Critical Factors for Optimum Biodegradation of Bast Fiber’s Gums in Bacterial Retting

Abstract

Bast fiber plants require a post-harvest process to yield useable natural cellulosic fibers, denoted as retting or degumming. It encompasses the degradation of the cell wall’s non-cellulosic gummy substances (NCGs), facilitating fibers separations, setting the fiber’s quality, and determining downstream usages. Due to the inconvenience of traditional retting practices, bacterial inoculum and enzyme applications for retting gained attention. Therefore, concurrent changes of agroclimatic and socioeconomic conditions, the conventional water retting confront multiple difficulties, bast industries become vulnerable, and bacterial agents mediated augmented bio-retting processes trying to adapt to sustainability. However, this process’s success demands a delicate balance among substrates and retting-related biotic and abiotic factors. These critical factors were coupled to degrade bast fibers NCGs in bacterial retting while holistically disregarded in basic research. In this study, a set of factors were defined that critically regulates the process and requires to be comprehended to achieve optimum retting without failure. This review presents the bacterial strain characteristics, enzyme potentials, specific bast plant cell wall’s structure, compositions, solvents, and interactions relating to the maximum NCGs removal. Among plants, associated factors pectin is the primary biding material that determines the process’s dynamics, while its degree of esterification has a proficient effect through bacterial enzymatic degradation. The accomplished bast plant cell wall’s structure, macerating solvents pH, and temperature greatly influence the bacterial retting process. This article also highlights the remediation process of water retting pollution in a biocompatible manner concerning the bast fiber industry’s endurance.

Evaluation of bamboo water-retting for fiber bundle extraction

“…57,58 Texazym SER-5 (Inotex) is the only commercial product that involves LiP. 51 Based on our results, it was necessary to add MnP in the first step of lignin degradation, followed by xylanase hydrolysis. Therefore, commercially available products for enzymatic retting might be unsuitable for bamboo retting.…”

“…The bacterial community structure in water-retting is non-selective, and some microbes secrete specific enzymes depending on the nutrient substance for their metabolic activities. 51 With the degradation of lignin, pectinase attacked pectin remaining in the primary cell wall and achieved the highest activity on day 21. Furthermore, hydrolysis of the xylan-rich wall, which can protect cellulose-rich fibers, 52 resulted in a noticeable enhancement of xylanase activity from day 9.…”

“…26 The minimal activity of cellulase is also beneficial for removing non-cellulosic compounds in bamboo, as lignin generates hemicellulose and cellulose clusters. 51 However, the activities of enzymes may be impacted by the retting products, which were used as nutrient substances by bacteria in the water-retting process. Unfortunately, avoiding this shortage is challenging.…”

Potential of lignocellulolytic biocatalysts of native and proposed genetically engineered microbial cell factories on jute fiber modification and jute waste recycling: A review

“…strain exhibits the ability to accomplish the jute degumming in 6 days (Haque et al 2003). (Tamburini et al 2003;Hossain et al 2021).…”

“…Though extensive research has been done on different bacterial and fungal strains, there are still so many organisms that are untouched and can be used for jute retting enhancement as these organisms can produce the enzymes required for the breakdown of lignocellulosic biomass. Jute itself is a composition of lignocelluloses made by lignin, pectin, cellulose, and Das & Ghosh hemicelluloses, and thus it can be retted by the ligninolytic enzyme-producing organisms (Hossain et al 2021). Pectin is the cementing material that helps to stick the phloem fiber with the bark of the stem.…”