Komagataeibacter rhaeticus grown in sugarcane molasses-supplemented culture medium as a strategy for enhancing bacterial cellulose production

Abstract

Komagataeibacter rhaeticus, a bacterium isolated from Kombucha tea, was used to produce bacterial cellulose (BC) through its cultivation in a static sugarcane molasses (SCM) supplemented-culture medium (totally or partially), as an alternative carbon source. BC membranes were characterized by different physicochemical analysis using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), thermogravimetry analysis (TGA) and PeakForce quantitative nanomechanics atomic force microscopy (PeakForce (QNM-AFM)). FTIR, XRD and TGA results suggest great similarity among all membranes produced by distinct culture media. Although the glucose (F1) and SCM (F6) media presented the lowest BC yield, all SCM-supplemented culture media (from F2 to F5) showed BC yield values similar to the HS culture medium (F0). FEG-SEM analysis showed that as higher SCM concentrations on culture media higher dense nanofibers network could be prepared. Quantitative nanomechanical results obtained by AFM technique corroborate FEG-SEM analysis besides show smoother and more flexible BC membranes as a function of the increasing of the SCM concentrations. The modification of the carbon source of the culture medium with an important by-product of Brazilian agroindustry appears as a viable alternative to reduce cost of BC production (of up to 20.06%) besides increase the possibilities of industrial scale BC preparation.