Utilization of Agro-Waste for Lignin Production and Assessment of Its Antibacterial Activity
Main Article Content
Abstract
Introduction: Agricultural sector plays a vital role in GDP of most of the Asian and African country. Agricultural practices produce a huge number of lignocellulosic wastes which is mostly burnt that adds to the air pollution. In order to add value to it, effective extraction process is needed to be carried out. Lignin, an important component of this biomass is always regarded as a non-useful component. However, studies have indicated its multipurpose application. Lignin is known to have antimicrobial activity, owing to the presence of phenolic group in it. Such a study of extracting lignin from agricultural waste, will not only add value to lignin but also contribute towards a sustainable development by having a scientific approach towards air quality index.
Objectives: to extract lignin by organosolv method and assess its antibacterial activity.
Methods: Rice stubble was taken for extraction of lignin. The stubble was powdered and treated with organic acid, made from a combination of acetic acid and formic acid. The residue collected after filtration is again treated with peroxy-organic acid and finally bleached with hydrogen peroxide to increase the brightness of the residue. The liquor collected was mixed with excess amount of water to precipitate the lignin. The precipitated lignin was filtered and dried. For characterization, FTIR, XRD and FE-SEM was done. Antimicrobial activity was conducted by estimating MIC.
Results: The organic acid-based extraction of lignin depends on the ratio FA/AA. The lignin extracted is called organosolv lignin and is the purest from of lignin. Through FTIR and XRD characterization it can be concluded that lignin was not modified and extracted in purest form. The structure was also amorphous. The anti-bacterial studies indicates that as lignin concentration is increased, antibacterial property enhances.
Conclusions: This method of extracting lignin from biowaste is an efficient method where pure lignin with no modification can be extracted. This is one of the few works where lignin was found to be effective against both gram positive and gram-negative bacteria.