Potencial biotecnológico de casca de soja para obtenção de nanopartículas de celulose e de lignina

Abstract

In this dissertation, different treatments for the production of cellulose and lignin nanostructures using soybean husk were studied. In order to use an efficient methodology to extract cellulose and lignin, without generating a lot of cost and causing a minimum of environmental impact, transforming it into a product with added value. First, by means of serial dilution, microorganisms were isolated from the fresh skin with the streaking technique until obtaining pure cultures, and their identification with molecular analysis. The tool used to compare the consensus sequences was the international nucleotide database of the National Center for Biotechnology Information GenBank (NCBI), through the BLAST tool. After pairing with the website's database, with a 99.99% similarity percentage, microorganisms were identified. The treatments were carried out in fermenters, with 30 grams of bark and 220 mL of deionized water, in triplicate, during the period of 40 days.Two treatments, Treatment 1, consisted of the action of microorganisms present in the peel to degrade cellulose, lignin, hemicellulose and Treatment 2, the peel went through a pretreatment with acetic acid (Acetosolv), to extract the lignin, and was inoculated the microorganisms isolated for the enzymatic hydrolysis process. Then, the samples were centrifuged to separate the solid phase from the liquid, and the liquid part was used for analysis of concentration (gravimetric test), and characterization (SEM and XRD). The microorganisms identified were the fungi Aspergilus flavus, Lichtheimia ramosa and Lentinus crinitus. From the results of the concentration, it was evaluated that treatment 1 (nanocellulose and nanolignin) showed higher values and, consequently, higher concentration, unlike treatment 2 (nanocellulose), where lignin was absent. With the results of XRD, it was found that in both treatments, nanocellulose and nanolignin were obtained in a smaller amount. The results of the Scanning Microscopy, showed that in the periods of 20 and 25 days of hydrolysis in both treatments, nanostructures of cellulose and lignin were obtained. The isolated microorganisms were deposited in the Microbiological Collection of Biotechnological Interest (CMIB) of UTFPR - Campus Ponta Grossa. The methodology used made it possible to allocate an agro-industrial residue for research, adding value to the substrate, and to contribute in the area of cellulose and lignin nanostructures with a biotechnological basis.