Nonionic surfactants and dispersants for biopolishing and stonewashing with Hypocrea jecorina cellulases

Cellulases are widely applied in textile finishing, such as for the removal of protruding surface fibrils to reduce pilling propensity and to achieve the worn‐out look in denim garments. The main drawback of enzymatic denim processing is the back‐staining of indigo, which reduces the desired blue–white contrast. Alongside an accurate selection of the type of cellulase or vigorous post‐washing of the garments, the simultaneous application of auxiliaries in the enzymatic treatment may help to reduce back‐staining and improve cellulase efficiency. In the present work, the influence of additives such as surfactants and dispersing agents on indigo adsorption and on the treatment of an undyed cotton fabric with Hypocrea jecorina cellulases was investigated. Indigo adsorption was successfully reduced by more than 75% with ethoxylated nonionic surfactants at concentrations below 0.2 g l^?1. The weight loss of cotton fabrics after 120 min treatment was significantly increased with nonionic surfactants and polyvinylpyrrolidone. It could be further shown that protein adsorption on the cotton fabric decreased with the increasing concentration of the additives, while the nonionic surfactants were more efficient than the polyvinylpyrrolidone. Adsorption of a complete cellulase mixture was affected differently by the surfactants than by an exoglucanase‐free endoglucanase‐rich preparation.     

Simultaneous saccharification and fermentation of pretreated Antigonum leptopus (Linn) leaves to ethanol

Simultaneous saccharification and fermentation (SSF) of alkaline hydrogen peroxide pretreated Antigonum leptopus (Linn) leaves to ethanol was optimized using cellulase from Trichoderma reesei QM‐9414 (Celluclast® from Novo) and Saccharomyces cerevisiae NRRL‐Y‐132 cells. Contrary to the saccharification optima (2.5% w/v substrate concentration, 50 °C, 4.5 pH, 40 FPU cellulase g⁻¹ substrate and 24 h reaction time), the SSF optima was found to be somewhat different (10% w/v substrate, 40 °C, 100 FPU cellulase g⁻¹ substrate and 72 h). Better ethanol yields were obtained with SSF compared with the traditional saccharification and subsequent fermentation (S&F) and when the cellulase was supplemented with β‐glucosidase. © 1999 Society of Chemical Industry     

Determination of Ozone In Water By The Indigo Method: A Submitted Standard Method

The indigo method for the determination of ozone as formulated for the new Swiss Standard Methods for Drinking Water Analysis is presented with an international list of suppliers of indigo trisulfonate. Such a new selective and simple method will be needed in many countries because current methods for ozone analysis are generally non-selective when applied on real drinking waters or wastewaters.

Ozone rapidly and stoichiometrically decolorizes indigo trisulfonate in acidic solution. The decrease in absorbance at 600 nm is linear with ozone residual and is 0.42±0.01 cm^-1 per mg/L (Δ = 20,000 L Mol^-1cm^-1 at 600 nm when compared to the uv absorption of pure ozone of = 2900 L Mol^-1cm^-1 at 258 nm). The limits of detection are 2 µg/L for an instrumental and 10 µg/L for a visual field method.     

Efficient and Response Surface Optimized Aqueous Enzymatic Extraction of Camellia oleifera (Tea Seed) Oil Facilitated by Concurrent Calcium Chloride Addition

This paper reports an efficient aqueous enzymatic extraction (AEE) method for Camellia oleifera seed oil with the aid of response surface analysis. A maximum oil recovery of ~93.5% was obtained when a 2‐step AEE process was performed using 0.80% cellulase (v/w) solution at pH 6.0 maintained at 50 °C for 1 h followed by a solution of 0.70% Alcalase® with pH 9.2 at 57 °C for 4.1 h. It was found that the addition of Ca²⁺ during the proteolysis stage improved the free oil yield from ~62.1 to ~86.6%. This was attributed to the removal of tea saponins, cross‐linkage of anionic polysaccharides, and destabilization of cream emulsion by Ca²⁺. This was verified by decreased tea saponin and polysaccharide levels in the cream emulsion and bulk solution as well as lowering of the emulsion fraction. It was determined that addition of CaCl₂ solution in continuous flow to the proteolysate is superior to one‐time or batch addition in inhibiting emulsion formation. The addition of CaCl₂ may provide a means of replacing the more laborious, time‐consuming demulsification process otherwise required.     

Saccharification of microcrystalline cellulose by cellulase of Morchella conica mushroom mycelium in comparison with a commercial cellulase

A comparison was made of the hydrolysis of microcrystalline cellulose Avicel using the cellulolytic complex of the ascomycete Morchella conica and a commercial cellulase. An enzyme concentration of 1 U AVase mg^?1 substrate gave the best results during the hydrolytic processes. At 24 h, the M. conica enzyme complex achieved 35.5% and the commercial cellulase 31·2% saccharification, with glucose 84·2% and 52% of the total reducing sugars liberated, respectively. The specific rates of hydrolyses were 0·77 and 0·14 h^?1 for reducing sugars and 0·54 and 0·12 h^?1 for glucose formation with M. conica and the commercial cellulase, respectively. At 96 h, the degree of saccharification reached 46% for M. conica and 49% for the commercial cellulase, with glucose 76·5% and 65·9% of the total reducing sugars liberated, respectively. Both the complexes were quite stable with a residual activity of 62% CMCase and 47% AVase for M. conica, and 74% CMCase and 57% AVase for the commercial cellulase at 96 h of hydrolysis. The qualitative analysis of the hydrolysis products by TLC indicated, for M. conica, an earlier appearance of cellobiose, which was quickly hydrolyzed to glucose.     

Enzymatic saccharification of dissolution pretreated waste cellulosic fabrics for bacterial cellulose production by Gluconacetobacter xylinus

BACKGROUND: Waste textiles, such as dyed cellulosic and/or polyester blended fabrics have the potential to serve as an alternative feedstock for the production of biological products via microbial fermentation. Dissolution pretreatment was employed to enhance the enzymatic saccharification of dyed and synthetic fiber blended cellulosic fabrics. The fermentable reducing sugars obtained from waste cellulosic fabrics were used to culture Gluconobacter xylinus for value‐added bacterial cellulose (BC) production. RESULTS: Concentrated phosphoric acid was the ultimate cellulose solvent for dissolution pretreatment since 5% w/w cellulosic fabric can be completed dissolved at 50 °C. After regeneration in water, the cellulosic precipitate was subjected to cellulase hydrolysis, resulting in at least 4‐fold enhancement of saccharification rate and reducing sugars yield. The colored saccharification products can be utilized by G. xylinus to produce BC, approximately 1.8 g L^?1 BC pellicle was obtained after 7 days static cultivation. CONCLUSION: Dyed and blended waste fabric can be pretreated effectively by dissolution to produce fermentable sugars by cellulase hydrolysis. Dissolution pretreatment can expose the dyed or polyester fiber covered digestible cellulosic fibers to cellulase and leads to a significant enhancement of saccharification yield. The colored saccharification products have no significant inhibiting effect on the fermentation activity of G. xylinus for BC production. Copyright © 2010 Society of Chemical Industry     

Ultrasonic atomization and polyelectrolyte complexation to produce gastroresistant shell–core microparticles

In this study ultrasound‐assisted atomization technique was combined with two‐stages polyelectrolyte complexation to produce enteric shell–core microparticles encapsulating a non‐steroidal, anti‐inflammatory gastrolesive active ingredient indomethacin. In particular, a solution of the anionic biopolymer alginate, containing indomethacin, was sprayed in fine droplets which were complexed with a cationic (meth)acrylate copolymer, Eudragit^® E 100, which, in turn, was complexed by the anionic copolymer Eudragit^® L30D‐55. The first complexation stage was applied to achieve a high drug encapsulation efficiency; the second one to assure good gastroresistance feature. The novel protocol has been found more effective in terms of loading, encapsulation efficiency, and enteric properties during in vitro release tests, than conventional procedures which involved alginate cross‐linking by charged ions. Furthermore ultrasonic atomization–polyelectrolytes complexation preparation approach was performed using mild conditions, aqueous solutions, in the absence of organic solvents and chemical cross‐linkers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42976.     

Microwave‐assisted immobilization of lipase from Candida rugosa on Eupergit® supports

BACKGROUND: Immobilization of lipase (triacylglycerol acylhydrolase EC 3.1.1.3) from Candida rugosa on Eupergit^® C and Eupergit^® C 250L was performed under microwave irradiation in order to reduce immobilization time. Lipase loading, hydrolytic activity, esterification activity and operational stability in organic solvent of immobilized lipase preparation were determined. RESULTS: The microwave‐assisted procedure resulted in a 29% lower lipase loadings, compared with immobilized lipase obtained without microwaves. In hydrolytic activity assay, lipase immobilized under microwaves exhibited a 23% higher specific activity. Slight activation of lipase by microwave‐assisted immobilization was observed, since specific activity was around 5% higher than for free lipase. Lipase of highest activity was obtained after 2 min immobilization on Eupergit^® C. The same preparation exhibited high esterification activity in organic medium and a half life of 212 h was determined in multiple use assay. CONCLUSION: The application of microwave irradiation leads to reduction of immobilization time from 2 days to only 2 min. The immobilized lipase obtained has prospects for further application due to its high retained activity and stability. Copyright © 2009 Society of Chemical Industry     

DNA adsorption on a poly‐L‐lysine‐immobilized poly(2‐hydroxyethyl methacrylate) membrane

The DNA adsorption properties of poly‐L ‐lysine‐immobilized poly(2‐hydroxyethyl methacrylate) (pHEMA) membrane were investigated. The pHEMA membrane was prepared by UV‐initiated photopolymerization and activated with epichlorohydrin. Poly‐L ‐lysine was then immobilized on the activated pHEMA membrane by covalent bonding, via a direct chemical reaction between the amino group of poly‐L ‐lysine and the epoxy group of pHEMA. The poly‐L ‐lysine content of the membrane was determined as 1537 mg m^?2. The poly‐L ‐lysine‐immobilized membrane was utilized as an adsorbent in DNA adsorption experiments. The maximum adsorption of DNA on the poly‐L ‐lysine‐immobilized pHEMA membrane was observed at 4 °C from phosphate‐buffered salt solution (pH 7.4, 0.1 M; NaCl 0.5 M) containing different amounts of DNA. The non‐specific adsorption of DNA on the plain pHEMA membrane was low (about 263 mg m^?2). Higher DNA adsorption values (up to 5849 mg m^?2) were obtained in which the poly‐L ‐lysine‐immobilized pHEMA membrane was used. Copyright © 2003 Society of Chemical Industry     

Preparation of nano‐ZIF‐8 in methanol with high yield

This article systematically presented analysis results of factors affecting the preparation of nano‐ZIF‐8 in methanol for high yield. Samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Brunauer‐Emmett‐Teller (BET) adsorption, and thermogravimetry‐differential thermal analysis (TG/DTA). Synthesized nano‐ZIF‐8 had advantages over commercial ZIF‐8 (Basolite^® Z1200 from Sigma‐Aldrich) such as a higher surface area, consisting of not only micropores like Basolite^® Z1200 but also subordinate mesopores, formed by an assembly of nano‐ZIF‐8 crystals, which was 30 nm. Specifically, for the first time, nano‐ZIF‐8 was prepared in methanol with the yield of 61.2 %.

     

A chelating cellulose adsorbent for the removal of Cu(II) from aqueous solutions

Regenerated cellulose wood pulp was grafted with the vinyl monomer glycidyl methacrylate (GMA) using ceric ammonium nitrate as initiator and was further fuctionalised with imidazole to produce a novel adsorbent material, cellulose‐g‐GMA‐imidazole. All cellulose, grafted cellulose and functionalized cellulose grafts were physically and chemically characterized using a number of analytical techniques, including elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, and scanning electron microscopy. The cellulose‐g‐GMA material was found to contain 1.75 mmol g^?1 epoxy groups. These epoxy groups permitted introduction of metal binding functionality to produce the cellulose‐g‐GMA‐imidazole final product. Following characterization, a series of adsorption studies were carried out on the cellulose‐g‐GMA‐imidazole to assess its capacity in the removal of Cu²⁺ ions from solution. Cellulose‐g‐GMA‐imidazole sorbent showed an uptake of ～70 mg g^?1 of copper from aqueous solution. The adsorption process is best described by the Langmuir model of adsorption, and the thermodynamics of the process suggest that the binding process is mildly exothermic. The kinetics of the adsorption process indicated that copper uptake occurred within 30 min and that pseudo‐second‐order kinetics best describe the overall process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 2006     

Improved synthesis of a branched poly(ethylene imine)‐modified cellulose‐based adsorbent for removal and recovery of Cu(II) from aqueous solution

This study focuses on an improved synthesis of a branched poly (ethylene imine) (PEI)‐modified cellulose‐based adsorbent (Cell‐g‐PGMA‐PEI). We aim to improve the adsorbent capacity by reducing side reaction of epoxide ring opening during graft copolymerization of glycidyl methacrylate (GMA) onto cellulose which increases the content of epoxy groups, anchors to immobilize branched PEI moieties. FTIR spectra provided the evidence of successful graft copolymerization of GMA onto cellulose initiated by benzoyl peroxide (BPO) and modification with PEI. The amount of epoxy groups of Cell‐g‐PGMA was 4.35 mmol g^?1 by epoxy titration. Subsequently, the adsorption behavior of Cu(II) on cell‐g‐PGMA‐PEI in aqueous solution has been investigated. The data from the adsorption kinetic experiments agreed well with pseudo‐second‐order model. The adsorption isotherms can be interpreted by the Langmuir model with the maximum adsorption capacity of 102 mg g^?1 which was largely improved compared with the similar adsorbent reported. The dynamic adsorption capacity obtained from the column tests was 119 mg g^?1 and the adsorbent could be regenerated by HCl of 0.1 mol L^?1. Results indicate that the novel pathway for the synthesis of Cell‐g‐PGMA‐PEI exhibits significant potential to improve the performance of adsorbents in removal and recovery of Cu(II) from aqueous solution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Characterization of absorbent polymers for the removal of volatile hydrophobic pollutants from air

BACKGROUND: An emerging innovation for the treatment of polluted air consists in using a liquid–solid biphasic system, in which the sequestering phase contains inert polymer beads. The different polymers tested here for this purpose were; Hytrel^® G3548L, Hytrel^® G4078W, styrene butadiene copolymer, 28% and 31%, silicone rubber, PEBAX^® 2533, and rubber tires. The selection of the most effective polymer(s) first requires a determination of the uptake of the pollutants by the solid phase in terms of key polymer properties such as partition coefficient, diffusion coefficient and biodegradability. RESULTS: A significant difference was found in the uptake levels of α‐pinene from the gas phase for the different polymers tested. Based on partition coefficient measurements, relatively non‐polar polymers such as Kraton^® tend to uptake α‐pinene better than polar ones, such as Hytrel^®. A reduction in the partition coefficient of α‐pinene into polymers in the presence of water has also been observed. It was also proven that the tested polymers are not biodegradable. CONCLUSIONS: The uptake of α‐pinene by the different polymers tested was determined and it was shown that such polymers could be used for air pollution control. Furthermore, their non‐biodegradability justifies their use as absorbents. This paper provides a new opportunity to work with biofilters (BFs)/biotrickling filters (BTFs) using polymers as a sequestering phase. Copyright © 2010 Society of Chemical Industry     

Enzymatic oil‐degumming by a novel microbial phospholipase

Phospholipase A‐mediated oil‐degumming is a well‐established process step (Enzy‐Max^®) in physical refining of vegetable oils (rape seed, soy bean, sunflower seed). A screening programme for microbial phospholipases of type A has been carried out. The target has been to develop a stable and robust phospholipase with optimal oil‐degumming performance in the pH‐range 4—5 and in the temperature range 30— 70 °C. One phospholipase of type A1 from Fusarium oxysporum, given the trade name Lecitase^® Novo, has been studied in detail. Some of the characteristics of this novel microbial phospholipase in the oil‐degumming application are: pH optimum ∼5, temperature optimum 40—45 °C. In laboratory tests the new phospholipase Lecitase^® Novo has proven to be superior to porcine pancreatic Lecitase^® 10L and other phospholipases with respect to oil‐degumming performance, and it has proven to be suited for degumming of different oil qualities ranging from water‐degummed to crude oil. A further advantage is that the new phospholipase acts at very low water content, which will make the problematic sludge recycling in the EnzyMax^® process superfluous. As demonstrated by an HPLC study, phospholipase‐mediated degumming is a unique process quite distinct from the well‐known acid degumming variations, since the phospholipids (both hydratable and non‐hydratable) present in the oil are hydrolysed to the corresponding lyso‐phospholipids, which migrate to the aqueous phase under the conditions employed. Lecitase^® Novo was introduced successfully for degumming of rapeseed oil at Cereol (Mannheim, Germany) mid 2000.     

Novel self‐supported natural and synthetic polymer membranes for air humidification

Novel self‐supported natural and synthetic polymer membranes of chitosan‐hydroxy ethyl cellulose‐montmorillonite (CS‐HEC‐MMT) and polyvinyl alcohol (PVA)‐polystyrene sulfonic acid (PSSA) are prepared by solution casting method followed by crosslinking. These membranes are employed for air humidification at varying temperatures between 30°C and 70°C and their performances are compared with commercial Nafion^® membranes. High water fluxes with desired humidified‐air output have been achieved for CS‐HEC‐MMT and PVA‐PSSA hybrid membranes at air‐flow rates of 1–10 slpm. Variation in the air/water mixing ratio, dew point, and relative humidity that ultimately results in desired water flux with respect to air‐flow rates are also quantified for all the membranes. Water flux values for CS‐HEC‐MMT are less than those for Nafion^® and PVA‐PSSA membranes, but the operational stability of CS‐HEC‐MMT membrane is higher than PVA‐PSSA and comparable with Nafion^® both of which can operate up to 70°C at repetitive cycles of humidification. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Novel magnetic nanoparticles for the hydrolysis of starch with Bacillus licheniformis α‐amylase

Novel magnetic nanoparticles with an average size of 350–400 nm with N‐methacryloyl‐(L )‐phenylalanine (MAPA) as a hydrophobic monomer were prepared by the surfactant‐free emulsion polymerization of 2‐hydroxyethyl methacrylate, MAPA, and magnetite in an aqueous dispersion medium. MAPA was synthesized from methacryloyl chloride and L ‐phenylalanine methyl ester. The specific surface area of the nonporous magnetic nanoparticles was found to be 580 m²/g. Magnetic poly[2‐hydroxyethyl methacrylate–N‐methacryloyl‐(L )‐phenylalanine] nanoparticles were characterized by Fourier transform infrared spectroscopy, electron spin resonance, atomic force microscopy, and transmission electron microscopy. Elemental analysis of MAPA for nitrogen was estimated as 4.3 × 10^?3 mmol/g of nanoparticles. Then, magnetic nano‐poly[2‐hydroxyethyl methacrylate–N‐methacryloyl‐(L )‐phenylalanine] nanoparticles were used in the adsorption of Bacillus licheniformis α‐amylase in a batch system. With an optimized adsorption protocol, a very high loading of 705 mg of enzyme/g nanoparticles was obtained. The adsorption phenomena appeared to follow a typical Langmuir isotherm. The inverse of enzyme affinity for free amylase (181.82 mg/mL) was higher than that for immobilized enzyme (81.97 mg/mL). Storage stability was found to increase with adsorption. It was observed that the enzyme could be repeatedly adsorbed and desorbed without a significant loss in the adsorption amount or enzyme activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Structural change in mercerized cotton fibers on cellulase treatment

Cotton fibers treated with liquid ammonia and sodium hydroxide were hydrolyzed with crude cellulase. The structural change in the fibers due to the cellulase treatment was examined in relation to the apparent affinity of Congo Red. The cellulose III crystalline structure collapsed and generated intermediate‐molecular‐ordered regions on cellulase treatment. Adsorption of Congo Red occurred on the crystallite surfaces of cellulose II and cellulose III that was transformed from cellulose II. The fiber, the dominant crystallite phase of which was cellulose III that was transformed from cellulose II, had a considerably increased apparent affinity after cellulase treatment. The intermediate structure on the crystallite surface was associated with the adsorption of Congo Red in the cases of cellulose II and cellulose III. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1675–1680, 2001     

Enzymatic hydrolysis of autohydrolyzed barley husks

BACKGROUND: Barley husks were subjected to non‐isothermal autohydrolysis of different severities, yielding a liquid phase rich in hemicellulose‐derived compounds and a solid phase, composed mainly of cellulose and lignin. This solid phase was subjected to enzymatic hydrolysis in order to assess the effects of severity on the susceptibility of substrates to enzymatic hydrolysis. The effects of the liquid to solid ratio (LSR, in the range 6 to 18 g g^?1) and cellulase to substrate ratio (CSR, in the range 3.3 to 8.2 FPU g^?1) on the enzymatic hydrolysis were assessed. RESULTS: Up to 25.8 g oligomers per 100 g raw material were present in liquors from the hydrothermal processing. Enzymatic hydrolysis of solid phases obtained under selected conditions (log Ro = 4.14, LSR = 6 g g^?1 and CSR = 5.8 FPU g^?1) yielded glucose concentrations up to 67 g L^?1 (corresponding to cellulose to glucose conversions close to 100%). CONCLUSION: It was shown that autohydrolysis is an effective method for improving the enzymatic susceptibility of barley husks. High cellulose conversions resulting in high glucose yields were achieved by enzymatic hydrolysis at low LSR and CSR. The liquid fraction obtained upon autohydrolysis contained large amounts of hemicellulose‐derived compounds. Copyright © 2010 Society of Chemical Industry     

Synthese von Cellulose-Austauschern mit chelatbildenden funktionellen Gruppen

A new widely applicable method for the preparation of compounds for selective exchange on the basis of cellulose is described. For the synthesis the reaction principle for the preparation of ?Remazol”?^® (TM of Hoechst AG) dye stuffs is used in a modified form. Two variants are used. According to variant A functional groups are bound directly to cellulose. In variant B they are bound by diazo-coupling.     

Effect of different anchor groups on adsorption behavior and effectiveness of poly(N,N‐dimethylacrylamide‐co‐Ca 2‐acrylamido‐2‐methylpropanesulfonate) as cement fluid loss additive in presence of acetone–formaldehyde–sulfite dispersant

The impact of various anchor groups on adsorption behavior of AMPS® copolymers was studied. The anchor groups differ in anionic charge density. Copolymer adsorption and water retention of oil well cement slurries achieved from CaAMPS®‐co‐NNDMA in the presence of an acetone–formaldehyde–sulfite (AFS) dispersant were improved by incorporation of minor amounts (～ 1% by weight of polymer) of acrylic acid (CaAMPS®‐co‐NNDMA‐co‐AA), maleic acid anhydride (CaAMPS®‐co‐NNDMA‐co‐MAA), or vinyl phosphonic acid (CaAMPS®‐co‐NNDMA‐co‐VPA), respectively. Performance of these terpolymers was studied by measuring static filtration properties of oil well cement slurries at 27°C and 70 bar pressure. All fluid loss additives possess comparable molar masses and show the same adsorption behavior and effectiveness when no other admixture is present. In the presence of AFS dispersant, however, adsorption of CaAMPS®‐co‐NNDMA and hence fluid loss control is dramatically reduced, whereas effectiveness of CaAMPS®‐co‐NNDMA‐co‐AA is less influenced because of acrylic acid incorporated as additional anchor group. Even more, CaAMPS®‐co‐NNDMA‐co‐MAA combined with AFS allows simultaneous adsorption of both polymers and thus produces good fluid loss control. CaAMPS®‐co‐NNDMA‐co‐VPA no longer allows adsorption of AFS dispersant. This was also confirmed by rheological measurements. The results show that, in a binary admixture system, adsorption of the anionic polymer with anchor groups possessing higher charge density is preferred. Surface affinity of the anchor groups studied increase in the order ? SO → ? COO^? → vic‐(? COO^?)₂→ ? PO. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007