Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents

Three thermoalkaliphilic bacteria, which were grown at pH 9.3–10 and 60–65 °C were isolated out of a textile wastewater drain. The unknown micro-organisms were identified as thermoalkaliphilic Bacillus sp. Growth nditions were studied and catalase activities and stabilities compared. Catalases from Bacillus SF showed high stabilities at 60 °C and pH 9 (t1/2=38 h) and thus this strain was chosen for further investigations, such as electron microscopy, immobilization of catalase and hydrogen peroxide degradation studies. Degradation of hydrogen peroxide with an immobilized catalase from Bacillus SF enabled the reuse of the water for the dyeing process. In contrast, application of the free enzyme for treatment of bleaching effluents, caused interaction between the denaturated protein and the dye, resulting in reduced dye uptake, and a higher color difference of 1.3 ΔE* of dyed fabrics compared to 0.9 ΔE* when using the immobilized enzyme

An acid-stable laccase from sclerotium rolfsii with potential for wool dye decolourization

The plant pathogen basidiomycete S. rolfsii secretes two laccases (SRL1 and SRL2) with molecular weights of 55 and 86 kDa, respectively. Laccase production was shown to be inducible by the addition of 2,5-xylidine to the cultural media. After treatment with a combination of chitinase and -1,3-glucanase, two different laccases were isolated from the sclerotia depending on the stage of sclerotia development. The more prominent laccase, SRL1, was purified and found to decolourize the industrially important wool azo dye Diamond Black PV 200 without the addition of redox mediators. The enzyme (pI 5.2) was active in the acidic pH range, showing an optimal activity at pH 2.4, with ABTS as substrate. The optimum temperature for activity was determined to be 62 ◦C. Enzyme stability studies revealed that SRL1 was notably stable at 18 ◦C and pH 4.5, retaining almost full activity after a week. Oxidation of tyrosine was not detectable under the reaction conditions but the enzyme did oxidize a variety of the usual laccase substrates. SRL1 was strongly inhibited by sodium azide and fluoride. Dye solutions decolourized with the immobilized laccase were successfully used for redyeing.(undefined

Direct enzymatic esterification of cotton and Avicel with wild-type and engineered cutinases

In this work, the surface of cellulose, either Avicel or cotton fabric, was modified using cutinases without any previous treatment to swell or to solubilise the polymer. Aiming further improvement of cutinase ester synthase activity on cellulose, an engineered cutinase was investigated. Wild-type cutinase from Fusarium solani and its fusion with the carbohydrate-binding module N1 from Cellulomonas fimi were able to esterify the hydroxyl groups of cellulose with distinct efficiencies depending on the acid substrate/solvent system used, as shown by titration and by ATR-FTIR. The carbonyl stretching peak area increased significantly after enzymatic treatment during 72 h at 30 °C. Cutinase treatment resulted in relative increases of 31 and 9 % when octanoic acid and vegetable oil were used as substrates, respectively. Cutinase-N1 treatment resulted in relative increases of 11 and 29 % in the peak area when octanoic acid and vegetable oil were used as substrates, respectively. The production and application of cutinase fused with the domain N1 as a cellulose ester synthase, here reported for the first time, is therefore an interesting strategy to pursuit.This work was co-funded by the European Social Fund through the management authority POPH and FCT, Postdoctoral fellowship reference: SFRH/BPD/47555/2008. The authors also want to thank Doctor Raul Machado for his valuable help on FTIR spectral data treatment

Influence of cellulases on indigo backstaining

We have found that increasing concentrations of fungal cellulases on a fabric decrease indigo staining levels. Deletion of the cellulose binding domains (CBD) from either bacterial or fungal cellulases decreases indigo staining levels and generally causes less backstaining than the entire enzyme. Increasing the concentration of cellulases with a CBD of family I on fabric decreases indigo staining, whereas increasing the concentration of cellulase with a CBD of family II has no effect on staining. After-washing experiments of indigo-stained cotton fabrics show that it is easier to remove indigo adsorbed on cellulase adsorbed onto cotton than indigo directly adsorbed onto cotton

Enzymatic surface hydrolysis of poly(ethylene terephthalate) and bis(benzoyloxyethyl) terephthalate by lipase and cutinase in the presence of surface active molecules

A lipase from Thermomyces lanuginosus and cutinases from Thermobifida fusca and Fusarium solani hydrolysed poly(ethylene terephthalate) (PET) fabrics and films and bis(benzoyloxyethyl) terephthalate (3PET) endo-wise as shown by MALDI-Tof-MS, LC–UVD/MS, cationic dyeing and XPS analysis. Due to interfacial activation of the lipase in the presence of Triton X-100, a seven-fold increase of hydrolysis products released from 3PET was measured. In the presence of the plasticizer N,N-diethyl-2-phenylacetamide (DEPA), increased hydrolysis rates of semi-crystalline PET films and fabrics were measured both for lipase and cutinase. The formation of novel polar groups resulted in enhanced dye ability with additional increase in colour depth by 130% and 300% for cutinase and lipase, respectively, in the presence of plasticizer.Many thanks to Ulrike Gewessler and Matthias Pretzler for lab work. The research was financed by the SFG, the FFG, the city of Graz and the province of Styria

Influence of age, BMI, gender and lumbar level on T1ρ magnetic resonance imaging of lumbar discs in healthy asymptomatic adults

Ziel: Ermittlung der Größenordnung der T1ρ Werte der lumbalen Bandscheiben in gesunden asymptomatischen Probanden bei 1,5 T. Zusätzlich wurde der Einfluss von Alter, body mass index (BMI), Geschlecht und lumbaler Level auf die T1ρ Relaxation. Material und Methoden: In der prospektiven Studie wurden 81 freiwillige Probanden zwischen 20 und 80 Jahren eingeschlossen und in drei Altersgruppen unterteilt (A, 20 – 39 Jahre; B, 40 – 59 Jahre; C, 60 – 80 Jahre). Alle Probanden wurden in einem 1,5 T MRT untersucht und sagittale T1ρ Bilder akquiriert. Die ermittelten T1ρ Relaxationszeiten wurden korreliert mit Alter, BMI, Geschlecht und lumbalem Level jeweils bezogen auf die gesamte Bandscheibe, den Annulus fibrosus und den Nucleus pulposus. Ergebnisse: Das Alter zeigte einen signifikanten Einfluss auf die T1ρ Relaxationszeit in allen lumbalen Leveln wobei zunehmendes Alter mit abnehmenden Relaxationszeiten verbunden war. Darüber hinaus zeigte sich ein signifikanter Unterschied zwischen den Altersgruppen A vs. C und B vs. C (P = 0,0008 und P = 0,0149). Kein signifkanter Unterschied bestand zwischen den T1ρ Relaxationszeiten von Männern und Frauen (P > 0,05). Der BMI zeigte eine signifikant negative Korrelation mit der T1ρ Relaxationszeit (P < 0,0001). Hinsichtlich des lumbalen Levels zeigte sich eine signifikante Abnahme der Relaxationszeiten von L 1/2 zu L5 / S1 (P = 0,0013). Schlussfolgerung: Steigendes Alter korrelierte signifikant mit zunehmender Degeneration lumbaler Bandscheiben bei asymptomatischen Probanden, insbesondere ab einem Alter von 60 Jahren. Ein hoher BMI korrelierte ebenfalls signifikant mit zunehmender Degeneration. Die unteren lumbalen Bandscheiben zeigten insgesamt eine fortgeschrittenere Degeneration als die oberen