Chapter 18 - Bacterial retting agents: sustainable bioremediation of bast fibers farming strains

Abstract

Bast fiber has gained momentum due to its renewable, biodegradable, multipurpose, and affordable features. After harvest, bast fiber plants are require to undergo a processing phase known as retting or degumming. It involves the separation of cellulosic bast fibers from heterogeneous inherent gummy substances, mainly hemicellulose, pectin, and lignin. While bast fibers are biocompatible, the current retting process involves environmental pollutants and is a complicated traditional or artificial process. Traditional retting processes, that is, water retting and dew retting, have been implemented for bast fiber production since its inception. With the augmented process, traditional retting processes are currently facing many difficulties, such as pollution, inefficiency, and the deficit of inputs. Traditionally, retting is achieved by naturally growing microbial mixtures and maceration in open field conditions. Currently, the demand for freshwater bodies is in competition with other agricultural sectors. Therefore the unavailability of sufficient retting niches, many bast mass has been concentrated on the same place, halting the biological oxygen supply to aquatic flora and fauna. Due to global climate change, uneven and low precipitation has increased the entire bast industry’s instability. Hence, the alternative retting process by manipulating retting elements with potential microbial agents has gained attention in this sector. The inoculation of potential bacterial agents as an initial starter is considered in many studies, giving upscaling insights into triggering the retting process, but its success depends on some crucial factors. This study discusses bast fiber retting processes, both bacterial formulations and enzymes, focused on selection criteria, separation efficiency, and the interaction with other retting factors.