Rapid Deconstruction of Cotton, Coir, Areca, and Banana Fibers Recalcitrant Structure Using a Bacterial Consortium with Enhanced Saccharification

Abstract

This study aims to establish a bacterial consortium to deconstruct the coir, areca, banana, and cotton fibers recalcitrant structure. Hence, lignocellulase secreting bacterial strains were isolated from cow rumen, dung garbage, and vermicompost samples. After selecting desired strains, a mixed-batch bacterial consortium (MBBC) was made by mixing of cellulase batch (Bacillus sp. HSTU-2, Bacillus sp. HSTU-3, Citrobacter sp. HSTU-AAJ4), pectinase batch (Acinetobacter sp. HSTU-6, Bacillus sp. HSTU-7, Enterobacter sp. HSTU-AAH8), and amylase batch (Bacillus sp. HSTU-9, and Bacillus sp. HSTU-10) strains. Separately, each batch and MBBC strains were largely grown in the culture medium enriched with coir, areca, banana, and cotton fibers; as a consequence, the hardy lignocellulosic fibers were degraded. FTIR study indicated that the peak intensities for lignin was diminished, but sharpened for cellulose in the MBBC than that of the single batch pretreatment. The MBBC pretreatment could remove 64–73% lignin from banana, areca, and coir fibers, resulting in increasing cellulose amounts. The crystallinity index was observed 31.5%, 21.71%, 35%, and 29.26% for the untreated and 13.69%, 18.27%, 17.72%, and 25.20% for the MBBC pretreated cotton, areca, coir, and banana fibers, respectively. The MBBC pretreated banana, areca, coir, and cotton fibers could generate reducing sugars that scaled up to 5.3-, 3.9-, 3.68-, and 2.68-fold greater than the untreated samples. Hence, it is radically feasible to produce bioethanol precursors from the 4-days long MBBC pretreated banana, areca, and coir lignocelluloses. This research revealed the shortest lignocellulose pretreatment duration with a bacterial consortium holding minimal community members.