Extracting cellulase from bagasse, a widely available byproduct of the sugarcane industry, can be a sustainable source of enzyme technology for the cotton biopolishing process, a team of researchers has concluded.
- Cellulases are enzymes produced by microorganisms that specifically target cellulose to produce glucose. In some cases, cellulase-based enzyme cocktails are produced for highly enhanced yields to promote industrial scale-up of bioprocesses.
THE STUDY: The paper ‘Eco-friendly biopolishing of cotton fabric through wasted sugarcane bagasse-derived enzymes’ has just been published in Heliyon.
- The objective of the study was to find an alternative and sustainable source of cellulase enzymes from wasted sugarcane bagasse to use in textile biopolishing applications and compare its performance with commercially used cellulase enzymes.
- The researchers were Md Shah Ikbal, Fahmida Akter Tisha, Abdullah Ibn Asheque, Enamul Hasnat, and Mohammad Abbas Uddin.
THE CELLULASE CONTEXT: Traditional textile chemical processing methods in industry have been water-intensive and have generated substantial effluent, posing significant environmental challenges.
- The textiles industry is increasingly turning towards enzyme-based processes. Enzymes are biodegradable, reaction-specific biocatalysts, used for particular wet-processing applications of textiles such as biopolishing, bioscouring, desizing, etc.
- Enzymes eliminate excess colourants from dyed fabrics and enhance colour fastness. The hydrolase group of enzymes, such as amylase, cellulase, pectinase, protease, and catalase, are commonly used in textile preparation to catalyse chemical compounds hydrolyse. These work well in low-temperature, low-pH environments, remain unchanged during the process, and are considered a safer alternative to toxic chemicals.
- There are about 4000 enzymes, which are classified into six categories by the International Union of Biochemistry and Molecular Biology (IUBMB). Among these categories, hydrolase-based enzymes are mostly used in the textiles industry.
- Cellulase has attracted much attention over the past two decades as an enzyme with significant industrial importance and many commercial applications. Cellulase has recently been ranked as the third-most significant industrial enzyme in the global retail industry.
- Cellulases are also the second largest industrial enzyme based on monetary value. Their production for commercial use started in the early 1980s with denim finishing, and their demand has been on the rise since 1995, mainly in the paper, biofuel, animal feed, detergent, and textile industries.
- Cellulase enzymes were also obtained from crude leaf extract. Biopolishing of cotton knitted fabric was done with chloroplast endoglucanases obtained from crude leaf extract.
- Biopolishing is a process aimed at removing protruding fibres, reducing hairiness, and preventing pilling in cellulose-based fabrics, resulting in textiles with a velvety, smooth texture, vibrant colours, and softened fabric touch.
- Cellulase enzymes are instrumental in achieving these desired effects due to their specificity for cellulose substrates. These enzymes are ideal for biopolishing textiles because of their slow kinetics and lack of negative impact on fabric quality.
LEFTOVERS FROM SUGARCANE: The leftover material from sugarcane is sugarcane bagasse after cane juice is extracted from sugarcane.
- Sugarcane bagasse is rich in cellulose (45%), hemicellulose (32%), and lignin (17%) [20]. Chemically, bagasse is composed of 2.4% ash, 30% pentosans, and approximately 50% α-cellulose.
- It is the by-product of the sugarcane industry, produced in large quantities and biodegradable. Therefore, it can be used as a cost-effective and available alternative for producing microbial enzymes.
- In Bangladesh, 15 public sugar mills produced 25,300 metric tonnes of sugarcane press mud and 255,162 metric tonnes of sugarcane bagasse as by-products from 2015 to 2016.
- Like most agricultural wastes, bagasse biomass is rich in carbon, abundant, and useful for the generation of biofuel or biochar.
- Several studies have explored the possibility of producing biofuel from bagasse, but little attention has been given to textile applications.
- Typically, sugarcane bagasse is incinerated to turn into solid waste used in landfills. Consequently, it pollutes the air and the landfill with many toxic substances.
- Using it as a source of raw materials for the enzyme industry will be a more practical and efficient way towards sustainable alternatives of synthetic chemicals and dyes, which are difficult to remove from the environment.
- The waste sugarcane bagasse-derived enzyme can meet the demands of the industry as the enzymes extracted from waste sugarcane bagasse are of natural origin and, therefore, will be environment-friendly and can be sourced locally, reducing global footprint.
THE PROJECT: The study introduced a sustainable and economical approach for textile biopolishing through extracting cellulase enzymes from wasted sugarcane bagasse.
- The raw extract solution, obtained through an aqueous medium, underwent biopolishing with variations in pH and time, and enzyme activity was evaluated using the testing method called BUTEXDCE2022C01.
- The optimal biopolishing condition removed nearly 100% of protruding fibres. During the processing, reductions in fabric weight (up to 5.26%) and strength (up to 10.54%) were observed, which validated the effectiveness of this enzymatic processing.
- Comparative analysis with commercial samples affirmed the viability of cellulase enzymes, exhibiting comparable biopolishing effectiveness.
- The coherence between the optimal pH range for acid cellulase enzymes (4.5–6), cellulase activity range (30–60 °C), and established commercial practices at pH 4.5–5.5 and 50 to 60 °C temperature underscored the efficacy of the specific biopolishing conditions uncovered in the study.
