) as solvents in the pretreatment step, before enzymatic saccharification, for both forest residues (Eucalyptus (Eucalyptus globulus Labill.) and Lenga (Nothofagus pumilio (POEPP. EX. ENDL.) KRASSER) and for agricultural residues (wheat and corn). The procedure was evaluated at four different temperatures (80, 121, 150 and 170 °C) for 30 and 60 min, respectively, with 1-ethyl-3-methylimidazolium chloride ([EMIM+][Cl-]). Subsequent enzymatic hydrolysis of these materials was carried out at 47 °C, for 72 h, with commercial cellulases. The results demonstrated that the best experimental conditions found for wheat, corn and Eucalyptus residues were the following: 150 °C, for 60 min, yielding a total of 46, 48 and 30% sugars, respectively; in the case of Lenga residues, the optimum conditions were: 150 °C for 30 min, yielding a total of 40% sugars after saccharification. Temperatures exceeding 170 °C are not recommended for this type of pretreatment with [EMIM+][Cl-], because significant portions of cellulose could be dissolved in this IL. Finally, an analysis of the solid material after ionic liquid pretreatment is required, to determine the changes related to lignin, cellulose and hemicellulose composition.
|
|
| 4. |
- Leyton, A., et al.
(författare)
-
Identification and efficient extraction method of phlorotannins from the brown seaweed Macrocystis pyrifera using an orthogonal experimental design
- 2016
-
Ingår i: Algal Research. - : Elsevier. - 2211-9264. ; 16, s. 201-208
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract The brown seaweed contains a type polyphenol compound characteristic of its species, the phlorotannins, which are produced from the polymerization of phloroglucinol units. They have been extensively studied due to their pharmacological and nutraceutical properties, but there is still a need for an optimized extraction protocol. In this study, the brown seaweed Macrocystis pyrifera was employed to determine the best conditions for extraction of phlorotannins. A set of different variables were evaluated such as the use of pre-treatment, type of solvent, drying temperature, particle size, temperature and extraction time as well as the solid/liquid ratio upon extraction. The optimal conditions for the extraction of phlorotannins were: pre-treatment with hexane, extraction with water, drying temperature 40 °C, particle size below 1.4 mm, at 55 °C for 4 h and a solid-to-liquid ratio of 1:15. Under these conditions, the concentration of phlorotannins achieved in the extract was 200.5 ± 5.6 mg gallic acid equivalent (GAE)/100 g dry seaweed (DS) and total antioxidant activity of the extract of 38.4 ± 2.9 mg trolox equivalent (TE)/100 g DS. Further, it was possible to identify two phlorotannins through HPLC-ESI-MS analyses: phloroeckol and a tetrameric phloroglucinol. These phlorotannins have been reported in the literature to have an antidiabetic effect and prevention of Alzheimer's disease for phloroeckol, and free radical scavenging ability and antiallergic effect for tetrameric phloroglucinol. Therefore, the extract of phlorotannins has potential as medicinal foods or therapeutics for human health applications.
|
|
| 5. |
- Leyton, A., et al.
(författare)
-
Improvement in carbohydrate and phlorotannin extraction from Macrocystis pyrifera using carbohydrate active enzyme from marine Alternaria sp. as pretreatment
- 2017
-
Ingår i: Journal of Applied Phycology. - : Springer Science and Business Media LLC. - 0921-8971 .- 1573-5176. ; 29:4, s. 2039-2048
-
Tidskriftsartikel (refereegranskat)abstract
- The commercial importance of brown seaweed has been increasing over the past decade, especially due to industries interested in the extraction of phycocolloids and, more recently, of polyphenol compounds such as phlorotannins. The objective of this work was to optimize the extraction conditions of carbohydrates and phlorotannins from Macrocystis pyrifera, evaluated enzymatic pretreatment and different parameters of extraction using design of experiment. The optimal conditions upon extraction of the carbohydrates and phlorotannins were determined by means of a pretreatment protocol taking advantage on a carbohydrate active enzyme, followed by an alkaline hydrolysis with 0.5 N NaOH at 100 °C, 180 min, and S/L ratio of 1/20. In order to extract the carbohydrates, the best conditions found for the pretreatment procedure were 37 °C, pH 7.0 for 24 h, and a S/L ratio of 1/10, giving an extraction yield (EY) of 89.67 ± 12.3 wt.%. In turn, for the extraction of phlorotannins, the best conditions identified in terms of the pretreatment were 25 °C, pH 7.0 for 36 h, and a S/L ratio of 1/20, thus giving a yield (EY) of 2.14 ± 0.25 wt.%. Statistical analysis of both processes revealed a maximum EY of 91.24 wt.% for carbohydrates and 3.31 wt.% EY for phlorotannins.
|
|
