Enzymatic saccharification of the polysaccharides in Arthrocaulon macrostachyum biomass: Characterization and application in methylene blue removal

Wild Arthrocaulon macrostachyum biomass has been less studied for biotechnological and environmental applications. This study examines the saccharification of biomass from this coastal halophyte using multienzyme preparations from two endophytic bacteria, Bacillus sp. TKE1 (GenBank accession ON060353.1) and B. vallismortis E4 (Genome Project id: JBIMFA000000000). Under optimum conditions, the multienzyme from TKE1 demonstrated 37.8 IU mL^-1 of amylase and 34.6 IU mL^-1 of xylanase. While the multienzyme from the strain E4 exhibited 36.3 IU mL^-1 amylase and 37.4 IU mL^-1 xylanase. The preparations from TKE1 and E4 yielded 59.4 % and 37.8 % saccharification, releasing 0.66 and 0.42 mg/g of total reducing sugars, respectively. Matrix made up of saccharified biomass showed up to 98 % MB dye removal, compared to 84.9 % by the unsaccharified biomass. The pseudo-second order reaction kinetics indicated chemical adsorption. SEM images of the saccharified biomass showed significant fiber degradation, matrix loosening, and increased surface area, enhancing dye removal capacity. FTIR analysis confirmed changes in the saccharified substrate, particularly in the regions of 3074.533, 2997.38, and 2872.007 cm^-1 for cellulose; 1093.639 to 829.391 cm^-1 for starch, and 1720.503 cm^-1 for hemicelluloses. The study concludes that biomass from halophyte can be utilized for generating value-added chemicals and environmental remediation.