Cellulosic Waste Research Articles

Addition of expansin to cellulase enhanced bioethanol production

Abstract A metagenomic clone (pUC-189) that exhibited clear zone on CMC agar plate showed homology with glycosyl hydrolase (GH) family 12 endoglucanase. Purified recombinant cellulase (C18) exhibited the highest activity towards CMC followed by Avicel PH101 and waste paper which was confirmed by chromatography. Role of expansin (E11CB) was investigated to address the poor activity of C18 towards waste paper. The Langmuir isotherm for binding of the purified E11CB to waste paper showed a good fit (R 2 = 0.97). Recombinant E11CB protein bound to waste paper was detected in situ by UV fluorescence of [Ln(DPA) 3 ] 3− complex. Scanning electron microscopy confirmed that binding of E11CB transformed smooth microfibrils into rough and amorphic surface. Improvement in the enzymatic hydrolysis of pure cellulose and lignocelluloses was observed after treatment with purified E11CB at low cellulase loading. The enzymatic hydrolysate of waste cellulose paper was then used as the substrate for bioethanol production by Saccharomyces cerevisiae.

Synthesis and grafting of carboxymethyl cellulose from environmental pollutant cellulosic wastes of textile industry

Purpose This study aims to explore the use of knitted rag by synthesizing different grades of carboxymethyl cellulose (CMC) by applying multiple-step carboxymethylation techniques. Design/methodology/approach CMC was synthesized from knitted rag, a cellulosic waste of textile and garment industries, in aqueous ethanolic sodium hydroxide and subsequently mono-chloroacetic acid reaction medium. Low-substituted to high-substituted products were obtained from single-step to seven-step carboxymethylation of cellulose. In this way, it was possible to produce low-cost and different grades of substituted carboxymethylated cellulose. The synthesized CMC was characterized, and their physical properties were investigated. The structure of CMC and grafted CMC were investigated by Fourier transform infrared spectroscopy. Findings Solubility, CMC content, degree of substitution and molecular weight of CMC were increased gradually with the increase in the number of reaction steps, although fourth step attained the optimum. The cellulosic waste of knitted rag can easily be used to produce value-added products such as CMC and other cellulose derivatives, and that will ultimately reduce the pollution problems from this waste. Originality/value Grafting of prepared CMC film with methyl methacrylate monomer increased their strength, although decreased rigidity and moisture content because the incorporation of hydrophobic methyl methacrylate monomer was observed.

Hydroliza odpadow celulozowych katalizowana enzymami celulolitycznymi immobilizowanymi na nosniku polimerowym

Hydroliza odpadow celulozowych katalizowana enzymami celulolitycznymi immobilizowanymi na nosniku polimerowym

Biological pretreatment of rice straw with Streptomyces griseorubens JSD-1 and its optimized production of cellulase and xylanase for improved enzymatic saccharification efficiency

ABSTRACTBiological pretreatment of rice straw and production of reducing sugars by hydrolysis of bio-pretreated material with Streptomyces griseorubens JSD-1 was investigated. After 10 days of incubation, various chemical compositions of inoculated rice straw were degraded and used for further enzymatic hydrolysis studies. The production of cellulolytic enzyme by S. griseorubens JSD-1 favored the conversion of cellulose to reducing sugars. The culture medium for cellulolytic enzyme production by using agro-industrial wastes was optimized through response surface methodology. According to the response surface analysis, the concentrations of 11.13, 20.34, 4.61, and 2.85 g L−1 for rice straw, wheat bran, peptone, and CaCO3, respectively, were found to be optimum for cellulase and xylanase production. Then the hydrolyzed spent Streptomyces cells were used as a nitrogen source and the maximum filter paper cellulase, carboxymethylcellulase, and xylanase activities of 25.79, 78.91, and 269.53 U mL−1 were achieved. The crude cellulase produced by S. griseorubens JSD-1 was subsequently used for the hydrolysis of bio-pretreated rice straw, and the optimum saccharification efficiency of 88.13% was obtained, indicating that the crude enzyme might be used instead of commercial cellulase during a saccharification process. These results give a basis for further study of bioethanol production from agricultural cellulosic waste.

Newly invented biobased materials from low-carbon, diverted waste fibers: research methods, testing, and full-scale application in a case study structure

This project demonstrates newly invented, biobased construction materials developed by applying low-carbon, biomass waste sources through the Authors' engineered fiber processes and technology. If manufactured and applied large-scale the project inventions can divert large volumes of cellulose waste into high-performance, low embodied energy, environmental construction alternatives that lessen society’s dependence on greenhouse gas emitting products associated with global warming. Biobased materials produced in this work include: 1. High strength-to-weight-ratio as a dense, thin, multi-purpose construction hardboard from 100% waste sources and without resins, binders, or adhesives. Bioboards are used in flat and multidimensional form to create the project inventions. 2. Modular, three-dimensional-core, structural insulated wall, floor, and roof panels developed using bioboards as main structural components. BioSIPs received patenting during the project. This publication describes research and computational methodologies, testing of project materials, and their full-scale application as the exterior and interior materials and construction system for a solar-powered case-study building. The authors are currently advancing project inventions for commercialization.

An endolytic mutanase from novel strain Paracoccus mutanolyticus: its application potential in dentistry

Mutanase, α-(1→3)-glucanase, belonging to the family glucanohydrolase, catalyses mutan [α-(1→3)-glucan] synthesized by cariogenic streptococci and hence has potential in caries prophylaxis. A novel bacterial strain with potential to produce higher mutanase (glucanohydrolase) activity was isolated from soils contaminated with cellulosic waste. One of the isolated strains, RSP-02, was subjected to biochemical and 16S rRNA molecular analysis, and we noticed that it belongs to the genus Paracoccus. The mutanase production (800- 1200 U l-1) in this strain was growth associated and substrate induced, and the activity was comparable with the strains reported earlier. The enzyme displayed a molecular mass of 138 kDa by native PAGE studies, showed endolytic activity and produced nigerose as end product. In vitro studies revealed production of 140±2.82 µg of glucose equivalents in 30 min from the biofilm formed on glass surface indicating its potentiality in dentistry. To the best of our knowledge, this is the first report on the production of mutanase by Paracoccus sp.; hence, this isolated bacterial strain is designated as Paracoccus mutanolyticus RSP-02.

Using tobacco waste extract in pre-culture medium to improve xylose utilization for l-lactic acid production from cellulosic waste by Rhizopus oryzae

The aim of this work was to study the high-titer l-lactic acid production from cellulosic waste using Rhizopus oryzae. The tobacco waste water-extract (TWE) added with 5g/L glucose and 0.1g/L vitamin C was optimized as pre-culture medium for R. oryzae. Results found that compared to traditional pre-culture medium, it improved xylose consumption rate up to 2.12-fold and enhanced l-lactic acid yield up to 1.73-fold. The highest l-lactic acid concentration achieved was 173.5g/L, corresponding to volumetric productivity of 1.45g/Lh and yield of 0.860g/g total reducing sugar in fed-batch fermentation. This process achieves efficient production of polymer-grade l-lactic acid from cellulosic feedstocks, lowers the cost of fungal cell pre-culture and provides a novel way for re-utilization of tobacco waste.

Ozone bleaching of cotton fabrics with the aid of ultrasonic humidifier

Cotton is an important industrial commodity for textile production. Its finishing is complicated and requires energy, chemicals and water. In this respect, for its sustainable production, some precautions should be taken. Today, due to consumer’s awareness of environmental issues, studies on ecologic alternative finishing processes have attracted much attention. In this study cotton, which is a natural cellulosic fiber, was bleached via the use of ozone gas and ultrasonic humidifier. Then the coloration of the fabrics was conducted by using green walnut shells (husks). In this way, it was planned to introduce alternative sustainable methods for cotton fabric finishing. It was found that ozone can be used for bleaching of cotton fabrics and even when no mordanting was applied; good colors with sufficient fastnesses were obtained from the cotton fabrics dyed with green walnut shells (husks). Moreover a way to utilize green walnut shells (husks), which are in fact cellulosic waste, was also introduced.

Glucose and 5-hydroxymethylfurfural production from cellulosic waste by sequential alkaline and acid hydrolysis

Glucose and 5-hydroxymethylfurfural production from waste paper towel was evaluated by sequential alkaline and acid hydrolysis. Effects of alkali/acid doses, treatment time and temperature on hydrolysis performance were investigated by using Box-Behnken and Box-Wilson statistical experiment design methods. Operation parameters for alkaline hydrolysis were percent NaOH, treatment time and temperature and for acid hydrolysis percent acid and treatment time. Total paper conversion of the sequential process was 72% indicating significant waste reduction beside glucose and 5-hydroxymethylfurfural formation. The maximum yields for glucose and 5-hydroxymethylfurfural were 61.23% and 19.70% in acid and alkaline hydrolysis, respectively. Main products in the effluent of alkaline hydrolysis were glucose and 5-hydroxymethylfurfural. Highest glucose concentration (25.2 gL−1) in alkaline hydrolysis was obtained at 16% NaOH, 119 °C, and 74 min. The 5-hydroxymethylfurfural concentration and paper conversion at this condition was 7.22 gL−1 and 28.47%, respectively. When the solid residue of alkaline hydrolysis was treated with 5% H2SO4 at 135 °C for 120 min then 30.7 gL−1 glucose and 0.87 gL−1 5-hydroxymethylfurfural was obtained with 44.35% paper conversion.

Insights from the Molecular Dynamics Simulation of Cellobiohydrolase Cel6A Molecular Structural Model from Aspergillus fumigatus NITDGPKA3.

Global demand for bioethanol is increasing tremendously as it could help to replace the conventional fossil fuel and at the same time supporting the bioremediation of huge volume of cellulosic wastes generated from different sources. Ideal genetic engineering approaches are essential to improve the efficacy of the bioethanol production processes for real time applications. A locally isolated fungal strain Aspergillus fumigatus NITDGPKA3 was used in our laboratory for the hydrolysis of lignocellulose with good cellulolytic activity when compared with other contemporary fungal strains. An attempt is made to sequence the cellobiohydrolases (CBHs) of A. fumigatus NITDGPKA3, model its structure to predict its catalytic activity towards improving the protein by genetic engineering approaches. Herein, the structure of the sequenced Cellobiohydrolases (CBHs) of A. fumigatus NITDGPKA3, modelled by homology modelling and its validation is reported. Further the catalytic activity of the modelled CBH enzyme was assessed by molecular docking analysis. Phylogenetic analysis showed that CBH from A. fumigatus NITDGPKA3 belongs to the Glycohydro 6 (Cel6A) super family. Molecular modeling and molecular dynamics simulation suggest the structural and functional mechanism of the enzyme. The structures of both the cellulose binding (CBD) and catalytic domain (CD) have been compared with most widely studied CBH of Trichoderma reesei. The molecular docking with cellulose suggests that Gln 248, Pro 287, Val236, Asn284, and Ala288 are the main amino acids involved in the hydrolysis of the β, 1-4, glycosidic bonds of cellulose.

Adaptor Scaffoldins: An Original Strategy for Extended Designer Cellulosomes, Inspired from Nature.

ABSTRACTDesigner cellulosomes consist of chimeric cohesin-bearing scaffoldins for the controlled incorporation of recombinant dockerin-containing enzymes. The largest designer cellulosome reported to date is a chimeric scaffoldin that contains 6 cohesins. This scaffoldin represented a technical limit of sorts, since adding another cohesin proved problematic, owing to resultant low expression levels, instability (cleavage) of the scaffoldin polypeptide, and limited numbers of available cohesin-dockerin specificities—the hallmark of designer cellulosomes. Nevertheless, increasing the number of enzymes integrated into designer cellulosomes is critical, in order to further enhance degradation of plant cell wall material. Adaptor scaffoldins comprise an intermediate type of scaffoldin that can both incorporate various enzymes and attach to an additional scaffoldin. Using this strategy, we constructed an efficient form of adaptor scaffoldin that possesses three type I cohesins for enzyme integration, a single type II dockerin for interaction with an additional scaffoldin, and a carbohydrate-binding module for targeting to the cellulosic substrate. In parallel, we designed a hexavalent scaffoldin capable of connecting to the adaptor scaffoldin by the incorporation of an appropriate type II cohesin. The resultant extended designer cellulosome comprised 8 recombinant enzymes—4 xylanases and 4 cellulases—thereby representing a potent enzymatic cocktail for solubilization of natural lignocellulosic substrates. The contribution of the adaptor scaffoldin clearly demonstrated that proximity between the two scaffoldins and their composite set of enzymes is crucial for optimized degradation. After 72 h of incubation, the performance of the extended designer cellulosome was determined to be approximately 70% compared to that of native cellulosomes.

Adding Cellulosic Ash to Composting Mix as a Soil Amendment

Solid waste generation and composition in Baghdad is typically affected by population growth, urbanization, improved economic conditions, changes in lifestyles and social and cultural habits.
 A burning chamber was installed to burn cellulosic waste only. It was found that combustion reduced the original volume and weight of cellulosic waste by 97.4% and 85% respectively.
 A batch composting study was performed to evaluate the feasibility of co-composting organic food waste with the cellulosic bottom ash in three different weight ratios (w/w) [95/5, 75/25, 50/50].
 The composters were kept in controlled aerobic conditions for 7 days. Temperature, moisture, and pH were measured hourly as process successful indicators. Maximum temperature ranged between (41 to 53) ºC.
 Results showed that the blend of M2 [OFMSW: BCA] [75:25] was the most beneficial to composting. It maintained the highest temperature for the longest duration for 9hrs. at (53) ºC, achieved the highest nitrogen content(1.65%) , a C/N ratio of (14.18 %), nitrification index(N-NH4/N-NO3) of (0.29),nitrogen, phosphorous and potassium(NPK)(1.65, 1.22, 1.73)% respectively, seed germination 80% indicating that the achieved compost is mature and stable.
 Heavy metal contents (Cd, Cr, Cu, Mn, Ni, Pb and Zn) were detected in the above compost and all were lower than the regulation limits of the metal quality standards for compost and stabilized bio-waste.
 

Cellulase Enzyme based Biodegradation of Cellulosic Materials: An Overview

Cellulose, a macromolecule of β -D- anhydroglucopyranose units linked by β (1,4)-glycosidic bonds, is the world’s most abundant organic polymer and is the main component of plant biomass that provides stability. Due to its sta-ble fibrous property, it has become one of the most important commercial raw materials for many industries. However, accumulation of waste cellulose due to natural and/or anthropogenic sources is a matter of concern in terms of environmental pollution. Wastes cellulosic substrates can be utilized as sources of energy through controlled hydrolysis using cellulases- a complex group of enzymes capable of degrading all types of cellulosic waste materials. A number of bacteria, fungi and insects are having the capability to degrade cellulose by production of cellulase enzymes. Further, the symbiotic insect-microbe relationships present in the insect gut microbiome for the production of cellulolytic system is of immense importance as this would lead to applications in different fields like biodegradation of cellulosic wastes, pollution reduction, biofuel production, insect/pest control etc. Cel-lulase gene can also be improved by genetic or protein engineering methods using recent technological advances. This review deals with the advances of cellulase enzymes and its utilization for different application.

Isolation of cellulolytic microcosms from bagasse compost in co-digested fibrous substrates

Symbiotic cellulolytic microcosms represent a promising microbial agent for enhancing degradation of cellulosic materials in biotechnological processes. In this study, structurally stable lignocellulose-degrading microbial communities were constructed from cellulolytic seed culture from sugarcane bagasse compost using swine manure and Napier grass as co-digested carbon sources under static aerobic condition at 55 °C. The lignocellulolytic microbial consortium enriched in peptone and yeast extract-based medium (PLMC) showed higher cellulose-degrading activity compared to lignocellulolytic microbial consortium isolated in the water-based medium (WLMC). The composite microbes in both consortia were originated from the seed culture and the co-digested substrates according to denaturing gradient gel electrophoresis profile. PLMC exhibited higher CMCase, xylanase, FPase, and avicelase activities in the supernatant than those of WLMC and was capable of degrading 70 % of filter paper within 1 week. PLMC was capable of degrading substrate with higher efficiency than the control by 11.7, 9.2, 15.5, and 11.9 % of total solid, suspended solid, volatile solid, and volatile suspended solid, respectively. The work demonstrated the potential of cellulolytic microcosms enriched by this approach on enhancing conversion efficiency in biogas production from cellulosic wastes.

Techno-economic appraisal of waste cellulose processing

Huge quantities of waste cellulose fibres are being produced in textile, food and particularly paper industries. Their incineration without a costly external increase of the combustion temperature raises environmental concerns because hazardous substances may be formed due to the fact that commercially produced biomass is routinely exposed to excessive amounts of agrochemicals. Fermentation techniques are also unfavourable as the naturally low biodegradability of cellulose requires energy-intensive pretreatment, long hydraulic retention times and heating of huge volumes or costly catalysts. A technical-economic assessment was carried out in a newly developed pyrolysis apparatus that prevents production of tar and flue gases and produces exclusively solid pyrolysis residues. It was confirmed that such a solution could be economically and environmentally beneficial.

Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid.

The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50 °C, respectively, after 24 h of incubation, with a yield of 31.56 mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24 h by using a two-step hydrolysis. Significant lactic acid production (27.8 mg/mL) was obtained by separate saccharification and fermentation after 72 h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate.

Synthesizing a Cellulase like Chimeric Protein by Recombinant Molecular Biology Techniques.

In order to meet the Renewable Fuels Standard demands for 30 billion gallons of biofuels by the end of 2020, new technologies for generation of cellulosic ethanol must be exploited. Breaking down cellulose by cellulase enzyme is very important for this purpose but this is not thermostable and degrades at higher temperatures in bioreactors. Towards creation of a more ecologically friendly method of rendering bioethanol from cellulosic waste, we attempted to produce recombinant higher temperature resistant cellulases for use in bioreactors. The project involved molecular cloning of genes for cellulose-degrading enzymes based on bacterial source, expressing the recombinant proteins in E. coli and optimizing enzymatic activity. We were able to generate in vitro bacterial expression systems to produce recombinant His-tag purified protein which showed cellulase like activity.

Use of Cellulase enzyme obtained from Monilia (Moniliophthora roreri) for treatment of solid waste of Cob, Rice husks and Cocoa shell

Ecuador generates lots of lingo cellulosic organic waste from cocoa, rice and corn agribusiness, and these products are rich in cellulose and can be used in fermentation processes by enzyme producing yeasts. In this study, the phytopathogenic fungus Moniliophthora roreri was isolated, characterized and the kinetics of production of cellulose was studied using rice husks, cocoa shell and cob as a growth inducer substance for a period of 20 days. The carboxymethylcellulose (CMC) was used as specific substrate to evaluate the kinetic parameters of the enzyme at different concentration of 0.5%, 1% and 1.5%; to evaluate the Vmax, Km, specific activity, kcatwe worked with the Michaelis-Menten and Lineweaver-Burk linearization and the crude enzyme was purified with ammonium sulfate. The enzyme production was increased on 10th, 15th and 20th day in rice hulls, cocoa husk and cob, respectively. There was also an increased enzyme activity and the kinetic parameters obtained from rice husk. The purification is a step to increase the specific activity of the enzyme in each of the extracts is under study.

Biomass fuel based on wastes from the paper industry

Wastes from paper industry are mostly combustible. It is possible to recycle them with energy recovery. These wastes have a high moisture content (up to 60%) and thus a small calorific value. An alternative to waste incineration is the production of solid recovered fuel. The benefits are: easy adjustment of the physical and chemical properties of the fuel (via the change of proportions of ingredients), low moisture and high calorific value. The study involved the following types of cellulose wastes: - Belmer - the rejects from recovered paper, Krofta - deinking sludge, sludge - wastewater treatment sludge, bark - the rejects from virgin pulps. The results of investigations of waste produced in one of the biggest Polish paper mill - are shown. Following aspects were investigated: energy properties, content of carbon, hydrogen, sulfur, chlorine and nitrogen, chemical composition of ash. Authors proposed two formulas of the biomass fuel. The properties of the fuel such as the content of carbon, hydrogen, sulfur, chlorine or nitrogen, the chemical composition of the ash were investigated. Due to the fact that the combustion of the biomass fuel is preferred in view of law regulations (zero CO2 emission, green certificates) the content of biodegradable fraction was examined. It has been shown that the fuel is a biomass one. Fuel from waste can be a substitute for approx. 25% of primary fuel (coal) used by the paper mill.

Occurrence of Cellulose Degraders in Fruit and Vegetable Decaying Wastes

The present study aims at isolation and characterisation of cellulose degrading bacterial and fungal strains from fruit and vegetable decaying waste such a banana peel, sugarcane bagasse, coconut coir, citrus wastes, potato peel, sponge guard, cucumber peel. 23 bacterial colonies and 12 fungal colonies were obtained on Nutrient Agar and PDA respectively by plating the aliquots of fivefold serially diluted decaying samples. 7 bacterial strains and 4 fungal strains were cellulose degraders as screened on CMC agar flooded with iodine. Also, the Z: C ratio of the fungal and bacterial isolates were recorded to see the degradation potential. Further, characterization of cellulose degraders on the basis of culture and morphology was done and for bacterial isolates biochemical tests were also performed. Results of the Biochemical tests were fed into the ABIS online bacterial identification tool and the bacterial isolates were identified as Bacillus subtilis ~98% (acc: 30%), Bacillus licheniformis ~99% (acc: 32%), Streptococcus ~97% (acc:20%), Bacillus smithii 99% (acc: 30%), Bacillus firmus 99% (acc: 33%), Brevibacillus laterosporus 98% (acc: 32%), Pseudomonas chlororaphis 75% (acc: 33%). However, the 16s rRNA sequencing has to be performed for confirmation of the bacterial isolates. While the fungal isolates obtained were identified as Aspergillus niger, Penicillium, Aspergillus flavus and Rhizopus on the basis of cultural and morphological characterization. The isolated bacterial strains will not only help in the production of useful end products from bio-degradation of the abundant, inexpensive and renewable cellulose wastes but also help in the proper disposal of agricultural and domestic wastes.