This study was carried out to demonstrate the biotechnological potential of xylano-pectinolytic enzymes on scouring of ramie fibers. Optimization of bioscouring process showed a maximum effect of ...enzymes with 50-mM strength of buffer, pH 8.5, fibers to liquid ratio of 1 : 20 (g:ml). Xylanase and pectinase dosage of 7.5 and 3.0 IU, respectively, was found to be best for removal of xylan and pectin impurities, after treatment time of 1.5 h, at 50 °C temperature and 55 rpm agitation rate. EDTA and Tween 80 at concentration of 1.5 mM and 1.25 %, respectively, were found to be the best for effective removal of impurities, in order to improve hydrophilicity of the fibers. After bioscouring, brightness and whiteness values of bioscoured fibers were increased by 9.72 and 7.10% in comparison with control fibers. After enzymatic scouring, a reduction of 14.45 % in yellowness was also seen in ramie fibers. Enzymatic treatment resulted in 6.97% increased brightness, 10.64% increased whiteness, and 4.11% decreased yellowness as compared with scoured ramie fibers. The results indicated that scouring using xylanase and pectinase enzymes could be a substitute for chemical scouring technique. Enzymatic scouring is, therefore, environmentally sustainable and saves energy, also decreases the consumption of harmful chemicals used in alkaline scouring. This is the first report showing the effect of xylanase and pectinase enzymes, produced by a bacterial isolate, on physico-chemical and various optical properties of ramie fibers.
This study was undertaken to investigate the potential of bioscouring in the processing of undegummed sisal fibers, using xylano-pectinolytic enzymes. Optimum bioscouring was obtained at pH 8.5 and ...50 mM buffer molarity, using xylanase (10 IU) and pectinase (8 IU), with a material to liquor proportion of 1:25 (g:ml), EDTA (2 mM) and Tween 80 (0.5%), at 50 °C temperature with agitation rate of 55 rpm and treatment period of 60 min. Enzymatic treatment of sisal fibers enhanced the brightness and whiteness by 11.52 and 6.83%, respectively, and reduced the yellowness by 7.14% in comparison to control. The use of xylanase and pectinase enzymes completely replaced the chemical scouring method for removing non-cellulosic impurities. Thus, enzymatic scouring is energy saving and ecofriendly, since it completely eliminated the use of toxic chemicals used in alkaline scouring. An increase of 23.75% and 11.58% in brightness and whiteness of enzymatically scoured cum bleached fibers, as compared to chemically scoured cum bleached fibers was finally obtained, along with reduction in yellowness by 27.99%. This is the first report demonstrating environmentally sustainable enzymatic approach for scouring of undegummed sisal fibers, using enzymes, simultaneously produced from a bacterial isolate.
The objective of this research was to find out the potential of bioscouring using xylano-pectinolytic enzymes, for degumming of aloe fibers. Bioscouring was optimized with 1 : 20 fiber to buffer ...ratio, using 10 IU xylanase and 3.2 IU pectinase in 50 mM buffer (pH 8.5), EDTA (3 mM), and Tween 80 (1%), at 50°C temperature with agitation rate of 50 rpm and treatment period of 60 min. Enzymatic treatment of aloe fibers increased brightness and whiteness by 55.67% and 24.88%, respectively and decreased yellowness by 44.11% as compared to alkaline fiber scouring, thereby replacing chemical scouring completely. Additionally, the pretreatment of aloe fibers with enzymes resulted in a 50% less consumption of bleaching chemicals with similar optical properties as obtained by 100% bleaching. This is the first report showing the eco-friendly bioscouring approach of aloe fibers, using enzymes produced concurrently from a bacterial isolate.
Microbial enzymes such as xylanases enable new technologies for industrial processes. Xylanases (xylanolytic enzyme) hydrolyze complex polysaccharides like xylan. Research during the past few decades ...has been dedicated to enhanced production, purification, and characterization of microbial xylanase. But for commercial applications detailed knowledge of regulatory mechanisms governing enzyme production and functioning should be required. Since application of xylanase in the commercial sector is widening, an understanding of its nature and properties for efficient and effective usage becomes crucial. Study of synergistic action of multiple forms and mechanism of action of xylanase makes it possible to use it for bio-bleaching of kraft pulp and for desizing and bio-scouring of fabrics. Results revealed that enzymatic treatment leads to the enhancement in various physical properties of the fabric and paper. This review will be helpful in determining the factors affecting xylanase production and its potential industrial applications in textile, paper, pulp, and other industries.
Bacillus pumilus ASH produced a high level of an extracellular and thermostable xylanase enzyme when grown using solid-state fermentation (SSF). Among a few easily available lignocellulosics tested, ...wheat bran was found to be the best substrate (5,300 U/g of dry bacterial bran). Maximum xylanase production was achieved in 72 h (5,824 U/g). Higher xylanase activity was obtained when wheat bran was moistened with deionized water (6,378 U/g) at a substrate-to-moisture ratio of 1:2.5 (w/v). The optimum temperature for xylanase production was found to be 37°C. The inoculum level of 15% was found to be the most suitable for maximum xylanase production (7,087 U/g). Addition of peptone stimulated enzyme production followed by yeast extract and mustard oil cake, whereas glucose, xylose and malt extract greatly repressed the enzyme activity. Repression by glucose was concentration-dependent, repressing more than 60% of the maximum xylanase production at a concentration of 10% (w/v). Cultivation in large enamel trays yielded a xylanase titre that was slightly lower to that in flasks. The enzyme activity was slightly lower in SSF than in SmF but the ability of the organism to produce such a high level of xylanase at room temperature and with deionized water without addition of any mineral salts in SSF, could lead to substantial reduction in the overall cost of enzyme production. This is the first report on production of such a high level of xylanase under SSF conditions by bacteria.
The purpose to effectuate this research work is to investigate the efficiency of crude xylano-pectinolytic enzymes in extraction and clarification of fruit juices, so as to improve their physical ...(clarity, viscosity and soluble solid), functional (total polyphenolic content) and sensory characteristics (acceptability). In this study, various conditions like enzyme dose, treatment time and stirring speed have been optimized. The extraction and clarification efficiency were found to be optimum at enzyme dose between 2:8 and 4:16 IU/g pulp, treatment time between 30 to 60 min and stirring speed of 50 and 60 rpm for different fruit juices. Enzymatic treatment enhanced the physicochemical, organoleptic and nutritional properties and generated juice with improved yield and clarity. After xylano-pectinolytic enzymatic treatment of various fruit juices, maximum increase in yield (95%), filterability (40%) and maximum decrease in viscosity (58%) was found in case of Tamarindus indica. Maximum increase in clarity (39%) and polyphenolic content (37%) was observed in case of Aegle marmelos. Maximum increase in reducing sugars was found in case of Fragaria ananassa along with other properties. All these attributes of xylano-pectinolytic enzymes indicate an adequate prospect for bio-industrial research.
A very high level of cellulase-free, thermostable xylanase has been produced from newly isolated strain of
Bacillus pumilus under submerged fermentation in a basal medium supplemented with wheat bran ...(2%, w/v) pH 8.0 and at 37
°C. After optimization of various production parameters, an increase of nearly 13-fold in xylanase production (5407
IU/ml) was achieved. The produced xylanase is stable in neutral to alkaline pH region at 70
°C. The suitability of this xylanase for use in the bioleaching of eucalyptus Kraft pulp was investigated. A xylanase dose of 5
IU/g of oven dried pulp of 10% consistency exhibited the optimum bleach boosting of the pulp at pH 7.0 and 60
°C after 180
min of treatment. An increase of 5% in brightness along with an increase of 21% and 28% in whiteness and fluorescence respectively, whereas 18% decrease in the yellowness of the biotreated pulp was observed. Enzyme treated pulp when subjected to chemical bleaching, resulted in 20% reduction in chlorine consumption and up to 10% reduction in consumption of chlorine dioxide. Also a reduction of about 16% in kappa number and 83% in permanganate number, along with a reduction in COD value and significant improvement in various pulp properties, viz. viscosity, tensile strength, breaking length, burst factor, burstness, tear factor and tearness were observed in comparison to the conventional chemical bleaching.
An alkaline and thermostable pectinase production from
Bacillus subtilis SS was optimized under submerged fermentation and its application was tested in textile industry for desizing and bioscouring ...of cotton and micropoly fabrics. Desizing of fabric was the best with 5
U/g pectinase treatment for 120
min at pH 9.5 and 65
°C. Under optimized conditions of bioscouring, desized cotton showed highest reducing sugar liberation and weight loss than desized micropoly. Along with enzyme, addition of chelating (EDTA) and wetting agent markedly enhanced the weight loss compared to single use of enzyme or EDTA alone. Agitation (50
±
2) enhanced the weight loss values of cotton (1.9%) and micropoly fabric (1.7%) at pH 9.5 after treatment time of 2
h. Bioscouring of fabrics with pectinase resulted in enhancement of various physical properties of fabrics viz. whiteness (1.2%), tensile strength (1.6%) and tearness (3.0%) over conventionally alkaline scoured fabrics.
A highly active alkalothermophilic cellulase free xylanase (3446
U/g of dry substrate) has been produced from newly isolated strain of
Bacillus stearothermophilus under solid-state fermentation using ...wheat bran (2.5%, w/v) pH 7.0 and at 37
°C. The xylanase was stable over broad range of pH (6.0–12.5) and temperature (37–85
°C) and hence was used in the bioprocessing of fabrics as an alternative to conventional chemical method. The desizing and bioscouring treatments were most efficient at 70
°C after 90 and 180
min of incubation respectively using 5
g/l of xylanase dose in the medium of pH 9.5. Enzymatically desized fabrics when subjected to bioscouring resulted in 0.91%, 0.88% weight loss for micropoly and 0.83%, 0.80% for cotton respectively under agitated (50
±
2
rpm) and non-agitated conditions. Consequently Whiteness index for cotton (11.81%) and micropoly (52.15%) fabrics was increased. Induction in the release of reducing sugars was also observed for cotton (8.37%) and micropoly (16.79%) fabric over conventional method. Enzymatically processed fabric samples possessed 1.12% and 1.95% more tensile strength than reference. Tearness value also increased for bio-treated cotton (1.57%) and micropoly (2.37%) fabric samples as compared to control.
In this study, the efficacy of xylano-pectinolytic enzymes in scouring of banana fibers has been reported. Maximum efficiency of bioscouring was recorded using xylanase and pectinase doses of 15 and ...4.8 IU, respectively (produced by a bacterial isolate) at a material-to-liquor proportion of 1:25 having 8.5 pH, treatment time of 1 h, speed of 50 rpm, temperature 50 °C, 3 mM EDTA and 1% Tween-80, with maximum sugar release, enhanced fiber water absorbing power and the finest optical characteristics. Enzymatic treatment resulted in 13.27% increase in whiteness, 16.14% increase in brightness and 8.63% decrease in yellowness as compared to raw banana fibers. The bioscouring also resulted in 50% reduction in scouring chemicals, in order to achieve the similar optical characteristics as obtained by the chemically treated fibers with 100% scouring and bleaching. It decreased the consumption of environment polluting chemicals and energy. Therefore, this has proven to be an environment safe method for removing the non-cellulosic impurities. This is the first report mentioning the scouring of banana fibers using xylano-pectinolytic enzymes.
