Nata de fique: A cost-effective alternative for the large-scale production of bacterial nanocellulose

Abstract

Bacterial nanocellulose (BNC) is a biopolymer with an expanding market due to its properties. One important aspect related to BNC production is the culture medium composition, which is rich in carbon and nitrogen, and it represents 30% of the total cost of production. The aim of this work was to evaluate the use of fique juice, a by-product of the fique fiber isolation process, as an alternative source to produce BNC using the Komagataeibacter medellinensis strain, denominated as nata de fique. First, the fique juice was chemically characterized to determine its nutrient content. The nata de fique yield was calculated as gram of dry cellulose per littler of the medium; the physicochemical characterization of the nata de fique was analyzed using Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-Ray diffraction and BET (Brunauer-Emmett-Teller) surface area analysis. Finally, the environmental impact and financial analysis were also determined. It was found that using fique juice as a culture medium, the BNC production yield was 2.2 g BNC/L medium compared to BNC-HS, which was 1.14 g BNC/L medium, due to the chemical composition of fique juice, which presented a higher content of nitrogen and additives like Mg2+ and Ca2+. In the morphological analysis, the same nanoribbon structure was observed, and no changes in the crystalline parameters were detected. Nevertheless, there was a slight decrease in the thermal stability temperature, the crystalline index, and the surface area in the BNC produced with fique juice, due to the presence of some remaining impurities after the purification step. In the environmental analysis, nata de fique decreased the water consumption, carbon footprint, and raw material consumption, and the BNC production cost was twice cheaper than the HS culture medium. This research demonstrates that nata de fique is an alternative source of BNC regarding economic and environmental impact.