Pneumatosis Intestinalis Induced by Alpha-Glucosidase Inhibitors in Patients with Diabetes Mellitus.

Alpha-glucosidase inhibitor (αGIs)-induced pneumatosis intestinalis (PI) has been narrated in case reports but never systematically investigated. This study aimed to investigate the concurrency of PI and αGIs. A literature search was performed in PubMed, Google Scholar, WorldCat, and the Directory of Open-Access Journals (DOAJ) by using the keywords "pneumatosis intestinalis", "alpha-glucosidase inhibitors", and "diabetes". In total, 29 cases of αGIs-induced PI in 28 articles were included. There were 11 men, 17 women, and one undefined sex, with a median age of 67. The most used αGI was voglibose (44.8%), followed by acarbose (41.4%) and miglitol (6.8%). Nine (31%) patients reported concomitant use of prednisone/prednisolone with or without immunosuppressants. The main symptoms were abdominal pain (54.5%) and distention (50%). The ascending colon (55.2%) and the ileum (34.5%) were the most affected. Nineteen (65.5%) patients had comorbidities. Patients with comorbidities had higher rates of air in body cavities, the portal vein, extraintestinal tissues, and the wall of the small intestine. Only one patient was found to have non-occlusive mesenteric ischemia. Twenty-five patients were treated with conservative therapy alone, and two patients received surgical intervention. All patients recovered. In conclusion, comorbidities, glucocorticoids, and immunosuppressants aggravate αGIs-induced PI. Conservative therapy is recommended when treating αGIs-induced PI.

Bioanalytical method by HPLC-FLD for curcumin analysis in supplemented athletes.

In sports, curcumin, a substance derived from the rhizome of Curcuma longa (turmeric) plant with antioxidant effect 8 times greater than vitamin E, has attracted the attention of scientists because of its potent antioxidant action, since in athletes subjected to intense exercise the-endogenous mechanisms of neutralization of reactive species are saturated. However, the pharmacokinetic characteristics of curcumin do not favor its medicinal use due to its low absorption, accelerated metabolism and rapid systemic elimination. Thus, the determination of plasma levels in supplemented patients is a crucial step in their pharmacodynamic evaluation. Therefore, the objective of this work was to develop and validate an analytical method by HPLC-FLD for curcumin evaluation in plasma of supplemented athletes. Luna column (C18; 150 × 4 mm; 3 µm), acetonitrile: acetic acid pH 3.2 (45:55 to 60:40) as mobile phase, flow rate of 1 mL min-1, excitation at 429/285 nm and emission at 529 nm and injection of 10 µL were the chromatographic conditions used. Plasma samples were extracted using ethylacetate and methanol (95: 5, 500 µL) and estradiol (30 µg mL-1) as internal standard, with subsequent stirring (3 min) and centrifugation (8 min) (triple extraction). The organic fraction was evaporated under N2 (20 min) and the dried residue reconstituted in acetonitrile. The method was linear between 44 and 261 ng mL-1, showing intra-day (2.05.6%) and inter-day (4.0-5.1%) precision with accuracy and selectiveness (curcumin tR = 8.7 min and internal standard tR = 13.9 min with relative recovery of 83.2%). So, it can be successfully used for curcumin evaluation in plasma samples from supplemented athletes, as well as being an alternative and advantageous method to UV-Vis and MS/MS in bioavailability studies.

Clinical updating study at 3 years on 278 patients treated by modern artificial hair implant technique (automatic biofibre®).

In this study, we report our multicentric experience of synthetic medical certified polyamide hair implants in male androgenetic, female menopausal, and chronic alopecia. Biofibre hair implantation was performed by means of a standardized, mini-invasive technique followed by regular postoperative care along 3 years. From May 2015, 278 patients were enrolled and 253 completed the trial; 202 men (79.9%) versus 51 women (20,1%). The average age was 43(± 4.29); 179 patients (70.1%) had taken previous treatments for alopecia. We evaluated efficacy (as judged by Hamilton scale grading, covered area percent, surgeon, and patient's subjective evaluation) and safety (as judged by adverse events). The overall scalp surface restored with artificial hair (mm2 spaced) and pre-postoperative general customers' satisfaction (by Hamilton scale grading) are reported, showing a significant (98,14%) subjective and objective improvement of the self-image. Twenty-two cases (8.75%) declared minor side effects generally counteracted by topical or short course systemic antibiotic and anti-inflammatory treatment. The average number of implanted fibers was 2,295 (SD 2.805; SE 200.9) ranging from 300 to 16,000. The average duration of pain and tenderness at the implant area was 2.2 days (SD 4.096; SE 0.2933) ranging from 1 to 20 days. A diagrammatic comparison of the Hamilton scale grading before and after the trial showed a dramatic improvement with the majority of the patients being in Hamilton grade II after implantation.

Optimization of laccase-alginate-chitosan-based matrix toward 17 α-ethinylestradiol removal.

Laccase extract (LE) from Pycnoporus sanguineus was immobilized on calcium and copper alginate-chitosan beads and applied for the removal of 17α-ethinylestradiol (EE2). Effects of immobilization conditions such as: sodium alginate (SA) concentration; LE/SA ratio and chitosan/ion (Ca+2 or Cu+2) ratio on the immobilization yield were investigated. Immobilized LE on Ca-beads and Cu-beads was then used to degrade an EE2 solution. The optimal conditions for LE immobilization on Ca-beads were: 1.5% (w/v) SA, 1:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Ca+2). The optimal conditions for immobilization on Cu-beads were 2.0% (w/v) SA, 0.5:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Cu+2). The best result was obtained for immobilized LE on Ca-beads in buffer-absent medium. Furthermore, the immobilized enzyme was reused in five cycles for EE2 removal. The formation of EE2 dimers by LE treatment has been demonstrated by electrospray ionization coupled to time of flight mass spectrometer (ESI-TOF-MS). The results evidenced that immobilized LE in alginate-chitosan-divalent cation bead is an effective alternative for EE2 removal.

Stability of immobilized laccase on Luffa Cylindrica fibers and assessment of synthetic hormone degradation.

In this work were studied the pH, thermal, and storage stability of free and immobilized laccases. Enzymes were produced by Pleurotus ostreatus on potato dextrose (PD) broth and potato dextrose modified (PDM) broth, and immobilized using Luffa cylindrica fibers as support. Both free and immobilized enzymes were assessed on their respective enzymatic activities and for 17α-ethinylestradiol (EE2) degradation. The optimum pH conditions concerning laccase activity ranged from 3.6 to 4.6, while temperature ranged between 30 °C and 50 °C for both free and immobilized enzyme. Laccase produced using PD broth presented greater storage stability and thermal stability than that of PDM. Best EE2 removals were of 79.22% and 75.00% for the free and immobilized enzymes, respectively. Removal rates were assessed during 8 h at pH 5. The removal of 17α-ethinylestradiol was stabilized in the fourth cycle of use. Results imply that immobilization promoted stability towards pH and temperature variations, although media played a decisive role in the enzymatic activity. Both free and immobilized laccases of P. ostreatus were able to degrade EE2, whereas immobilized laccase in PDM medium presented possible reuse applicability, albeit removal was not optimal when compared to other reports.

Degradação do repelente DEET pelas lacases do Pleurotus ostreatus / Degradation of repellent DEET by Pleurotus ostreatus laccases

Objetivo: Avaliar a capacidade de remediação do DEET em meio líquido, pelo fungo de decomposição branca Pleurotus ostreatus usando como indutor enzimático os resíduos sólidos do cacau e realizar bioensaios de toxicidade com as amostras pós-tratamento, para aplicações em tratamentos de águas. Método: Foi realizada a produção enzimática com resíduos do Cacau. A biorremediação com o caldo enzimático foi realizada em erlenmeyers de 250mL, contendo a solução do composto, tampão acetato de sódio pH 5 e o caldo batata, incubados à 28°C, com rotação de 120 rpm, por 48 horas. Já com o fungo ativo, o mesmo foi incubado a 28 ºC e teve em seu meio a adição do composto. As amostras foram quantificados em Cromatografia líquida de alta performance (CLAE). O teste de adsorção foi feito com o fungo autoclavado e analisado após 14 dias. Resultado: O composto se apresentou possivelmente tóxico e a remediação mostrou uma tendência linear de degradação com o fungo de 39%. Conclusão: Pleurotus ostreatus é um candidato promissor para o tratamento de contimanações geradas por DEET.

Objective: We evaluated the remediation capacity of DEET in liquid medium by the white decomposition fungus Pleurotus ostreatus using the solid residues of cocoa as an enzymatic inducer and performed toxicity bioassays with the post-treatment samples, for water treatment applications. Method: Enzymatic production with cocoa residues was performed. Bioremediation with the enzyme broth was performed in a 250mL erlenmeyer flasks, containing the solution of the compound, sodium acetate buffer pH 5 and the potato broth, incubated at 28 °C, with rotation of 120 rpm, for 48 hours. With the active fungus, the same was incubated at 28 ºC and had in its culture medium the addition of the compound. The samples were quantified in high performance liquid chromatography (HPLC). The adsorption test was performed with the autoclaved fungus and analyzed after 14 days. Results: The compound was possibly toxic and the remediation showed a linear tendency of degradation of 39% with the fungus. Conclusion: Pleurotus ostreatus is a promising candidate for the treatment of contaminants generated by DEET.

Cupuaçu (Theobroma grandiflorum) residue and its potential application in the bioremediation of 17-Α-ethinylestradiol as a Pycnoporus sanguineus laccase inducer.

Bioremediation is a strategy to mitigate environmental impacts of hazardous pollutants from anthropogenic sources. Natural byproducts, including agroindustrial wastes (AW) can be used to induce enzyme biosynthesis, leading up to enhancement of pollutants degradation process. Therefore, this study aimed to evaluate the use of cupuaçu, Theobroma grandiflorum AW as Pycnoporus sanguineus Laccase (Lac) inducer in order to promote 17-α-ethinylestradiol (EE2) bioremediation. The macro and micro-nutrients levels of cupuaçu AWs were evaluated in order to establish further correlations with enzymatic biosynthesis induction. The fungus was cultivated for 7 days in temperature of 28 ± 2 °C and agitation of 150 rpm. For bioremediation, Lac enzymatic extract was added to EE2 solution (10 µg mL-1) and the percentage of removal was evaluated by HPLC after 1-24 hr of reaction. At optimized conditions, the enzyme extract production was remarkably enhanced by adding only 1% (w/v) of cupuaçu AW. Lac activity reached 1642 U mL-1 on the 6th day of culture, which was higher than positive control (511 U mL-1). 86% of EE2 removal was reached after 4 hr, and after 8 hr of reaction, 96.5% was removed. Analysis by direct infusion in MS-ESI-TOF exhibited intermediary compounds formed by radical hydroxilation.

Removal of synthetic sex hormones by hydrothermal carbonization.

One of the most prominent fields of environmental chemistry is the study and the removal of micro-pollutants from aqueous matrices. Analytical techniques for their identification and quantification are becoming more sensitive and comprehensive and, as a result, an increasing number of drugs have been detected in environmental samples. However, the literature shows that conventional treatments for drinking water and wastewater are not sufficient for remove these compounds. This study aims to check whether the process of hydrothermal carbonization (CHT) is effective in removing the synthetic sex hormones: ethinyl estradiol, gestodene and cyproterone acetate from aqueous samples. The system used in CHT basically consists of a pressurized reactor made of stainless steel and solutions of compounds of interest, both individual and mixed, with a concentration of 1.0 µg.L-1 and a pH range of 2.0 to 3.0. The maximum surface temperature in the reactor was about 180 °C, the internal pressure was 20 bar with 90 minutes for the reaction. Four experiments were conducted, one for each hormone and one with the three hormones together. In individual tests removal of the compounds was found to be 99.8% for ethinyl estradiol, 99.3% for gestodene and 100% for cyproterone acetate. For a mixture of the hormones treated under the same conditions, the mean values of CHT-removal of Ethinylestradiol, Gestodene and Cyproterone Acetate were 99.60%, 96.80% and 68.90%, respectively. The impact of the matrix effect may have affected the efficiency of the hormone removal process by CHT.

Automatic Artificial Hair Implant: Safety and Efficacy in Androgenetic Alopecia. A Prospective Study with a Highly Biocompatible Fiber.

AIM: A multi - centre two years the long prospective open clinical study was conducted in five countries located in four different continents from May 2015 to evaluate the clinical safety and efficacy of Automatic Biofibre hair implant in male and female androgenetic alopecia. Biofibre®is a CE/TGA certified medical grade polyamide fibre suitable for implantation. MATERIAL AND METHODS: A total of 213 patients were enrolled in the study. Patients were assessed pre -operatively by Hamilton scale grading and the percentage of scalp covered by hair. All the patients underwent Biofibre hair implantation by a standardised surgical technique followed by adequate post-operative care. Efficacy of the implant was evaluated by surgeons and patients bimonthly for the first year and trimonthly during the second year. Any adverse effects were recorded during these visits. RESULTS: At the completion of the study period, a total of 194 patients concluded the trial and the results were statistically evaluated. Both Hamilton scale grading and covered area percent improved at the end of the study, and subjective and objective evaluations revealed satisfactory results. Side effects were reported in only 18 cases (9.27%) which were easily controlled by either topical or systemic treatment in 8 to 10 days. CONCLUSION: Overall a successful result was noticed in 97.94% of patients with great psychological satisfaction.

Electroanalysis and laccase-based biosensor on the determination of phenolic content and antioxidant power of honey samples.

Honey is a functional food widely consumed. Thus, the evaluation of honey samples to determine its phenolic content and antioxidant capacity (AOC) is relevant to determine its quality. Usually AOC is performed by spectrophotometric methods, which lacks reproducibility and practicality. In this context, the electroanalytical methods offer higher simplicity and accuracy. Hence, the aim of this work was to use of electroanalytical tools and laccase based biosensor on the evaluation of AOC and total phenol content (TPC) of honey samples from different countries. The antioxidant power established by electrochemical index presented good correlation with the spectrophotometric FRAP (Ferric Reducing Ability of Plasma) and DPPH (2,2-Diphenyl-1-Picrylhydrazyl) radical scavenging assays. Also, TPC results obtained by the biosensor agreed with the Folin-Ciocalteu (FC) assay. In addition to the semi quantitative results, the electroanalysis offered qualitative parameters, which were useful to indicate the nature of major phenolic compounds.

Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection.

The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 µM (r = 0.99), showing detection limits of 0.4 µM. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compounds.

Estudo da descoloração do corante FD&C azul no 2 Indigotina pelo tratamento combinado do fungo Trametes versicolor e processo de filtração lenta / Study of decolorization of FD&C blue # 2 indigotine by fungus Trametes versicolor combined with slow sand filtration

O uso de fungos na descoloração de corantes com métodos economicamente viáveis de produção de água bacteriologicamente segura há muito vem sendo descrito por diversos autores. Este trabalho teve por objetivo investigar a eficiência da remoção de corante artificial FD&C azul no 2 Indigotina, com uso do fungo de degradação branca Trametes versicolor em combinação com a filtração lenta. Para a realização dos trabalhos, foram instalados dois protótipos de filtros lentos denominados FL-A e FL-B - no sobrenadante do filtro FL-A foi inoculado o referido fungo, e o filtro FL-B foi utilizado como controle (sem inoculação do microrganismo). O melhor percentual de remoção do corante pelo fungo Trametes versicolor em combinação com a filtração lenta foi de 44,74% 24 horas após a atividade máxima registrada de lacase. Os resultados mostraram que a filtração lenta combinada com o tratamento com o fungo T. versicolor não apresenta grande potencial para remoção de cor em 21 dias de tratamento, visto que os produtos microbianos gerados interferem no processo de filtração, diminuindo a eficiência do processo físico. Entretanto, restringindo o tempo de tratamento a 24 horas após a atividade enzimática máxima, o tratamento combinado apresentou boa eficiência.

The use of fungi in the decolorization of dyes with economically viable methods of producing bacteriologically safe water has long been described by several authors. This study aimed to investigate the removal efficiency of artificial coloring FD&C Blue no 2 Indigo, using the degradation white fungus Trametes versicolor in combination with slow sand filtration. Two prototype filters slowly termed FL-A and FL-B were installed - the supernatant water of filter FL-A was inoculated with the fungus, while filter FL-B was used as control. The best percentage of dye removal by the fungus Trametes versicolor in combination with the slow sand filtration was 44.74% achieved 24 hours after the maximum laccase activity. The results show that the combination of the fungus T. versicolor with slow sand filtration treatment presents no great potential for color removal at 21 days of treatment, whereas microbial products generated interfere with the filtration process, lowering the efficiency of the physical process. However, with the restriction of the handling time into 24 hours after the maximum enzymatic activity, combined treatment showed good efficiency.

Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 crude extract

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis.

Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 Crude extract.

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis.

Production of laccase by Pynoporus sanguineus using 2, 5 - Xylidine and ethanol

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5 - xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5 - xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.

Production of laccase by Pynoporus sanguineus using 2,5 - Xylidine and ethanol.

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5-xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L(-1) of 2,5-xylidine or 50 g.L(-1) of ethanol, the maximum activity of laccase was 2019 U.L(-1) and 1035 U.L(-1), respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L(-1), inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.

Aspectos técnicos e legais do gerenciamento de resíduos químico-farmacêuticos / Technical and legal aspects on management of chemical and pharmaceutical residues

O risco ambiental decorrentes da geração de resíduos tem aumentado com o progresso tecnológico, bem como com o aumento populacional. Destacam-se, neste contexto, os riscos potenciais decorrentes da rotina de indústrias químico-farmacêuticas, bem como de laboratórios de ensino e pesquisa associados. Por esta razão, vários projetos visando à otimização do tratamento de resíduos industriais e/ou laboratoriais vêm sendo propostos. A presente revisão apresenta uma síntese das estratégias implantadas no sentido de minimizar ou solucionar problemas relacionados ao manejo dos resíduos, provenientes de indústrias, instituições de pesquisa e ensino, entre outros potenciais geradores de resíduos. Apresentam-se as diretrizes legais mais gritantes e alguns aspectos técnicos relacionados à segregação, acondicionamento, tratamento e descarte final destes resíduos.

The environmental risks from waste production has arisen with the technological progress, as well as with the world population increase. The risks from the industrial or academic routines in pharmaceutical or fine chemical plants and projects are remarkable. For this reason, many projects focusing on the optimization of waste treatment in these places have been proposed. This paper, reviews some of the main strategies introduced, in order to solve or decrease the problems, in the management of pharmaceutical-chemical wastes in industry, universities, among other potential kind of waste generators. The main regulatory and technical aspects, associated to segregation, packaging, treatment and final disposal of these wastes are presented.

Artificial hair fiber restoration in the treatment of scalp scars.

BACKGROUND: There is presently no treatment for scalp scars that is fully satisfactory. The modalities of treatment currently in use are surgery, hair transplantation, and micropigmentation. Scalp implantation with artificial hair fibers is used by some physicians as an adjunctive treatment. OBJECTIVE: The objective was to assess the utility of artificial hair fibers to treat scalp scars. METHODS: Data were collected by the principal author from 10 hair restoration practitioners who tested polyamide hair fiber (Biofibre CE 0373/TGA by Medicap Ltd., Carpi (MO), Italy) implantation for scalp scars. RESULTS: Artificial hair fiber implantation occurred between June 1996 and December 2000, and observations continued until December 2004. Data from 54 scars from 44 patients treated showed: (1) no complications in 49 scars (90.7%); (2) mild adverse outcomes in 4 scars (7.4%)-temporary superficial inflammation-infection that subsided following topical cortisone and local/systemic antibiotic treatment; and (3) moderately adverse outcomes in 1 scar (1.9%)-significant inflammation and generalized infection requiring removal of artificial implant to alleviate. Occasional minor skin reactions, sebum plugs, and hyperseborrhea were successfully controlled and well accepted by patients. Fiber fall rate was 20% on average per annum. CONCLUSION: Data show that polyamide hair fiber restoration can be considered an adjunctive treatment for scalp scars in selected cases.

Studies on the Pycnoporus sanguineus CCT-4518 laccase purified by hydrophobic interaction chromatography.

A laccase from Pycnoporus sanguineus was purified by two steps using phenyl-Sepharose columm. A typical procedure provided 54.1-fold purification, with a yield of 8.37%, using syringaldazine as substrate. The molecular weight of the purified laccase was 69 and 68 kDa as estimated by 12% (w/v) SDS-PAGE gel and by gel filtration, respectively. The K (m) values for the substrates ABTS, syringaldazine, and guaiacol were 58, 8.3, and 370 muM, respectively. The enzyme's pH optimum for syringaldazine was 4.2 and optimal activity was 50 degrees C. The enzyme showed to be thermostable because when kept at 50 degrees C for 24 and 48 h it retained 93 and 76% activity. This laccase was inhibited by L: -cysteine, beta-mercaptoethanol, NaN(3), NaF, and HgCl(2).

Properties of laccases produced by Pycnoporus sanguineus induced by 2,5-xylidine.

Two isoforms of laccase produced from the culture supernatant of Pycnoporus sanguineus were partially purified by phenyl-Sepharose chromatography. Molecular masses of the enzymes were 80 kDa (Lac I) and 68 kDa (Lac II). Optimum activity of Lac I was at pH 4.8 and 30 degrees C, and Lac II was at pH 4.2 and 50 degrees C over 5 min reaction. The Km values of enzymes toward syringaldazine were 10 microM: (Lac I) and 8 microM: (Lac II). Sodium azide inhibited Lac I (85%) and Lac II (75%) activities.